Side-groove effect on fracture mechanical fatigue testing of PLA material

Abstract

PLA polymer is probably the most used thermoplastic material in FDM technology nowadays. Besides prototyping purposes, FDM materials are also considered for functional application use, thanks to the fast fabrication of components, relatively simple workflow, and the absence of material waste that this technology offers. Except for static material properties, data concerning the expected lifetime and reliability of AM parts under cyclic loading are also necessary for functional purposes. Due to the exceptional structural complexity of FDM parts, minor modifications in material testing must be used sometimes. The subject of this paper is the fracture mechanics-based fatigue testing of CT specimens that results in crack kinetics description like the Paris’ law. One of the objectives is also to describe the effect of SGs placed on the surface of CT specimens, and the effect of different layer heights. The main intention of the SGs is to secure a straight crack propagation path, thus imposing the crack to follow the Mode I condition, predominantly. A set of regular CT specimens and specimens with SGs was prepared with a full infill density interior and with different layer heights (0.1 mm and 0.3 mm). Crack kinetics measured on these specimens are presented in this paper and discussed.PLA polymer is probably the most used thermoplastic material in FDM technology nowadays. Besides prototyping purposes, FDM materials are also considered for functional application use, thanks to the fast fabrication of components, relatively simple workflow, and the absence of material waste that this technology offers. Except for static material properties, data concerning the expected lifetime and reliability of AM parts under cyclic loading are also necessary for functional purposes. Due to the exceptional structural complexity of FDM parts, minor modifications in material testing must be used sometimes. The subject of this paper is the fracture mechanics-based fatigue testing of CT specimens that results in crack kinetics description like the Paris’ law. One of the objectives is also to describe the effect of SGs placed on the surface of CT specimens, and the effect of different layer heights. The main intention of the SGs is to secure a straight crack propagation path, thus imposing the crack to follow the Mode I condition, predominantly. A set of regular CT specimens and specimens with SGs was prepared with a full infill density interior and with different layer heights (0.1 mm and 0.3 mm). Crack kinetics measured on these specimens are presented in this paper and discussed.