부산대학교 도서관

Summary: ``This work proposes a stress-constrained topology optimization formulation to design minimum volume structures that are both fail-safe and manufacturing error tolerant. The goal is to obtain an optimized topology that satisfies the stress failure criterion before and after the occurrence of any damage, also taking into account slight imperfections that may occur during the structure manufacturing process. In order to achieve this goal, the conventional volume minimization formulation with local stress constraints is generalized to simultaneously accommodate possible damage scenarios, considering a simplified damage model of removal of failure regions with predefined shape, size and position from the design domain, and possible manufacturing scenarios, which are included via the three-field density projection approach based on intermediate, eroded and dilated designs. Two numerical examples are addressed: L-shaped and Cantilever problems; both are solved for different arrangements of damage scenarios. Stress constraints are handled via the augmented Lagrangian method, without using aggregation techniques, and problems with up to 82.5 million stress constraints are solved. Numerical investigations demonstrate that: (1) the proposed formulation is able to obtain results which are at the same time fail-safe and tolerant to uniform manufacturing error, as for any manufacturing situation the maximum stress does not exceed the allowable design stress after the occurrence of any predefined damage; (2) when manufacturing error tolerance is not considered, extremely sensitive results are obtained, being truly fail-safe for unique manufacturing situations.''