Structural topology optimization with design-dependent pressure loads

This paper presents an approach for the topology optimization of structures under design-dependent pressure loading. Compared with traditional optimization problems with a fixed load, in a design-dependent load problem, the location, direction, and magnitude of the load change with respect to the design at every iteration. Using the SIMP model, the current method proposes a material boundary identification scheme by iteratively connecting points of equal density, with the use of a predefined void region. This predefined void region allows the structure to be loaded by pressure from outside the domain, as well as by pressure that is completely enclosed within the domain. This is particularly useful when there are multiple pressure vessels that can be interacting, or when symmetry cannot be used to bisect the pressure vessel. Also, by using an iso-density line to define the boundary, no additional artificial parameters that might affect the final solution are needed. An analytical method for deriving the sensitivity of the loads is also presented; this is an alternative to the finite-difference method and it could reduce the number of function calls. Numerical examples are presented to show the advantages and robustness of the proposed method.