Experimental analysis of FDM structures in shape memory polylactic acid

The behavior of solid cellular structures in polylactic acid (PLA) manufactured by Fused Deposition Modeling (FDM) is herein investigated. In particular, the manuscript investigates the capability of permanently deformed PLA structures to restore their starting shapes, once a thermal stimulus is applied on them. In this study, a structure called Rototetrachiral was produced, which originates from Rotochiral and Tetrachiral. The latter was tested to verify its mechanical response and its ability to absorb energy when subjected to a compression stress, repeated over several cycles. The experimental results showed a close connection between the structure’s ability to absorb energy and its extent of damage, which gradually increases with the number of cycles. Microscopic analysis shows that the central cells are the most deformed. However, the applied thermal stimulus allows to recover the deformation, ensuring good performance of the structure for a certain number of cycles.