JP2023103859A - panel material - Google Patents

Abstract

To provide a panel material configured to improve thermal insulation performance by employing a lip channel steel, as a low-heat-transfer steel, having a perforated web and a thickness of 2.3 mm or smaller, thereby suppressing reduction in bearing force due to buckling specific to the low-heat-transfer steel.SOLUTION: A panel material 10 includes: a lip channel steel 12 having a thickness of 2.3 mm or smaller, configured to include a web 12A, a pair of flanges 12B, and a pair of lips 12C, the web 12A having perforations (slits 16) for improving thermal insulation performance of the channel steel; and a surface material 14 jointed to a plate surface of at least one of the flanges 12B. The length of the lip 12C connected to the flange 12B with the surface material 14 jointed thereto is equal to or longer than an effective length [mm] defined by 240/√F)×t, wherein F is an F value [N/mm2] of the lip channel steel 12 and t is a plate thickness [mm] of the lip channel steel 12.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to paneling.

2. Description of the Related Art Conventionally, low heat-transfer shaped steel is known as a steel material used for panel materials such as outer walls and floor materials. A low heat transfer section can be made, for example, by drilling one or more holes in a channel steel web of studs forming a thermal bridge in the outer wall.

The drilled holes extend the length of the heat transfer path through the web located between the pair of flanges and reduce the cross-sectional area of the transfer path. As a result, the thermal conductivity of the web is reduced, so that the heat insulation performance of the low heat transfer section steel using the channel section steel having the perforated web is enhanced. The thermal insulation performance of low heat transfer sections using channel steel with perforated webs was compared, for example, with channel steels of the same shape and size, channel steels with non-perforated webs were used. Better than the case.

In this specification, hereinafter, for convenience of explanation, a lip channel steel having a perforated web is referred to as a "low heat transfer section steel", and a lip channel steel having a non-perforated web is referred to as a "regular section steel". ” is also called.

As a technology related to low heat transfer shaped steel, for example, Patent Document 1 discloses a lip channel steel as a frame material used for panel materials such as building wall materials. In the lip channel steel of Patent Document 1, regarding the cross-sectional area of the web when cut along a plane orthogonal to the material axis direction, the cross-sectional area at the center position in the height direction of the web is made smaller than the cross-sectional area near the flanges at both ends. This reduces the thermal conductivity of the web. Japanese Patent Laid-Open No. 2002-200000 discloses a technique of forming holes in the plate surface of a web as an example of a method for reducing the cross-sectional area.

Further, Patent Document 2 discloses a low heat transfer type in which cuts for reducing thermal conductivity are formed in the web by cutting and raising the plate surface of a web of channel steel, which is a metal plate for construction, as a side. Steel is disclosed.

JP-A-2000-87505 JP-A-2002-146936

Here, in the channel steel of the low heat transfer section steel, the holes formed in the web act as cross-sectional defects in the web. Therefore, the heat insulation performance of the panel material is enhanced. On the other hand, in terms of structural performance, the bending capacity of channel steel with perforated webs is lower than that of channel steels with non-perforated webs. In particular, when a bending load due to wind pressure, etc. is applied to the flange from the face material joined to the flange, the lip channel steel with a plate thickness of 2.3 mm or less will have a characteristic of low heat transfer shape steel. strain buckling, i.e., local deformation of the web.

In this regard, Patent Literature 1 does not disclose any technology for improving strength by suppressing buckling peculiar to low heat transfer section steel when a bending load is applied to the channel steel. For this reason, the technique of Patent Document 1 alone cannot solve the problem of reduced strength due to buckling peculiar to low heat transfer lip channel steel having a plate thickness of 2.3 mm or less.

In addition, Patent Document 2 is a technique related to low heat transfer shaped steel, but as a result of examination by the present inventors, even if a side is provided, it can be applied to the lip channel steel of low heat transfer shaped steel. It has been found that the problem of strength reduction due to peculiar buckling cannot always be fully resolved. For this reason, there is a demand for a new technique that can suppress the decrease in yield strength due to buckling in lip channel steel, which is a low heat transfer steel.

In view of the above problems, the present disclosure provides a panel material that has a perforated web as a low heat transfer section steel and uses a lip channel steel with a plate thickness of 2.3 mm or less to improve heat insulation performance. It is an object of the present invention to provide a panel member capable of suppressing a reduction in yield strength due to buckling that is peculiar to low heat transfer shaped steel.

A panel member according to an aspect of the present disclosure has a web, a pair of flanges, and a pair of lips, the web is provided with holes that improve the heat insulation performance of channel steel, and the plate thickness is 2.3 mm or less. The length of the lip, which has a lip channel steel and a face plate joined to the plate surface of at least one flange, and which is continuous with the flange to which the face plate is joined, is the F value of the lip channel steel [N /mm ² ] is F and the plate thickness [mm] of the lip channel steel is t, it is equal to or greater than the effective lip length [mm] defined by the formula (240/√F)×t.

The inventors have found that in a low heat transfer section steel using a lip channel steel having a perforated web and a plate thickness of 2.3 mm or less, bending from the outside to the flange to which the face plate is joined is performed. The length of the lip continuous to the flange, which is the side where the face plate is joined and subjected to compression when a load is applied, was examined. As a result of examination, when the lip length is more than the effective lip length [mm], the bending stress increases compared to the lip channel steel with the same specifications except that the lip length is the required lip length. I found out to do.

Here, the bending stress indicates the distortion buckling strength of the lip channel steel. The formula for defining the effective lip length is given in "Guidance for Designing Thin Plate Lightweight Steel Buildings, 2nd Edition" (Iron and Steel Federation of Japan), p. 56 Table 3.4.4. It is the same as the calculation formula for calculating the effective width of the lip described therein. In addition, as a result of studies by the present inventors, in the case of non-porous conventional shaped steel, the bending stress of the conventional shaped steel requires the length of the lip even if the length of the lip is extended beyond the effective lip length. It was found that there was no increase in bending stress compared to the lip length case.

For this reason, in the panel material according to one aspect of the present disclosure, it is possible to suppress a decrease in yield strength due to buckling peculiar to the low heat transfer section steel in the lip channel steel of the low heat transfer section steel with improved heat insulation performance.

Therefore, according to the present disclosure, it is a panel material that has a perforated web as a low heat transfer section steel and has improved heat insulation performance by using a lip channel steel with a plate thickness of 2.3 mm or less. Therefore, it is possible to provide a panel material that can suppress a decrease in yield strength due to buckling, which is peculiar to low heat transfer shaped steel.

1 is a perspective view illustrating a panel material according to an embodiment of the present disclosure; FIG. FIG. 2(A) is a front view of the outer surface of the lip channel steel web of the frame member according to the present embodiment, and FIG. 2(B) is the line 2B-2B in FIG. It is a sectional view. FIG. 10 is a front view of the outer surface of the web when the joints of the slits are arranged in series; 7 is a graph for explaining the relationship between the slit ratio and the rate of decrease in heat transmission coefficient by changing the arrangement pattern of the slits. FIG. 2 is a diagram illustrating an overview of an analysis model of a lip channel steel of a low heat transfer steel according to Example 1; FIG. 6A is a diagram for explaining cross-sectional deformation at the central portion in the material axis direction of the analysis model according to Example 1, and FIG. FIG. 6C is a diagram for explaining cross-sectional deformation of a portion, and FIG. 6C is a diagram for explaining cross-sectional deformation at the central portion in the material axial direction of the analysis model according to the second comparative example. FIG. 5 is a diagram illustrating the relationship between the displacement and the load at the central portion of each analysis model of Example 1, a first comparative example, and a second comparative example; 7 is a graph for explaining the relationship between the effective lip length ratio and the short-term bending strength in the analytical model of Example 2. FIG. 7 is a graph for explaining the relationship between the effective lip length ratio and the maximum bending strength in the analysis model of Example 2. FIG. 7 is a graph for explaining the relationship between the effective lip length ratio and the short-term bending strength in the analysis model of the second comparative example.

Embodiments of the present disclosure are described below. In the following description of the drawings, identical or similar parts are given the same or similar reference numerals. However, the relationship between the thickness and the plane dimension in the drawings, the ratio of the thickness of each device and each member, etc. are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. In addition, there are portions with different dimensional relationships and ratios between the drawings.

<Panel material>
First, a panel member according to this embodiment will be described with reference to FIGS. 1 to 4. FIG. As shown in FIG. 1, the panel member 10 according to the present embodiment includes a lip channel steel 12 as a frame member, a face member 14 joined to the upper flange 12B, and a lower flange 12B joined to and a face material 22 . A filling member 24 is arranged between the upper face member 14 and the lower face member 22 . In addition, in FIG. 1 , for ease of viewing of the lip channel steel 12, a part of the face members 14 and 22 is exemplarily divided.

(lip channel steel)
The lip channel steel 12 has a web 12A, a pair of flanges 12B and a pair of lips 12C. The lip channel steel 12 can be made from a sheet of steel plate, for example by bending. In the present disclosure, the plate thickness of the steel plate is 2.3 mm or less.

In this embodiment, the lip channel steel 12 may be formed using a high strength steel plate of 500 MPa or more. In this specification, the term "high-strength steel sheet" means a steel sheet (steel material) having an F value as strength of 500 MPa or more and 1000 MPa or less. Further, in comparison with the "high-strength steel sheet", a steel sheet having an F value of less than 500 MPa may be referred to as a "normal steel sheet". In the present embodiment, for example, a steel material having an F value of 280 MPa for a 400 steel plate as a normal steel plate and an F value for a high strength steel plate of 500 MPa may be used, or the F value of a high strength steel plate may be , 500 MPa steel may be used.

If the F-value as strength of the steel plate exceeds 1000 MPa, the strength becomes too high, and workability when forming the steel plate into the lip channel steel 12, such as roll forming, is lowered. Therefore, in the present embodiment, the strength of the high-strength steel sheet is specified to be 1000 MPa or less. Note that, in the present disclosure, the strength of the high-strength steel sheet is not limited to this, and can be changed as appropriate.

(lip)
In this embodiment, the lip lengths L of the pair of lips 12C are equal to each other, but in the present disclosure the lip lengths of the pair of lips may differ from each other. "Lip length L" is the maximum length of the lip 12C measured in the cross section orthogonal to the material axial direction D of the lip channel steel 12, as shown in Fig. 2(B).

Here, in this embodiment, it is assumed that the flange 12B that joins the face member 14 receives a compressive force along the out-of-plane direction of the face member 14 from the outside, that is, bends.

(face material)
As shown in FIG. 1, the face material 14 is a rectangular building member when viewed from the front. The face material 14 is, for example, a plate-like base member, a gypsum board, or the like. In the present embodiment, the face material 14 is an exterior wall material, but the present disclosure is not limited to this, and may be other panel material such as floor material. Further, in the present embodiment, the case where the face material is joined to both the pair of flanges 12B is exemplified, but the present disclosure is not limited to this, and the face material is joined only to the upper flange 12B in FIG. Alternatively, it may be joined only to the lower flange 12B.

Further, the upper face member 14 and the lower face member 22 in FIG. 1 may be members having the same function, or may be members having different functions. The face material 14 may be joined to the plate surface of at least one of the flanges 12B by the joining member 20 .

(Filling member)
In this embodiment, the filling member 24 is, for example, a heat insulating material such as glass wool or cellulose fiber, but the present disclosure is not limited to this and can be changed as appropriate. Also, in the present disclosure, a filler member is not required.

(joining member)
The joining member 20 is, for example, a screw or the like, and is a building member that joins the flange 12B and the face member 14 together. In FIG. 1, a plurality of joining members 20 are linearly arranged along the axial direction of the lip channel steel 12 when the wall surface of the face member 14 is viewed from the front. In addition, in the present disclosure, the number of rows of the joining members 20 can be arbitrarily set to one row or two or more rows.

(web)
As shown in FIG. 2(A), in this embodiment, the web 12A is provided with a row including a plurality of slits 16 linearly arranged at approximately equal intervals G along the axial direction D of the material. The plurality of slits 16 are holes that improve the heat insulation performance of the channel steel. Three rows including a plurality of slits 16 are formed at approximately equal intervals G along the vertical direction in FIG. 2(A). The "material axial direction D" is the direction in which the web 12A and the flange 12B of the lip channel steel 12 extend along the left-right direction in FIG. 2(A). That is, the material axial direction D is equal to the longitudinal direction.

As shown in FIG. 2B, the "web height HW" is the vertical linear distance from the end on the side of one flange 12B to the end on the side of the other flange 12B. Further, the "flange width WF" is the linear distance in the left-right direction from the end on the web 12A side to the end on the lip 12C side in FIG. 2(B). Also, the "lip length L" is the vertical linear distance from the end of the lip 12C on the one flange 12B side to the end of the other lip 12C in FIG. 2(B). For example, the lip length L of the upper lip 12C in FIG. is the straight-line distance between

Also, in the present disclosure, the number of rows in which the slits 16 are included is not limited to three rows, and may be one row, or any multiple rows of two or more rows, such as five rows. From the viewpoint of improving heat insulating performance, it is desirable to form three or more rows of slits 16 .

Further, in the present disclosure, the gaps G in the material axial direction D between adjacent slits 16 in one row are not limited to being equal, and may be different. Also, the spacing G between adjacent rows in the web height direction is not limited to being equal, and may be different. In order to avoid stress concentration, the shape of the ends of the slits 16 in the longitudinal direction is preferably arcuate as illustrated in FIG.

(Coupling part)
In the present embodiment, in the web 12A, a plate member of the web 12A is formed in a portion where an interval G in the material axial direction D is formed between linear slits 16 having a constant length M that are adjacent in one row. A connecting portion 18 is configured to connect these in the height direction.

In the present disclosure, the shape and dimensions of the holes made in the web 12A are not limited to slits, and can be changed as appropriate. Also, in the present disclosure, the number of slits included in one row is arbitrary as long as it is two or more. In the present disclosure, as long as the required strength as a member can be secured, at least one connecting portion should be formed.

In the present embodiment, when viewed from the front of the plate surface of the web 12A, the arrangement pattern of the plurality of coupling portions 18 included in the rows of the three slits 16 is a zigzag arrangement. Specifically, the slits 16 included in each of the three rows are staggered so as not to overlap on a straight line along the web height direction.

In other words, when the slits 16 are arranged in a zigzag pattern, when viewing the plate surface of the web 12A from the front, the path along which heat moves from one flange 12B side toward the other flange 12B side is the same as the web height HW. Formation of the shortest distance state is inhibited. In addition, when "the slits 16 are arranged in a zigzag arrangement", there may occur a case where "the connecting portions 18 are arranged in a zigzag arrangement".

In addition, in the present disclosure, "the state in which the slits are arranged in a zigzag arrangement" is not limited to the case where the slits are arranged in a zigzag arrangement in all the rows of the slits 16 formed in the web 12A. In the present disclosure, the state in which the slits are arranged in a zigzag arrangement may also be included in the “state in which the slits are arranged in a zigzag arrangement” when the slits are partially formed in at least one of the material axis direction D and the web height direction.

In addition, in the present disclosure, the arrangement pattern of the plurality of slits is not limited to the zigzag arrangement. As shown in FIG. 3, the slits 16 may be arranged in series so as to overlap each other on a straight line along the web height direction (vertical direction in FIG. 3).

(Slit rate)
In the present disclosure, the slit ratio is defined as the sum of the distances G between adjacent slits 16 in the axial direction D in the web 12A divided by the sum of the lengths M of the slits 16 . In the present disclosure, the “slit interval” includes the interval formed between two slits and the interval formed between one slit and the end of the web in the axial direction. interval.

(Analytical test of heat transmission coefficient decrease rate)
In FIG. 4, using finite element numerical analysis (FEM), the heat transmission coefficient of the panel material using the low heat transfer section steel of the lip channel steel 12 having different slit ratios was calculated from the results of analysis. The heat transmission coefficient decrease rate is exemplified. Specifically, the rate of decrease in heat transmission coefficient of the analysis model of the lip channel steel 12 in which the arrangement pattern of the joints 18 is arranged in series, and the analysis of the lip channel steel 12 in which the arrangement pattern of the joints 18 is staggered. The heat transmission coefficient decline rate of the model is exemplified, respectively.

The lip channel steels 12 used in the two analytical models in FIG. Further, in FIG. 4, the data points when the arrangement pattern of the joints 18 is staggered are illustrated by five black circles, and the data points when the arrangement pattern of the joints 18 is serially arranged are It is exemplified by seven white circles.

In the analysis test 1, as a model for analysis, a low heat transfer shaped steel of a lip channel steel 12 which is a stud material, a face material 14 on one side for structure, a heat insulating material as a filling member 24, and a face on the other side Five outer wall members to which gypsum boards as materials 22 were attached were set with different slit ratios. Specifically, in the shape of the lip channel steel 12 having three rows of slits 16 illustrated in FIG. The slit ratio of was varied. All of the set arrangement patterns of the five joints 18 are staggered. Then, by executing the analysis for the set analysis model, each heat transmission coefficient was analyzed.

Also, as a reference model for comparison, a lip channel steel 12 having the same shape and dimensions as the analysis model and having a non-porous web 12A was set. Then, the heat transmission coefficient of the standard model was analyzed by executing the analysis for the set standard model.

The “heat transmission coefficient decrease rate” on the vertical axis of the graph in FIG. 4 is a value obtained by dividing the heat transmission coefficient of the analysis model having the slits 16 by the heat transmission coefficient of the reference model. The larger the value of the heat transmission coefficient decrease rate, that is, the closer the value of the heat transmission coefficient decrease rate is to 1, the smaller the degree of decrease, which means that the heat insulation performance is not improved. On the other hand, the smaller the value of the rate of decrease in heat transmission coefficient, the greater the degree of decrease, which means that the heat insulation performance is improved.

As can be seen from the data points of black circles in FIG. 4, when the connecting portions 18 are arranged in a zigzag arrangement, the rate of decrease in heat transmission coefficient is 85% or less when the slit ratio is 20% or less. In other words, it becomes possible to improve the heat insulation performance by 15% or more. On the other hand, when the slit ratio exceeds 20%, the improvement rate of the heat insulation performance becomes less than 15%.

From the viewpoint of heat insulation performance, a smaller slit ratio is preferable, but if the slit ratio is too small, the strength of the lip channel steel 12 as a structural member, that is, the structural performance becomes unstable. For this reason, in the present embodiment, the slit ratio is set in the range of 5% or more and 20% or less as a range in which structural performance and heat insulation performance can be balanced. In addition, in the present disclosure, the range of the slit ratio is not limited to this, and can be changed as appropriate according to the desired specifications of the lip channel steel 12 .

Further, as can be seen from the data points indicated by the white circles in FIG. 4, even if the joints 18 are arranged in series, if the slit ratio is set within the range of 5% or more and 20% or less, the heat insulation performance is effective. can be improved to However, even if the slit ratio is the same, the analysis model of the lip channel steel 12 in which the joints 18 are arranged in a staggered manner is better than the analysis model of the lip channel steel 12 in which the joints 18 are arranged in series. Thermal insulation performance is further improved due to the small rate reduction rate.

(Lip length)
Next, the lip length L of the lip 12C according to this embodiment will be specifically described. First, in a lip channel steel of a normal shape steel that is not a low heat transfer shape steel, it is usually enough to secure the necessary lip length as the lip length L. However, in the present embodiment, the lip length L continuing to the flange 12B to which the face member 14 is joined is set to be longer than the required lip length and equal to or longer than the effective lip length.

(required lip length)
For the required lip length, refer to "Guidelines for Designing Thin Plate Lightweight Steel Buildings, 2nd Edition" (The Iron and Steel Federation of Japan), p. 83, it is defined by the following formula.


C _min : Required lip length [mm]
b: Width of plate element of flange such as lip channel steel [mm]
F: F value of lip channel steel [N/mm ² ]
t: Plate thickness of lip channel steel [mm]

(effective lip length)
In addition, the effective lip length is described in "Guidelines for Designing Thin Plate Lightweight Steel Buildings, 2nd Edition" (The Iron and Steel Federation of Japan), p. 56 Table 3.4.4. It is the same as the "effective width of the lip" described therein. Specifically, it is defined by the following formula.

Effective lip length [mm] = (240/√F) x t

In addition, the plate thickness t is based on the “Guidance for Designing Thin Plate and Lightweight Steel Buildings, 2nd Edition”, p. It is set according to the design plate thickness described in "(1) Plate thickness of steel material" regarding the structural calculation of the effective cross section of No. 52. That is, in principle, a plate thickness of 90% of the nominal plate thickness is used.

In addition, the arrangement of the effective cross section of the bending members is described in "Guidance for Designing Thin Plate Lightweight Steel Buildings, 2nd Edition", p. Fig. 3.4.5.55. and the arrangement described in P.S. 56 "(6) Effective section modulus Ze of bending member". That is, in the calculation of the allowable stress of the bending member, the compression side flange 12B of the lip channel steel 12 subjected to strong axial bending is evaluated by providing an ineffective portion equivalent to the compression side and evaluating the entire plate element. The arrangement of the effective cross-section of the bending member is different depending on when it is regarded as

Next, Examples 1 and 2, which were carried out on the lip channel steel 12 of the panel material 10 according to the present embodiment, in which the lip length L was set to be equal to or greater than the effective lip length, are shown in FIGS. will be described with reference to

<Example 1: Relationship between displacement and load>
In Example 1, an analysis was performed using FEM to measure the yield strength against the compressive force acting along the out-of-plane direction of the lip channel steel 12 . Since bending is dominant as a load acting on the low heat transfer section steel, here, the force acting on the lip channel steel 12 of the low heat transfer section steel is compression along the material axial direction D. It is assumed that forces, ie axial forces, are not included.

Specifically, an analysis model was set as shown in FIG. The length of the analysis model in the material axis direction D is 3900 mm, the web height is 100 mm, the flange width WF is 50 mm, and the plate thickness is 1.6 mm. In Example 1, the lip length L was set as four parameters of 10 mm, 20 mm, 30 mm, and 40 mm.

In the analysis, it was assumed that the face material 14 was joined to the upper flange side of the lip channel steel of the analysis model in FIG. In addition, the lip channel steel is divided into four equal parts in the material axial direction D, and by setting forced displacement in the vertical direction from the upper side to the lower side in FIG. A four-point bending test was performed in which force was applied to the central portion sandwiched between two points. In addition, displacement in the width direction of the central portion of the flange was constrained so as not to cause lateral buckling. In addition, as boundary conditions, one end of the lip channel steel in the material axial direction D was set to be pin-supported, and the other end was set to be roller-supported.

Then, a load was applied to each of the set analysis models, and the deformation state of the central portion in the material axial direction D was analyzed. Moreover, each bending yield strength was measured from the analysis result. The analysis results of the lip channel steel 12 having the lip length L greater than or equal to the effective lip length will be described as Example 1 below. Also, the analysis result of the lip channel steel 12 whose lip length L is less than the effective lip length will be described as a first comparative example.

Also, as a second comparative example, analysis and measurement similar to those of the first example and the first comparative example were carried out on a normal shaped steel that is a lip channel steel having non-porous webs 12A. The specifications of the lip channel steel according to the second comparative example are the same as the specifications of the lip channel steel 12 according to the first embodiment except that it is non-porous and the lip length L is 12 mm. is.

In FIGS. 6(A) to 6(C), the cross-sectional shape of the central portion in the material axial direction D before the compressive force acts from the upper side is illustrated by a broken line, and the compressive force acts from the upper side. The state of the cross-sectional shape that is deflected downward and deformed at the time of the maximum yield strength is illustrated by the solid line. FIG. 6A illustrates the cross-sectional shape of the analysis model according to Example 1 having a lip length L that is equal to or greater than the effective lip length. Further, FIG. 6B illustrates the cross-sectional shape of the analysis model according to the first comparative example having a lip length L less than the effective lip length. Further, FIG. 6(C) illustrates the cross-sectional shape of the analysis model according to the second comparative example of normal shaped steel.

As shown in FIGS. 6A and 6B, the buckling deformation of Example 1 was suppressed more than that of the first comparative example. In addition, in the analysis model according to the second comparative example illustrated in FIG. Buckling deformation like Example 1 and the first comparative example hardly occurred.

Further, in FIG. 7, respective trajectories showing the relationship between the vertical displacement δy of the central portion in the material axial direction D and the load P are illustrated for Example 1, the first comparative example, and the second comparative example. It is The low heat transfer section steel with the lip length L of 10 mm illustrated by the dotted line in FIG. 7 is the lip channel section steel according to the first comparative example. In FIG. 7, a low heat transfer shaped steel with a lip length L of 20 mm illustrated by a dashed line, a low heat transfer shaped steel with a lip length L of 30 mm illustrated by a thin solid line, and a thick solid line illustrated The low heat transfer section steel with a lip length L of 40 mm is the lip channel section steel 12 according to the first embodiment. Moreover, the lip channel steel illustrated by the dashed line in FIG. 7 is the lip channel steel of the normal shape steel according to the second comparative example.

As shown in FIG. 7, the low heat transfer shaped steel having a lip length L of 20 mm according to Example 1 was able to withstand a maximum load of about 85% of the maximum load of the normal shaped steel. Further, the maximum load in the case of the low heat transfer shaped steel with a lip length L of 30 mm according to Example 1 and the maximum load of the low heat transfer shaped steel with a lip length L of 40 mm according to Example 1 are both It was more than the maximum load of normal shaped steel. With the lip channel steel 12 according to Example 1, it was found that even a low heat transfer steel having a perforated web 12A can suppress a reduction in yield strength due to cross-sectional defects.

<Example 2: Relationship between short-term bending strength increase rate and lip length>
Next, in Example 2, the short-term bending strength of the lip channel steel 12 when the lip length L was changed was analyzed using FSM (finite strip method). The analysis model was set in the same manner as in Example 1 except for the lip length L. Moreover, as shown in FIG. 8, in Example 2, the plate thickness of the analysis model was set to three different values of 1.2 mm, 1.6 mm, and 2.3 mm.

The short-term bending yield strength increase rate is set on the vertical axis of the graph in FIG. As the short-term bending strength increase rate, first, the allowable bending stress degree is calculated from the buckling strength calculated by the FSM. Then, it is obtained by dividing the short-term bending strength calculated by multiplying the calculated allowable bending stress by the section modulus of the effective cross-sectional area by the short-term bending strength calculated from the analysis model having the effective lip length. The obtained value can be calculated as the short-term bending strength increase rate. Also, the effective lip length ratio set on the horizontal axis of the graph in FIG. 8 is a value obtained by dividing the lip length L by the effective lip length.

As shown in FIG. 8, in Example 2, short-term bending increases as the lip length L becomes longer than the effective lip length, regardless of whether the plate thickness t is 1.2 mm, 1.6 mm, or 2.3 mm. It was found that the rate of increase in strength increased. That is, in the low heat transfer steel of the lip channel steel 12 according to the present embodiment, when the plate thickness t is 1.2 mm or more and 2.3 mm or less, the effect of increasing the bending yield strength can be obtained. I understand.

Further, as shown in FIG. 9, a similar effect was also confirmed by analysis using FEM (finite element method). As shown in FIG. 9, when the plate thickness t is 1.2 mm, 1.6 mm, or 2.3 mm, as the lip length L becomes longer than the effective lip length, the maximum bending yield strength increase rate increases. Become. Therefore, it can be seen that the maximum bending yield strength can be increased when the plate thickness t of the lip channel steel 12 of the low heat transfer steel is 1.2 mm or more and 2.3 mm or less.

On the other hand, as shown in FIG. 10, a similar analysis was performed for the short-term bending strength using an analytical model of conventional shaped steel having a non-perforated web 12A. The analytical model of the normal shaped steel in Example 2 illustrated in FIG. 10 has specifications similar to those of the second comparative example described in Example 1. In the case of the conventional shaped steel according to the second comparative example, it was found that the shorter the lip length L becomes longer than the effective lip length, the shorter the short-term bending strength becomes, contrary to the case of the second example.

Specifically, as shown in FIG. 10, when the lip length L is shorter than the effective lip length, the longer the lip length L is, the more the short-term bending resistance increases in the normal section steel. However, when the lip length L reaches the effective lip length, the proof stress of the lip channel steel reaches its peak and local buckling occurs. It was also confirmed that when the lip length L exceeds the effective lip length, the short-term bending resistance tends to decrease as the lip length L becomes longer than the effective lip length. In other words, it can be seen that the lip length L does not need to be extended beyond the effective lip length in the case of the normal shaped steel.

(Effect)
In the low heat transfer steel using the lip channel steel 12 according to the present embodiment, the lip length L continuing to the flange 12B, which is the side where the face material 14 is joined and subjected to compression, is greater than or equal to the effective lip length. be. For this reason, in this embodiment, the lip channel steel of the low heat transfer steel having the same specifications, except that the lip length L is the required lip length, increases the bending strength. As a result, in the panel member 10 according to the present embodiment, it is possible to suppress a decrease in yield strength due to buckling peculiar to the low heat transfer section steel in the lip channel steel 12 of the low heat transfer section steel with improved heat insulation performance.

In addition, in this embodiment, since the lip lengths L of the pair of lips 12C are equal to each other, the cross-sectional shape of the lip channel steel 12 has symmetry compared to the case where the pair of lips 12C have different lip lengths L from each other. Therefore, the panel material 10 using the lip channel steel 12 is well-balanced as a building member and is excellent in design and workability.

Further, in the present embodiment, the slit ratio defined by dividing the sum of the intervals G of the slits 16 in the axial direction D of the web 12A by the sum of the lengths of the slits 16 is 5% or more and 20% or less. . Therefore, it is possible to realize the lip channel steel 12 which is a low heat-transfer steel whose heat insulation performance is ensured.

Also, when the plurality of slits 16 are arranged in a zigzag arrangement, the separation distance between the coupling portions 18 forming the heat paths becomes longer than when the plurality of slits 16 are arranged in series, so the heat insulation of the panel material 10 is improved. High performance. For this reason, it is possible to more preferably achieve both structural performance and heat insulating performance.

Further, in the present embodiment, the low heat transfer section steel of the lip channel steel 12 is formed using a high-strength steel sheet having an F-value of 500 MPa or more. By using a high-strength steel plate for the low heat transfer shaped steel, even if the thickness of the low heat transfer shaped steel is thinner than that of the normal steel plate, the low heat transfer shaped steel can achieve yield strength equal to or greater than that of the normal steel plate.

<Other embodiments>
Although the present disclosure has been described through the above embodiments, this description is not intended to limit the present disclosure. It should be considered that various alternative embodiments, examples and operational techniques will become apparent to those skilled in the art from this disclosure.

For example, the present disclosure can be configured by partially combining the configurations shown in FIGS. 1 to 10. FIG. The present disclosure includes various embodiments and the like not described above, and the technical scope of the present disclosure is defined only by the invention specifying matters of the scope of claims that are valid from the above description.

10 Panel material 12 Lip channel steel 12A Web 12B Flange 12C Lip 14 Face material 16 Slit 18 Joint part 20 Joining member 22 Face material 24 Filling member D Material axial direction G Spacing HW Web height L Lip length M Slit length WF Flange width t Plate thickness δy Displacement

Claims (5)

A lip channel steel having a web, a pair of flanges, and a pair of lips, wherein the web is provided with holes for improving the heat insulation performance of the channel steel, and the plate thickness is 2.3 mm or less;
a face member joined to the plate surface of at least one of the flanges,
For the length of the lip that is continuous with the flange to which the face plate is joined, the F value [N/mm ² ] of the lip channel steel is F and the plate thickness [mm] of the lip channel steel is t. is equal to or greater than the effective lip length [mm] defined by the formula (240/√F)×t,
panel material. the lengths of a pair of said lips are equal to each other;
The panel material according to claim 1. the hole is a slit,
A slit ratio defined by dividing the sum of the intervals of the slits in the axial direction of the web by the sum of the lengths of the slits is 5% or more and 20% or less.
The panel material according to claim 1 or 2. When the plate surface of the web is viewed from the front, the plurality of slits are arranged in a zigzag manner.
The panel material according to claim 3. The lip channel steel is formed using a high-strength steel plate having an F value of 500 MPa or more,
The panel material according to any one of claims 1-4.