Finite element modeling of the aluminothermic welding with internal defects and experimental analysis

Abstract

There are several hundreds aluminothermic welds and tenth of new welds being made daily on the Moroccan rail network. Although the aluminothermic welding technique is well proven, it is a critical safety component of the rail infrastructure. The consequences of a single failure could result in the derailment. The observations suggest that these defects are mainly of two types: defects of adhesion (or bonding defects) and porosity defects (or multiple blisters defects). Each of these defects may constitute a privileged site of stress concentration. Depending on the level of these stresses, potential damage process may be developed and put off the rail. It therefore seems necessary to model the mechanical behavior of these welds with these defects in order to classify them by their criticality. In this study, we therefore modeled with the same load and with the same boundary conditions, the weld seam for each type of defect. The numerical and experimental results show that the defects of adhesion tend to concentrate the most constraints.