The Numerical Analysis Of Mechanics Characteristic And Optimization Design Of Light-weight Portal Rigid Frame Structure

The light-weight portal rigid frame structure which is one of the most widely used structure form of industrial plants in currently of China.It has many advantages such as convenient construction,light weight,flexible expansion,etc.Although in our country,the design of portal rigid frame structure,production,installation and other aspects of building technology has matured,but the current design method of commonly used is depending on the designer's experience level,may directly lead to the increase of engineering construction cost.Therefore,the optimization design of light-weight portal rigid frame structure has practical significance.In practical engineering,there are many forms of light-weight portal rigid frame structure,if according to the unified model for mechanical analysis and optimal design is difficult.In order to satisfy the design institute of fast calculation analysis and optimization design of actual requirements.The paper based on the ANSYS software,using the Ansys Parametric Design Language to edit the overall process APDL orders of pretreatment,loading and solving,post processing,and then analyzes the mechanical characteristics of portal rigid structure.Finally,carry on the optimization design of structure by using the Design Opt module.For other forms of structure,only make corresponding modification of APDL orders before calculated.In this paper,firstly introduces the structure features of light-weight portal rigid frame structure,the domestic and foreign research present situation of the optimization design and optimization design of light-weight portal rigid frame structure.Secondly,introduces the Ansys Parametric Design Language in brief,optimization principle,optimization method,optimization steps.On this basis,according to a design institute design of three spans with crane of the light variable cross-section portal rigid frame structure factory as an example,modeling a finite element model of structure by using APDL.Considering the building is located in Shenyang,Liaoning province,therefore,consider the load has dead load,live load,snow load,wind,crane and earthquake action,the snow load is dominant load.Combine these load conditions,and calculate the structure by numerical method,work out the maximum stress and displacement of structure.Compared with the specification,determine the strength and stiffness of the original structure of excess reserves.Then,set the beam section size as design variable,set maximum stress and maximum displacement as state variables,set the total weight of the structure as the objection function before optimize design of one rigid frame.The optimization results show that,the weight of one frame is reduced from 7772.9kg to 6572.1kg,15.4%less than the original design,the total weight of structures can accumulate save 15610.4kg steel,and the optimization effect is obvious.Finally,optimize design of the rigid frame structure by setting the 6.6m?6.9m?7.2m?7.8m etc.column space respectively.In this paper,according to relevant design specifications,analyzes the mechanical characteristics and optimization design of portal rigid structure,after optimization design,reasonable structure stress,structure of total weight significantly reduced,and achieve the purpose of reducing construction cost.