JP4166061B2 - Railcar structures - Google Patents

Description

【００２７】
こうした平均コンプライアンスの最小化に関しては、例えば、日本機械学会論文集（Ａ編）６０巻５７８号（１９９４−１０）第１４４〜１５０頁に掲載する「線形弾性問題における領域最適化解析」に詳細に記載されている。その概要は以下の通りである。
「線形弾性問題における領域最適化解析」は、線形弾性体の領域形状を設計変数にした領域最適化問題を連続体のままで定式化しておいて、分布系の最適化理論を適用することによって導出される領域変動の支配方程式を基礎にして領域最適化問題にアプローチしている。数値解析法は、支配方程式を解くための方法として定式化され、その１つの方法として力法が提案されている。力法は、領域変動の支配方程式を線形弾性問題の境界値問題に置き換えて解くために、有限要素法などを利用することができる。また、支配方程式に現れる形状勾配関数も有限要素法などを利用して解析することができる。そこで、「線形弾性問題における領域最適化解析」は、平均コンプライアンスの最小化問題を定式化し、それに対する最適性基準と最適化基準に基づいて算出される形状勾配関数を明らかにした上で、形状勾配関数を用いた力法を線形弾性体の領域問題に適用している。
【００２８】
鉄道車両用構体の形状を最適化するプログラムは、上記「線形弾性問題における領域最適化解析」を適用したものであり、初期形状の鉄道車両用構体を有限な要素に分割し、形状勾配関数の演算結果が収束するまで、つまり、数１に示す平均コンプライアンスが最小になるまで初期形状の鉄道車両用構体の形状を変化させることにより、鉄道車両用構体の形状を最適化している。図３は、鉄道車両用構体の形状を最適化するプログラムのフローチャートである。図４は、鉄道車両用構体の一部を有限要素に分割した概念図である。
【００２９】
コンピュータ３０のＣＰＵ３１は、記憶手段３３から鉄道車両用構体の形状を最適化するプログラムを読み出し、図３のステップ１（以下、「Ｓ１」いう。）において、初期形状解析モデル（有限要素法）を入出力装置３２に入力する。
【００３０】
次に、図３のＳ２において強度解析を行う。強度解析は、コンピュータ３０のＣＰＵ３１が初期形状解析モデルを読み出し、それに基づいて変位量と発生応力を算出して行う。
【００３１】
次に、Ｓ３において、感度解析を行う。感度解析では、数２に示す形状勾配関数Ｇを演算する。
【００３２】
【数２】

【００３３】
この数２に示す形状勾配関数Ｇは、図４に示す各要素Ｅの境界面上に分布する法線方向を向いたベクトル関数である。ここで、式に現れる変数の値は、Ｓ２の強度解析の解析結果から得られるものであり、ｆは物体力、ｅは弾性テンソル、ｕは変位、ΛはＬａｇｒａｎｇｅ定数である。
【００３４】
そして、図３のＳ４において、収束判定を行う。収束判定は、感度解析を実行して得られた感度が十分小さいか否かで判断される。感度が十分小さいと判断した場合には（Ｓ４：ＹＥＳ）、処理を終了する。一方、感度が十分小さくないと判断した場合には（Ｓ４：ＮＯ）、Ｓ５へ進み、形状変更における制約条件が入力されているか否かを判断する。制約条件が入力されていると判断した場合（Ｓ５：ＹＥＳ）には、そのままＳ７へ進む。
【００３５】
一方、制約条件が入力されていないと判断した場合（Ｓ５：ＮＯ）には、Ｓ６において、制約条件として形状の変更を許さない点、移動方向の制約、体積（三次元の問題）又は面積（二次元の問題）を入出力装置３２から入力して記憶装置３３に記憶させてから、Ｓ７へ進む。そして、Ｓ７において、初期形状の鉄道車両用構体の形状を変更したら、Ｓ３以降の処理を再度繰り返す。
【００３６】
こうした鉄道車両用構体の形状を最適化するプログラムは、以下のように動作する。
コンピュータ３０の入出力装置３２に初期形状解析モデルを入力する（図３のＳ１）。具体的には、例えば、図４に示すように、初期形状の鉄道車両用構体全体を有限な要素Ｅに分割し、各要素Ｅの節点●に座標データを付け、例えば、４個の節点●（ｉ〜ｌ）を一組にする旨の有限要素法の要素情報を入力する。また、例えば、構体厚Ａの初期値を５０ｍｍに設定し、鉄道車両用構体の材料特性としてアルミニウム合金のヤング率とポアソン比を入力する。また、例えば、強度解析などを行う際に利用される境界条件として拘束条件と荷重条件を入力する。拘束条件としては、台枠側梁に相当する側構体の固定部を固定すること、及び、鉄道車両用構体の構体幅方向の中心線に対称条件を加えることを入力する。ここで、対称条件を加えるのは、演算量を減らして、演算時間を短縮するためである。また、荷重条件としては、気密荷重を想定して外向きに等分布荷重を与えることを入力する。
【００３７】
そして、初期形状解析モデルのアルミニウム合金のヤング率・ポアソン比などに基づいて強度解析を行ったら、初期形状解析モデルと強度解析結果とに基づいて形状勾配関数Ｇを求める（図３のＳ２、Ｓ３）。収束判定において感度が十分に小さくない場合、すなわち、形状勾配関数Ｇが急激な勾配を有する場合には、制約条件が入力されているか否かを判断し、制約条件が入力されていない場合には、制約条件を入力してから形状を変更する（図３のＳ４：ＮＯ、Ｓ５：ＮＯ、Ｓ６、Ｓ７）。
【００３８】
具体的には、収束判定において感度が十分に小さくなっておらず、制約条件が入力されていない場合には、例えば、中空形材５の外側面板６（図１０参照）から４０ｍｍの厚さに位置する節点●の移動を許さないこと、各要素Ｅの節点（図４参照）をｘ方向のみに（一次元的に）移動させること、外側面板６と内側面板７で囲まれる面積を初期形状と同一にすることなどといった制約条件を入力する（図３のＳ４：ＮＯ、Ｓ５：ＮＯ、Ｓ６）。ここで、中空形材５の外側面板６（図１０参照）から４０ｍｍの厚さを固定するのは、構体各部において最低限の剛性及び強度を確保するために、構体厚Ａが４０ｍｍ以下になることを回避するためである。また、各要素Ｅの節点（図４参照）をｘ方向のみに（一次元的に）移動させるのは、各要素Ｅを構体断面方向に伸縮させるためである。
【００３９】
そして、入力した制約条件と形状勾配関数Ｇの演算結果に基づいて初期形状の鉄道車両用構体の形状を変更する（図３のＳ７）。具体的には、例えば、形状勾配関数Ｇが局部的に大きい場合は、その形状勾配関数Ｇが大きい部分について、側構体及び屋根構体の外側から４０ｍｍの節点●を移動させないことや、節点●の移動方向をｘ方向に限定することなどの制約条件に基づいて、側構体及び屋根構体の内側から１０ｍｍ以内の部分における要素Ｅの節点●を内向きに移動させ、要素Ｅの大きさを大きくする。また、外側面板６と内側面板７との間の面積が一定である制約条件があるので、形状勾配関数Ｇが小さい部分について、側構体及び屋根構体の内側から１０ｍｍ以内の部分における要素Ｅの節点●を外向きに移動させ、要素Ｅの大きさを小さくする。こうして移動させた節点●の座標データを書き換える。これにより、節点●が内側に移動したところでは構体厚Ａが厚くなり、節点●が外側に移動したところでは構体厚Ａが薄くなるため、鉄道車両用構体の形状が変更される。鉄道車両用構体の形状を変更したら、Ｓ３以降の処理を再度繰り返す。これら一連の処理は、収束判定において感度が十分小さいと判断されるまで自動的に行われる。
【００４０】
そして、収束判定において感度がこれ以上小さくならないと判断された場合、すなわち、形状勾配関数Ｇの値が前回計算より小さくならない場合には、処理を終了し（図３のＳ４：ＹＥＳ）、図１に示すように最適化された鉄道車両用構体１０を入出力装置３２に出力する。
【００４１】
図１の鉄道車両用構体１０は、側構体２と屋根構体３の構体厚Ａが構体各部で変化している。側構体２と屋根構体３が結合する部分（以下、「構体肩部」という。）１４の構体厚Ｗ１は、側構体２を台枠４に固定するための固定部２ａを除いて、構体のうちで最も厚く形成されている。そして、側構体２では、中央付近の構体厚Ｗ４が薄く形成されている。また、屋根構体３では、構体幅方向の中心位置３ａにおける構体厚Ｗ２が厚く形成され、構体中心部３ａと構体肩部１４との間の構体厚Ｗ３が薄く形成されている。
【００４２】
そして、発明者は、車体外形線Ｍの異なる数種類の鉄道車両用構体について上記プログラムを実行して形状を最適化したところ、車両デザインすなわち車体外形線Ｍに基づいて車体内形線Ｎ１を決定することにより鉄道車両用構体の形状を最適化できることを確認した。
【００４３】
鉄道車両用構体１０は、最大幅位置を通る垂直線と、最大高さ位置を通る水平線によって構成される門型の領域内に曲線を用いて車体外形線Ｍを決定し、側構体２と屋根構体３を配置している。構体肩部１４は、一般的に曲率が大きくなるため、断面方向に曲げようとする大きな力を受け、応力値が大きくなる。従って、車体外形線Ｍに基づいて、屋根構体３の中心位置３ａから水平方向に第１直線Ｌ１を描き、構体最大幅位置から垂直方向に第２直線Ｌ２を描くことによって門型を形成し、第１直線Ｌ１と第２直線Ｌ２とが交差する第３点Ｐ３に相当する位置を車体外形線Ｍ上に何らかの方法で投影することができれば、鉄道車両用構体１０の中で最も応力値が高くなるおおよその部位を求めることができる。
【００４４】
かかる観点より、第１直線Ｌ１と第２直線Ｌ２とが公差する第３点Ｐ３は、車体外形線Ｍのうち構体肩部１４を形成する曲線の中心点である第４点Ｐ４と第５直線Ｌ５で結ばれ、第５直線Ｌ５が車体外形線Ｍと公差する点である第６点Ｐ６が求められる。この第６点Ｐ６は、第３点Ｐ３が車体外形線Ｍ上に投影されたものと考えられるため、鉄道車両構体１０は、固定部２ａを除いて、第６点が位置する部位の構体厚Ｗ１を構体のうちで最も厚くすればよいことになる。
【００４５】
そして、第６点Ｐ６が位置する部位の構体厚Ｗ１を最も厚くするためには、第５直線Ｌ５上に規定した第７点Ｐ７を中心点とする半径ｒ２の曲線で構体肩部１４の車体内形線Ｎ１を形成することが、必要十分である。
半径ｒ２は、構体肩部１４における車体外形線Ｍの半径ｒ１を１．１倍した値から８０ｍｍを差し引くことにより、簡単に決定することができる。ここで、関係式の係数を１．１としたのは、構体肩部１４の構体厚分布を最適なものとするためである。すなわち、係数を１．１より大きくすると、最大構体厚Ｗ１となる部位以外の構体肩部１４の構体厚Ａが不足し、剛性不足になる一方、係数を１．１より小さくすると、最大構体厚Ｗ１となる部位の剛性が、最大構体厚Ｗ１となる部位以外の構体肩部１４と比べて剛性不足となるからである。また、関係式の８０ｍｍは、構体厚Ａを調整するための調整項であり、調整項を８０ｍｍにした理由は、上記関係式の係数選択における理由と全く同じである。すなわち、調整項を８０ｍｍより大きくすると、最大構体厚Ｗ１となる部位以外の構体肩部１４の構体厚Ａが不足し、剛性不足になる一方、調整項を８０ｍｍより小さくすると、最大構体厚Ｗ１となる部位の剛性が、最大構体厚Ｗ１となる部位以外の構体肩部１４と比べて剛性不足となるからである。
【００４６】
第７点Ｐ７は、構体厚Ｗ１が側構体２と屋根構体３の構体厚Ａ全体を平均した平均構体厚の１．５〜１．６倍になるように半径ｒ２の曲線を描くべく、第５直線Ｌ５上に規定される。ここで、構体厚Ｗ１を平均構体厚の１．５〜１．６倍にしたのは、平均構体厚の１．５倍未満にすると、構体の剛性が不足する一方、平均構体厚の１．６倍より大きくすると、剛性が過剰になるとともに客室空間を不必要に狭めることになるからである。
【００４７】
本実施の形態では、構体肩部１４の車体外形線Ｍに係る半径ｒ１は４００ｍｍであり、これを半径ｒ２を算出する関係式（半径ｒ２（ｍｍ）＝半径ｒ１（ｍｍ）×１．１倍−８０（ｍｍ））にあてはめると、半径ｒ２は３６０ｍｍになる。本実施の形態の平均構体厚は５２．８ｍｍであるから、構体肩部１４の構体厚Ｗ１が平均構体厚の１．５〜１．６倍すなわち７９．２０〜８４．４８ｍｍになるように第７点Ｐ７を第５直線Ｌ５上に規定し、半径ｒ２（３６０ｍｍ）の曲線を描いて構体肩部１４の形状を決定する。本実施の形態では、構体肩部１４の構体厚Ｗ１が平均構体厚の１．５４倍である８１．０５ｍｍになるように第７点Ｐ７を規定している。
【００４８】
また、側構体２は、鉄道車両用構体１０の最大幅位置を含む範囲Ｒ２で構体厚Ｗ４を薄くする。すなわち、側構体２の下端部から構体厚Ｗ１が位置する構体肩部１４までの距離に対して下端部からおおよそ７分の３〜７分の５の範囲Ｒ２における構体厚Ｗ４を構体のうちで最も薄くする。当該部位を薄くできるのは、気密荷重によって側構体２を変形させようとする力と、屋根構体３が変形しようとする時に側構体２に伝えられる力とが互いに逆向きであるために打ち消し合うことになるためであると推定される。
本実施の形態では、構体厚Ｗ４が４０ｍｍになるように、最大幅位置を含む一定の範囲Ｒ２における車体内形線Ｎ１を形成している。
【００４９】
一方、屋根構体３は、中心位置３ａの構体厚Ｗ２を厚く、中心位置３ａと構体厚Ｗ１が位置する構体肩部１４との間の構体厚Ｗ３を薄くする。すなわち、屋根構体３は、中心位置３ａの構体厚Ｗ２が平均構体厚の１．１〜１．２倍になるように中心位置３ａの車体内形線Ｎ１を形成する。このように構体厚Ｗ２を平均構体厚の１．１〜１．２倍にするのは、平均構体厚の１．１倍未満にすると、構体の剛性が不足する一方、平均構体厚の１．２倍より大きくすると、剛性が過剰になるとともに客室空間を不必要に狭めることになるからである。
本実施の形態では、平均構体厚が５２．８ｍｍであるから、屋根構体３の中心位置３ａの構体厚Ｗ２を５８．０〜６３．３ｍｍにすることが望ましい。よって、本実施の形態では、屋根構体３の中心位置３ａの構体厚Ｗ２が平均構体厚の１．１６倍である６１ｍｍになるように、中心位置３ａの車体内形線Ｎ１を決定している。
【００５０】
また、屋根構体３は、構体厚Ｗ２が位置する中心位置３ａから構体厚Ｗ１が位置する構体肩部１４までの距離に対して中心位置３ａからおおよそ３分の１〜２分の１の範囲Ｒ１における構体厚Ｗ３を構体のうちで最も薄くする。このように構体厚Ｗ３を設ける位置に一定の範囲Ｒ１を設けるのは、屋根構体３の中心位置３ａで発生する曲げモーメントと構体肩部１４で発生する曲げモーメントの方向が逆向きであり、屋根構体３のうち曲げモーメントがゼロとなる位置を中心として構体厚Ｗ３を配置するのであるが、この位置は、車体外形線Ｍによって変動するためである。当該位置の構体厚Ｗ３を最も薄くするのは、前述の通り、曲げモーメントがゼロ又は非常に小さいために曲げ剛性を大きくする必要がないからである。
本実施の形態では、構体厚Ｗ２が位置する中心位置３ａから構体厚Ｗ１が位置する構体肩部１４までの距離に対して屋根構体３の中心位置３ａから２分の１程度の部位３ｂにおける構体厚Ｗ３が４０ｍｍになるように、屋根構体３の部位３ｂにおける車体内形線Ｎ１を決定している。
【００５１】
こうして、側構体２と屋根構体３において構体厚Ａを厚くする部位と薄くする部位とを決定したら、隣り合う部位同士をなめらかに結んで鉄道車両用構体１０全体の車体内形線Ｎ１を形成する。これにより、鉄道車両用構体の形状を短時間で最適化することが可能になる。
【００５２】
続いて、鉄道車両用構体１０の作用について説明する。
鉄道車両用構体１０は、例えば、トンネルに突入したときに、トンネル内の空気圧と鉄道車両用構体１０の客室空間内の気圧との間に生じる差圧により、構体断面方向の力と構体長手方向を回転軸とする曲げモーメントとによる応力が構体各部に発生する。特に、側構体２と屋根構体３とが連結する構体肩部１４と、屋根構体３の中心位置３ａでは、応力が大きくなりやすい。
【００５３】
鉄道車両用構体１０は、構体肩部１４の構体厚Ｗ１を側構体２の固定部２ａを除いた構体のうちで最も厚くすることにより構体の剛性と強度を高めており、これによって、屋根構体３と側構体２の変形を抑えることができる。また、屋根構体３は、例えば、気密荷重を受けた時に、構体幅方向の中心位置３ａが大きく上下方向に変形しようとするが、構体幅方向の中心位置３ａにおいて構体厚Ｗ２を平均構体厚より厚くして屋根構体３の剛性と強度を高めているので、屋根構体３の中心位置３ａにおける変形が抑えられる。また、結果として、その他の屋根構体３の変形量も抑えることができる。
【００５４】
こうした鉄道車両用構体１０は、構体各部に発生する応力の大きさに対応して構体厚Ａが分布しているため、応力分布を従来のものより均一なものに近づけることが可能であり、変形も滑らかである。
【００５５】
上記構成と作用を有する図１に示す鉄道車両用構体１０の形状を図１１に示す鉄道車両用構体１００の形状と比較すると、以下の共通点と相違点が認められる。
図１の鉄道車両用構体１０と図１１の鉄道車両用構体１００とは、車体外形線Ｍが同一で、構体肩部１４，１１４の構体厚Ｗ１，Ｗ５を厚くしている点で共通する。
【００５６】
しかし、図１の鉄道車両用構体１０と図１１の鉄道車両用構体１００とは、形状の決定方法が本質的に相違している。すなわち、図１１の鉄道車両用構体１００は、一様の構体厚Ａで形成された側構体１０２と屋根構体１０３とをフィレットを生成する形で構体肩部１１４の車体内形線Ｎ２を形成している。そのため、構体肩部１１４の車体内形線Ｎ２は、曲線で形成されているものの、曲線の中心点である第８点Ｐ８が、構体の最大高さ位置から水平に描いた第１直線Ｌ１と、構体の最大幅位置から垂直に描いた第２直線Ｌ２とが公差する第３点Ｐ３を、車体外形線Ｍのうち構体肩部１１４を形成する曲線の中心点である第４点Ｐ４と結ぶ第５直線Ｌ５上に位置していない。よって、図１１の鉄道車両用構体１００は、形状の決定方法の相違により、図１の鉄道車両用構体１０と形状が僅かに異なっている。
【００５７】
こうした形状の僅かな相違は、図１の鉄道車両用構体１０と図１１の鉄道車両用構体１００の変位や応力に大きな影響を及ぼしている。図５は、従来の鉄道車両用構体１００の変位図である。図６は、最適化された鉄道車両用構体１０の変位図である。
この変位に係る解析では、鉄道車両用構体１０，１００に対して外向きに０．００１ｋＰａの等分布荷重を与えている。
【００５８】
この解析の結果、図１１の鉄道車両用構体１００と図１の鉄道車両用構体１０は、図５及び図６に示すように外向きに膨らむように変形するが、最大変位量が異なる。図１１の鉄道車両用構体１００は、図５に示すように、屋根構体１０３の中心位置１０３ａにおける最大変位量が約２．１４ｍｍであるのに対して、図１の鉄道車両用構体１０は、図６に示すように、屋根構体３の中心位置３ａの変位量が約１．４８ｍｍであり、図１の鉄道車両用構体１０の最大変位量が図１１の鉄道車両用構体１００の最大変位量の約７０％程度である。これは、図１に示す鉄道車両用構体１０は、構体厚Ａを構体各部で変化させたことにより、構体肩部１４と屋根構体３の中心位置３ａの変形を図１１の鉄道車両用構体１００より効率的に抑えることができることを示している。
【００５９】
また、図７は、従来の鉄道車両用構体１００の側構体１０２と屋根構体１０３の最大応力を示す応力図であり、図８は、最適化された鉄道車両用構体１０の側構体２と屋根構体３の最大応力を示す応力図である。
この応力に係る解析では、鉄道車両用構体１０，１００の外側に０．００１ｋＰａの等分布荷重を与えている。
【００６０】
この解析の結果、図１１の鉄道車両用構体１００は、図７に示すように、構体各部で発生する応力値がまだらである。そして、屋根構体１０３の中心位置１０３ａと、構体肩部１１４の構体厚Ｗ５が位置する部位から側構体１０２側にずれた部位では、車体内形線Ｎ２と車体外形線Ｍ付近において応力が大きくなっており、特に、構体厚Ｗ５が位置する部位から側構体１０２側にずれた部位の車体内形線Ｎ２付近Ｚ１では、最大応力値８１．６３４ＭＰａを示している。
【００６１】
それに対して、図１の鉄道車両用構体１０では、図８に示すように、構体内部で発生する応力値が構体各部でより均一に近くなっている。そして、屋根構体３の中心位置３ａと構体肩部１４では、車体外形線Ｍと車体内形線Ｎ１付近において応力が大きくなっており、特に、構体肩部１４の構体厚Ｗ１が位置する部位の車体内形線Ｎ１付近Ｚ２では、最大応力値４５．９６２ＭＰａを示している。
【００６２】
よって、図１に示す鉄道車両用構体１０は、最大応力が発生する部位Ｚ２と構体厚Ｗ１が位置する部位とが一致する一方、図１１の鉄道車両用構体１００は、最大応力が発生する部位Ｚ１と構体厚Ｗ５が位置する部位とがずれている。また、図１に示す鉄道車両用構体１０の最大応力値は、図１１に示す鉄道車両用構体１００の最大応力値の約５５％程度に減少している。これは、図１に示す鉄道車両用構体１０において構体厚Ｗ１を設けた部位と構体肩部１４の形状が、図１１鉄道車両用構体１００より適切であることを示している。
また、図１の鉄道車両用構体１０は、側構体２の一定の範囲Ｒ２における構体厚Ｗ４と屋根構体３の部位３ｂにおける構体厚Ｗ３が、図１１の鉄道車両用構体１００の側構体１０２と屋根構体１０３の構体厚Ａより薄いにもかかわらず、図１１の鉄道車両用構体１００と同程度の応力を維持している。これは、図１の鉄道車両用構体１０は、応力が小さい部位の構体厚Ｗ３，Ｗ４を薄くしたことにより側構体２と屋根構体３をしなやかに変形させ、構体各部に応力を分散させていることを示している。
【００６３】
以上詳細に説明したように、本実施の形態の鉄道車両用構体１０によれば、外側面板６と内側面板７とを中板８で連結した中空形材５を複数接続して側構体２と屋根構体３とを別々に製作して、台枠４上に立設した側構体２の上に屋根構体３を載せて結合し、あるいは、側構体２と屋根構体３とを一体として製作し、台枠４に載せて結合したものであって（図９及び図１０参照）、車体外形線Ｍを一定とし、内側面板７の断面法線方向位置を構体各部で発生する応力に基づいて変化させ、応力が大きい位置では構体厚Ａを厚く、応力が小さい位置では構体厚Ａを薄くしているので、（図１参照）、構体の軽量化と高剛性化とを同時に実現することができる。
【００６４】
また、本実施の形態の鉄道車両用構体１０によれば、モーメントによる応力が大きくなる構体肩部１４と屋根構体３の中心位置３ａとを平均構体厚より厚くしたので（図１参照）、側構体２と屋根構体３の変形を抑えるとともに、構体全体においても変形量を小さくすることができる。
【００６５】
また、本実施の形態の鉄道車両用構体１０によれば、構体肩部１４は側構体２と屋根構体３とを側構体２および屋根構体３を構成する曲線よりも曲率の大きい曲線で結合したものであって、側構体２が台枠４に固定される固定部２ａを除いて、側構体２と屋根構体３の中で構体厚Ａを最も厚くする部位を有し、構体厚Ａを最も厚くする部位は、屋根構体３の中心位置３ａから水平方向に第１直線Ｌ１を描き、側構体２の最大幅位置から垂直方向に第２直線Ｌ２を描き、第１直線Ｌ１と第２直線Ｌ２とが交差する点を第３点Ｐ３として規定し、外側面板６によって形成される車体外形線Ｍのうち構体肩部１４を形成する曲線の中心点を第４点Ｐ４として規定し、第３点Ｐ３と第４点Ｐ４とを結んで第５直線Ｌ５を描き、第５直線Ｌ５が車体外形線Ｍと交差する点を第６点Ｐ６として規定したときに、その第６点Ｐ６が位置する部位であるので（図１参照）、側構体２の固定部２ａを除いて構体厚Ａを最も厚くする部位を車体外形線Ｍから簡単に求めることができる。
そして、構体肩部１４を形成する車体内形線Ｎ１は、第５直線Ｌ５上に第７点Ｐ７を設け、車体外形線Ｍの半径ｒ１に基づいて決定される半径ｒ２の曲線であるので（図１参照）、構体肩部１４の形状を簡単に決定することができる。
【００６６】
また、本実施の形態の鉄道車両用構体１０によれば、構体肩部１４の構体厚Ｗ１を平均構体厚の１．５〜１．６倍の厚さにするとともに（図１参照）、屋根構体３の中央位置における構体厚Ｗ２を平均構体厚の１．１〜１．２倍の厚さにすることで（図１参照）、構体の剛性を適正なものとしている。
【００６７】
また、本実施の形態の鉄道車両用構体１０によれば、屋根構体３の中心位置３ａと構体肩部１４との間に構体断面の中で構体厚Ｗ３が最も薄い部位３ｂを設けたので（図１参照）、軽量化とともに、客室空間を僅かでも広くすることにも貢献できる。
【００６８】
さらに、本実施の形態の鉄道車両用構体１０によれば、構体肩部１４の構体厚Ｗ１が位置する部位、屋根構体３の中心位置３ａと構体肩部１４との間に設けた構体厚Ｗ３が位置する部位３ｂ、屋根構体３の中心位置３ａなどをなめらかに結んで車体内形線Ｎ１を形成しているので（図１参照）、構体各部に応力を分散させて（図８参照）、図１１に示す従来の鉄道車両用構体１００より構体全体の変位量を小さくすることができる（図６参照）。
【００６９】
なお、本発明は、実施形態のものに限定されるわけではなく、その趣旨を逸脱しない範囲で様々な変更が可能であることはいうまでもない。
【００７０】
【発明の効果】
従って、本発明の鉄道車両用構体は、外側面板と内側面板とを中板で連結した中空形材を複数接続して側構体と屋根構体とを別々に製作して、台枠上に立設した側構体の上に屋根構体を載せて結合し、あるいは、側構体と屋根構体とを一体として製作し、台枠に載せて結合したものにおいて、外側面板の断面方向位置により決定される車体外形線を一定とし、内側面板の断面方向位置を構体各部で発生する応力に基づいて変化させ、外側面板と内側面板とで形成される構体断面方向の厚さを応力の大きい部位では厚く、応力の小さい部位では薄くしているので、構体の軽量化と高剛性化とを同時に実現することができる。
【図面の簡単な説明】
【図１】 発明の実施の形態において、鉄道車両用構体の側構体と屋根構体の断面図である。
【図２】 同じく、鉄道車両用構体の形状を最適化する際に使用されるコンピュータのブロック図である。
【図３】 同じく、鉄道車両用構体の形状を最適化するプログラムのフローチャートである。
【図４】 同じく、鉄道車両用構体の一部を有限要素に分割した概念図である。
【図５】 同じく、従来の鉄道車両用構体の側構体と屋根構体の変位図である。
【図６】 同じく、最適化された鉄道車両用構体の側構体と屋根構体の変位図である。
【図７】 同じく、従来の鉄道車両用構体の側構体と屋根構体の最大応力を示す応力図である。
【図８】 同じく、最適化された鉄道車両用構体の側構体と屋根構体の最大応力を示す応力図である。
【図９】 鉄道車両用構体の外観斜視図である。
【図１０】 中空形材の拡大断面図である。
【図１１】 同じく、従来の鉄道車両用構体の側構体と屋根構体の断面図である。
【符号の説明】
２ 側構体
２ａ 固定部
３ 屋根構体
３ａ 中心位置
３ｂ 部位
４ 台枠
５ 中空形材
６ 外側面板
７ 内側面板
８ 中板
１０ 鉄道車両用構体
１４ 構体肩部
Ａ 構体厚
Ｗ１ 構体厚
Ｗ２ 構体厚
Ｗ３ 構体厚
Ｗ４ 構体厚
Ｍ 車体外形線
Ｎ１ 車体内形線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure for a railway vehicle composed of a hollow shape member.
[0002]
[Prior art]
Conventionally, as shown in FIG. 9, a railway vehicle structure 100 is mounted on a base frame 101, a side structure 102 that is welded to the base frame 101 to form left and right surfaces, and a side structure 102. A roof structure 103 to be welded, and a wife structure 104 that forms surfaces that close both ends in the longitudinal direction of the vehicle body. A connector 109 is fixed to the end of the undercarriage 101 so that it can be connected to another railcar structure 100.
[0003]
On the railroad vehicle structure 100, vertical loads based on the weight of passengers and loaded equipment, front and rear loads during traveling, and the like are required to have predetermined strength and rigidity that can withstand such loads, As the running speed increases, weight reduction is required. Therefore, in recent railway vehicle structures 100, the rigidity and strength of the structure are ensured while reducing the weight by using the side structure 102 and the roof structure 103 in which a plurality of hollow members 105 are welded in the circumferential direction. (For example, refer to Patent Document 1).
[0004]
As shown in FIG. 10, the hollow shape member 105 is formed by extrusion so that an outer side plate 106 and an inner side plate 107 having a predetermined width are connected by an intermediate plate 108. When the hollow vehicle body structure 100 is formed using the hollow shape member 105, the thickness in the cross-section direction of the structure formed by the outer side face plate 106 and the inner side face plate 107 (hereinafter referred to as "structure thickness"). ) A, the thickness B of the outer side plate 106, the thickness C of the inner side plate 107, the arrangement of the middle plate and the plate thickness D are set as design parameters.
[0005]
In the railway vehicle structure 100, as shown in FIG. 11, the structure thickness A of the side structure 102 and the roof structure 103 is set to a uniform thickness. Since it is empirically known that the structure shoulder 114 where the side structure 102 and the roof structure 103 are coupled to each other is empirically known, it is thicker than the structure thickness A of the side structure 102 and the roof structure 103 ( For example, see Patent Document 2). In order to ensure a predetermined strength and rigidity with respect to the load applied to the structure in the state of the structure thickness distribution determined in this way, in the railway vehicle structure 100, an intermediate plate 108 is disposed, and the plate of the outer face plate 106 is disposed. The thickness B, the plate thickness C of the inner side plate 107, and the plate thickness D of the middle plate 108 are changed (see, for example, Patent Document 3).
[0006]
[Patent Document 1]
Japanese Patent No. 2784279 (see page 3, FIGS. 1 and 2).
[Patent Document 2]
Japanese Patent No. 2669535 (see page 4, FIG. 5).
[Patent Document 3]
Japanese Patent No. 3069037 (see page 4, FIG. 1 and FIG. 2).
[0007]
[Problems to be solved by the invention]
However, the conventional structure 100 for a rail vehicle greatly increases the weight even if only the thickness B of the outer side plate 106 and the thickness C of the inner side plate 107 are changed with respect to the vertical load and the longitudinal load. On the other hand, since a force is applied in the cross section of the structure in the airtight load, the rigidity and strength of the structure can be ensured only by changing the plate thickness B of the outer side plate 106 and the plate thickness C of the inner side plate 107. There was a problem that weight reduction could not be realized sufficiently.
[0008]
That is, the railway vehicle structure 100 has airtightness in the cabin space, and when entering the tunnel, the differential force generated between the air pressure in the cabin and the air pressure in the tunnel causes Stress due to a bending moment about the longitudinal direction of the structure is generated in each part of the side structure 102 and the roof structure 103, and a large deformation occurs in the structure cross-sectional direction. Although it is difficult to accurately know the magnitude and frequency of this load that is applied during the period when the vehicle is used, the value obtained by multiplying the yield strength of the material by the safety factor or the value of the fatigue limit as a strength standard from the measurement so far As a result, the plate thickness B of the outer side plate 106 and the plate thickness C of the inner side plate 107 are determined.
[0009]
However, it has been difficult to achieve a significant weight reduction while ensuring a predetermined strength and rigidity only by changing the plate thickness B of the outer side plate 106 and the plate thickness C of the inner side plate 107. That is, the force in the circumferential direction of the structure can be dealt with by changing the plate thickness B of the outer side plate 106 and the plate thickness C of the inner side plate 107, but bending with the longitudinal direction of the structure as the rotation axis is possible. Corresponding to the moment only by changing the plate thickness B of the outer side plate 106 and the plate thickness C of the inner side plate 107 is inefficient and results in an increase in weight.
[0010]
Therefore, an object of the present invention is to provide a railway vehicle structure capable of simultaneously realizing a reduction in weight and a high rigidity of the structure in order to solve such a problem.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1 of the present application is to separately manufacture a side structure and a roof structure by connecting a plurality of hollow shapes in which an outer side plate and an inner side plate are connected by an intermediate plate, In the structure for a railway vehicle in which the roof structure is mounted on the side structure erected on the underframe and combined, or the side structure and the roof structure are integrally manufactured and mounted on the underframe. The vehicle body outline determined by the cross-sectional direction position of the outer side plate is made constant, and the cross-sectional direction position of the inner side plate is changed based on the stress generated in each part of the structure. The thickness of the structure cross-sectional direction is determined by the structure, and the structure shoulder portion connecting the roof structure and the side structure is the side of the structure excluding the fixing portion where the side structure is fixed to the underframe. Among the structure and the roof structure, there is a portion that maximizes the thickness in the cross-section direction of the structure. , In the section of the structure, a first straight line is drawn in the horizontal direction from the center position of the roof structure or the maximum height position of the structure in the cross section of the structure, and a second straight line is drawn in the vertical direction from the maximum width position of the structure. A point where the second straight line intersects is defined as a third point, and a center point of a curve forming the body shoulder portion of the vehicle body outline formed by the outer face plate is defined as a fourth point, and the third point When a fifth straight line connecting the point and the fourth point is drawn and the point at which the fifth straight line intersects the vehicle body outline is defined as the sixth point, it is at the position of the sixth point It is characterized by that.
[0012]
In other words, the structure for railway vehicles has airtightness in the cabin space, and when entering the tunnel, the differential force generated between the atmospheric pressure in the cabin and the atmospheric pressure in the tunnel causes the force and structure in the circumferential direction of the structure. Stress due to a bending moment with the longitudinal direction as the rotation axis is generated in each part of the structure. In a railway vehicle structure, in a portion where the stress is large, the inner side plate is formed in a direction away from the outer side plate to increase the thickness in the cross section of the structure (hereinafter referred to as “structure thickness”), thereby suppressing deformation. In the portion where the stress is small, the structure thickness is reduced by forming the inner side plate in a direction approaching the outer side plate. Thereby, required rigidity and intensity | strength can be ensured in each part of a structure. Therefore, the structure for a railway vehicle does not make the side structure and the roof structure uniform, and the structure thickness of the side structure and the roof structure is changed in each part of the structure based on the stress. Stiffening can be realized at the same time.
[0013]
In addition, the structure for railway vehicles is Since the side structure is fixed to the underframe, for example, when an outwardly distributed load is applied, the roof structure and the side structure try to swell outward. A bending moment is generated. In the vicinity of the structure shoulder, the structure thickness is set to be thicker than the average structure thickness of the entire structure of the side structure and the roof structure (hereinafter referred to as the average structure thickness), so the rigidity and strength against the bending moment are sufficient. It is secured. Therefore, in the railway vehicle structure, the deformation of the roof structure can be suppressed, and the deformation amount of the entire structure can be reduced.
[0014]
The railway vehicle structure determines the vehicle body outline using a curve in a gate-shaped region composed of a vertical line passing through the maximum width position and a horizontal line passing through the maximum height position, and the side structure and roof structure are separated. It is arranged. Since the structure shoulder portion where the side structure and the roof structure are coupled generally has a large curvature, a large force to bend in the cross-sectional direction acts, and the stress value near the structure shoulder portion increases. Therefore, based on the vehicle body outline, the first straight line is drawn in the horizontal direction from the center position of the roof structure, and the second straight line is drawn in the vertical direction from the structure maximum width position, thereby forming the gate shape. If the position corresponding to the third point where the two straight lines intersect can be projected on the vehicle body outline by some method, an approximate site where the stress value becomes high in the railway vehicle structure can be obtained.
[0015]
From this point of view, the third point, which is the point where the first straight line and the second straight line intersect, is connected by the fourth point and the fifth straight line, which are the center points of the curves that form the body shoulder of the vehicle body outline. A sixth point is obtained, which is a point where the fifth straight line has a tolerance with the vehicle body outline. Since the sixth point is considered that the third point has moved on the vehicle body outline, the structure thickness of the portion where the sixth point is located may be formed to be the thickest of the structures. This tendency is also observed when the shape of several types of railway vehicle structures with different body outlines is optimized, and the part where the thickness of the structure is the thickest in the structure excluding the fixed parts of the side structures is the body outline. It is considered possible to derive from
[0016]
Also, Claim 2 The invention described in Claim 1 In the invention described in the above, the body shoulder portion of the body is formed by a curve centered on the seventh point defined on the fifth straight line, which is a reference line formed by the inner side plate. Features.
Also, Claim 3 The invention described in Claim 1 or claim 2 In the invention described in the item 1, the thickness in the cross-section direction of the structure is 1.5 to 1.1 times the thickness in the cross-section direction of the average of the side structure and the roof structure. It is formed with a thickness of 6 times.
[0017]
The sixth point In order to maximize the thickness of the structure at the position where it is located, it is necessary and sufficient to form the in-vehicle body shape line of the structure shoulder with a curve centered on the seventh point defined on the fifth straight line.
The seventh point is to draw the in-vehicle shape line of the shoulder of the structure so that the structure thickness of the part where the sixth point is located is 1.5 to 1.6 times the average structure thickness of the side structure and the roof structure. , Defined on the fifth straight line. Here, the structure thickness of the part where the sixth point is located is 1.5 to 1.6 times the average structure thickness. If the structure thickness is less than 1.5 times the average structure thickness, the structure rigidity is insufficient. This is because when the thickness is larger than 1.6 times the average structure thickness, the rigidity becomes excessive and the cabin space is unnecessarily narrowed.
[0018]
Therefore, the structure for a railway vehicle can easily determine from the vehicle body outline the part, shape, and the like that make the structure thickest in the structure, except for the fixing portion of the side structure. In addition, if a hollow structure is configured based on the structure thickness distribution determined in this way and a face plate is arranged, it is not necessary to extremely increase the face plate thickness, so that the weight of the structure can be reduced and each part of the structure can be reduced. The rigidity can be optimized.
[0019]
Also, Claim 4 The invention described in Claims 1 to 3 In the invention described in any one of the above, the thickness in the structure section direction at the center position in the structure width direction of the roof structure is thicker than the thickness in the structure section direction, which is the average of the side structures and the entire roof structure. To do.
That is, for example, when the roof structure is subjected to an airtight load, the center position in the structure width direction tends to be deformed in the vertical direction, but the center position in the structure width direction in the roof structure is formed to be thicker than the average structure thickness. Therefore, the deformation of the roof structure can be suppressed, and the deformation amount of the entire structure can be reduced.
[0020]
Also, Claim 5 The invention described in Claims 1 to 4 In the invention described in any one of the above, the thickness in the structure cross-sectional direction at the center position in the structure width direction of the roof structure is 1.1 to 1.1 mm of the thickness in the structure cross-sectional direction obtained by averaging the entire side structure and roof structure. The thickness is 1.2 times.
That is, the roof structure forms the vehicle body shape line at the center position so that the structure thickness at the center position is 1.1 to 1.2 times the average structure thickness. In this way, the structure thickness at the center position of the roof structure is 1.1 to 1.2 times the average structure thickness. If the structure thickness is less than 1.1 times the average structure thickness, the structure is insufficient in rigidity. This is because if the thickness is larger than 1.2 times the structure thickness, the rigidity becomes excessive and the cabin space is unnecessarily narrowed. Therefore, the structure for a railway vehicle can have appropriate rigidity at the center of the roof structure.
[0021]
Also, Claim 6 The invention described in Claims 1 to 5 The invention described in any one of the above is characterized in that a portion having the smallest thickness in the cross section of the structure is provided between the center position of the roof structure and the shoulder portion of the structure.
That is, since the bending moment is zero or very small at this portion, the deformation of the structure does not increase even if the structure thickness is reduced. By making the structure thin, it is possible to make the cabin space as small as possible while reducing the weight.
[0022]
Also, Claim 7 The invention described in Claim 6 In the invention described in the above, a portion where the thickness of the structure shoulder in the structure cross-sectional direction is the thickest, a portion where the thickness in the structure cross-sectional direction provided between the center position of the roof structure and the structure shoulder is the thinnest, and the roof A vehicle body shape line is formed by smoothly connecting the center position of the structure.
That is, since the rate of change of the structure thickness between the side structure and the roof structure is small, the deformation of the structure becomes smooth, the stress generated in each part of the structure can be made more uniform than the conventional one, and the stress value and the amount of deformation can be reduced. Can be small.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment according to the railway vehicle structure of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a side structure 2 and a roof structure 3 of a railway vehicle structure 10.
In the railcar structure 10 of the present embodiment, as in the prior art shown in FIG. 9, the side structure 2 and the roof structure 3 are constructed by welding a plurality of aluminum alloy hollow shapes 5 in the circumferential direction. However, as shown in FIG. 1, the thickness of the side structure 2 and the roof structure 3 in the sectional direction of the structure, that is, the structure thickness A (see FIG. 10) is changed based on the stress generated in each part of the structure. Thus, the side structure 102 and the roof structure 103 are different from the conventional structure having a uniform structure thickness A.
[0024]
FIG. 2 is a block diagram of the computer 30 used when optimizing the shape of the railway vehicle structure.
In the railway vehicle structure 10, the initial shape of the railway vehicle structure is optimized using the computer 30. In the computer 30, an input / output device 32, a storage device 33, and the like are connected to a CPU 31 that performs various calculations and controls. The input / output device 32 is used to input data and the like and output calculation results and the like. The storage device 33 stores information input from the input / output device 32, calculation results calculated by the CPU, a program for optimizing the shape of the railway vehicle structure, and the like.
[0025]
A program for optimizing the shape of a railway vehicle structure includes an initial shape of the railway vehicle structure (structure thickness A given as an initial value) and boundary conditions (load load, constraint conditions, etc.) given to the area. Considering the following equation (1) called average compliance (Φ) in continuum mechanics, the constraints (volume, partial structure thickness A fixation, structure thickness A given the average compliance) State that is minimized under the minimum value). ε is a strain, D is a stress-strain relationship, and Ω is a region to be studied.
[0026]
[Expression 1]

[0027]
For details on the minimization of the average compliance, see, for example, “Regional Optimization Analysis in Linear Elasticity Problems”, published in the Japan Society of Mechanical Engineers (A), Volume 60, 578 (1994-10), pages 144-150. Are listed. The outline is as follows.
“Regional optimization analysis in linear elasticity problems” is a method of formulating a domain optimization problem with the domain shape of a linear elastic body as a design variable as a continuum and applying distribution system optimization theory. We approach the domain optimization problem based on the derived governing equation of domain variation. The numerical analysis method is formulated as a method for solving the governing equation, and a force method is proposed as one of the methods. In the force method, a finite element method or the like can be used to solve the governing equation of domain variation by replacing it with a boundary value problem of a linear elasticity problem. Also, the shape gradient function appearing in the governing equation can be analyzed using the finite element method or the like. Therefore, “Regional Optimization Analysis in Linear Elasticity Problem” formulates the minimization problem of average compliance, clarifies the shape gradient function calculated based on the optimality criterion and the optimization criterion, and The force method using the gradient function is applied to the domain problem of linear elastic bodies.
[0028]
The program for optimizing the shape of a railway vehicle structure is an application of the above-mentioned “region optimization analysis in linear elasticity problems”. The initial shape of a railway vehicle structure is divided into finite elements, and the shape gradient function The shape of the railway vehicle structure is optimized by changing the shape of the initial shape of the railway vehicle structure until the calculation result converges, that is, until the average compliance shown in Equation 1 is minimized. FIG. 3 is a flowchart of a program for optimizing the shape of the railway vehicle structure. FIG. 4 is a conceptual diagram in which a part of a railway vehicle structure is divided into finite elements.
[0029]
The CPU 31 of the computer 30 reads a program for optimizing the shape of the railway vehicle structure from the storage means 33, and in step 1 of FIG. 3 (hereinafter referred to as “S1”), an initial shape analysis model (finite element method) is obtained. Input to the input / output device 32.
[0030]
Next, strength analysis is performed in S2 of FIG. The strength analysis is performed by the CPU 31 of the computer 30 reading the initial shape analysis model and calculating the displacement amount and the generated stress based on the model.
[0031]
Next, in S3, sensitivity analysis is performed. In the sensitivity analysis, the shape gradient function G shown in Equation 2 is calculated.
[0032]
[Expression 2]

[0033]
The shape gradient function G shown in Equation 2 is a vector function facing the normal direction distributed on the boundary surface of each element E shown in FIG. Here, the value of the variable appearing in the equation is obtained from the analysis result of the strength analysis of S2, where f is an object force, e is an elastic tensor, u is a displacement, and Λ is a Lagrange constant.
[0034]
Then, in S4 of FIG. 3, a convergence determination is performed. The convergence determination is made based on whether or not the sensitivity obtained by executing the sensitivity analysis is sufficiently small. If it is determined that the sensitivity is sufficiently small (S4: YES), the process is terminated. On the other hand, when it is determined that the sensitivity is not sufficiently low (S4: NO), the process proceeds to S5, and it is determined whether or not a constraint condition for shape change is input. If it is determined that the constraint condition has been input (S5: YES), the process proceeds directly to S7.
[0035]
On the other hand, when it is determined that no constraint condition has been input (S5: NO), in S6, the restriction of the shape is not permitted as a constraint condition, the constraint on the moving direction, the volume (three-dimensional problem) or the area ( The two-dimensional problem is input from the input / output device 32 and stored in the storage device 33, and then the process proceeds to S7. And in S7, if the shape of the structure for railcars of an initial shape is changed, the process after S3 will be repeated again.
[0036]
Such a program for optimizing the shape of a railway vehicle structure operates as follows.
An initial shape analysis model is input to the input / output device 32 of the computer 30 (S1 in FIG. 3). Specifically, for example, as shown in FIG. 4, the entire structure for an initial railway vehicle is divided into finite elements E, and coordinate data is attached to the nodes ● of each element E, for example, four nodes ●. The element information of the finite element method that inputs (i to l) to one set is input. Also, for example, the initial value of the structure thickness A is set to 50 mm, and the Young's modulus and Poisson's ratio of the aluminum alloy are input as material characteristics of the structure for a railway vehicle. Further, for example, a constraint condition and a load condition are input as boundary conditions used when performing strength analysis or the like. As the constraint condition, it is input that the fixing portion of the side structure corresponding to the frame side beam is fixed, and that a symmetry condition is added to the center line in the structure width direction of the structure for a railway vehicle. Here, the symmetry condition is added in order to reduce the calculation amount and the calculation time. In addition, as a load condition, it is input that an equally distributed load is applied outward assuming an airtight load.
[0037]
When strength analysis is performed based on the Young's modulus and Poisson's ratio of the aluminum alloy of the initial shape analysis model, the shape gradient function G is obtained based on the initial shape analysis model and the strength analysis result (S2, S3 in FIG. 3). ). When the sensitivity is not sufficiently small in the convergence determination, that is, when the shape gradient function G has a steep gradient, it is determined whether or not the constraint condition is input, and when the constraint condition is not input. Then, after inputting the constraint conditions, the shape is changed (S4: NO, S5: NO, S6, S7 in FIG. 3).
[0038]
Specifically, when the sensitivity is not sufficiently reduced in the convergence determination and no constraint condition is input, for example, the thickness is set to 40 mm from the outer face plate 6 (see FIG. 10) of the hollow shape member 5. The movement of the position of the node ● is not allowed, the node of each element E (see FIG. 4) is moved only in the x direction (one-dimensionally), and the area surrounded by the outer side plate 6 and the inner side plate 7 is the initial shape The constraint conditions such as making the same as the input are input (S4: NO, S5: NO, S6 in FIG. 3). Here, the thickness of 40 mm from the outer side plate 6 (see FIG. 10) of the hollow shape member 5 is fixed, so that the structure thickness A is 40 mm or less in order to ensure the minimum rigidity and strength in each part of the structure. This is to avoid this. The reason why the node (see FIG. 4) of each element E is moved only in the x direction (one-dimensionally) is to expand and contract each element E in the structure cross-sectional direction.
[0039]
Then, based on the input constraint condition and the calculation result of the shape gradient function G, the shape of the initial structure for a railway vehicle is changed (S7 in FIG. 3). Specifically, for example, when the shape gradient function G is locally large, the 40 mm node ● is not moved from the outside of the side structure and the roof structure for the portion where the shape gradient function G is large, Based on constraints such as limiting the movement direction to the x direction, the node E of the element E in the portion within 10 mm from the inside of the side structure and the roof structure is moved inward to increase the size of the element E. . In addition, since there is a constraint that the area between the outer side plate 6 and the inner side plate 7 is constant, the node of the element E in the portion within 10 mm from the inside of the side structure and the roof structure with respect to the portion where the shape gradient function G is small. ● Move outward to reduce the size of element E. The coordinate data of the moved node ● is rewritten. As a result, the structure thickness A increases when the node ● moves inward, and the structure thickness A decreases when the node ● moves outward, so that the shape of the railway vehicle structure is changed. If the shape of the railway vehicle structure is changed, the processes after S3 are repeated again. These series of processes are automatically performed until it is determined that the sensitivity is sufficiently low in the convergence determination.
[0040]
If it is determined in the convergence determination that the sensitivity is not further reduced, that is, if the value of the shape gradient function G is not smaller than the previous calculation, the process is terminated (S4 in FIG. 3: YES), and FIG. As shown in FIG. 4, the optimized structure 10 for a railway vehicle is output to the input / output device 32.
[0041]
In the railway vehicle structure 10 of FIG. 1, the structure thickness A of the side structure 2 and the roof structure 3 is changed in each part of the structure. The structure thickness W1 of the portion (hereinafter referred to as “structure shoulder portion”) 14 where the side structure 2 and the roof structure 3 are combined is the same as that of the structure except for the fixing portion 2a for fixing the side structure 2 to the frame 4. It is the thickest of all. In the side structure 2, the structure thickness W4 near the center is formed thin. Further, in the roof structure 3, the structure thickness W2 at the center position 3a in the structure width direction is formed thick, and the structure thickness W3 between the structure center part 3a and the structure shoulder part 14 is formed thin.
[0042]
Then, the inventor optimized the shape by executing the above-described program for several types of railway vehicle structures having different vehicle body outlines M, and determined the vehicle body profile line N1 based on the vehicle design, that is, the vehicle body outline M. It was confirmed that the shape of the railway vehicle structure can be optimized.
[0043]
The railcar structure 10 determines a vehicle body outline M using a curve in a gate-shaped region constituted by a vertical line passing through the maximum width position and a horizontal line passing through the maximum height position, and the side structure 2 and the roof. The structure 3 is arranged. Since the structure shoulder 14 generally has a large curvature, the structure shoulder 14 receives a large force to bend in the cross-sectional direction, and the stress value increases. Therefore, based on the vehicle body outline M, the first straight line L1 is drawn in the horizontal direction from the center position 3a of the roof structure 3, and the second straight line L2 is drawn in the vertical direction from the structure maximum width position to form a gate shape. If the position corresponding to the third point P3 where the first straight line L1 and the second straight line L2 intersect can be projected on the vehicle body outline M by any method, the stress value is the highest in the railway vehicle structure 10. An approximate site can be obtained.
[0044]
From this point of view, the third point P3 where the first straight line L1 and the second straight line L2 have a tolerance is the fourth point P4, which is the center point of the curve forming the structure shoulder 14 of the vehicle body outline M, and the fifth straight line. A sixth point P6, which is connected by L5 and is a point at which the fifth straight line L5 is in tolerance with the vehicle body outline M, is obtained. Since the sixth point P6 is considered to be the projection of the third point P3 on the vehicle body outline M, the railcar structure 10 has the structure thickness of the part where the sixth point is located, except for the fixed portion 2a. W1 should be the thickest of the structures.
[0045]
And in order to make the structure thickness W1 of the site | part in which the 6th point P6 is located the thickest, the vehicle of the structure shoulder part 14 by the curve of the radius r2 centering on the 7th point P7 prescribed | regulated on the 5th straight line L5. It is necessary and sufficient to form the body shape line N1.
The radius r2 can be easily determined by subtracting 80 mm from a value obtained by multiplying the radius r1 of the vehicle body outline M at the body shoulder 14 by 1.1. Here, the reason why the coefficient of the relational expression is 1.1 is to optimize the structure thickness distribution of the structure shoulder 14. That is, if the coefficient is greater than 1.1, the structure thickness A of the structure shoulder 14 other than the portion where the maximum structure thickness W1 is not sufficient, resulting in insufficient rigidity. On the other hand, if the coefficient is less than 1.1, the maximum structure thickness is obtained. This is because the rigidity of the portion that becomes W1 is insufficient as compared with the structure shoulder portion 14 other than the portion that becomes the maximum structure thickness W1. Further, 80 mm in the relational expression is an adjustment term for adjusting the structure thickness A, and the reason for setting the adjustment term to 80 mm is exactly the same as the reason for selecting the coefficient in the above relational expression. That is, if the adjustment term is larger than 80 mm, the structure thickness A of the structure shoulder portion 14 other than the portion having the maximum structure thickness W1 is insufficient and the rigidity is insufficient. On the other hand, if the adjustment term is smaller than 80 mm, the maximum structure thickness W1 is obtained. This is because the rigidity of the portion to be formed becomes insufficient compared to the structure shoulder portion 14 other than the portion having the maximum structure thickness W1.
[0046]
The seventh point P7 is to draw a curve with a radius r2 so that the structure thickness W1 is 1.5 to 1.6 times the average structure thickness averaged over the entire structure thickness A of the side structure 2 and the roof structure 3. It is defined on 5 straight lines L5. Here, the structure thickness W1 is set to 1.5 to 1.6 times the average structure thickness. When the structure thickness W1 is less than 1.5 times the average structure thickness, the structure rigidity is insufficient. If it is larger than 6 times, the rigidity becomes excessive and the cabin space is unnecessarily narrowed.
[0047]
In the present embodiment, the radius r1 related to the vehicle body outline M of the body shoulder 14 is 400 mm, and this is a relational expression for calculating the radius r2 (radius r2 (mm) = radius r1 (mm) × 1.1 times). −80 (mm)), the radius r2 is 360 mm. Since the average structure thickness of the present embodiment is 52.8 mm, the structure thickness W1 of the structure shoulder 14 is 1.5 to 1.6 times the average structure thickness, that is, 79.20 to 84.48 mm. Seven points P7 are defined on the fifth straight line L5, and the shape of the body shoulder 14 is determined by drawing a curve having a radius r2 (360 mm). In the present embodiment, the seventh point P7 is defined so that the structure thickness W1 of the structure shoulder 14 is 81.05 mm, which is 1.54 times the average structure thickness.
[0048]
Further, the side structure 2 reduces the structure thickness W4 in a range R2 including the maximum width position of the railway vehicle structure 10. That is, the structure thickness W4 in the range R2 of about 3/7 to 7/7 from the lower end with respect to the distance from the lower end of the side structure 2 to the structure shoulder 14 where the structure thickness W1 is located is Make it the thinnest. The part can be made thinner because the force to deform the side structure 2 by the airtight load and the force transmitted to the side structure 2 when the roof structure 3 is to be deformed are opposite to each other. It is presumed that this is because.
In the present embodiment, the in-vehicle body shape line N1 in the certain range R2 including the maximum width position is formed so that the structure thickness W4 is 40 mm.
[0049]
On the other hand, the roof structure 3 increases the structure thickness W2 at the center position 3a, and decreases the structure thickness W3 between the center position 3a and the structure shoulder 14 where the structure thickness W1 is located. That is, the roof structure 3 forms the vehicle body shape line N1 at the center position 3a so that the structure thickness W2 at the center position 3a is 1.1 to 1.2 times the average structure thickness. Thus, the structure thickness W2 is set to 1.1 to 1.2 times the average structure thickness. If the structure thickness W2 is less than 1.1 times the average structure thickness, the structure rigidity is insufficient, while the average structure thickness is 1. This is because if it is larger than twice, the rigidity becomes excessive and the cabin space is unnecessarily narrowed.
In this embodiment, since the average structure thickness is 52.8 mm, it is desirable that the structure thickness W2 at the center position 3a of the roof structure 3 is 58.0 to 63.3 mm. Therefore, in the present embodiment, the vehicle body shape line N1 at the center position 3a is determined so that the structure thickness W2 at the center position 3a of the roof structure 3 is 61 mm, which is 1.16 times the average structure thickness. .
[0050]
Further, the roof structure 3 has a range R1 of approximately one third to one half from the center position 3a with respect to the distance from the center position 3a where the structure thickness W2 is located to the structure shoulder 14 where the structure thickness W1 is located. The structure thickness W3 is made the thinnest among the structures. Thus, the fixed range R1 is provided at the position where the structure thickness W3 is provided because the bending moment generated at the center position 3a of the roof structure 3 and the bending moment generated at the structure shoulder 14 are opposite to each other. This is because the structure thickness W3 is arranged around the position of the structure 3 where the bending moment becomes zero, but this position varies depending on the vehicle body outline M. The structure thickness W3 at the position is the thinnest because, as described above, since the bending moment is zero or very small, it is not necessary to increase the bending rigidity.
In the present embodiment, the structure in the portion 3b of about a half from the center position 3a of the roof structure 3 with respect to the distance from the center position 3a where the structure thickness W2 is located to the shoulder 14 of the structure where the structure thickness W1 is located. The in-vehicle body shape line N1 in the part 3b of the roof structure 3 is determined so that the thickness W3 is 40 mm.
[0051]
In this way, when the portion where the structure thickness A is increased and the portion where the structure thickness A is reduced are determined in the side structure 2 and the roof structure 3, the adjacent portions are smoothly connected to form the vehicle body shape line N1 of the entire railway vehicle structure 10. . This makes it possible to optimize the shape of the railway vehicle structure in a short time.
[0052]
Next, the operation of the railway vehicle structure 10 will be described.
For example, when the railcar structure 10 enters a tunnel, the force in the cross-section direction of the structure and the length of the structure are generated by a differential pressure generated between the air pressure in the tunnel and the air pressure in the cabin space of the railcar structure 10. Stress is generated in each part of the structure due to a bending moment whose direction is the axis of rotation. In particular, stress is likely to increase at the structure shoulder 14 where the side structure 2 and the roof structure 3 are connected, and at the center position 3 a of the roof structure 3.
[0053]
The railway vehicle structure 10 increases the rigidity and strength of the structure by making the structure thickness W1 of the structure shoulder 14 the thickest of the structures excluding the fixing portion 2a of the side structure 2, thereby increasing the rigidity and strength of the structure. 3 and the side structure 2 can be prevented from being deformed. For example, when the roof structure 3 receives an airtight load, the center position 3a in the structure width direction tends to be greatly deformed in the vertical direction, but the structure thickness W2 is set to be greater than the average structure thickness at the center position 3a in the structure width direction. Since the thickness and thickness of the roof structure 3 are increased, the deformation at the center position 3a of the roof structure 3 can be suppressed. As a result, the deformation amount of the other roof structure 3 can also be suppressed.
[0054]
In such a railway vehicle structure 10, since the structure thickness A is distributed corresponding to the magnitude of the stress generated in each part of the structure, it is possible to make the stress distribution closer to a more uniform one than the conventional one. Is also smooth.
[0055]
Comparing the shape of the railway vehicle structure 10 shown in FIG. 1 having the above configuration and operation with the shape of the railway vehicle structure 100 shown in FIG. 11, the following common points and differences are recognized.
The railcar structure 10 in FIG. 1 and the railcar structure 100 in FIG. 11 are common in that the vehicle body outline M is the same, and the body thicknesses W1 and W5 of the body shoulders 14 and 114 are increased.
[0056]
However, the method for determining the shape of the railway vehicle structure 10 in FIG. 1 and the railway vehicle structure 100 in FIG. 11 are essentially different. That is, the railcar structure 100 in FIG. 11 forms the in-car body shape line N2 of the body shoulder 114 in a form in which a fillet is generated between the side structure 102 and the roof structure 103 formed with a uniform structure thickness A. ing. Therefore, although the vehicle body shape line N2 of the structure shoulder 114 is formed by a curve, the eighth point P8, which is the center point of the curve, is the first straight line L1 drawn horizontally from the maximum height position of the structure. The third point P3 where the second straight line L2 drawn perpendicularly from the maximum width position of the structure has a tolerance is connected to the fourth point P4 which is the center point of the curve forming the structure shoulder 114 of the vehicle body outline M. It is not located on the fifth straight line L5. Therefore, the shape of the railcar structure 100 in FIG. 11 is slightly different from that of the railcar structure 10 in FIG. 1 due to the difference in the shape determination method.
[0057]
The slight difference in shape greatly affects the displacement and stress of the railway vehicle structure 10 in FIG. 1 and the railway vehicle structure 100 in FIG. 11. FIG. 5 is a displacement diagram of a conventional railway vehicle structure 100. FIG. 6 is a displacement diagram of the optimized railway vehicle structure 10.
In the analysis relating to this displacement, an evenly distributed load of 0.001 kPa is applied outward to the railway vehicle structures 10 and 100.
[0058]
As a result of this analysis, the railcar structure 100 of FIG. 11 and the railcar structure 10 of FIG. 1 are deformed so as to bulge outward as shown in FIGS. 5 and 6, but the maximum displacement is different. As shown in FIG. 5, the railcar structure 100 in FIG. 11 has a maximum displacement amount of about 2.14 mm at the center position 103 a of the roof structure 103, whereas the railcar structure 10 in FIG. As shown in FIG. 6, the displacement amount of the center position 3a of the roof structure 3 is about 1.48 mm, and the maximum displacement amount of the railway vehicle structure 10 of FIG. 1 is the maximum displacement amount of the railway vehicle structure 100 of FIG. About 70% of the total. This is because the structure 10 for a railway vehicle shown in FIG. 1 changes the structure thickness A at each part of the structure, thereby deforming the structure shoulder 14 and the center position 3a of the roof structure 3 as shown in FIG. It shows that it can be suppressed more efficiently.
[0059]
FIG. 7 is a stress diagram showing the maximum stresses of the side structure 102 and the roof structure 103 of the conventional railway vehicle structure 100, and FIG. 8 shows the optimized side structure 2 and roof of the railway vehicle structure 10. 5 is a stress diagram showing the maximum stress of the structure 3. FIG.
In the analysis relating to the stress, an equally distributed load of 0.001 kPa is applied to the outside of the railway vehicle structures 10 and 100.
[0060]
As a result of this analysis, as shown in FIG. 7, the railway vehicle structure 100 of FIG. 11 has a mottled stress value generated in each part of the structure. The stress increases in the vicinity of the vehicle body inner shape line N2 and the vehicle body outline M at the center position 103a of the roof structure 103 and the part shifted to the side structure 102 side from the part where the structure thickness W5 of the structure shoulder 114 is located. In particular, a maximum stress value of 81.634 MPa is indicated in the vicinity of the vehicle body shape line N2 at the position shifted from the position where the structure thickness W5 is located to the side structure 102 side.
[0061]
On the other hand, in the railway vehicle structure 10 of FIG. 1, as shown in FIG. 8, the stress values generated inside the structure are closer to each other in the structure. At the center position 3a of the roof structure 3 and the structure shoulder 14, stress is increased in the vicinity of the vehicle body outline M and the vehicle body shape line N1, and in particular, the region where the structure thickness W1 of the structure shoulder 14 is located. A maximum stress value of 45.962 MPa is shown in the vicinity of the vehicle body shape line N1 Z2.
[0062]
Therefore, in the railway vehicle structure 10 shown in FIG. 1, the part Z2 where the maximum stress is generated coincides with the part where the structure thickness W1 is located, whereas the railway vehicle structure 100 shown in FIG. 11 is the part where the maximum stress is generated. Z1 and the part where structure thickness W5 is located have shifted. Further, the maximum stress value of the railway vehicle structure 10 shown in FIG. 1 is reduced to about 55% of the maximum stress value of the railway vehicle structure 100 shown in FIG. This indicates that the structure provided with the structure thickness W1 and the shape of the structure shoulder 14 in the railway vehicle structure 10 shown in FIG. 1 are more appropriate than those in the railway vehicle structure 100 shown in FIG.
1 has a structure thickness W4 in a certain range R2 of the side structure 2 and a structure thickness W3 in a portion 3b of the roof structure 3 as compared with the side structure 102 of the structure 100 for a railcar in FIG. Despite being thinner than the structure thickness A of the roof structure 103, the same stress as that of the railway vehicle structure 100 of FIG. 11 is maintained. This is because the structure 10 for a railway vehicle in FIG. 1 flexibly deforms the side structure 2 and the roof structure 3 by thinning the structure thicknesses W3 and W4 of the portion where the stress is small, and distributes the stress to each part of the structure. It is shown that.
[0063]
As described in detail above, according to the railway vehicle structure 10 of the present embodiment, a plurality of the hollow members 5 in which the outer side plate 6 and the inner side plate 7 are connected by the middle plate 8 are connected to the side structure 2. The roof structure 3 is manufactured separately, and the roof structure 3 is mounted on the side structure 2 erected on the underframe 4 and combined, or the side structure 2 and the roof structure 3 are manufactured integrally. It is mounted on the frame 4 (see FIGS. 9 and 10), the vehicle body outline M is constant, and the cross-sectional normal direction position of the inner side plate 7 is changed based on the stress generated in each part of the structure. Since the structure thickness A is thick at the position where the stress is large and the structure thickness A is thin at the position where the stress is small (see FIG. 1), it is possible to simultaneously realize the weight reduction and high rigidity of the structure.
[0064]
Moreover, according to the railway vehicle structure 10 of the present embodiment, the structure shoulder 14 and the center position 3a of the roof structure 3 where the stress due to the moment increases are thicker than the average structure thickness (see FIG. 1). The deformation of the structure 2 and the roof structure 3 can be suppressed, and the deformation amount can be reduced in the entire structure.
[0065]
Further, according to the railway vehicle structure 10 of the present embodiment, the structure shoulder 14 joins the side structure 2 and the roof structure 3 with a curve having a larger curvature than the curves constituting the side structure 2 and the roof structure 3. The side structure 2 has a part where the structure thickness A is the thickest among the side structure 2 and the roof structure 3 except for the fixing portion 2a where the side structure 2 is fixed to the underframe 4. For the thickened portion, the first straight line L1 is drawn in the horizontal direction from the center position 3a of the roof structure 3, the second straight line L2 is drawn in the vertical direction from the maximum width position of the side structure 2, and the first straight line L1 and the second straight line L2 are drawn. Is defined as the third point P3, and the center point of the curve forming the body shoulder portion 14 of the vehicle body outline M formed by the outer face plate 6 is defined as the fourth point P4. The fifth straight line L5 is drawn connecting P3 and the fourth point P4, and the fifth straight line L5 is the vehicle body outline. When the point intersecting with M is defined as the sixth point P6, since the sixth point P6 is a position (see FIG. 1), the structure thickness A is the thickest except for the fixing portion 2a of the side structure 2. The part to be performed can be easily obtained from the vehicle body outline M.
The in-vehicle body shape line N1 that forms the structure shoulder 14 is a curve having a radius r2 that is determined based on the radius r1 of the vehicle body outline M by providing the seventh point P7 on the fifth straight line L5 ( 1), the shape of the body shoulder 14 can be easily determined.
[0066]
Further, according to the railcar structure 10 of the present embodiment, the structure thickness W1 of the structure shoulder 14 is 1.5 to 1.6 times the average structure thickness (see FIG. 1), and the roof. By setting the structure thickness W2 at the center position of the structure 3 to 1.1 to 1.2 times the average structure thickness (see FIG. 1), the rigidity of the structure is made appropriate.
[0067]
Further, according to the railway vehicle structure 10 of the present embodiment, the portion 3b having the smallest structure thickness W3 in the section of the structure is provided between the center position 3a of the roof structure 3 and the shoulder 14 of the structure ( As shown in FIG. 1, it can contribute to making the cabin space a little wider as well as lighter.
[0068]
Furthermore, according to the railcar structure 10 of the present exemplary embodiment, the structure thickness W3 provided between the position where the structure thickness W1 of the structure shoulder 14 is located, the center position 3a of the roof structure 3 and the structure shoulder 14 is provided. Since the vehicle body inner shape line N1 is formed by smoothly connecting the part 3b where the position is located and the center position 3a of the roof structure 3 (see FIG. 1), the stress is distributed to each part of the structure (see FIG. 8). The displacement amount of the whole structure can be made smaller than the conventional railway vehicle structure 100 shown in FIG. 11 (see FIG. 6).
[0069]
In addition, this invention is not necessarily limited to the thing of embodiment, It cannot be overemphasized that various changes are possible in the range which does not deviate from the meaning.
[0070]
【The invention's effect】
Therefore, the railway vehicle structure of the present invention is constructed by separately connecting a plurality of hollow shapes in which the outer side plate and the inner side plate are connected by the middle plate, and separately manufacturing the side structure and the roof structure, and standing on the frame. The vehicle body outer shape determined by the position of the outer side plate in the cross-sectional direction in which the roof structure is placed on the side structure and joined together, or the side structure and the roof structure are manufactured integrally and placed on the underframe. The cross-sectional position of the inner side plate is changed based on the stress generated in each part of the structure, and the thickness of the structure cross-sectional direction formed by the outer side plate and the inner side plate is thick at the part where the stress is large. Since the small part is made thin, it is possible to simultaneously realize the weight reduction and high rigidity of the structure.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a side structure and a roof structure of a railway vehicle structure in an embodiment of the invention.
FIG. 2 is also a block diagram of a computer used when optimizing the shape of a railway vehicle structure.
FIG. 3 is also a flowchart of a program for optimizing the shape of a railway vehicle structure.
FIG. 4 is also a conceptual diagram in which a part of a railway vehicle structure is divided into finite elements.
FIG. 5 is also a displacement diagram of a side structure and a roof structure of a conventional railway vehicle structure.
FIG. 6 is also a displacement diagram of the side structure and the roof structure of the optimized railway vehicle structure.
FIG. 7 is also a stress diagram showing the maximum stress of the side structure and the roof structure of the conventional railway vehicle structure.
FIG. 8 is also a stress diagram showing the maximum stress of the side structure and the roof structure of the optimized railway vehicle structure.
FIG. 9 is an external perspective view of a railway vehicle structure.
FIG. 10 is an enlarged cross-sectional view of a hollow shape member.
FIG. 11 is a cross-sectional view of a side structure and a roof structure of a conventional railway vehicle structure.
[Explanation of symbols]
2 side structure
2a fixed part
3 Roof structure
3a Center position
3b site
4 underframe
5 Hollow profile
6 Outside plate
7 Inside plate
8 Middle plate
10 Railcar structures
14 Body shoulder
A Structure thickness
W1 Structure thickness
W2 structure thickness
W3 structure thickness
W4 structure thickness
M body outline
N1 body shape line

Claims (7)

A plurality of hollow members in which an outer side plate and an inner side plate are connected by an intermediate plate are connected to separately produce a side structure and a roof structure, and the roof structure is placed on the side structure erected on a frame. In the structure for a railway vehicle in which the side structure and the roof structure are manufactured as a unit and mounted on the underframe and combined,
That the outer and the vehicle body outline constant which is determined by the cross-sectional direction position of the side plates, to determine the inner side plate cross-sectional direction position the thickness of the structure cross-sectional direction by Rukoto varied based on the stress generated in the structure each part of And
The structure shoulder portion connecting the roof structure and the side structure has a thickness in the cross-sectional direction of the structure in the side structure and the roof structure except for a fixing portion where the side structure is fixed to the underframe. Has the thickest part ,
The site is
Draw a first straight line in the horizontal direction from the center position of the roof structure or the maximum height position of the structure in the structure section,
Draw a second straight line vertically from the maximum width position of the structure,
A point where the first straight line and the second straight line intersect is defined as a third point;
The center point of the curve forming the body shoulder portion of the vehicle body outline formed by the outer face plate is defined as the fourth point,
Draw a fifth straight line connecting the third point and the fourth point,
When the point where the fifth straight line intersects the vehicle body outline is defined as the sixth point,
A railway vehicle structure characterized by being at the position of the sixth point . The structure for a railway vehicle according to claim 1 ,
The shoulder of the structure is formed by a curve having a vehicle interior shape line, which is a reference line formed by the inner side plate, centered on a seventh point defined on the fifth straight line. Railway vehicle structure. In the railcar structure according to claim 1 or 2 ,
In the region where the thickness in the cross section of the structure is maximized, the thickness in the cross section of the structure is 1.5 to 1.6 times the thickness in the cross section of the structure, which is the average of the side structures and the roof structure. A railway vehicle structure characterized by being formed with a thickness. In the railway vehicle structure according to any one of claims 1 to 3 ,
A structure for a railway vehicle, wherein a thickness in a structure section direction at a center position in a structure width direction of the roof structure is thicker than a thickness in a structure section direction that is an average of the side structure and the roof structure as a whole. In the railway vehicle structure according to any one of claims 1 to 4 ,
The thickness in the cross section of the structure at the center position in the width direction of the structure of the roof is 1.1 to 1.2 times the thickness in the cross section of the structure, which is the average of the side structures and the roof structure. A structure for railway vehicles. In the railway vehicle structure according to any one of claims 1 to 5 ,
A structure for a railway vehicle, wherein a portion having a thinnest thickness in a cross-section direction of the structure is provided between a center position of the roof structure and a shoulder portion of the structure. The structure for a railway vehicle according to claim 6 ,
A portion having the thickest thickness in the cross-sectional direction of the structure shoulder, a portion having a thinnest thickness in the cross-sectional direction of the structure provided between the center position of the roof structure and the shoulder of the structure, and the roof structure A railway vehicle structure characterized by smoothly connecting a center position to form a vehicle body shape line.

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