Experimental and numerical analysis of additively manufactured foamed sandwich beams

Abstract

This work examines the feasibility of using foamable polymer filaments to create lightweight composite beams using additive manufacturing. To accomplish this, monolithic and sandwich beams, with non-foamed face sheets and a foam core were fabricated using MEX 3D printers. The non-foamed and foamed PLA components were created by extruding foamable PLA with nozzle temperatures of 200 °C and 220 °C, respectively. Tensile testing samples were printed and tested and used to provide data for numerical models. A range of different sandwich structures were printed and tested in 3-point bending and their performance was compared to monolithic non-foamed and foam beams and to analytical and numerical models.The stiffness, yield load, and maximum load of sandwich beams with non-foamed face sheets and foamed cores are much greater than those of pure foamed beams. With sandwich foam beams, weight reductions of around 30 % are both observed and predicted compared to non-foamed beams with equivalent stiffness. Analytical and numerical models using experimental data show value in aiding the design of sandwich structures of this type.