Abstract
This paper investigates the weight minimization of stiffened panels simultaneously optimizing sizing, layout, and topology under stress and buckling constraints. An effective topology optimization parameterization is presented using multiple level-set functions. Plate elements are employed to model the stiffened panels. The stiffeners are parametrized by implicit level-set functions. The internal topologies of the stiffeners are optimized as well as their layout. A free-form mesh deformation approach is improved to adjust the finite element mesh. Sizing optimization is also included. The thicknesses of the skin and stiffeners are optimized. Bending, shear, and membrane stresses are evaluated at the bottom, middle, and top surfaces of the elements. A p-norm function is used to aggregate these stresses in a single constraint. To solve the optimization problem, a semi-analytical sensitivity analysis is performed, and the optimization algorithm is outlined. Numerical investigations demonstrate and validate the proposed method.
Highlights
Stiffened panel structures have been a long standing interest of Professor Haftka, whose first journal paper in 1968 investigated the buckling of stiffened shells (Singer and Haftka 1967)
We have recently demonstrated the feasibility of applying the level-set topology optimization method to simultaneously optimize size, layout, and topology of stiffened panels against buckling (Chu et al 2021a, b)
This paper presents the level-set-based optimization method for both of the critical failure criteria, stress, and buckling, enabling the weight minimization of stiffened panels simultaneously optimizing size, layout, and topology
Summary
Stiffened panel structures have been a long standing interest of Professor Haftka, whose first journal paper in 1968 investigated the buckling of stiffened shells (Singer and Haftka 1967). Venkataraman et al (2003) performed optimization for both metallic and laminated composite-stiffened shells, and investigated how stiffener type, material choice, and manufacturing constraints influence the weight of optimized designs, as well as the conservativeness of the approximate analyses and design freedom (the number of design variables). We have recently demonstrated the feasibility of applying the level-set topology optimization method to simultaneously optimize size, layout, and topology of stiffened panels against buckling (Chu et al 2021a, b) This employs plate elements to model stiffeners which are parametrized by multiple implicit level-set functions (LSFs), optimizing the shape (straight or curved, and internal topology) and size of each stiffener, simultaneously with the orientation and number of the stiffeners and the panel thickness. This paper presents the level-set-based optimization method for both of the critical failure criteria, stress, and buckling, enabling the weight minimization of stiffened panels simultaneously optimizing size, layout, and topology.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
