Thermoplasticity in topology optimization based on finite strain

A thermoplastic finite strain model is used to model heat generation due to plastic work. Isotropic hardening is used, where the mechanical dissipation acts as heat source in the heat equation. The multiplicative split of the deformation gradient makes it possible to separate plastic and elastic effects. The model is solved by using the Newmark time integration scheme with the finite element method using total Lagrangian formulation. The model is also aimed for implementation with gradient based topology optimization for finite strains with the objective to maximize the the plastic dissipation. The method of moving asymptotes (MMA) is used in the optimization to make the problem convex. The sensitivities required to form the gradient is calculated using the adjoint method where the sensitivities are derived for the thermoplastic case. Helmholtz’s partial differential equation is used for regularization and a Heaviside filter is used to make the topology more precise.Kan man låta datorn bestämma den säkraste designen för en bil? och kommer en ökning av temperaturen i det använda materialet att påverka denna design? I examensarbetet ”Thermoplasticity in topology optimization based on finite strain” undersöks hur den genererade temperaturen vid en snabb och stor ihoptryckning av en struktur påverkar den design som ̈är bäst på att absorbera energi vid t.ex. en krock. Det visar sig att temperaturen har en avsevärd inverkan på den bästa designen