KR20120058822A - Method for designing a damping device utilizing genetic algorism - Google Patents

Abstract

PURPOSE: A damping apparatus using a genetic algorithm and design method thereof are provided to improve the earthquake resistant performance of a building by providing an optimal design method which determines the capacity, height, and position of a damping apparatus. CONSTITUTION: Dynamic features of a building are extracted based on a design variable of the building(S100). Initial data for the capacity of a damping apparatus and the installation position of the damping apparatus is created by using the dynamic features(S200). A time history is analyzed for a virtual building structure including the damping apparatus according to the initial data(S300). Values for an objective function are calculated by establishing the objective function(S400). A generic algorithm is executed based on established values(S500).

Description

Method for designing a damping device utilizing genetic algorism

The present invention relates to a method of determining the capacity and installation location of a damping device for improving the seismic performance of a building.

In general, the seismic design concept for building structures allows damage to the collapse level of building structures against earthquakes more than a certain magnitude, and plastic deformation of structural members at the level of life safety or collapse prevention performance occurs even in performance-based design methods. do.

At this time, since most building structures are covered by finishing materials, enormous costs and time are required to find and repair the damaged parts by the earthquake. However, if an additional damping device is placed in place on the structure to meet the required level of performance for a given design earthquake level, damage can be concentrated in the damping device, thus reducing the plastic deformation of the major structural members of the building structure. There is an advantage in that it can prevent and reduce the time and cost required for the repair of building structures.

Therefore, it is important and most suitable method to restore the function of the building structure in a short time after the earthquake, and it is desirable to effectively realize the design of the building based on the performance of the damping device. In developed countries such as the United States and Japan, seismic design using damping devices is already common, and a method of installing seismic retrofitting damping devices in new or existing buildings is being used.

The damping device is installed on the rooftop of the building according to the installation location to increase the damping ratio of the structure. Therefore, the top floor type damper, which is effective for wind response control, is installed between floors of the building. It can be divided into an inter-story type damper that can effectively control the (inter-story type damper).

The interlayer damping device dissipates the vibration energy caused by the earthquake into heat energy, effectively reducing the dynamic response generated in the building structure, and it is relatively easy to install the device and the cost is relatively low. It is widely applied to improve the seismic performance of building structures. The type is semi-active using passive damping devices such as viscoelastic dampers and friction dampers and highly controllable magneto-reological fluids or damper fluids. active damping device.

However, such an interlayer mounted damping device has difficulty in application because it has not been studied on the design of the damping device, that is, a design method for comprehensively determining the required damping capacity, height direction, and mounting position on a plane.

Meanwhile, a non-linear time history analysis for performance verification of the damping device (damping device) can be performed using a commercial program that can verify the objective reinforcing performance. However, a commercial program does not have an algorithm for optimal design of the attenuation device, and when using a commercial program, analysis time becomes very long. That is, in a commercial program, it takes a long time to store the final result, such as nonlinear time history analysis and calculating the member force after analysis.

The present invention proposes an optimal design method for determining the capacity and height of the damping device and the installation position on the plane when the damping device is installed to improve the seismic performance of the building structure.

That is, the present invention can extract the dynamic characteristics of the structure required for the design of the damping device from the commercial structural analysis program and minimize the capacity and installation position of the damping device while satisfying the seismic performance of the building structure required by the designer using genetic algorithms. Present the design method.

According to an aspect of the present invention, there is provided a method of designing a damping device for a building, including extracting dynamic characteristics of a building structure based on design variables of the building structure; Generating initial data on the capacity of the damping device and the installation position of the damping device using the dynamic characteristics of the building structure; Analyzing a time history for the virtual building structure in which the damping device is installed according to the initial data; Setting an objective function and calculating a value for the objective function; Performing a genetic algorithm based on the set capacity of the damping device and the installation position of the damping device; And determining whether the capacity and the installation position of the set damping device satisfy the calculated bottom shear force and inter-floor displacement of the building. And performing the genetic algorithm repeatedly until the capacity of the damping device and the installation position of the damping device that satisfy the calculated bottom shear force and the interlayer displacement of the building are searched for.

Here, the dynamic characteristics of the building structure may be extracted using a commercial structural analysis program, and the objective function of the building may include a bottom shear force and an interlayer displacement.

As described above, the damping device design method according to the present invention extracts the dynamic characteristics of the structure required for the damping device design from a commercial structural analysis program and uses the genetic algorithm to satisfy the seismic performance of the building structure required by the designer, The installation location can be minimized. At this time, since a simple model is generated from the dynamic characteristics of the extracted structure and the analysis is performed, the time required for the time history analysis can be greatly reduced, thereby securing the applicability of the genetic algorithm requiring a large amount of iteration calculation.

1 is a flow chart illustrating a design method of a building damping device according to the present invention.
Figures 2a to 2d are graphs showing the results of the optimal design to determine the optimum capacity of the damping device with the objective function for the experimental building in accordance with the present invention.

Hereinafter, with reference to the accompanying drawings an embodiment according to the present invention will be described in detail.

The present invention is to set the conditions for the shear force and floor displacement of the building which has the greatest impact on the seismic performance of the building structure, and to set the attenuation capacity of the damping device and the optimum installation position of the damping device satisfying the set conditions. will be.

To this end, the present invention proceeds through the following process.

1 is a flow chart illustrating a method of determining the capacity and installation position of a damping device according to the invention.

The method of determining the capacity and installation position of the damping device according to the present invention is largely determined by ① extracting the dynamic characteristics of the building structure, ② generating initial data on the capacity and installation position of the damping apparatus using the dynamic characteristics, and ③ A time history analysis step, ④ setting and calculating an objective function (limiting condition), ⑤ selecting a damping device that satisfies the constraint using the genetic algorithm, and ⑥ determining whether the selected damping device converges.

Each step constituting the present invention as described above will be described in detail.

First, the dynamic characteristics of the building structure are extracted based on all design variables of the building structure (step S100). The dynamic characteristics of building structures are mass, damping and stiffness. At this stage, the dynamic characteristics of building structures are calculated and extracted using a general commercial structural analysis program.

Initial data on the capacity of the damping device and the installation position of the damping device is generated using the dynamic characteristics of the extracted building structure (step S200). Then, the capacity of the damping device and the installation position of the damping device are determined according to the initial data for the damping device, and the time history for the virtual building structure in which the damping device is installed is analyzed (step S300).

Thereafter, the objective function is set and a value for the objective function is calculated (step S400).

As described above, the most influential factors in the seismic performance of building structures are the shear forces and the interlaminar displacement of the building structures. In step S400, the objective function of the building, that is, the bottom shear force and the floor displacement, is calculated based on the dynamic characteristics of the building extracted in step S100.

The genetic algorithm is performed based on the capacity of the damping device set in step S300, the installation position of the damping device, and the bottom shear force and the interlaminar displacement calculated in step S400 (step S500). That is, the genetic algorithm is performed based on the capacity of the damping device and the installation position of the damping device.

The genetic algorithm is repeatedly performed until the capacity of the damping device and the installation position of the damping device that satisfy the bottom shear force and the floor displacement of the building calculated in step S400 are searched for.

That is, in step S500, it is determined whether the capacity and installation position of the set damping device satisfy the bottom shear force and the floor displacement of the building calculated in step S400. If the bottom shear force and the floor displacement of the building calculated in the step are not obtained, steps S200 to S500 are repeatedly performed.

If the bottom shear force and the interlaminar displacement of the building calculated by the set capacity of the damping device and the installation position of the damping device are satisfied, then all procedures are completed.

Genetic algorithm performing steps (steps S200 to S500) may be repeated repeatedly until the target criterion (calculated bottom shear force and interlayer displacement) is reached. The iterative process involves selecting new individuals (creating new offspring using crossover and mutation operators for selected populations), evaluating selected individuals (object functions of newly created offspring and populations) Bottom shear force and interlaminar displacement) to prioritize objects with small objective function values, sorting them from top to bottom, and then removing the following objects except the number of objects of the original parent population), mating, and mutation It proceeds to the operation (selecting descendant populations in the top sort order, crosses and mutates to create a new population).

As a result of this iterative process, the optimal individual in the last generation is selected as a solution to obtain a combination of design variables for the calculated base shear force and interlaminar displacement.

On the other hand, step S600 is a step of evaluating whether the optimal combination of design variables found through the genetic algorithm execution step satisfies the actual optimal design conditions. In other words, the capacity of the damping device and the installation position of the damping device are calculated for the optimum bottom shear force and the interlaminar displacement to evaluate whether the bottom shear force and the interlaminar displacement satisfy the design criteria.

The combination of design variables when the design criteria are satisfied is the optimum capacity of the damping device and the installation position of the damping device.

 However, the optimization process may be performed to determine the optimal capacity of the damping device that satisfies the design criteria and the installation position of the damping device. To this end, in the present invention, in S600, the bottom shear force and the interlaminar displacement calculated by calculating the bottom shear force and the interlaminar displacement with respect to the capacity of the damping device and the installation position of the damping device determined by the genetic algorithm are extracted. At the same time, it is determined whether the extracted bottom shear force and interlaminar displacement satisfy the design criteria.

If the bottom shear force and the interlaminar displacement extracted in step S500 satisfy the design criteria, the extracted bottom shear force and the interlaminar displacement become the optimal design variable combination, and if the bottom shear force and interlaminar displacement extracted in step S500 do not meet the design criteria, After regenerating initial data on the capacity and installation location of the device and repeatedly executing the genetic algorithm, step S600 is repeated.

[Example]

This embodiment has the following objective function for the experimental building (3 floors (3.5 meters high), length 76.5 meters, width 9.6 meters, total weight 756.8 tons) and proceeds to the optimum design to determine the optimum capacity of the damping device. The results are shown in the graphs of FIGS. 2A to 2D.

Objective function 1: Minimize bottom shear force

Objective 2: Minimize the damping device capacity by limiting the bottom shear force required for the similar elastic design of the member (1.5 times the yield strength) and the interlaminar displacement ratio of the immediate use criteria

Objective Function 3: Minimizing Interlayer Displacement

In the graph of FIG. 2A, the bottom shear force (bar 1; unit tonf) when the damping device having a damping capacity selected according to the objective function for minimizing the bottom shear force is installed (bar 1; unit tonf), and the objective function for minimizing the damping capacity is selected. The bottom shear force (bar 2) when the damping device with the damped capacity is installed (bar 2) and the bottom shear force (bar 3) when the damping device with the damping capacity selected according to the objective function for minimizing the top floor displacement. Indicates.

In the graph of FIG. 2B, the top-floor displacement (bar 1; unit cm) when the damping device is installed with the damping capacity selected according to the objective function for minimizing the bottom shear force (bar 1; unit cm), is selected according to the objective function for minimizing the damping capacity. Top displacement value when a damping device with attenuated capacitance is installed (bar 2) and top displacement value when a damping device with damping capacity selected according to the objective function for minimizing top displacement (bar 3) Respectively.

In the graph of Fig. 2C, the interlaminar displacement ratio (bar 1) when the damping device having the damping capacity selected according to the objective function for minimizing the bottom shear force (bar 1), the damping selected according to the objective function for minimizing the damping capacity is shown. The interlayer displacement ratio (bar 2) when the damping device with capacity is installed (bar 2) and the interlayer displacement ratio (bar 3) when the damping device with damping capacity selected according to the objective function for minimizing the top-floor displacement, respectively. Indicates.

In addition, in the graph of FIG. 2D, the total amount of damping of the damping device selected according to the objective function for minimizing the bottom shear force (bar 1), and the total amount of damping of the damping device selected according to the objective function for minimizing the damping capacity (bar 2 And the total amount of attenuation (bar 3) of the damping device selected according to the objective function for minimizing top-level displacement.

As can be seen from the graphs shown in FIGS. 2A to 2D, in the case of an objective function for minimizing bottom shear force and top-floor displacement, damper capacities for minimizing each objective function can be found, but damper capacities are excessively required. Given that the installation cost increases with damper capacity, objective functions 1 and 3 are difficult to use as the optimal design of damper capacity required for structural designers. However, as shown in FIG. 2D, the damper capacity determined by the objective function 2 satisfies the constraints of the structural design, and economical design results are obtained in which the damper capacity is minimized.

Although the present invention has been described in detail with reference to the described embodiments, those skilled in the art to which the present invention pertains will be capable of various substitutions, additions and modifications without departing from the technical spirit described above. It is to be understood that such modified embodiments also fall within the protection scope of the present invention as defined by the appended claims below.

Claims (4)

Extracting dynamic characteristics of the building structure based on the design variables of the building structure;
Generating initial data on the capacity of the damping device and the installation position of the damping device using the dynamic characteristics of the building structure;
Analyzing a time history for the virtual building structure in which the damping device is installed according to the initial data;
Setting an objective function and calculating a value for the objective function;
Performing a genetic algorithm based on the set capacity of the damping device and the installation position of the damping device; And
And determining whether or not the set capacity and installation position of the damping device satisfy the calculated bottom shear force and inter-floor displacement of the building. 2. The method of claim 1, further comprising repeatedly performing the genetic algorithm until the capacity of the damping device and the installation location of the damping device are searched for satisfying the calculated base shear force and inter-layer displacement of the building. . The method of claim 1, wherein the dynamic characteristics of the building structure are extracted using a commercial structural analysis program. The method of claim 1, wherein the objective function of the building comprises a bottom shear force and an interlaminar displacement.

Images