JPH08304253A - Method and instrument for measuring shock absorbing property - Google Patents
Method and instrument for measuring shock absorbing propertyInfo
- Publication number
- JPH08304253A JPH08304253A JP13619095A JP13619095A JPH08304253A JP H08304253 A JPH08304253 A JP H08304253A JP 13619095 A JP13619095 A JP 13619095A JP 13619095 A JP13619095 A JP 13619095A JP H08304253 A JPH08304253 A JP H08304253A
- Authority
- JP
- Japan
- Prior art keywords
- sample
- depth
- impact
- maximum penetration
- measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、プラスチックや金属材
料等の試料の衝撃吸収性能を簡易に評価することが可能
な衝撃吸収性測定方法及び装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing property measuring method and apparatus capable of easily evaluating the shock absorbing performance of a sample such as a plastic or a metal material.
【０００２】[0002]
【従来の技術】従来、一般に樹脂材料等の試料の衝撃試
験にはシャルピーやアイゾット衝撃試験、あるいは落錘
衝撃試験等があり、これらはいずれも試料を破断させる
際の衝撃エネルギー［Ｊ］または衝撃値［Ｊ／ｍ2 ］を
求め、試料の衝撃破壊性を評価するものである。それに
対し、これらの試験法を計装化し、得られた応力−歪あ
るいは荷重−変位曲線から全歪エネルギーＥT に対する
試料が吸収したエネルギーＥP の比（ＥP ／ＥT ）を求
めたものが衝撃吸収（衝撃エネルギー吸収）率であり、
上記曲線における最大衝撃荷重の逆数が衝撃吸収度に対
応する。これら衝撃吸収率及び衝撃吸収度を用いて試料
の衝撃吸収性能を評価することができる。衝撃吸収率及
び衝撃吸収度は、上述のような試験により得られる衝撃
値とは全く異なる衝撃特性評価指標である。2. Description of the Related Art Conventionally, there have been generally Charpy and Izod impact tests, or drop weight impact tests for impact tests of samples such as resin materials, all of which are impact energy [J] or impact when breaking a sample. The value [J / m 2 ] is determined and the impact fracture resistance of the sample is evaluated. On the other hand, these test methods were instrumented and the ratio of the energy E P absorbed by the sample to the total strain energy E T (E P / E T ) was determined from the obtained stress-strain or load-displacement curve. Is the impact absorption (impact energy absorption) rate,
The reciprocal of the maximum impact load in the above curve corresponds to the impact absorption. The impact absorption performance of the sample can be evaluated using the impact absorption rate and the impact absorption degree. The impact absorption rate and impact absorption rate are impact characteristic evaluation indexes that are completely different from the impact values obtained by the above-described tests.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上述の
方法によって衝撃吸収率及び衝撃吸収度を得ようとした
場合、まず、応力−歪あるいは荷重−変位曲線を求める
ために、ハンマあるいは落錘等の加撃体の衝突によって
増加する荷重及び加撃体が遠ざかることによって減少す
る荷重を正確に求める必要があり、加撃体の質量や衝突
速度の制限を受ける。従って、質量及び衝突速度を広範
囲に変えることが難しく、現状では一定の制約された条
件下の試料間の比較しか行われていない。ところが、衝
撃吸収性は加撃体の質量や衝突速度に大きく依存するの
は明らかであり、一定の制約された条件下の衝撃吸収性
能では試料の正しい評価に繋がらない。そこで、本発明
は上述した問題点を解決するためになされたものであ
り、応力−歪あるいは荷重−変位曲線を得ることなく、
簡易に、かつ任意の条件下で衝撃吸収率及び衝撃吸収度
を求めることができ、衝撃吸収性能の正しい評価を可能
とする衝撃吸収性測定方法及び装置を提供することを目
的とする。However, when the shock absorption rate and the shock absorption rate are to be obtained by the above-mentioned method, first, in order to obtain the stress-strain or load-displacement curve, a hammer or a falling weight is used. It is necessary to accurately determine the load that increases due to the collision of the attacker and the load that decreases as the attacker moves away, and the mass of the attacker and the collision speed are limited. Therefore, it is difficult to change the mass and the collision velocity in a wide range, and at present, only comparison between samples under certain restricted conditions is performed. However, it is obvious that the shock absorption property depends largely on the mass of the attacking body and the collision speed, and the shock absorption performance under certain restricted conditions does not lead to a correct evaluation of the sample. Therefore, the present invention has been made to solve the above-mentioned problems, without obtaining a stress-strain or load-displacement curve,
It is an object of the present invention to provide a shock absorbing property measuring method and device capable of easily determining a shock absorbing rate and a shock absorbing degree under arbitrary conditions and enabling a correct evaluation of a shock absorbing performance.
【０００４】[0004]
【課題を解決するための手段】上記目的を達成するため
に請求項１の発明は、試料の衝撃吸収性測定方法におい
て、試料に、半径（Ｒ）の球状で質量（ｍ）の加撃体、
又は、半径（Ｒ）の円柱状若しくは半径（Ｒ）の円錐台
形部を先端に有する円柱状で質量（ｍ）の加撃体を、任
意の衝突速度（Ｖ）で衝突させ、この衝突により試料に
生じた加撃体の最大侵入深さ（δT ）及び加撃体の衝突
・回復した後の永久へこみ深さ（δP ）を求め、これら
最大侵入深さと永久へこみ深さとの比（δP ／δT ）を
衝撃吸収率とし、又は、質量（ｍ）と衝突速度（Ｖ）の
積を最大侵入深さ（δT ）で割った値を衝撃吸収度とす
るものである。また、請求項２の発明は、請求項１に記
載の衝撃吸収性測定方法において、試料の加撃体衝突面
に薄膜を塗布し、試料に加撃体が衝突した後の薄膜の脱
離径及び永久へこみ深さを測定し、試料に生じた加撃体
の最大侵入深さを、薄膜の脱離径と加撃体の形状から計
算により求めるものである。また、請求項３の発明は、
試料の衝撃吸収性測定装置において、試料に向けて発射
される球又は円柱又は円錐台形の加撃体と、加撃体が衝
突される試料を固定する試料固定用手段と、加撃体が衝
突した後の試料のへこみの縁の径及び永久へこみ深さを
測定する変位測定手段と、加撃体の試料への衝突速度を
測定する加撃体速度測定手段とを備え、変位測定手段に
より得られた試料のへこみの縁の径と加撃体の形状から
計算により最大侵入深さを求め、さらに、この最大侵入
深さと永久へこみ深さの比から衝撃吸収率を求め、又は
加撃体の質量と衝突速度の積を最大侵入深さで割って衝
撃吸収度を求めるものである。In order to achieve the above object, the invention of claim 1 is a method of measuring shock absorption of a sample, wherein the sample is spherical and has a radius (R) and a mass (m). ,
Alternatively, an impacting body having a radius (R) or a columnar mass having a radius (R) frustoconical portion at the tip and having a mass (m) is caused to collide at an arbitrary collision speed (V), and the sample is The maximum penetration depth (δ T ) of the attacking body and the permanent dent depth (δ P ) after the collision and recovery of the attacking body are found, and the ratio of these maximum penetration depth and permanent dent depth (δ P / δ T ) is the shock absorption rate, or the product of mass (m) and collision velocity (V) divided by the maximum penetration depth (δ T ) is the shock absorption rate. Further, the invention of claim 2 is the method for measuring impact absorption according to claim 1, wherein a thin film is applied to the impacting body collision surface of the sample, and the desorption diameter of the thin film after the impacting body collides with the sample. And the permanent dent depth is measured, and the maximum penetration depth of the attacking body generated in the sample is calculated from the desorption diameter of the thin film and the shape of the attacking body. The invention of claim 3 is
In a shock absorption measuring apparatus for a sample, a sphere, a cylinder, or a truncated cone-shaped attacking body that is fired toward the sample, a sample fixing unit that fixes the sample on which the impacting body collides, and the impacting body collide with each other. The displacement measuring means for measuring the diameter of the dent edge and the permanent dent depth of the sample after crushing, and the accelerating body velocity measuring means for measuring the impact velocity of the accelerating body to the sample are provided by the displacement measuring means. Calculate the maximum penetration depth from the dent edge diameter of the sample and the shape of the attacker, and then calculate the shock absorption rate from the ratio of this maximum penetration depth and permanent dent depth, or The product of mass and collision velocity is divided by the maximum penetration depth to obtain the shock absorption.
【０００５】[0005]
【作用】本発明の方法乃至装置によれば、加撃体の試料
への最大侵入深さ及び永久へこみ深さを求めることによ
り、試料の衝撃吸収率又は衝撃吸収度が得られる。従っ
て、従来の衝撃吸収率を得るための応力−歪あるいは荷
重−変位曲線を求める必要がなく、比較的簡単に衝撃吸
収率又は衝撃吸収度を求めることができる。最大侵入深
さは、試料面に塗布された薄膜が加撃体の侵入によって
脱離した部分の径を測定するか、薄膜を塗布されない試
料のへこみの縁の径を測定し、既知の加撃体の形状から
計算により求められる。永久へこみ深さは、加撃後のへ
こみの深さであり、測定は容易である。球状の加撃体を
用いることで、加撃体の回転を考慮に入れなくてよいの
で、高い衝突速度の試験が可能であり、従って、広範囲
の衝突速度域で試料の衝撃吸収率を得ることが可能であ
る。また、加撃体の質量、衝突速度を任意に設定するこ
とができ、運動方程式を用いれば、加撃体の衝突速度が
非常に遅い準静的な押込み条件から高い衝突速度にわた
り、試料の衝撃吸収性能を評価することが可能となる。According to the method and apparatus of the present invention, the impact absorption rate or the impact absorption rate of the sample can be obtained by obtaining the maximum penetration depth and permanent dent depth of the impacting body into the sample. Therefore, it is not necessary to obtain the stress-strain or load-displacement curve for obtaining the conventional impact absorption rate, and the impact absorption rate or impact absorption degree can be relatively easily determined. The maximum penetration depth is measured by measuring the diameter of the part where the thin film applied to the sample surface is detached due to the intrusion of the attacker or by measuring the diameter of the dent edge of the sample not coated with the thin film. Calculated from the body shape. The permanent dent depth is the depth of the dent after the attack and is easy to measure. By using the spherical impact body, it is not necessary to take the rotation of the impact body into consideration, so that it is possible to test at a high collision speed, and therefore to obtain the shock absorption rate of the sample in a wide range of collision speed range. Is possible. In addition, the mass and collision speed of the impacting body can be set arbitrarily, and if the equation of motion is used, the impact speed of the impacting body is extremely slow, from the quasi-static pushing condition to the high collision velocity. It is possible to evaluate the absorption performance.
【０００６】ただし、前述したように衝撃吸収率及び衝
撃吸収度は、加撃体の質量（ｍ）及び初期衝突速度
（Ｖ）に依存して変化するので、衝撃吸収性の評価を行
う際のパラメータとして、運動量（ｍＶ）又は力積（Ｆ
ｔ）を用いる。また、衝撃吸収率は、後述する弾性変形
と塑性変形の割合（押込みの割合）によっても変化する
ので、加撃体の半径（Ｒ）に対する最大侵入深さ（δ
T ）の比である「へこみの度合（δT ／Ｒ）」も用い
る。すなわち、加撃体の運動方程式は、However, as described above, since the impact absorption rate and the impact absorption rate change depending on the mass (m) of the impacting body and the initial collision velocity (V), the impact absorption property is evaluated. As a parameter, momentum (mV) or impulse (F
t) is used. Further, since the impact absorption rate also changes depending on the ratio of elastic deformation and plastic deformation (ratio of pushing), which will be described later, the maximum penetration depth (δ) with respect to the radius (R) of the impacting body.
The “degree of dent (δ T / R)”, which is the ratio of T 2) is also used. That is, the equation of motion of the attacking body is
【数１】ｄＶ／ｄｔ＝−Ｆ／ｍ （１）である。 前記式（１）を積分し、境界条件（加撃体が試料に接触
し始めた時間ｔ＝０のときＶ＝Ｖ0 、加撃体が静止する
時間ｔ＝ｔ1 のときＶ＝０）のもとで前記式（１）を解
くと、## EQU1 ## dV / dt = -F / m (1) Integrating the equation (1), the boundary condition (V = V0 when the attacking body starts contacting the sample at time t = 0, V = 0 when the attacking body remains stationary at t = t1) Solving equation (1) with
【数２】 [Equation 2]
【０００７】前記式（２）を用いることにより、加撃体
の質量ｍ及び初期速度Ｖ0 から力積が求められる。一般
に、加撃体が１０-3ｍ／ｓ以下の速度で試料に侵入する
場合を、衝撃的ではないために、「準静的押込みによる
深さ率」と定義し、高い速度における深さ率、すなわ
ち、衝撃吸収率と区別する。しかし、本発明では、準静
的押込みによる深さ率と衝撃吸収率はともに同義の深さ
率（δP ／δT ）を意味する。パラメータとして力積を
用いることにより、準静的押込みによる深さ率を高い速
度における深さ率（衝撃吸収率）と比較することも容易
となる。By using the equation (2), the impulse can be obtained from the mass m of the impacting body and the initial velocity V0. Generally, when the attacking body penetrates the sample at a speed of 10 -3 m / s or less, it is not shocking and is defined as "depth ratio by quasi-static indentation". That is, it is distinguished from the shock absorption rate. However, in the present invention, the depth rate by quasi-static indentation and the impact absorption rate both mean the same depth rate (δ P / δ T ). By using the impulse as a parameter, it becomes easy to compare the depth ratio due to quasi-static indentation with the depth ratio (impact absorption rate) at high speed.
【０００８】[0008]
【実施例】以下、本発明を具体化した一実施例を図面を
参照して説明する。図１は衝撃吸収性測定装置１の概念
図である。球状、又は円柱、又は円錐台形の加撃体２
は、試料台３上に設けられた試料固定用バイス４に固定
された試料５に向けて（矢印方向）、図示されない加撃
体発射装置であるガス銃又は図示されない加撃体自由落
下装置により付勢され、発射される。また、図示してい
ないが、本装置１は、加撃体２が衝突した後の試料５の
へこみの淵の径及び永久へこみ深さを測定する変位測定
装置（表面粗さ計又は顕微鏡）と、加撃体２の試料５へ
の衝突速度を測定する加撃体速度測定装置とを備えてい
る。試料５の加撃体２衝突面には、必要に応じて薄膜６
が塗布される。加撃体２の材質は、球状の場合、工具
鋼、円柱又は円錐台形の場合、焼入れ炭素鋼を用いれば
よく、プラスチック材料等の試料５に比し大幅に硬度の
高いものである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram of a shock absorption measuring device 1. Ball-shaped, column-shaped, or truncated cone-shaped attacking body 2
Is directed toward the sample 5 fixed on the sample fixing vise 4 provided on the sample table 3 (in the direction of the arrow) by a gas gun which is an unillustrated attacker launching device or an unillustrated free-falling attacker device. Energized and fired. Further, although not shown, the present device 1 is a displacement measuring device (a surface roughness meter or a microscope) for measuring the diameter of the dent and the permanent dent depth of the sample 5 after the impact body 2 collides. , An attacking body speed measuring device for measuring the collision speed of the attacking body 2 on the sample 5. If necessary, a thin film 6 may be formed on the impact surface of the impact body 2 of the sample 5.
Is applied. As for the material of the impacting body 2, if it is spherical, tool steel, if it is columnar or frustoconical, then quenching carbon steel may be used, and the hardness is significantly higher than that of the sample 5 such as a plastic material.
【０００９】図２（ａ）（ｂ）は、ＡＢＳ樹脂（試料）
に球状及び円錐台形の加撃体を準静的押込みにより衝突
させた時の、試料のへこみ断面を表面粗さ計によって測
定した一例である。それぞれの荷重は、１２７４Ｎ
（Ｎ：ニュートン），１８６２Ｎとした。永久へこみ深
さは、表面粗さ計によって実線のように求められる。ま
た、加撃体の最大侵入深さは、塗布された薄膜に型どら
れたへこみの径、又は、塗布されない試料に残ったへこ
みの縁の径を、例えば表面粗さ計又は顕微鏡を用いて測
定し、これと既知の加撃体の形状とから計算により２点
鎖線のように求められる。このようにして求められた深
さの比（δP ／δT ）を取ることにより、深さ率つまり
衝撃吸収率が得られる。また、加撃体の運動量（ｍＶ）
を、ガス銃又は自由落下装置で得られる同様な最大侵入
深さで除した値（ｍＶ／δT ）を求めることにより、衝
撃吸収度が得られる。2A and 2B show ABS resin (sample).
It is an example of measuring the dented cross section of the sample by a surface roughness meter when a spherical and frustoconical impact body is collided by quasi-static indentation. Each load is 1274N
(N: Newton), 1862N. The permanent dent depth is determined by a surface roughness meter as shown by the solid line. In addition, the maximum penetration depth of the striker is the diameter of the dent that is modeled in the coated thin film, or the edge diameter of the dent that remains in the uncoated sample, for example, using a surface roughness meter or a microscope. It is determined from the measurement and the known shape of the attacking body as shown by a two-dot chain line. By taking the depth ratio (δ P / δ T ) thus obtained, the depth ratio, that is, the shock absorption rate can be obtained. Also, the momentum of the attacking body (mV)
The shock absorption can be obtained by calculating the value (mV / δ T ) divided by the maximum penetration depth obtained by a gas gun or a free fall device.
【００１０】図３は、円柱状の加撃体をＡＢＳ樹脂に準
静的に複数の押込み速度にて押込んだときの深さ率（δ
P ／δT ）を測定した結果であり、荷重（加撃体の最大
侵入時の値）が１７６４Ｎと１２７４Ｎの場合の押込み
速度に対する深さ率を示す。同一の押込み速度であるに
も関わらず、荷重が小さい程、深さ率も低いことが分か
る。また、押込み速度の増加につれて深さ率はわずかに
低下する傾向を示す。FIG. 3 shows the depth ratio (δ) when the cylindrical impact body is quasi-statically pushed into the ABS resin at a plurality of pushing speeds.
P / δ T ) is the result of measurement, and shows the depth ratio with respect to the indentation speed when the load (value at maximum penetration of the impacting body) is 1764N and 1274N. It can be seen that the depth ratio is lower as the load is smaller, although the pushing speed is the same. Further, the depth ratio tends to slightly decrease as the pushing speed increases.
【００１１】図４は、球状の加撃体をＡＢＳ樹脂に準静
的に複数の押込み速度にて押込んだときの深さ率（δP
／δT ）を測定した結果であり、荷重が１２７４Ｎと７
８４Ｎの場合の押込み速度に対する深さ率を示す。図３
と比較すると、深さ率の加撃体質量及び押込み速度依存
性については、加撃体が円柱状であっても球状であって
も、同様な結果を示すことが分かる。FIG. 4 shows the depth ratio (δ P when a spherical impact body is quasi-statically pushed into the ABS resin at a plurality of pushing speeds.
/ Δ T ) was measured and the load was 1274 N and 7
The depth ratio with respect to the pushing speed in the case of 84N is shown. FIG.
Comparing with, it can be seen that the dependency of the depth ratio on the mass of the attacking body and the pushing speed shows similar results regardless of whether the attacking body is cylindrical or spherical.
【００１２】図５は、ＡＢＳ樹脂及びポリエチレン（試
料）について、加撃法の異なる３種類の試験法（準静的
押込み、自由落下、ガス銃）及び多種類の加撃体（ＡＢ
Ｓ樹脂に対して２種類の球と１種類の円柱及び円錐台
形、ポリエチレンに対して１種類の球）を用いて広範囲
の力積における衝撃吸収率を求め、これを表したもので
ある。ガス銃で得られる力積は接触時間が短いため小さ
く、１０-2程度であるが、準静的押込みにおける力積は
かなり大きく１０5 程度である。パラメータとして力積
Ｆｔを用いることで加撃法の種類に関わらず、試料の衝
撃吸収性能を一律に評価することができる。ただし、衝
撃吸収率はへこみの度合や加撃体の形状の影響をある程
度受けるため、材料間の衝撃吸収率を比較する場合に
は、加撃体の形状及びへこみの度合を一定にする必要が
ある。準静的押込みによる力積は測定が容易な荷重−変
位曲線から得られた∫Ｆｄｔを用いた。また、へこみの
度合が小さいほど衝撃吸収率が小さくなっているのは、
へこみの度合が小さくなるにつれて塑性変形エネルギー
に対する弾性変形エネルギーの比が増加することに因
る。また、ＡＢＳ樹脂とポリエチレンの衝撃吸収性の評
価が力積によっては逆転する。従って、ある一つの衝撃
条件では材料の評価を誤る可能性があり、従来の評価方
法では問題があったが、本発明では多くの衝撃条件での
測定が容易に行え、その問題が解消される。FIG. 5 shows three types of test methods (quasi-static indentation, free fall, gas gun) and various types of attack bodies (AB) for ABS resin and polyethylene (sample).
The impact absorption rate in a wide range of impulses was determined by using two types of spheres for S resin, one type of cylinder and a truncated cone, and one type of sphere for polyethylene. The impulse obtained with the gas gun is small due to the short contact time and is about 10 -2 , but the impulse in quasi-static indentation is considerably large and is about 10 5 . By using the impulse Ft as the parameter, the impact absorption performance of the sample can be uniformly evaluated regardless of the type of the hitting method. However, since the impact absorption rate is affected to some extent by the degree of dents and the shape of the impact body, it is necessary to make the shape of the impact body and the degree of dent constant when comparing the impact absorption rates between materials. is there. For the impulse by quasi-static indentation, ∫Fdt obtained from the load-displacement curve that is easy to measure was used. Also, the smaller the degree of dents, the smaller the shock absorption rate is
This is because the ratio of elastic deformation energy to plastic deformation energy increases as the degree of dent decreases. Also, the evaluation of the impact absorption properties of ABS resin and polyethylene is reversed depending on the impulse. Therefore, there is a possibility that the material may be erroneously evaluated under a certain impact condition, and there is a problem in the conventional evaluation method, but in the present invention, measurement under many impact conditions can be easily performed, and the problem is solved. .
【００１３】図６は、ガス銃を用いた場合の球状の加撃
体におけるＡＢＳ樹脂及びポリエチレンの衝撃吸収度を
示したものである。この図から、狭い運動量の範囲で
は、運動量に関係なく衝撃吸収度はあまり変化しない傾
向を示す。また、図５と比較すると、ＡＢＳ樹脂及びポ
リエチレンでは、衝撃吸収率は異なるものの、衝撃吸収
度に大差はないことが分かる。FIG. 6 shows the impact absorption of ABS resin and polyethylene in a spherical striker when a gas gun is used. From this figure, in a narrow range of momentum, there is a tendency that the impact absorption does not change much regardless of the momentum. In addition, comparing with FIG. 5, it can be seen that the ABS resin and polyethylene have different impact absorption rates, but there is no great difference in impact absorption degree.
【００１４】図７は、球及び円錐台形の加撃体を準静的
に押込んだときの、加撃体の衝突後のへこみの縁の径か
ら計算により求められた最大侵入深さと、実測された最
大侵入深さの関係を示す。球の加撃体の場合には、実測
値と計算値がほぼ一致し、円錐台形の加撃体の場合に
は、へこみの度合が大きければ両者の深さは良く一致す
ることが分かる。対象材料によっては加撃体の力積が低
い場合に回復の度合が大きくなるため、衝突後のへこみ
の縁の径は加撃体の最大侵入時の径よりも小さくなる場
合がある。そこで、へこみ現象に影響を与えない程度の
薄膜を試料面に塗布し、加撃体の侵入によって薄膜が脱
離した部分の径を測定することで、真の最大侵入深さを
得ることができる。FIG. 7 shows the maximum penetration depth obtained by calculation from the diameter of the edge of the dent after the impact of the impact body when the impact body of the spherical and frustoconical shape is quasi-statically pushed, and the actual measurement. The relationship of the maximum penetration depth is shown. It can be seen that the measured value and the calculated value are almost the same in the case of a ball hitting body, and the depths of both are well matched in the case of a truncated cone-shaped hitting body if the degree of dent is large. Depending on the target material, the degree of recovery increases when the impulse of the attacking body is low, and therefore the diameter of the edge of the dent after the collision may be smaller than the diameter at the time of maximum intrusion of the attacking body. Therefore, the true maximum penetration depth can be obtained by applying a thin film that does not affect the dent phenomenon to the sample surface and measuring the diameter of the part where the thin film has detached due to the penetration of the attacker. .
【００１５】図８は従来の方法で得られる荷重−変位曲
線を用いたエネルギー吸収率と押込み速度の関係を示
す。この図は本発明による深さ率（δP ／δT ）を示す
図３及び図４に酷似しており、深さ率が従来のエネルギ
ー吸収率（ＥP ／ＥT ）に代わる指標となることを示し
ている。ただし、本発明で示す深さ率と従来のエネルギ
ー吸収率の間には図９に示すような差が見られる。その
差は深さ率が小さいほど大きい。従って、深さ率が大き
い程、本発明による衝撃吸収率は従来のそれに近くな
り、正しい評価が可能となる。FIG. 8 shows the relationship between the energy absorption rate and the pushing speed using the load-displacement curve obtained by the conventional method. This figure is very similar to FIGS. 3 and 4 showing the depth rate (δ P / δ T ) according to the present invention, and the depth rate serves as an index to replace the conventional energy absorption rate (E P / E T ). It is shown that. However, there is a difference as shown in FIG. 9 between the depth ratio shown in the present invention and the conventional energy absorption ratio. The difference is larger as the depth ratio is smaller. Therefore, the greater the depth ratio, the closer the impact absorption rate according to the present invention is to that of the conventional one, and correct evaluation is possible.
【００１６】図１０は荷重−変位曲線を模式的に示した
もので、曲線ＯＡＢが荷重時、曲線ＢＤが除荷時の挙動
である。曲線ＯＡＢの内、ＯＡは初期荷重による弾性変
形を生じている領域、ＡＢは塑性変形が生じている領域
であり、Ａは降伏点である。この図から本発明による衝
撃吸収率が従来の荷重−変位曲線から得られる衝撃吸収
率と理論的に近いことを説明することができる。図１０
より、 全歪エネルギー＝四角形ＯＡＢＣ＝三角形ＯＡＥ＋四角形ＡＢＣＥ ＝1/2 δY ＦY ＋1/2 （δT −δY ）（ＦT ＋ＦY ） である。一方、 吸収エネルギー＝四角形ＯＡＢＤ＝平行四辺形ＯＡＦＤ＋三角形ＡＢＦ ＝δP ＦY ＋1/2 δP （ＦT −ＦY ）＝1/2 δP （ＦT ＋ＦY ）である。 よって、 衝撃吸収率 ＝四角形ＯＡＢＤ／四角形ＯＡＢＣ ＝1/2 δP （ＦT ＋ＦY ）／1/2 （δY ＦY ＋（δT −δY ） （ＦT ＋ＦY ））＝δP （ＦT ＋ＦY ）／（δT ＦY ＋（δT −δY ）ＦT ） δY 《δT のとき、上式はδP ／δT となる。δY 《δ
T はへこみの度合が大きい場合を意味し、δP ／δT は
本発明による衝撃吸収率である。FIG. 10 schematically shows a load-displacement curve. The curve OAB shows the behavior under load, and the curve BD shows the behavior during unloading. In the curve OAB, OA is a region in which elastic deformation due to an initial load is occurring, AB is a region in which plastic deformation is occurring, and A is a yield point. From this figure, it can be explained that the shock absorption rate according to the present invention is theoretically close to the shock absorption rate obtained from the conventional load-displacement curve. Figure 10
Therefore, total strain energy = square OABC = triangle OAE + square ABCE = 1/2 δ Y F Y +1/2 (δ T −δ Y ) (F T + F Y ). On the other hand, the absorption energy = square OABD = parallelogram OAFD + triangle ABF = δ P F Y +1/2 δ P (F T -F Y) = 1/2 δ P (F T + F Y). Therefore, the impact absorption rate = square OABD / square OABC = 1/2 δ P ( F T + F Y) / 1/2 (δ Y F Y + (δ T -δ Y) (F T + F Y)) = δ P When (F T + F Y ) / (δ T F Y + (δ T −δ Y ) F T ) δ Y << δ T , the above formula becomes δ P / δ T. δ Y << δ
T means that the degree of dent is large, and δ P / δ T is the impact absorption rate according to the present invention.
【００１７】また、衝撃吸収性を評価する方法として、
上述した衝撃吸収率の他に衝撃吸収度を用いることもあ
り、後者は絶対値的な性質を持ち、この衝撃吸収度を評
価するには衝撃荷重を用いることが多いが、この衝撃荷
重の変りに、上述した最大侵入深さを用いることもでき
る。それを検証したのが図１１である。すなわち、図１
１には、ポレエチレンに対してガス銃により衝撃試験を
行った時の衝撃荷重と最大侵入深さの関係を示してお
り、同図から、両者は比例的に相関することが分かる。Further, as a method of evaluating the shock absorption,
In addition to the impact absorption rate described above, the impact absorption rate may be used. The latter has an absolute value property, and impact load is often used to evaluate this impact absorption rate. Alternatively, the maximum penetration depth described above may be used. This is verified in FIG. That is, FIG.
1 shows the relationship between the impact load and the maximum penetration depth when an impact test was conducted on polyethylene with a gas gun. From the figure, it can be seen that the two are proportionally correlated.
【００１８】[0018]
【発明の効果】以上のように本発明に係る衝撃吸収性測
定方法及び装置によれば、応力−歪あるいは荷重−変位
曲線を得ることなく、加撃体の試料への最大侵入深さ及
び永久へこみ深さを求めることにより、試料の衝撃吸収
率又は衝撃吸収度を簡易に得ることができ、しかも、任
意の条件下での衝撃吸収率又は衝撃吸収度を求めること
ができ、正しい衝撃吸収性能の評価が可能となる。従っ
て、衝撃吸収材の特性を知る必要がある、例えば、車の
バンパー材の開発やスポーツシューズのソール等の開発
分野において正確な考察を行うことが可能となる。As described above, according to the shock absorbing property measuring method and apparatus according to the present invention, the maximum penetration depth and permanent force of the impacting body into the sample can be obtained without obtaining the stress-strain or load-displacement curve. By obtaining the dent depth, it is possible to easily obtain the shock absorption rate or shock absorption rate of the sample, and furthermore, it is possible to obtain the shock absorption rate or shock absorption rate under any conditions, and the correct shock absorption performance. Can be evaluated. Therefore, it is necessary to know the characteristics of the shock absorbing material, and it is possible to make an accurate consideration in the field of development of, for example, a bumper material for a car and a sole for sports shoes.
【図１】本発明の一実施例による衝撃吸収性測定装置の
概念図である。FIG. 1 is a conceptual diagram of a shock absorption measuring device according to an embodiment of the present invention.
【図２】（ａ）（ｂ）は、試料に球状及び円錐台形の加
撃体を準静的押込みにより衝突させた時の試料のへこみ
断面を測定した一例を示す図である。2 (a) and 2 (b) are diagrams showing an example in which a dented cross section of a sample is measured when a ball-shaped and frustoconical impact body is collided with the sample by quasi-static pushing.
【図３】円柱状の加撃体をＡＢＳ樹脂に準静的に複数の
押込み速度にて押込んだときの深さ率を測定した結果を
示す図である。FIG. 3 is a diagram showing a result of measuring a depth ratio when a cylindrical impact body is quasi-statically pushed into the ABS resin at a plurality of pushing speeds.
【図４】球状の加撃体をＡＢＳ樹脂に準静的に複数の押
込み速度にて押込んだときの深さ率を測定した結果を示
す図である。FIG. 4 is a view showing a result of measuring a depth ratio when a spherical hitting body is quasi-statically pushed into the ABS resin at a plurality of pushing speeds.
【図５】ＡＢＳ樹脂及びポリエチレンについて、加撃法
の異なる試験法及び多種類の加撃体を用いて広範囲の押
込み速度にわたって衝撃吸収率を求め、これを力積をパ
ラメータとして示した図である。FIG. 5 is a diagram showing the impact absorption rate of ABS resin and polyethylene over a wide range of indentation speeds using different test methods and various types of attackers, and showing the impulse as a parameter. .
【図６】ガス銃を用いた場合の球状の加撃体におけるＡ
ＢＳ樹脂及びポリエチレンの衝撃吸収度を示した図であ
る。FIG. 6 A in a spherical attacking body when a gas gun is used
It is the figure which showed the impact absorption degree of BS resin and polyethylene.
【図７】球及び円錐台形の加撃体を準静的に押込んだと
きの衝突後のへこみの淵の径から計算により求められた
最大侵入深さと、実測された最大侵入深さの関係を示す
図である。[Fig. 7] Relationship between the maximum penetration depth obtained by calculation from the diameter of the recessed edge after collision and the actually measured maximum penetration depth when a ball and a truncated cone-shaped attacker are quasi-statically pushed in FIG.
【図８】従来の方法で得られる荷重−変位曲線を用いた
エネルギー吸収率と押込み速度の関係を示す図である。FIG. 8 is a diagram showing a relationship between an energy absorption rate and a pushing speed using a load-displacement curve obtained by a conventional method.
【図９】深さ率と従来のエネルギー吸収率の関係を示す
図である。FIG. 9 is a diagram showing a relationship between a depth rate and a conventional energy absorption rate.
【図１０】荷重−変位曲線を模式的に示した図である。FIG. 10 is a diagram schematically showing a load-displacement curve.
【図１１】衝撃荷重と最大侵入深さの関係を示す図であ
る。FIG. 11 is a diagram showing the relationship between impact load and maximum penetration depth.
１ 衝撃吸収性測定装置 ２ 加撃体 ４ 試料固定用バイス ５ 試料 ６ 薄膜 1 Shock Absorbency Measuring Device 2 Attacker 4 Vise for Fixing Sample 5 Sample 6 Thin Film
Claims (3)
いて、 試料に、半径（Ｒ）の球状で質量（ｍ）の加撃体、又
は、半径（Ｒ）の円柱状若しくは半径（Ｒ）の円錐台形
部を先端に有する円柱状で質量（ｍ）の加撃体を、任意
の衝突速度（Ｖ）で衝突させ、この衝突により試料に生
じた加撃体の最大侵入深さ（δT ）及び加撃体の衝突・
回復した後の永久へこみ深さ（δP ）を求め、これら最
大侵入深さと永久へこみ深さとの比（δP ／δT ）を衝
撃吸収率とし、又は、質量（ｍ）と衝突速度（Ｖ）の積
を最大侵入深さ（δT ）で割った値を衝撃吸収度とする
ことを特徴とする衝撃吸収性測定方法。1. A method for measuring the impact absorption performance of a sample, comprising: a spherical impactor having a radius (R) and a mass (m); or a columnar or radius (R) having a radius (R). The maximum penetration depth (δ T ) of the impacting body generated in the sample by colliding a cylindrical impacting body having a truncated cone portion with a mass (m) at an arbitrary collision velocity (V) And the collision of the attacking body
The permanent dent depth (δ P ) after recovery is determined, and the ratio of these maximum penetration depth and permanent dent depth (δ P / δ T ) is taken as the shock absorption rate, or the mass (m) and collision velocity (V ) Is the product of the maximum penetration depth (δ T ) and the value is defined as the impact absorbency.
し、前記試料に加撃体が衝突した後の薄膜の脱離径及び
永久へこみ深さを測定し、前記試料に生じた加撃体の最
大侵入深さを、前記薄膜の脱離径と加撃体の形状から計
算により求めることを特徴とする請求項１に記載の衝撃
吸収性測定方法。2. A thin film is applied to the impacting body collision surface of the sample, and the desorption diameter and the permanent dent depth of the thin film after the impacting body collides with the sample are measured, The impact absorption measuring method according to claim 1, wherein the maximum penetration depth of the striker is calculated from the desorption diameter of the thin film and the shape of the striker.
体と、 前記加撃体が衝突される試料を固定する試料固定用手段
と、 前記加撃体が衝突した後の試料のへこみの縁の径及び永
久へこみ深さを測定する変位測定手段と、 前記加撃体の前記試料への衝突速度を測定する加撃体速
度測定手段とを備え、 前記変位測定手段により得られた試料のへこみの縁の径
と前記加撃体の形状から計算により最大侵入深さを求
め、さらに、この最大侵入深さと永久へこみ深さの比か
ら衝撃吸収率を求め、又は前記加撃体の質量と衝突速度
の積を最大侵入深さで割って衝撃吸収度を求めることを
特徴とする衝撃吸収性測定装置。3. A shock absorption measuring apparatus for a sample, comprising: a ball-shaped, cylindrical-shaped or truncated-cone-shaped hitting body that is launched toward the sample; and a sample fixing means that fixes the sample on which the hitting body collides. Displacement measuring means for measuring the diameter of the dent edge and the permanent dent depth of the sample after the impacting body has collided, and an impacting body speed measuring means for measuring the impact velocity of the attacking body on the sample The maximum penetration depth is obtained by calculation from the diameter of the dent edge of the sample obtained by the displacement measuring means and the shape of the attacker, and from the ratio of the maximum penetration depth and the permanent dent depth. A shock absorption measuring device, wherein a shock absorption rate is obtained, or a product of the mass of the attacking body and a collision speed is divided by a maximum penetration depth to obtain a shock absorption degree.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13619095A JPH08304253A (en) | 1995-05-09 | 1995-05-09 | Method and instrument for measuring shock absorbing property |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13619095A JPH08304253A (en) | 1995-05-09 | 1995-05-09 | Method and instrument for measuring shock absorbing property |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08304253A true JPH08304253A (en) | 1996-11-22 |
Family
ID=15169456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13619095A Withdrawn JPH08304253A (en) | 1995-05-09 | 1995-05-09 | Method and instrument for measuring shock absorbing property |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08304253A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102214257A (en) * | 2011-05-20 | 2011-10-12 | 中国汽车技术研究中心 | Parameter recognition method of automobile collision wave form features |
| CN102214256A (en) * | 2011-05-20 | 2011-10-12 | 中国汽车技术研究中心 | Method for extracting characteristic parameters of automotive crash waveform and establishing trapezoidal wave |
| KR20160077490A (en) * | 2014-12-23 | 2016-07-04 | 주식회사 포스코 | Apparatus for simulating impact in refractories, apparatus for measuring impact in refractories and method for estimating impact in refractories |
| JP2022529613A (en) * | 2019-04-12 | 2022-06-23 | ビーエーエスエフ コーティングス ゲゼルシャフト ミット ベシュレンクテル ハフツング | How to inspect the coating on the probe surface |
-
1995
- 1995-05-09 JP JP13619095A patent/JPH08304253A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102214257A (en) * | 2011-05-20 | 2011-10-12 | 中国汽车技术研究中心 | Parameter recognition method of automobile collision wave form features |
| CN102214256A (en) * | 2011-05-20 | 2011-10-12 | 中国汽车技术研究中心 | Method for extracting characteristic parameters of automotive crash waveform and establishing trapezoidal wave |
| KR20160077490A (en) * | 2014-12-23 | 2016-07-04 | 주식회사 포스코 | Apparatus for simulating impact in refractories, apparatus for measuring impact in refractories and method for estimating impact in refractories |
| JP2022529613A (en) * | 2019-04-12 | 2022-06-23 | ビーエーエスエフ コーティングス ゲゼルシャフト ミット ベシュレンクテル ハフツング | How to inspect the coating on the probe surface |
| US11859962B2 (en) | 2019-04-12 | 2024-01-02 | Basf Coatings Gmbh | Method for examining a coating of a probe surface |
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