Continuum Topology Optimization With Fatigue Life Constraint

In topology optimization design for continuous structure, common mechanical properties are considered, such as structural strength, stiffness and stability. To investigate the influence of fatigue on structural topology in optimization design, filter function of fatigue life was introduced and then the model and solution method of fatigue topology optimization for continuous structures were proposed based on independent continuous mapping (ICM) method. With structure minimum weight as objective and the fatigue life as constraints, the fatigue topological optimization model was established and solved by transforming fatigue life constraint into stress constraint. The numerical examples verified the feasibility and effectiveness of theory of fatigue topology optimization. By comparing different coefficients of stiffness filter function and fatigue life filter function, influences from filter function coefficients on structural weight and structural configuration were obtained. Moreover, the differences of topological results were investigated using fatigue and stress as constraints, respectively, structural weight and structural configuration were obtained by giving numerical examples with different cyclic external loads cases. The results extend the ICM method and this basic theory provides a new idea for fatigue topology optimization of continuum structures.