A topology optimization method with multi-load fatigue life constraints

Abstract

The invention relates to a topology optimization method for multi-load fatigue life constraints. Aiming at the random vibration loads suffered by components, the positions of structural dangerous points are obtained through the finite element method and the stress time history is extracted; the stress time history is calculated by the rainflow counting method. Counting processing, sorting according to the amplitude and changing the interval into segments; then according to the equivalent principle of fatigue damage, using the Miner linear cumulative damage method to convert the damage equivalent, and combining the load cycles in the interval into one load cycle; then, based on Based on the principle of linear damage accumulation and multi-axial fatigue analysis, the design life of the component is required to calculate the maximum stress level that causes fatigue damage to the component, and use this stress level as the constraint condition of topology optimization to obtain the optimal structure of the component. The invention can efficiently transform the fatigue life constraints under complex random loads into stress constraints, thereby realizing the lightweight design of the structure while satisfying the fatigue strength, which is beneficial to engineering applications.

Description

technical field [0001] The invention relates to a topology optimization method with multi-load fatigue life constraints, belonging to the technical field of structural lightweight design. Background technique [0002] The purpose of structural optimization is to improve the performance of the structure. Under the premise of meeting the design requirements, the material can be optimally distributed by changing the topological form and size of the structure. Topology optimization is widely used in aviation, aerospace, automobiles and other fields, making the structure lighter and lighter, and its performance continuously improved. At present, a large number of studies have been carried out on topology optimization under the constraints of displacement, stiffness, strength, frequency, volume, and mass in engineering practice. When the allowable stress is selected as the stress constraint in topology optimization, the value of the safety factor will vary due to different design...

AI Technical Summary

Problems solved by technology

When the allowable stress is selected as the stress constraint in topology optimization, the value of the safety factor will vary due to different designers, which will affect the lightweight results; under the action of actual cyclic loads, the work that causes fatigue failure of the mechanical structure Stresses are often lower than the calculated allowable stress values

As a result, the optimization results often do not meet the fatigue strength requirements

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