Design for Additive Manufacturing (DfAM) framework for integrating structural optimization, path planning and manufacturing signatures in automated composites manufacturing

Abstract

As composite structures become more prevalent in aerospace applications, Automated Fiber Placement (AFP) has replaced traditional hand layup as a method of choice for manufacturing large, contoured structures. However, straight fiber paths still dominate current designs. Curvilinear fiber paths offer improved stiffness distribution but are limited by manufacturing constraints and increased defect formation. This work presents a framework to design curvilinear fiber paths that are amenable to AFP-based manufacturing. A Python-based tool is developed to generate AFP models by offsetting an initial fiber path defined as a Bezier spline on a given 3D surface. Further, nonlinear stability analysis is conducted using the commercial finite element software, Abaqus to ascertain the performance under axial compressive loads. As a proof of concept, an open rectangular cutout from a curved, conical-cylindrical shell as part of a rocket fairing is considered. First, an optimal straight-fiber configuration is selected and used as the benchmark. Curvilinear fiber paths are then explored, showing an increase in the critical buckling load. The influence of manufacturing parameters on the optimal solutions is also considered.