Abstract
A method is presented for shape optimization of latticed shells defined by parametric surfaces. The latticed shells with rectangular and triangular grids are optimized for maximum stiffness (minimum strain energy) and constructability (uniform member lengths). It is first shown that the latticed shells with completely uniform member length can be generated by solving an optimization problem with nodal coordinates as design variables. Next, the latticed shells are modeled using Bézier surfaces in order to reduce the number of design valiables while maintaining the complexity and smoothness of the shell surface. Although the shape of a parametric surface is usually optimized using the coordinates of control points as design variables, we use the parameter values at the nodes of the grids, in addition to the coordinates of control points, as design variables. The optimization results using different design variables are compared in the numerical examples.
