Local Modal Frequency Improvement with Optimal Stiffener by Constraints Transformation Method

Applied Sciences

Wenjing Shi¹  Shenyan Chen²  Ziqi Dai²  Jianhongyu Li²  Yanjie Liu² 

[1] Beijing Institute of Spacecraft System Engineering, Beijing 100094, China;School of Astronautics, Beihang University, Beijing 100191, China;

关键词: structural vibration;    structural optimization;    frequency constraint;    local mode;   

DOI  :  10.3390/app112211072

来源: DOAJ

【 摘 要 】

Local modal vibration could adversely affect the dynamical environment, which should be considered in the structural design. For the mode switching phenomena, the traditional structural optimization method for problems with specific order of modal frequency constraints could not be directly applied to solve problems with local frequency constraints. In the present work, a novel approximation technique without mode tracking is proposed. According to the structural character, three reasonable assumptions, unchanged mass matrix, accordant modal shape, and reversible stiffness matrix, have been used to transform the optimization problem with local frequency constraints into a problem with nodal displacement constraints in the local area. The static load case is created with the modal shape equilibrium forces, then the displacement constrained optimization is relatively easily solved to obtain the optimal design, which satisfies the local frequency constraints as well. A numerical example is used to verify the feasibility of the proposed approximation method. Then, the method is further applied in a satellite structure optimization problem.

【 授权许可】

Unknown