Furring strip designing method and furring strip

Abstract

To provide a furring strip designing method and a furring strip excellent in economy, workability, and rationality by performing evaluation with consideration given to a composite stress state in which different external forces in two directions are simultaneously applied in accordance with an actual condition in place of conventional evaluation performed by adding stress degrees of different external forces in two directions regarding a method for testing stress in the furring strip.SOLUTION: A furring strip 2 is designed on the basis of a testing result of a stress degree under the condition that a value obtained by dividing a stress degree (σy2) in a wind load direction when different external forces in two directions of a wind load and the weight of a wall material 6 are simultaneously applied on the furring strip by a design standard strength (F) satisfies a testing equation of a stress degree of lower than 1.0. The wind load is positive pressure or negative pressure applied on the furring strip. The application range of the wind load is 0.516-4.965 kN / m2. The weight of the wall material is applied on the furring strip when the wall material and the furring strip are fastened by a joining tool. The application range of the weight of the wall material is 20-250 N / m2.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention belongs to the technical field of a design method for a furring strip used as a base material for attaching exterior materials of a building, wall materials such as exterior walls, etc.

Background Art

[0002] In a steel frame structure (S structure) building, as illustrated in FIGS. 1A and 1B, a furring strip 2 is used as a base material for attaching wall materials 6 such as exterior materials of the building and exterior walls (see also reference numeral 2 in Patent Document 1 and reference numeral 11 in Patent Document 2). On the furring strip 2, wind loads acting on the building and the weight (self-weight) of the wall material 6 act via the wall material, and in terms of structural design, the stress and deformation of the furring strip 2 are tested against these external forces. Incidentally, in the drawings, reference numeral 1 indicates a stud (column), reference numeral 3 indicates a bolt member, reference numeral 4 indicates a nut member, and reference numeral 5 indicates a projecting member such as an angle.

[0003] Among the above tests, regarding stress, as shown in FIG. 2 together with the stress test formula for the conventional furring strip design method, for two different external forces in two directions of wind load (q y ) and the weight of the wall material 6 (q x ), at present, a design is carried out to ensure safety such that the sum of the stress intensities when one-directional external forces act respectively does not exceed the design reference strength (F) (see Non-Patent Document 1 as a reference).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, the verification (formula) of the stress intensity at the hull edge is evaluated by adding the stress intensities due to different external forces in two directions. However, in reality, it is in a complex stress state where external forces in two directions act simultaneously. Also, with respect to wind loads in different directions such as positive pressure and negative pressure, although the actual situation has different resistance mechanisms for positive pressure and negative pressure, in design, both positive pressure and negative pressure are represented by the same model. From the above, the current design method for the hull edge is greatly deviated from the actual situation. Specifically, the fact is that the stress verification ratio is overestimated. Therefore, when designed with the current hull edge design method, it is assumed that there are various problems such as the cross-section and dimensions of the hull edge being determined in a state that does not match the actual situation.

[0006] Therefore, if the verification method for the stress of the hull edge is not evaluated by adding the stress intensities due to different external forces in two directions as in the conventional method, but by considering the complex stress state where different external forces in two directions act simultaneously in accordance with the actual situation, for example, it can be understood that even if the cross-sectional size of the hull edge determined by the above-mentioned conventional hull edge design method is implemented with a size slightly smaller (reducing the cross-sectional size), there will be no problems in terms of structural design. It is obvious that this is beneficial both economically and in terms of construction.

[0007] Therefore, the present invention has been devised in view of the problems of the above-described background art, and the object is to, instead of evaluating the verification method for the stress of the hull edge by adding the stress intensities due to different external forces in two directions as in the conventional method, by considering the complex stress state where different external forces in two directions act simultaneously in accordance with the actual situation, to provide a hull edge design method and a hull edge that are excellent in economy, constructability, and rationality.

Means for Solving the Problems

[0008] As a means for solving the above problems, the method for designing a trunk edge according to the invention described in claim 1 is such that when external forces in two different directions, namely the wind load and the weight of the wall material, act on the trunk edge simultaneously, the stress in the wind load direction (σ y2 ) is designed based on the test result of the stress satisfying the test formula in which the value obtained by dividing by the design reference strength (F) is less than 1.0.

[0009] The invention described in claim 2 is the method for designing a trunk edge according to claim 1, wherein the test result of the stress is obtained by numerical analysis performed in advance for each different cross-section of the trunk edge, and if all of the second moment of area, section modulus, wind load, and weight of the wall material of the trunk edge to be tested are within the range of the numerical analysis, it is based on the test result of the stress satisfying the test formula of the stress in the wind load direction without using the weight of the wall material.

[0010] The invention described in claim 3 is the method for designing a trunk edge according to claim 1, wherein the wind load is a positive or negative wind load acting on the trunk edge. The invention described in claim 4 is the method for designing a trunk edge according to claim 1 or 3, wherein the application range of the wind load is 0.516 - 4.965 kN / m 2 and is characterized by this.

[0011] The invention described in claim 5 is the method for designing a trunk edge according to claim 1, wherein the weight of the wall material is the weight acting on the trunk edge when the wall material and the trunk edge are tightly fastened by a joining tool. The invention described in claim 6 is the method for designing a trunk edge according to claim 1 or 5, wherein the application range of the weight of the wall material is 20 - 250 N / m 2 and is characterized by this.

[0012] The invention described in claim 7 is the method for designing a trunk edge according to claim 1, wherein the stress in the wind load direction (σ y2 ) is calculated based on FEM analysis in which the cross-sectional shape of the trunk edge, wind load, weight of the wall material, and load boundary conditions are set.

[0013] The invention described in claim 8 is characterized in that, in the method for designing the barrel edge described in claim 1, the load boundary condition is that, in the case of positive pressure, the wind load and the weight of the wall material act on the barrel edge through the wall material, and in the case of negative pressure, the wind load and the weight of the wall material act on the joint between the barrel edge and the wall material.

[0014] The invention described in claim 9 is characterized in that, in the method for designing the barrel edge described in claim 1 or 2, the cross-sectional shape of the barrel edge is the cross-sectional shape of square steel or C-shaped steel.

[0015] The barrel edge according to the invention described in claim 10 is characterized by being used in the method for designing the barrel edge described in claim 9.

Advantages of the Invention

[0016] According to the method for designing the barrel edge and the barrel edge according to the present invention, the following effects can be achieved. Instead of evaluating by adding the stress intensities due to two different external forces in the conventional method, an evaluation is made by considering the complex stress state in which two different external forces act simultaneously, in accordance with the actual situation, thereby realizing a more accurate and efficient method for designing the barrel edge than in the prior art.

[0017] For example, it can be seen that even if the cross-sectional size of the barrel edge determined by the conventional method for designing the barrel edge (current design) is reduced by one size (cross-sectional size reduction), no problems will occur in the structural design. Thus, a method for designing the barrel edge and a barrel edge that are superior to the prior art in terms of economy, constructability, and rationality can be realized.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiment for Carrying Out the Invention

[0019] Next, a design method for the body edge and an example of the body edge according to the present invention will be described with reference to the drawings.

[0020] The design method for the body edge according to the present invention is characterized in that, based on the test result of the stress intensity, the value (test ratio) obtained by dividing the stress intensity (σ y2 ) in the wind load direction when two different external forces in the wind load direction and the weight of the wall material act on the body edge simultaneously by the design reference strength (F) is less than 1.0, and the body edge is designed. That is, the design method for the body edge according to the present invention can be represented by the following <Equation 1>. <Equation 1> σ y2 (Stress intensity in the wind load direction) / F(Design reference strength) < 1 Referring to FIG. 1 for explanation, the constituent members of the bolt joints such as the intermediate column 1 (or column 1) and the body edge 2 according to this embodiment are made of metal. The positions of the bolt member 3 and the nut member 4 are not limited to the illustrated example, and may be in the upside-down position (refer to the comparison of FIGS. 11A and B).

[0021] In short, the applicant has considered the complex stress state in which different external forces in two directions act simultaneously in accordance with the actual situation in the method for designing the frame edge, and as a result of careful consideration and study as described below, has devised the new method for designing the frame edge (evaluation method) described above. That is, the present invention replaces the evaluation of the sum of the stress degrees caused by different external forces in two directions, such as the stress degree test formula (σx / F + σy / F < 1) according to FIG. 2, where the conventional wind load (q y ) and the weight of the wall material 6 (q x ), with the simple design using the above <Formula 1>, and has discovered that a more reasonable and economical method for designing the frame edge (evaluation method) can be realized. Explained in mathematical formulas, it is established by replacing the left side (σx / F + σy / F) of the above conventional formula with σ y2 / F.

[0022] Here, the background of the applicant's devising of the present invention (the above <Formula 1>) will be explained. The applicant first performed a FEM analysis (finite element method analysis) that faithfully reproduced the actual frame edge 2 and confirmed the influence when the above two-directional loads act simultaneously. The results were compared with the current design method (hereinafter referred to as the current design), and a design method that enables reduction of the (stress degree) test ratio was inferred, and analysis was performed based on this. Note that the current design is performed based on a simple model in which the frame edge member is linearly replaced, and the position of the load acting on the frame edge 2 is a design method that greatly deviates from the actual situation. Under the same conditions as this design method, a FEM analysis that faithfully reproduced the cross-sectional shape of the frame edge 2, the wind load, the weight of the wall material 6, and the load boundary conditions was performed as follows.

[0023] The outline of the above FEM analysis will be explained. The cross-sectional shape of the frame edge is a cross-sectional shape of square steel or C-shaped steel. The wind load is a positive pressure or negative pressure wind load acting on the frame edge. The weight of the wall material is the weight acting on the frame edge when the wall material and the frame edge are tightly fastened by a joining tool. The load boundary condition means that in the case of positive pressure, the wind load and the weight of the wall material act on the barrel edge through the wall material, and in the case of negative pressure, the wind load and the weight of the wall material act on the joint between the barrel edge and the wall material.

[0024] The barrel edge 2 targeted in this analysis is made of C-shaped steel (hereinafter, appropriately referred to as "C") or square steel (hereinafter, appropriately referred to as "□"). <Analysis variable> (Cross-sectional dimensions) The following 12 types (Ix represents the moment of inertia about the strong axis, Iy represents the moment of inertia about the weak axis, Zx represents the section modulus about the strong axis, Zy represents the section modulus about the weak axis, and A represents the cross-sectional area, which are indicated at key points) ·C-100×50×20×1.6mm ·C-100×50×20×2.3mm ·C-100×50×20×3.2mm ·C-100×75×20×1.6mm ·C-100×75×20×2.3mm ·C-100×75×20×3.2mm ·□-100×100×1.6mm ·□-100×100×2.3mm ·□-100×100×3.2mm ·□-125×75×1.6mm ·□-125×75×2.3mm ·□-125×75×3.2mm (Boundary conditions) The influence of the self-weight acting on each of the two types of boundary conditions (see FIGS. 3A and 3B) simulating the positive and negative pressures acting on the barrel edge 2 was confirmed.

[0025] (Comparison between the current design and the analysis results (the design according to the present invention)) The verification ratio σ1 / F calculated by the current design was compared with the verification ratio σ2 / F obtained by the analysis to confirm the influence of the weight of the wall material. Note that the definitions of the verification ratio σ1 / F and the verification ratio σ2 / F are shown in FIG. 4 respectively. Here, the current design and the FEM analysis calculated the verification ratio under the following design conditions (specifically shown in FIG. 5). (Explanation of Parameters in Figure 5) Wind load: 0.516, 1.000, 4.965 kN / m 2 , Wall self-weight (self-weight of wall material): 250 N / m 2 , Body edge pitch: 910 mm, body edge span L: 4000 mm (however, for □125×75×1.6, □125×75×2.3, □125×75×3.2, it is 6000 mm), cross-sectional area (A): 3.672 cm 2 to 12.13 cm 2 , Section modulus Z (section modulus Z about the strong axis x : 11.7 cm 3 to 41.1 cm 3 , Section modulus Z about the weak axis y : 4.47 cm 3 to 37.5 cm 3 ) Moment of inertia I (moment of inertia I about the strong axis x : 58.4 cm 4 to 257 cm 4 , Moment of inertia I about the weak axis y : 4.47 cm 4 to 37.5 cm 4

[0026] Incidentally, Figure 6 shows a list of each verification ratio for the positive pressure and negative pressure of the current design and FEM analysis (the design according to the present invention) when the wind load is 1.000 kN / m 2 .

[0027] From Figure 5 summarizing the verification ratios etc. when the wind load is 0.516, 1.000, 4.965 kN / m 2 , in the case of positive pressure, the verification ratio is 5.5% - 47.7%, and in the case of negative pressure, the verification ratio is 2.8% - 22.3%, which is lower than the current design. Each number indicates the range of the minimum value and the maximum value of the difference between the verification ratio of the current design and the verification ratio of the new design (the design according to the present invention) in Figure 5. Specifically, the said 5.5% related to the positive pressure is when the cross-sectional dimension is "□ (square steel pipe) - 100×100×3.2 mm" and the wind load is 4.965 kN / m 2in the case where the cross-sectional dimension is "C (channel steel) - 100×50×20×1.6 mm" and the wind load is 0.516 kN / m 2 in the case of. On the other hand, the said 2.8% related to negative pressure is in the case where the cross-sectional dimension is "□ (square steel pipe) - 100×100×3.2 mm" and the wind load is 1.000 kN / m 2 in the case where the cross-sectional dimension is "C (channel steel) - 100×50×20×1.6 mm" and the wind load is 0.516 kN / m 2 in the case of. From the above, it can be seen that the verification ratio can be reduced when considering the combined stress state in which the external forces in the two directions act simultaneously.

[0028] <Application range of wind load> Based on Article 87 of the Enforcement Order of the Building Standards Act, the wind load qy is calculated by the following formula. qy = W = q·Cf (W: wind pressure (N / m 2 ), q: velocity pressure (N / m 2 ), Cf: wind force coefficient)

[0029] Here, the velocity pressure q is expressed by the following formula. Note that the symbols E and Vо shall define the methods and numerical values calculated by the Minister of Land, Infrastructure, Transport and Tourism respectively. q: 0.6E·Vо 2 (E: coefficient indicating the distribution of the velocity pressure in the height direction, Vо: reference wind speed (m / s) in that area) In addition to the case where the wind force coefficient Cf is determined by a wind tunnel test, it is based on the numerical values determined by the Minister of Land, Infrastructure, Transport and Tourism according to the cross-sectional and planar shapes of the building or structure.

[0030] In the above formula, since the reference wind speed is 30 - 46 m / s, the building height is 2 - 60 m, the wind force coefficient is 0.8 - 1.0, and the ground surface roughness classification is I - IV applicable to the present invention, the application range of the wind load is qy = 0.516 - 4.965 (kN / m).

[0031] <Application range of the weight of the wall material> The weight of the wall material refers to the load obtained by combining the self-weights of the wall material (such as exterior finishing materials and outer walls of buildings), the eaves, the studs, and the finishing materials. In the present invention, PC boards and ALC boards that do not require eaves and studs are excluded, and the applicable range of the weight of the wall material of the present invention is qx = 20 to 250 (N / m 2 ).

[0032] (Effect when implemented by the method for designing eaves according to the present invention) Fig. 7 shows the relationship between (σ1 / F) / (σ2 / F) and the section modulus (Zx) / span (L). From Fig. 7, since all of the above (σ1 / F) / (σ2 / F) are greater than 1, it can be said that the test ratio is reduced with respect to the current design and it can be positioned advantageously in terms of design.

[0033] In addition, in Fig. 5 described above, for the current design (conventional design) and the new design (design according to the present invention), a column for "pass / fail determination" is provided. For this pass / fail determination, if the "test ratio" shown in the column on the left is less than 1.000 (that is, test ratio < 1.000), it is determined as pass (○), and if the test ratio is 1.000 or more, it is determined as fail (×). According to Fig. 5, it can be seen that in the current design, even when the pass / fail (○×) determination for the test ratio is fail (×), in the new design, a result of pass (○) is obtained. Specifically, in the case of the current design, for an eaves with a cross-sectional dimension of □-125×75×1.6 mm (refer to the first row of the cross-section), the determination of pass / fail (○×) is divided between pass (○) and fail (×). As a result, considering safety etc., an eaves with one size increased (size-up) is adopted. According to the new design, from the determination of all being pass (○), there is an excellent advantage that it can be quantitatively and objectively understood that there is no need for size-up. Furthermore, by using the analysis results related to Fig. 5, it is possible to realize an eaves design method and eaves that are excellent both economically and in terms of construction without using FEM analysis again. That is, using a numerical analysis method such as FEM analysis, σ y2(By calculating the stress in the wind load direction or the above-mentioned <Equation 1> in advance and then using this calculation result as a condition when designing furring strips 2, it is possible to realize a design method and furring strips that are both economical and superior in terms of construction. In other words, the above-mentioned stress test results are obtained in advance by numerical analysis performed on each different cross section of the furring strip, and as long as the second moment of area, section modulus, wind load, and weight of the wall material of the furring strip to be tested are all within the ranges of the above-mentioned numerical analysis, it is possible to design furring strips based on the stress test results, which are conditional on satisfying the test formula for the stress in the wind load direction, without using the weight of the wall material, thereby realizing a design method and furring strips that are both economical and superior in terms of construction.

[0034] Therefore, as described above, as a result of the study based on Figures 3 to 7, by implementing the furring strip design method of the present invention (see <Formula 1>) instead of the conventional design method (see Figure 2), it becomes possible to design with more leeway than with the conventional furring strip design method. By making the design with more leeway possible, it becomes possible to flexibly respond to changes in the pitch, span, and size of the furring strip, and it becomes possible to design economically and rationally. Specifically, it has the great advantage of being able to quantitatively and objectively determine whether to lengthen the pitch of the furring strips, increase the span, or reduce the size.

[0035] Although the embodiments have been described above based on the drawings, it should be noted that the present invention is not limited to the illustrated examples and includes the range of design modifications and application variations that would normally be made by a person skilled in the art, provided that they do not deviate from the technical concept of the present invention. For example, as shown in the variations illustrated in Figures 8A to 8F (Figure 8A corresponds to Figure 1), the protruding member 5 (an angle, which is merely one example in the illustrated example) and the furring strip 2 (a C-shaped steel, which is merely one example in the illustrated example) provided on the side of the column 1 or stud 1 can be combined in a variety of forms that have been conventionally implemented, and as long as they are implemented using bolt (including screw and screw) joining means, the design method for the furring strip according to the present invention can be applied, so it should be noted that the various combinations of forms that have been conventionally implemented are naturally subject to the application of the present invention. In short, the present invention is an invention regarding a method for designing the body edge between the column 1 or the intermediate column 1 and the body edge 2. The form (shape) of the protruding member 5 provided on the column 1 or the intermediate column 1 side to which the design method is applied is not limited, and the form (shape) of the body edge 2 is also not limited, such as C-shaped steel or angle steel. In the present invention, the body edge 2 means a base material for attaching a wall finishing lath, boards, corrugated iron sheets, etc. to the main structure, and the wall material means an exterior finishing material such as a steel plate exterior wall (corrugated, large wave, spandrel, small wave, rib wave, etc.) provided around the building.

Explanation of reference numerals

[0036] 1 Intermediate column (column) 2 Body edge 3 Bolt member 4 Nut member 5 Protruding member 6 Wall material

Claims

1. The stress intensity (σ ｙ２ in the wind load direction when two different external forces in two directions, namely the wind load and the weight of the wall material, act on the barrel edge simultaneously) is divided by the design reference strength (F), and the barrel edge is designed based on the test result of the stress intensity that satisfies the test formula of the stress intensity with a value less than 1.

0. A method for designing a barrel edge, characterized by this.

2. The verification result of the stress is obtained by numerical analysis performed in advance for each cross-section with different barrel edges. If all of the second moment of area, section modulus, wind load, and weight of the wall material of the barrel edge to be verified are within the range of the numerical analysis, based on the verification result of the stress on the condition that the stress verification formula in the wind load direction is satisfied without using the weight of the wall material. The design method of the barrel edge according to claim 1, characterized in that it is based on this.

3. The wind load is a positive or negative wind load acting on the barrel edge. The design method of the barrel edge according to claim 1, characterized in that it is as described above.

4. The applicable range of the wind load is 0.516 to 4.965 kN / m ２ The method for designing the hull edge according to claim 1 or 3, characterized in that it is set as such.

5. The weight of the wall material is the weight acting on the barrel edge when the wall material and the barrel edge are fastened by a joining tool. The design method of the barrel edge according to claim 1, characterized in that it is as described above.

6. The applicable range of the weight of the wall material is 20 to 250 N / m ２ A method for designing a body edge according to claim 1 or 5, characterized in that it is set as such.

7. The stress in the wind load direction (σ ｙ２ ) is calculated based on a FEM analysis in which the cross-sectional shape of the barrel edge, the wind load, the weight of the wall material, and the load boundary conditions are set, and the method for designing the barrel edge according to claim 1 is characterized by this.

8. The load boundary condition is that in the case of positive pressure, the wind load and the weight of the wall material act on the barrel edge through the wall material, and in the case of negative pressure, the wind load and the weight of the wall material act on the joint between the barrel edge and the wall material. The design method of the barrel edge according to claim 1, characterized in that it is as described above.

9. The cross-sectional shape of the barrel edge is the cross-sectional shape of square steel or C-shaped steel. The design method of the barrel edge according to claim 1 or 2, characterized in that it is as described above.

10. A barrel edge, characterized in that it is used in the design method of the barrel edge according to claim 9.

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