Multiobjective optimization of isotropic plates with cutouts in the presence of obstacle using isogeometric analysis

In this paper, the problem of multiobjective shape optimization of an edge-loaded isotropic finite thin plate with a cutout and a passing through obstacle is investigated. The stress analysis is done through isogeometric method, which incorporates the accurate shape of hole boundary into finite element formulation. The design variables are coordinates of some points on the hole boundary, by which and through using NURBS, the hole boundary is shaped as a continuous smooth curve. The bounding values on these coordinates are specified by the obstacle and the plate. The two objective functions are maximum stress concentration factor in the plate, and the empty space between the hole boundary and the object outline, both to be minimized. The strength criterion in the plate is taken as the problem constraint. Because of the nature of the problem, a multiobjective genetic algorithm is used. The Pareto front of optimization is derived and different points on it are discussed. It is seen that the range of hole shape vary from the object’s circumscribing circle (for minimum stress concentration factor) to a shape very similar to the obstacle outline but with smooth corners.

کلیدواژه ها:

Optimization ، Isogeometric analysis ، NURBS ، Plates with cutouts ، Multiobjective genetic algorithm