JP5618200B2 - Collapse simulation program for wooden buildings - Google Patents

Description

  The present invention relates to a collapse simulation program for a wooden building that performs a time history response analysis until the collapse of the wooden building during an earthquake.

  The earthquake damage performance of wooden buildings has been attracting attention due to the great damage to existing wooden buildings in a large-scale earthquake, and the full-scale shaking table test of wooden buildings has also been conducted in the research field. It has become. However, the full-scale shaking table experiment has a problem of enormous costs, labor and time.

  Therefore, in recent years, along with the improvement in the performance of computers, time history response analysis of buildings has been performed by calculating and simulating the behavior of buildings during earthquakes using a simulation program.

  Conventionally, the time history response analysis of such a building is generally performed by a simulation program using a finite element method (FEM) typified by a matrix method.

  However, in the finite element method, the total stiffness matrix must be calculated, so extreme non-linearity must be taken into account in order to trace to collapse, especially breakage of members (breakage of wood), cracks It was a difficult problem to deal with the unbalanced force in the calculation in the state where the destruction progressed extremely such as the progress of. In particular, with wooden buildings, the collapse limit can reach a large deformation range where the interlaminar deformation angle exceeds 1/5 rad. With a simulation program based on the finite element method, wooden buildings from the state where deformation progressed to collapse It was extremely difficult to accurately calculate and simulate the behavior of objects so as to match the actual behavior of buildings during an earthquake.

  In order to solve this problem, the present inventor is one of the discontinuous body analysis methods for accurately simulating the actual behavior at the time of the earthquake from the large deformation region where the fracture has progressed to the collapse. We thought that it would be effective to use the Distinct Element Method (DEM), and developed a simulation program according to the present invention based on the Discrete Element Method. This simulation method using the discrete element method was developed as a technique for analyzing the behavior of non-continuous bodies such as earth and sand and bedrock collapse in the civil engineering field. Until the inventor tries to apply it, it is a wooden building. The individual element method was not used for response analysis during earthquakes.

  In addition, although it is not the response analysis at the time of an earthquake, as an example which applied the individual element method to the building, the "building collapse simulation method" is disclosed by patent document 1. FIG. However, the building collapse simulation method described in Patent Document 1 is a simulation method when an RC (steel reinforced concrete) building is collapsed by blasting, and is applied to an RC building shattered by blasting. However, it could not be applied to time history response analysis of wooden buildings during earthquakes.

JP 7-21148 A

  Therefore, the present invention solves the above-mentioned problems of the prior art, and can perform a time history response analysis up to collapse of a wooden building at the time of an earthquake with high accuracy so as to match the actual behavior at the time of an earthquake. The purpose is to provide a building collapse simulation program.

In order to solve the above-mentioned problem, the invention according to claim 1 is a collapse simulation program for a wooden building for causing a computer to execute a time history response analysis until the collapse of the wooden building at the time of an earthquake. First , the information of the analysis model obtained by modeling the wooden building by combining a plurality of nodes and a plurality of types of springs and the parameter information corresponding to the type of the spring included in the analysis model is read from the input file. A step, a second step of determining an element stiffness matrix according to the type of spring of the analysis model based on the parameter information read from the input file in the first step, and an element stiffness matrix determined in the second step a third step of calculating the stress acting on each spring with distinct element method, in the third step The stress acting on each spring out, a fourth step of adding for each node of each spring is connected, it has the analytical model, framing member elastoplastic spring and beam element of the wooden building And the parameter information corresponding to the elastic-plastic spring of this frame member includes the maximum bending moment indicating the bending strength of the beam element of the frame member, and in the third step , When calculating the stress acting on the elastic-plastic spring of the shaft member, the bending moment applied to the beam element of the shaft member is compared with the maximum bending moment, and based on the comparison result, It is characterized by determining breakage .

According to a second aspect of the present invention, in the collapse simulation program for a wooden building according to the first aspect, the breakage of the frame member is determined by a bending moment applied to a beam element of the frame member being the maximum bending. It is performed when the rotation angle reaches zero after exceeding the moment .

The invention according to claim 3 is the collapse simulation program for a wooden building according to claim 1 or 2, wherein the analysis model further includes an elastic-plastic spring at the joint, an elastic-plastic rotary spring at the joint, and a vertical plane. and Torasubane horizontal Plane, compression muscle differences spring, is modeled by dividing the tension Suji違spring, wherein the input file, the parameter information according to the type of these modeled spring is included It is characterized by.

According to a fourth aspect of the present invention, in the collapse simulation program for a wooden building according to any one of the first to third aspects , each of the basic reaction force, the horizontal force of each floor, the absolute displacement of the ground, and the absolute displacement of each floor of the analysis model. calculating a calculated value for each increment the input file specified time, and characterized by causing a computer to execute the outputting to the output file as time history data.

According to a fifth aspect of the present invention, in the collapse simulation program for a wooden building according to the fourth aspect , the output file includes a trajectory file in which time history data of coordinates of each element of the analysis model is stored. A calculation result file in which time history data of each calculation value is stored, and an analysis continuation file in which information on the analysis model after the calculation and information on the spring are stored, and each element of the analysis model The computer is caused to output a step of outputting information on the time history data of the coordinates, the time history data of each calculated value, the elements of the analysis model after the calculation, and the spring.

The present invention is as described above. According to the invention described in claim 1, the collapse of the wooden building for causing the computer to execute a time history response analysis until the collapse of the wooden building at the time of the earthquake. It is a simulation program , and inputs information on an analysis model obtained by modeling the wooden building by combining a plurality of nodes and a plurality of types of springs, and parameter information corresponding to the types of springs included in the analysis model. A first step of reading from a file; a second step of determining an element stiffness matrix according to the type of spring of the analysis model based on the parameter information read from the input file in the first step; and determining in the second step by the element stiffness matrix, and a third step of calculating the stress acting on each spring with distinct element method, the first The stress acting on each spring calculated in step, a fourth step of adding for each node of each spring is connected, it has the analytical model, framing members of the wooden buildings, and elastic-plastic spring The parameter information that is modeled by the beam element and that corresponds to the elastic-plastic spring of the frame member includes a maximum bending moment that indicates the bending strength of the beam element of the frame member, and In the step, when calculating the stress acting on the elastic-plastic spring of the shaft member, the bending moment applied to the beam element of the shaft member is compared with the maximum bending moment, and based on the comparison result, the shaft member is compared. since determining the breakage of the member, collapse from a state in which deformation can not be accurately simulated in the conventional simulation program, including finite element method has progressed The behavior of the wooden buildings of up to can be accurately calculated, simulated to match the behavior of the actual building during an earthquake. For this reason, the pillar of the time history response analysis leading up to the collapse of the wooden buildings at the time of the earthquake can be performed with high accuracy to match the actual behavior at the time of the earthquake, which was especially broken or continuous columns, with a hanging wall It is possible to express the breakage phenomenon at the horizontal member joint of the analysis by analysis.

According to a second aspect of the present invention, in the collapse simulation program for a wooden building according to the first aspect, the determination of the breakage of the frame member is performed by the bending moment applied to the beam element of the frame member. Since this is done when the maximum bending moment is exceeded and the rotation angle reaches zero, the breakage phenomenon of the through column and the breakage phenomenon at the horizontal member joint of the column with the hanging wall can be expressed accurately. .

According to the invention described in claim 3, in the collapse simulation program for a wooden building according to claim 1 or 2, the analysis model further includes an elastic-plastic spring of a joint, an elastic-plastic rotary spring of the joint, a vertical Plane and horizontal Plane Torasubane, compression muscle differences spring, is modeled by dividing the tension Suji違spring, the input file contains the parameter information corresponding to the type of modeled springs Therefore, in addition to the above-described effects, the structural characteristics of the wooden building constructed by the frame construction method can be utilized to perform calculation / simulation with higher accuracy.

According to a fourth aspect of the present invention, in the collapse simulation program for a wooden building according to any one of the first to third aspects, the basic reaction force, the horizontal force of each floor, the absolute displacement of the ground, the absolute displacement of each floor of the analysis model calculating a respective calculated value for each time step, which is defined in the input file, since it causes the computer to execute an output to the output file as time history data, in addition to the operational effect, the calculation results analysis is facilitated, It can contribute to various researches such as seismic design of wooden buildings and reduction of damage caused by the earthquake.

According to a fifth aspect of the present invention, in the collapse simulation program for a wooden building according to the fourth aspect , a trajectory in which time history data of coordinates of each element of the analysis model is stored in the output file. File, a calculation result file in which time history data of each calculation value is stored, and an analysis continuation file in which information on elements and springs of the analysis model after calculation are stored. Since the computer executes the step of outputting the time history data of the coordinates of each element, the time history data of each calculated value, the elements of the analysis model after the calculation and the spring, the use of the calculation result in addition to the above-described effects. It becomes easy to visualize and confirm the time history response analysis with animation, 3D images, or the like.

It is a conceptual diagram of the rock collapse simulation by the individual element method. It is explanatory drawing of the force calculated with the conventional separate element method. It is a conceptual diagram of modeling of a shaft group. It is explanatory drawing of the restoring force characteristic used for the modeling same as the above. It is a graph which shows the skeleton curve used for modeling same as the above. It is a conceptual diagram of modeling of a junction part. It is a graph which shows the restoring force characteristic of the elastic-plastic spring used for modeling same as the above. It is a graph which shows the restoring force characteristic of the elastic-plastic rotation spring used for modeling same as the above. It is a conceptual diagram of modeling of a vertical composition. It is explanatory drawing of the restoring force characteristic used for modeling of a vertical composition. It is a conceptual diagram of modeling of a struggle. It is explanatory drawing which shows the flow of the program calculation which concerns on the Example of this invention. It is explanatory drawing which shows the flow of creation of an analysis model file. It is explanatory drawing which shows the format of a shaft group file. It is explanatory drawing of each part of a shaft set model. It is explanatory drawing which shows the format of a composition file. It is explanatory drawing of each part of a surface model. It is explanatory drawing which shows the format of a struggle file. It is explanatory drawing of each part of a struggle model. It is explanatory drawing which shows the format of a weight file. It is explanatory drawing explaining the weight designation | designated of an analysis model. It is a figure which shows an example of the confirmation screen of an analysis model. It is a figure which shows an example of the detailed setting window of the external appearance of an analysis model. It is explanatory drawing which shows the format of a parameter file. It is explanatory drawing which shows the format at the time of setting a shaft group spring to a parameter file. It is explanatory drawing which shows the format at the time of setting a junction spring to a parameter file. It is explanatory drawing which shows the format at the time of setting a rotation spring to a parameter file. It is explanatory drawing which shows the format at the time of setting a surface spring to a parameter file. It is explanatory drawing which shows the format at the time of setting a muscle spring in a parameter file. It is explanatory drawing which shows the image of each external force input mode. It is explanatory drawing which shows the format at the time of the seismic wave input of an external force file. It is explanatory drawing which shows the format of the pushover analysis 1 of an external force file. It is explanatory drawing which shows the format of the pushover analysis 2 of an external force file. It is explanatory drawing which shows the format of a calculation condition file. It is a flowchart which shows the flow of main calculation of a calculation program. It is a floor plan of each floor of the wooden house to be tested. It is a graph which shows the acceleration response spectrum of the waveform which amplified the earthquake waveform (JMA Kobe) observed in the case of the Hyogoken Nanbu Earthquake to 150%. It is a graph which shows the time history waveform of the interlayer displacement of the 1st floor in comparison with a shaking table experiment and simulation of an analysis model.

[Individual element method]
First, the outline of the individual element method, which is the basic theory of the program according to the present invention, will be described.
As described in the background art, the program according to the present invention is generally used in the structural analysis in the conventional building field as an analysis method capable of accurately tracking the time history response analysis until the collapse of the wooden building at the time of the earthquake. Instead of the finite element method that has been used, the basic theory is the individual element method that can calculate acceleration, velocity, displacement increment, etc. without having to solve the overall stiffness matrix by calculating the stress acting on each element individually. Adopted. Since the individual element method is originally a “discontinuous body analysis method (a method for calculating the behavior of disjoint objects)” developed to calculate the collapse of soil and rock mass as shown in FIG. It is possible to naturally analyze the behavior of buildings from large deformation areas to collapse.

  The individual element method is in the category of dynamic explicit method among the numerical analysis methods. In the analysis method using the conventional individual element method, as shown in FIG. It was only necessary to calculate the repulsive force and frictional force. For this reason, there are no structural elements generally used in structural analysis of buildings such as beam elements and truss elements. For this reason, there are few examples of research using the individual element method in the building field, and at present, there is no time history response analysis tool using the individual element method for wooden buildings.

(Numerical analysis method)
Next, the numerical analysis method of the individual element method will be described.
Similar to the finite element method, the analysis model is constructed by combining nodes and springs. For a spring i, the displacement vector and stress vector in the global coordinate system at the time t-1 between the nodes 1 and 2 at both ends are as follows (formula 1), the displacement vector [Di] _{t-1 of the} spring i, and the stress vector [Fi ] displacement vector in the local coordinate system at time t-1 of _t-1, the stress vector following (equation 2), the increment between Δt time t-1 to t for each vector as follows (equation 3), the time Assuming that there is a displacement increment of [Δdi] _t at the nodes 1 and 2 at both ends of the spring i due to the action of an external force at t-1, the element stiffness matrix [Ki] _t and the spring i of the damping matrix [Ci] _{t have} the following ( [Fi] _t can be calculated by Equation 4).

Here, when the coordinate transformation matrix of the entire coordinate system → the member coordinate system is [Ti] _t , the above (Formula 4) can be expressed as the following (Formula 5).

Formula 5 is calculated for each spring, and stress vectors [fi] _t1 and [fi] _t2 at each node are calculated. The stress vector [F _A ] _t acting on the node A is calculated by adding the stress vector to all the springs connected to the node A (Formula 6).

The stress vector calculated by this formula is numerically integrated by Newmark's β method (average acceleration method β = 1/4), and acceleration [a _A ] _t , velocity [v _A ] _{t at time t} , displacement increment [ΔD _A ] _t is calculated (formula 7).

  By performing the above calculation for each element and each time, the response of the entire model to the external force is calculated. Thus, the point that the stress is calculated individually for each element without solving the entire stiffness matrix is a feature of the individual element method that is not found in the conventional finite element method. In other words, since the balance is maintained by the propagation of stress between the elements as time advances, the processing of unbalanced force and the behavior after collapse can be analyzed without any special processing.

(Construction of analysis model)
Next, a method for modeling each component member of the wooden building will be described. In the present invention, when modeling a wooden building constructed by a frame construction method, each component member and its joint are made into a shaft, joint, vertical composition, vertical composition, and streak. Modeled separately.

(Modeling of shaft)
First, the modeling of the shaft group will be described.
As shown in Fig. 3, the frame members such as columns, bundles, beams, girders, window bases, lintels, etc. are modeled with elastic-plastic rotating springs (plastic hinges) + elastic beam elements in order to take account of breakage of the members. Went. As the restoring force characteristic (history characteristic) representing the relationship between the input load and deformation of this model, the hysteresis law shown in FIG. 4 was used. Here, the bending strength of the member was set based on experimental results and literatures, and the maximum bending moment was determined according to the section modulus.
Further, as shown in FIG. 5, this skeleton curve is defined by the M-θ relationship, and when the maximum bending moment is exceeded, the moment begins to decrease, and when the bending moment reaches a rotation angle of zero, the member breaks down. The rotation spring between the members is changed to a pin joint.
By setting in this way, it became possible to analyze and analyze the breakage phenomenon of the through column and the breakage phenomenon at the horizontal member joint of the column with the hanging wall.

(Modeling of joints)
Next, modeling of the joint between the shaft groups will be described.
As shown in FIG. 6, the joint portion between the shaft groups was modeled using an elasto-plastic rotating spring + an elasto-plastic spring (rigid against shear). The restoring force characteristics of the compression / tensile elasto-plastic spring (hereinafter referred to as the joint spring) are of the one-side elasticity + one-side slip type shown in FIG. 7, and this skeleton curve was set based on experimental data. .
The hysteresis characteristics of the elasto-plastic rotary spring used the slip type shown in FIG. 8, and the skeletal curve was determined from the literature. The elastic-plastic rotary spring is set so as to act independently in each direction of the strong axis and the weak axis.

(Modeling of vertical and horizontal surfaces)
Next, modeling of the vertical composition and the horizontal composition will be described.
As shown in FIG. 9, the shearing force was modeled by replacing braces with truss springs for vertical surfaces such as walls, hanging walls, and waist walls. For the restoring force characteristics, the bilinear + slip type hysteresis law shown in FIG. 10 was used.
Similarly, horizontal surfaces such as floors and roofs were modeled by replacing the braces with truss elements, and the restoring force characteristics were also based on bilinear + slip type hysteresis rules. The illustrated skeleton curve was set with reference to literature and experimental results.

(Modeling of struggles)
Next, the modeling of differences will be described.
As shown in FIG. 11, the strut member was modeled by arranging two truss elements, compression and tension, for one streak. By setting the non-compressed spring to not act on the force in the tensile direction and the non-tensioned spring to not act on the spring in the compressive direction, the asymmetric horizontal restoring force of the stiffening wall is expressed. ing. In addition, we designed the beam and girder push-up behavior due to the difference in compression by setting the joint point with the frame on the horizontal member. As the restoring force characteristic, a bilinear + slip type hysteresis law was adopted as in the case of the spring of the construction (see FIG. 10).

  In modeling each component member, numerical integration was set to be an average integration method, attenuation was set to be an instantaneous stiffness proportional type, and 0% was set for a downward slope.

  Below, the collapse simulation program of the wooden building which concerns on the Example of this invention is demonstrated with reference to drawings.

(Summary of calculation)
First, an outline of a program according to an embodiment of the present invention will be described with reference to FIG. The calculation program (calc.exe) shown in FIG. 12 is a wooden building collapse simulation program exemplified as an embodiment of the present invention, and gui.exe in the figure is an interface program that is support software for the calculation program. is there. As shown in FIG. 12, the calculation program (calc.exe) includes an analysis model file (test.mod), a parameter file (parm.csv), an external force condition file (load.csv), a calculation condition file (default) .ini) based on information stored in a total of four input files (see Table 1), the computer executes a predetermined calculation for each specified time step (= Δt ₀ ), and a trajectory file (out. trj) is a wooden building collapse simulation program that outputs three output files (see Table 2): a calculation result file (detaout.csv) and an analysis continuation file (cont.mod).

  The interface program (gui.exe) is an interface program for the calculation program (calc.exe), and supports the creation of an analysis model file to be described later, which is an input file, and visualizes the analysis model as a three-dimensional (3D) image. This is a program that causes a computer to execute the visualization of the time history data of the coordinates of each element of the analysis model stored in the locus file, which is an output file, as an animation.

[Analysis model file]
As shown in FIG. 13, the analysis model file includes an axis file (frame.csv), a surface file (wall.csv), a striation file (brace) to which information such as the coordinates of the end part of the analysis model is input. .csv) and weight file (weight.csv) are created by the interface program (gui.exe) from 4 CSV files (comma separated text file), and information on analysis model elements and springs is input. File. As described above, the analysis model of the present invention is modeled by dividing it into a shaft group, a joint, a vertical composition, a vertical composition, and a striation, so that the analysis model file also matches these analysis models. In the interface program (gui.exe), various information such as the coordinates of the member end of each model, which will be described later, is input from a CSV file of four types of formats, a frame file, a surface file, a striation file, and a weight file. ) Can be visualized as an analysis model.

(Axis file)
As shown in FIG. 14, the axis group file (frame.csv) is a CSV file with a format consisting of 13 columns in which one row corresponds to one of the axis group members. It is a file to which information on the joint part of is input. As shown in Table 3, the first column is a part for inputting the type of shaft set, and 1 is input for horizontal members such as beams and girders, and 2 is input for column members such as columns and bundles. The In the second to fourth columns, the absolute coordinates of the end 1 (see FIG. 15) of the shaft member are input in XYZ order, and in the fifth to seventh columns, the absolute coordinates of the end 2 (see FIG. 15) of the shaft member. Are sites that are input in XYZ order. The eighth column is a portion where the winning or losing of the joint portion of the end portion 1 of the shaft assembly member is input. When winning, 1 is input, and when losing, 0 is input. If there is no joint at the end, 1 is entered. The ninth row is a portion where the winning or losing of the end portion 2 of the shaft assembly member is inputted as in the eighth row. The tenth column is the cross-sectional width of the shaft assembly member, the eleventh column is the cross-section component (sei: height), and the twelfth column is the parameter ID (spring number) of the shaft assembly member. ) Is input, and the 13th column is a portion where the parameter IDs of the joint portions at both ends of the shaft assembly member are input. This parameter ID must be the same as the parameter ID number specified in the parameter file described later. Also, all coordinate units are meters, and are input in the core-core coordinates.

  When the coordinates of the end portions of the members are the same, the joint portion of the analysis model is automatically generated by the interface program (gui.exe). At this time, since the member to be “losing” is input in the core-core coordinates, it is automatically offset by the width of the counterpart member. Further, although the coordinate input format is three-dimensional, two-dimensional simulation is possible by setting all the Y coordinates (see FIG. 15) to zero.

(Composite file)
As shown in FIG. 16, the composition file (wall.csv) is a CSV file in a format consisting of 7 columns corresponding to one of each composition surface surrounded by piers. This is a file into which information on the vertical composition and horizontal composition of the image is input. As shown in Table 4, in the first to third columns, the absolute coordinates of the end 1 (see FIG. 17) of each composition surface are input in the order of XYZ, and in the fourth to sixth columns, the end 2 of each composition surface. This is a part where absolute coordinates (see FIG. 17) are input in the order of XYZ. As with the axis file, all coordinate units are meters and are entered in core-core coordinates. The seventh column is a region where the composition parameter ID is input. This parameter ID must be the same as the ID number specified in the parameter file described later.
In addition, the end of the frame is required at the end of the construction surface, and if there is an opening on the wall, add horizontal material (window base, lintel) above and below the opening to the axis file And add the drooping wall and the waist wall to the composition file.

(Different file)
As shown in FIG. 18, the striation file (brace.csv) is a CSV file with a format consisting of seven columns with one line corresponding to one of the striation members. This file is used to input information about the struggle. As shown in Table 5, in the first to third columns, the absolute coordinates of the end 1 of the strut member (see FIG. 19) are input in the order of XYZ, and in the fourth to sixth columns, the end 2 of the stagger member. This is a part where absolute coordinates (see FIG. 19) are input in the order of XYZ. The unit of coordinates of the striation file is all meters, and is input in the core-core coordinates. The seventh column is a part where the parameter ID of the muscle member is input, and this parameter ID needs to be the same as the ID number specified in the parameter file described later.
It should be noted that the end of the strut member is also required at the end of the strut member, and when struts are put on the hook, the input is divided into two lines assuming that there is a single streak.

(Weight file)
In the weight file (weight.csv), as shown in FIG. 20 and Table 6, the first line is the rank of the analysis model, the second line is the height of each floor of the analysis model, and the third line is the analysis model. It is a CSV file in a format that can input up to 5 columns in which the weight of each layer is input.
The first column of the second row is GL (ground level) (h0 in FIG. 21), the second and subsequent columns are the second floor level (h1 in FIG. 21), the third floor level (not shown),... The floor level of each floor is input in units of meters, and the level of the roof beam (h2 in FIG. 21) is input in the last column.
As shown in FIG. 21, the third row is a part where the equivalent mass when the analysis model is replaced by skewered dumping centered on each floor is input in kN units, and the first column is below the first floor. Half of the weight is entered, and the last column is entered with the top half of the top floor plus the weight of the cabin set.
The weight input here is divided by the number of elements present at the height, and is distributed evenly.

  As described above, if you input four CSV files, the axis file (frame.csv), the surface file (wall.csv), the strut file (brace.csv), and the weight file (weight.csv), By starting the interface program (gui.exe) and performing a predetermined operation, information such as the absolute coordinates of each model described above input to each file is read, and as shown in FIG. (Dimensional) images can be displayed, and the analysis model can be saved as an analysis model file.

  In addition, the interface program (gui.exe) according to the present embodiment can not only visually check the analysis model on the confirmation screen by operating the mouse, the Ctrl button, the button on the screen, etc. 23), as shown in FIG. 23, the appearance of the analysis model, the wall transmittance, the position of the light source, the number of ground meshes (see FIG. 22), the relative position display, etc. are programmed to be changeable. .

[Parameter file]
Next, the parameter file will be described.
As shown in FIG. 24, the parameter file (parm.csv) is a CSV file corresponding to one of the springs to be replaced when one line is modeled with the analysis model. A parameter ID is assigned to each wall (for example, for each specification when walls with different specifications coexist). Then, in the second column, according to the modeling method described above, as shown in Table 7, numerical values of 1 to 7 are input according to the types of springs to be modeled such as members and joints. Thereafter, the format is such that various parameters that differ according to the type of spring input in the second column are input over a plurality of columns.
Hereinafter, parameters to be input for each type of spring will be described.

(Spring setting of shaft assembly member)
When the type of spring is a frame spring, that is, when parameters of a frame member such as columns, bundles, beams, girders, windows, and lintels are input to the parameter file, as shown in FIG. In the second column, 1 representing the shaft spring is input. Since the shaft assembly member is modeled by an elastic-plastic rotation spring (plastic hinge) + elastic beam element as described above, the Young's modulus (vertical length) of the shaft assembly member is set as the spring parameter in the third row. Elastic modulus) [kN / m ² = 10 ⁻⁶ GPa] is input, and in the fourth and fifth columns, the cross-sectional secondary moment [m ⁴ ] of the shaft assembly member (for example, the shaft assembly member is a beam) Are input in the order of width and width, the maximum bending moment “kNm” (Mp in FIG. 5) is input in the sixth and seventh columns, and the cross-sectional area [m ² ] is input (see also Table 8).

(Joint spring setting)
When the type of spring is a joint spring, that is, when the parameter of the joint is input to the parameter file, as described above, the joint is composed of an elasto-plastic rotating spring + an elasto-plastic spring (which is rigid against shearing). ) (= Joint Spring), the input is divided into the joint spring and the rotary spring.

As shown in FIG. 26 and Table 9, the parameters of the elasto-plastic springs of the joints are input 2 in the second column, which represents the joint springs of the joints, and in the third to fifth columns, FIG. The first to third stiffnesses [kN / m] of the restoring force characteristics shown are input, and the inflection points D ₁ and D ₂ [m] of the skeleton curve are input in the sixth and seventh columns (FIG. 7). reference).

As shown in FIG. 27 and Table 10, the parameter of the rotational spring of the joint is input as 3 representing the rotational spring of the joint in the second row, and FIG. 8 shows the third through fifth rows. The first to third stiffness [kN / m] of the restoring force characteristic is input, and the inflection points D ₁ and D ₂ [m] of the skeleton curve are input to the sixth and seventh columns (see FIG. 8). .

(Set surface spring)
When the type of spring is a composition spring, that is, when a vertical composition or horizontal composition parameter is input to the parameter file, 5 representing the composition spring is input in the second column. As described above, the vertical or horizontal surface is modeled by replacing the brace with a truss element. As shown in FIG. 28 and Table 11, the third to sixth columns are shown in FIG. The load P _{1 to} P ₄ [kN] at the break point of the restoring force characteristic is input, and the displacement D _{1 to} D ₄ [m] of the break point of the restoring force characteristic is input to the 7th to 10th columns. In the column, a spring damping constant is input.

Since the parameter information of this surface spring is automatically used for calculation after correcting the dimensions and angles of the two brace replacement springs, the structure of the dimensions of 1P (0.91m) x 3P (2.73m) is obtained from the experimental results. The surface load deformation relationship (bilinear + slip type restoring force characteristics shown in FIG. 10) is obtained, and input values such as the loads P _{1 to} P ₄ and displacements D _{1 to} D ₄ are input as parameters.

(Setting the wrong spring)
When the type of spring is a staggered spring, that is, when a staggered member parameter is input to the parameter file, the staggered spring acts on the force in the tensile direction as described above. Since the model does not act on the spring in the compression direction, it is modeled by arranging two truss elements for compression and tension for one strut. Input the stiffeners by dividing them into tension stiffeners and compression stiffeners. In addition, since the tensile muscle difference and the compression muscle difference are modeled as a pair of one muscle difference, the parameter ID is the ID of the tensile muscle difference (example: 601) +100 is the ID of the compression muscle difference (example: 701). Need to be allocated.

  When inputting the parameter of the tension bar in the parameter file, 6 representing the tension bar is input in the second column, and when the parameter of the compression bar is input, the compression is in the second column. 7 representing a struggle is input.

Then, as shown in FIG. 29 and Table 12, the stirrup spring is modeled by replacing the brace with a truss element in the same manner as the surface spring, so the third to sixth columns are shown in FIG. Restoring force characteristic break point loads P _{1 to} P ₄ [kN] are input, and in the seventh to tenth columns, restoring force characteristic bending point displacements D _{1 to} D ₄ [m] are input, and eleventh column. The eye receives the spring damping constant.
Similar to the surface spring, the muscle deformation spring is based on the experimental results, etc., and the load deformation relationship of the muscle irregular surface with dimensions of 1P (0.91m) x 3P (2.73m) (bilinear + slip type restoration shown in Fig. 10). Force characteristics) and input as parameters.

[External force condition file]
Next, the external force condition file will be described.
The calculation program (calc.exe) according to the present embodiment executes three modes in which the seismic force is applied to the analysis models of “seismic wave input”, “pushover analysis 1”, and “pushover analysis 2”. It is programmed as possible. This “seismic wave input” mode is a mode in which forced disturbance input is applied to all ground level elements as shown in FIG. 30 (a), and the “pushover analysis 1” mode is shown in FIG. 30 (b). As shown, this is a mode in which ground level elements are fixed and all elements at a certain height of the analysis model are forced to be displaced in the horizontal direction. The “pushover analysis 2” mode is shown in FIG. As described above, this is a mode in which the ground level elements are fixed and the gravity acceleration in the horizontal direction is applied to all the analysis models.

In order to support these modes, the external force condition file (load.csv) inputs information on external forces such as seismic waves to be read when executing the three modes, “seismic wave input”, “pushover analysis 1”, There are three input formats to be input from the “pushover analysis 2” CSV file.
As shown in FIG. 31, the format of “seismic wave input” is a part for inputting an earthquake wave in the X direction on the first line, an earthquake wave in the Y direction on the second line, and an earthquake wave in the Z direction on the third line. As shown in FIG. 13, the first column is a part where a numerical value corresponding to each mode for selecting an input format is input. 1 is input in the case of “seismic wave input”, 2 is input in the case of “pushover analysis 1”, 3 is input in the case of “pushover analysis 2”, and 0 is input in the case of “fixed”. The “fixed” mode is a mode in which no seismic force is applied.

In the second column, the name of the time history file of the input seismic wave (the file in which the time history of displacement deformation is input in the first column) is input, and in the third column, the time history file of the seismic wave input in the second column Are input in units of [Hz], and in the fourth column, the units of numerical values input in the seismic time history file are input at a magnification relative to [m]. For example, 0.01 is input for [cm], 0.001 for [mm], and 1.0 for [m].
The fifth column is a portion to which an input magnification, which is a magnification for amplifying the seismic wave, is input. If a negative value is specified and input here, a disturbance input in the positive / negative reverse direction (reverse phase) is obtained.

  In the format of “Pushover Analysis 1”, as shown in FIG. 32, the first line inputs the X direction force, the second line the Y direction force, and the third line the Z direction force. As shown in Table 14, in the first column, as in the “seismic wave input” format, a numerical value corresponding to each mode for selecting an input format is input in the first column. 2 for selecting “pushover analysis 1” is input.

  The second and third columns are blank. In the fourth column, the height of the applied point is input in units of [m]. In the fifth column, the applied force speed, which is the speed of forced displacement, is [ m / sec]. If you enter a negative value here, the force will be applied in the opposite direction.

  The format of “pushover analysis 2” is the same as that of “pushover analysis 1”, as shown in FIG. 33, the first line is the X direction force, the second line is the Y direction force, and the third line is Each of the Z-direction force inputs is input. As shown in Table 15, 3 for selecting “pushover analysis 2” is input in the first column, and the second to fourth columns are blank. In the fifth column, the height of the applied point is input in units of [m], and in the fifth column, the acceleration of the horizontal force applied to the analysis model is input in units of [G]. The value to be input here is specified by the number of times the value of the gravitational acceleration 1 [G] that is reached after 1 second after gradually increasing the magnitude of the horizontal force applied to the analysis model from 0 [G]. If you specify a minus and enter it, the force will be applied in the opposite direction.

[Calculation condition file]
Next, the calculation condition file will be described.
As shown in FIG. 34, the calculation condition file (default.ini) is a file input from the CSV file format consisting of two lines. The first line stores information on the calculation conditions. The eye is a file in which information on the viewpoint when the analysis model is viewed with the interface program (gui.exe) described above is stored. In this calculation condition file, calculation condition information and viewpoint information are set and stored in advance, and a user can edit and correct necessary portions by using software that can edit a text file such as an editor or notepad. Use it.

In the first column of the CSV file, as shown in Table 16, the number of calculations performed by the calculation program (calc.exe) according to the present embodiment is stored. The time increment (= Δt ₀ ) that is incremented is stored. The increment value (Δt ₀ ) of the number of times of calculation × time is a specified time T that is a time when the time history response analysis is performed (see FIG. 35).
The third column stores the frequency of output, that is, the frequency of outputting the calculation result. For example, if 10000 is specified here, a snapshot for a moving image is recorded in a later-described trajectory file (out.trj), which is an output file, every time 10000 times are calculated, and 1 in 1000 times that of 1/10. Times, analysis load / deformation information, etc. are recorded as time history data in a calculation result file (dataout.csv) described later, which is an output file.

[Main flow of calculation]
Next, the main calculation flow of the calculation program (calc.exe) will be described with reference to FIG.
When the calculation starts, first, from the above input file [analysis model file (test.mod), parameter file (parm.csv), external force condition file (load.csv), calculation condition file (default.ini)] Necessary information is read (step 1), and an initial value of the analysis model is set (step 2). Then, at time t, t = 0 (step 3), and the minimum value (i = 1 in the illustrated embodiment) is substituted into the spring number i (parameter ID) (step 4), and the mode and calculation specified in the external force condition file The external force at time t is input to the analysis model according to the conditions, and calculation is started (step 5).

Next, the process proceeds to step 6 where it is determined whether or not the spring of the spring number i is a shaft assembly spring. Specifically, the i-th spring in the first column of the parameter file is determined based on whether the value in the second column of the same row is 1, and if it is 1, the process proceeds to step 7; , Go to Step 9. In step 7, the element stiffness matrix [Ki] _t shown in the above-described equation 4 of the spring i which is a frame spring is determined from the parameter information recorded in the third column and thereafter in the parameter file (step 7). Then, the stress vector [F _i ] _t acting on the spring i is calculated based on the above formulas 4 and 5 (step 8).
The element stiffness matrix [Ki] when the type of spring is a shaft spring is expressed by the following equation.

If the spring i is not a shaft assembly spring and the process proceeds to step 9, it is determined whether the spring i is a joint spring based on whether the value in the second column of the parameter file is 2 or not. , Go to step 10, otherwise go to step 12. In step 10, the element stiffness matrix [Ki] _t of the spring i which is a joint spring (compression spring / compression elastic-plastic spring) is determined from the parameter information recorded in the third and subsequent columns of the parameter file (step 10). 10) The stress vector [F _i ] _t acting on the spring i is calculated based on the above-described equations 4 and 5 (step 11).
The element stiffness matrix [Ki] when the type of spring is a joint spring is expressed by the following equation.

If the spring i is not a joint spring and the process proceeds to step 12, it is determined whether the spring i is a rotary spring based on whether the value in the second row of the parameter file is 3, and if it is 3, Proceed to step 13, otherwise proceed to step 15. In step 13, the element stiffness matrix [Ki] _t of the spring i, which is a rotary spring, is determined from the parameter information recorded in the third and subsequent columns of the parameter file (step 13). Based on the above, a stress vector [F _i ] _t acting on the spring i is calculated (step 14).
The element stiffness matrix [Ki] when the type of spring is a rotary spring is expressed by the following equation.

If the spring i is not a rotary spring and the process proceeds to step 15, it is determined whether the spring i is a surface spring by determining whether the value in the second column of the parameter file is 4 or not. Proceed to step 16, otherwise proceed to step 18. In step 16, the element stiffness matrix [Ki] _t of the spring i, which is a surface spring, is determined from the parameter information recorded in the third and subsequent columns of the parameter file (step 16). Based on 5, a stress vector [F _i ] _t acting on the spring i is calculated (step 17).
The element stiffness matrix [Ki] when the type of spring is a surface spring is expressed by the following equation.

If the spring i is not a surface spring and the process proceeds to step 18, it is similarly determined whether the spring i is a compression spring or not according to whether the value in the second column of the parameter file is 5 or not. Proceeds to step 19, otherwise proceeds to step 21. In step 19, the element stiffness matrix [Ki] _t of the spring i which is a compression stirrup spring is determined from the parameter information recorded in the third and subsequent columns of the parameter file (step 19). Based on Equation 5, a stress vector [F _i ] _t acting on the spring i is calculated (step 20).
The element stiffness matrix [Ki] when the spring is a compression spring is the same as that of the surface spring. However, the stress vector [F _i ] _t is calculated on the assumption that the spring i, which is a compression spring, does not act on the force in the tension direction.

When the process proceeds to step 21, the spring i automatically becomes a tension spring, so the element stiffness matrix [Ki] _t of the spring i which is the tension spring is determined (step 21), and the above-described formula 4. Based on Equation 5, the stress vector [F _i ] _t acting on the spring i is calculated assuming that the spring i does not act in the compression direction (step 22).

As described above, when the stress vector [F _i ] _t acting on the spring i is calculated, the process proceeds to step 23 where it is determined whether or not the spring number i has reached the maximum value i _max of the parameter ID. If i has not yet reached the maximum value i _max , the spring number i is incremented by 1 in step 24 and the process returns to step 6 to calculate the stress vector of the next spring i + 1.

When the stress vectors are obtained for all the springs, it is determined in step 23 that the spring number i has reached the maximum value i _max of the parameter ID, the process proceeds to step 25, and the calculation of the stress vector for the node A is started. . In step 25, the minimum value of the node number (1 in the case of illustration) is substituted for the node number A, and the stress vector acting on all the springs connected to a certain node A as shown in Equation 6 above. Is added to calculate the stress vector [F _A ] _t acting on the node A (step 26).
The node number is a number automatically assigned by the above-described interface program from the information in the analysis data file.

Then, as shown in Equation 7 above, the calculated stress vector of the node A is numerically integrated by Newmark's β method (average acceleration method β = 1/4), and the acceleration [a _A ] _{t at} time t is calculated. , Speed [v _A ] _t and displacement increment [ΔD _A ] _t are calculated (steps 27 to 29). After calculating each of these calculated values, the flow proceeds to step 30, if the node numbers A is determined whether reaches the maximum value A _max, node number A has not yet reached the maximum value A _max, the step At 31, the node number A is incremented by one and the process returns to step 26, and the calculation of the calculated values such as the stress vector of the next node A + 1 is repeated until the node number A reaches the maximum value _Amax .

As described above, when the calculation is completed for all the nodes, it is determined in step 30 that the node number A has reached the maximum value A _max and the process proceeds to step 32, and whether or not the time t has reached the specified time T. If the specified time T has not been reached, the time t is incremented by the time increment Δt ₀ specified in the second column of the calculation condition file in step 33 and the process returns to step 5 to the next time t + Δt _0. Input the external force at the time to the analysis model and repeat the above calculation. When the time t reaches the specified time T, the [basic reaction force], “horizontal force on each floor”, “absolute ground displacement”, and “absolute displacement at each floor specific point” are calculated from the calculated values described above. The calculation result is output and saved as time history data in a later-described trajectory file (out.trj) and calculation result file (dataout.csv) as an output file (step 34), and the calculation is terminated.
The specified time T is specified by the number of calculations input to the above-described calculation condition file × time increment value (Δt ₀ ).

[Output file]
Next, the output file will be described.
As described above, the calculation program according to the present embodiment has three files (refer to Table 2): a trajectory file (out.trj), a calculation result file (detaout.csv), and an analysis continuation file (cont.mod) as output files. The calculation result and the like are output to (see FIG. 12, Table 2).

(Track file)
The trajectory file (out.trj) is a file in which the time history data of the coordinates of each element (member or joint) of the analysis model is output and saved from the calculation program according to the present embodiment. It is a file for browsing with.

(Calculation result file)
The calculation result file (detaout.csv) is a CSV file in which numerical values are arranged in the order of [basic reaction force], “horizontal force on each floor”, “absolute displacement on the ground”, and “absolute displacement on each floor”, and the cycle is calculated as described above. This is the reciprocal of [number of calculations × time increment value (Δt ₀ )] specified in the condition file (default.ini). In this “absolute displacement on each floor”, absolute displacements at the four corners of each floor of the analysis model are recorded as time histories.
1st floor shearing force (base shear: base shearing force), floor shearing force of predetermined floor i = sum of horizontal forces of floors above i floor, correlation displacement of floor i = (absolute displacement of floor i + 1) -Calculated as (absolute displacement of the i-th floor).

(Analysis continuation file)
The analysis continuation file (cont.mod) is a file in which information about the elements and springs of the analysis model after calculation is input corresponding to the analysis model file of the input file, and this file is used as an input file in this embodiment. If the calculation program is input to the computer and recalculated, continuous collapse simulation is possible.

  As described above, according to the calculation program (calc.exe) according to the embodiment, the wooden building constructed by the frame construction method is used for the elastic-plastic spring of the frame, the elastic-plastic spring of the joint, and the elastic-plastic of the joint. Rotating springs, vertical and horizontal surface truss springs, compression springs, and tension bars are modeled separately, and parameter information corresponding to the type of these springs is input in advance. Since the element stiffness matrix is determined using the information and the stress vector acting on the spring is calculated, the behavior of the wooden building constructed by the frame construction method from the state where the deformation has progressed to the collapse is determined at the time of the earthquake. It can be calculated and simulated with high accuracy so as to match the actual building behavior. For this reason, the time history response analysis until the wooden building collapses at the time of the earthquake can be performed with high accuracy so as to match the actual behavior at the time of the earthquake.

(Effect confirmation experiment)
Next, in order to confirm the above-mentioned effects, the floor plan of each floor is as shown in FIG. 36. The actual size of a three-story wooden framed house with dimensions of 7.28 m × 7.28 m and a height of 10.1 m. A large shaking table experiment was conducted, and the result was compared with the analysis result by the above-described calculation program (calc.exe), which is a collapse simulation program of a wooden building according to an embodiment of the present invention.

  The weight for analysis was calculated by multiplying the weight measured when the whole wooden framed house was suspended with a crane by the weight ratio of each layer calculated by picking up the weight of each member, and distributed to each mass point. By the way, the second floor weight was 99.1kN, the third floor weight was 97.5kN, and the cabin part weight was 67.3kN.

As an input seismic wave, an acceleration response spectrum seismic wave (JMA Kobe) shown in FIG. 37 observed at the Kobe Ocean Meteorological Observatory during the Hyogoken-Nanbu Earthquake was input at 150%. In the modeling, the numerical integration is an average integration method every 10 ⁻⁵ seconds, and the viscous damping is 5% of the instantaneous stiffness proportional type.

  FIG. 38 shows a comparison between the time history of the 1F interlaminar displacement recorded in the wooden frame construction house recorded in the shaking table experiment and the time history response analysis by the aforementioned calculation program. The thick line is the shaking table experiment, and the thin line is the analysis result by the aforementioned calculation program. As shown in FIG. 38, the full-scale shaking table test and the simulation result of the analysis model are substantially the same, and the above-mentioned calculation program, which is a collapse simulation program of a wooden building according to the embodiment of the present invention, is used during an earthquake. It can be said that the time history response analysis up to the collapse of the three-story wooden frame construction house in was able to be performed with high accuracy to match the actual behavior at the time of the earthquake.

Claims (5)

A wooden building collapse simulation program for causing a computer to execute a time history response analysis until a wooden building collapses during an earthquake,
A first step of reading from an input file information on an analysis model obtained by modeling the wooden building by combining a plurality of nodes and a plurality of types of springs, and parameter information corresponding to the type of spring included in the analysis model When,
A second step of determining an element stiffness matrix according to the type of spring of the analysis model based on the parameter information read from the input file in the first step;
A third step of calculating the stress acting on each spring using the individual element method by the element stiffness matrix determined in the second step ;
A fourth step of adding stress acting on each spring calculated in the third step for each node to which each spring is connected ;
In the analysis model, the frame member of the wooden building is modeled by an elastic-plastic spring and a beam element, and the parameter information corresponding to the elastic-plastic spring of the frame member includes the parameter of the frame member. The maximum bending moment indicating the bending strength of the beam element is included,
In the third step, when calculating the stress acting on the elastic-plastic spring of the shaft member, the bending moment applied to the beam element of the shaft member is compared with the maximum bending moment, and based on the comparison result, A collapse simulation program for a wooden building, characterized by determining breakage of a frame member . The determination of breakage of the shaft member is performed when a bending moment applied to a beam element of the shaft member reaches a rotation angle of zero exceeding the maximum bending moment. Simulation program for collapse of wooden buildings. The analysis model is further modeled by dividing into an elastic-plastic spring at the joint, an elastic-plastic rotary spring at the joint, a truss spring with a vertical surface and a horizontal surface, a compression spring, and a tension spring.
Wherein the input file, collapse simulation program wooden structure according to claim 1 or 2, characterized in that the parameter information corresponding to the type of modeled springs are included. Basic reaction force of the analysis model, each floor horizontal force, the ground absolute displacement, each floor absolute displacement of the respective calculated values calculated for each time step, which is defined in the input file, the computer to output to the output file as time history data 4. The collapse simulation program for a wooden building according to any one of claims 1 to 3, wherein the program is executed. The output file includes a trajectory file storing time history data of coordinates of each element of the analysis model, a calculation result file storing time history data of each calculated value, and an analysis model after calculation. An analysis continuation file that stores information about elements and springs, and
Claim 4, characterized in that to execute the time history data of the coordinates of each element of said analysis model, time histories of the respective calculated values, the elements and steps of outputting information about the spring of the analysis model after calculation into the computer Simulation program for collapse of wooden buildings described in 1.