Shape Continuum Sensitivity Analysis using ASTROS and CAPS

摘要

Continuum Sensitivity Analysis (CSA) is an analytic method that may compute derivatives with respective to shape variables, which may be formulated in fundamentally different ways. The boundary velocity formulation of CSA presented here enables an element-agnostic implementation that hinges upon post-processing of output from the analysis solver using a nonintrusive spatial gradient reconstruction (SGR) technique. SGR has been implemented as a module in the Automated Structural Optimization System (ASTROS). SGR provides the spatial derivatives used in conjunction with geometric sensitivity, also known as the design velocity, to form the convective term of CSA boundary conditions. The Computational Aircraft Prototype Syntheses (CAPS) program represents parametric associative geometry of solids and surfaces that conveniently provides the geometric sensitivity essential to forming the CSA boundary conditions. A procedure is described here that uses CAPS to provide the surface geometry, geometric sensitivity, and mesh of a finite element model for which ASTROS is used to perform SGR of the structural analysis output and then perform CSA. Results from a simple beam bending model in two- and three-dimensional space verify, against an analytic solution, the implementation of shape CSA using ASTROS and CAPS.