Design optimizing method of truss structure

Abstract

The invention discloses a design optimizing method of a truss structure. The method includes steps of firstly, building up a mathematical model of a truss, and setting a target function; secondly, calculating stress of every rod and displacement of every node in the truss; thirdly, defining boundary conditions, wherein the stress of every rod is less than the maximum allowable stress, and every node displacement is less than the maximum allowable displacement; fourthly, setting an adaptation function; fifthly, setting the length, elasticity modulus, Poisson's ratio, density, maximum allowable stress, maximum allowable displacement, external load and value scale of section area of the rod piece; sixthly, selecting a penalty factor; seventhly, optimizing by means of CRO algorithm and setting related parameter of the CRO algorithm; eighthly, optimizing the truss structure by a simple genetic algorithm; ninthly, comparing the simple genetic algorithm with the result output by the CRO algorithm; tenthly, repeating step seven to step nine; selecting an optimal solution. The structure optimizing process is simple, and the universality is good; the optimizing efficiency and the convergence precision are improved.

Description

technical field [0001] The invention belongs to the field of structure optimization, in particular to a design optimization method for a truss structure. Background technique [0002] Optimal design method is a comprehensive applied engineering technique combining optimization principles with computer technology, and has been widely used in the field of design. With the continuous in-depth research on various complex optimization problems, the bottlenecks faced by traditional research methods are becoming more and more obvious. In solving the optimization problem of the ten-truss structure, the purpose of the truss structure optimization research is to achieve the optimal performance, stiffness, weight and engineering cost of the ten-truss structure under the condition of meeting various code standards and specific requirements. [0003] When the traditional optimization algorithm solves the complex problem with high dimensionality and many constraints of the ten-bar truss,...

AI Technical Summary

Problems solved by technology

[0003] Traditional optimization algorithms cannot meet the requirements of the problem in terms of solution accuracy and convergence speed when solving complex problems with high dimensions and many constraints of ten-bar trusses.

The reasons are: first, the traditional optimization method has certain limitations, such as the need for gradient information, unimodal problems, convex programming, etc.; second, the traditional internal penalty function processing method requires that all points obtained are feasible, Even if for some reason the optimization iterations do not go to the end, a viable design improvement over the original method can be obtained

; Third, the traditional internal penalty function requires a feasible initial design, which is difficult to deal with equality constraints, and the step size design of the local search is responsible for

For the constraint processing of truss structure optimization, the traditional constraint method is particularly difficult. The traditional penalty item builds an obstacle at the boundary, but this is a very "thin" obstacle

Once the step size is too large to cross this obstacle, such a method may fail

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