ISOGEOMETRIC DESIGN AND OPTIMIZATION OF SPATIALLY VARYING, MULTI-MATERIAL 3D PRINTED ROD STRUCTURES

With the capability to locally control the material composition of a structure, multi-material and multi-method 3D printing technologies provide a new level of design freedom beyond the realization of complex topologies. However, the precise design and optimization of spatially varying material compositions within a structure is beyond the capabilities of traditional computer-aided design approaches and tools. In this work, we apply the concept of isogeometric design and analysis to efficiently model, simulate and optimize spatially varying material compositions in the context of multi-material additive manufacturing. In particular, we apply this concept to nonlinear 3D beam structures with axially and transversally varying geometric and material parameters, including non-homogeneous, functionally graded and laminate cross-sections. In addition to discretizing the kinematic variables using an isogeometric collocation method, we also parameterize the geometric and material properties of the cross-sections as spline curves, which enables efficient modelling and optimization of axially varying material compositions and cross-section geometries. We demonstrate the applicability of the approach for design optimization of multi-material 3D printed, active rod structures with axially varying material distributions and direct 4D printing of self-assembling, multi-material laminate structures.