Abstracts: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.

Abstracts:It is very significant to comprehensively evaluate corrosion-resistant levels of an organic coating system after accelerated tests or outdoor exposures. In this study, the comprehensive evaluation model of the tested or exposed organic coating systems was established with Analytic Hierarchy Process (AHP) based on their eight types of the often observable and measureable failure modes, and that this model was verified by the electrochemical impedance data based on their electrochemical impedances spectroscopies (EIS). The corrosion-resistant performance levels of the tested or exposed organic coating systems were defined based on the comprehensively evaluated values. The relationship of their comprehensively evaluated values with the electrochemical impedances of the tested or exposed organic coating systems was proposed. Finally, this model was used to assess the corrosion-resistant performances of the coated aluminum alloys with three types of availably commercial organic coatings after accelerated tests. The results showed that the comprehensive evaluation model was verified to be reasonable to straightforwardly and comprehensively assess the corrosion-resistant performance levels of the tested or exposed organic coating systems after accelerated tests in a laboratory which simulate different corrosive atmospheric environments.