A new layout optimization method for stiffened panels based on ground stiffener structure (GSS) and thickness penalty

Abstract

The stiffener layout has a crucial impact on the load-bearing performance of stiffened panels. It is difficult for existing methods to directly obtain a stiffener layout design that meets the manufacturing requirements without post-processing. In this paper, a new layout optimization method for stiffened panels is proposed, in which the ground stiffener structure is pre-modeled and the optimal stiffener layout is obtained by optimizing the thickness of each stiffener, where the intermediate thickness is penalized to ensure that a clear stiffener layout is acquired. The enrichment constraint and its KS function are derived to restrict the local excessive concentration of stiffeners in the final optimization results, so as to ensure the manufacturability of the obtained stiffener layout. Moreover, the explicit and clear stiffener layout design scheme can be obtained from the pre-modeled ground stiffener structure, which can be imported directly into the CAD system, so no additional post-processing such as geometric reconstruction is required. Through eight typical examples, the effectiveness of the proposed method is verified, which will be a meaningful supplement to existing layout optimization methods of thin-walled stiffened structures.