Failure analysis of a plastic modular belt in-service

In this study, an analysis of the possible causes of the failure in-service of a section of a plastic modular belt was conducted. The study begins with a reproduction of the service conditions in a traction gear. An analysis of the fracture surfaces revealed the existence of defects in the interior of the parts. With the aim of determining the origin of the imperfections and their influence on the failure, an exhaustive mechanical and rheological characterization of the material was carried out. The development of an FE Analysis established that the reduction of the tensile strength of the part due to internal defects was around 70%. Tests also showed that the most stressed area was the area where the most defects appeared. A simulation of the injection process showed that the defects are caused by the geometry of the part, leading to the conclusion that its failure was caused by bad dimensioning of thicknesses.