Material parameters for the evaluation of PA welds using laser extensometry

The deformation and fracture behaviour of welded polymer slabs under tensile stress has been investigated by laser extensometry. The necessity of a position-sensitive materials testing method for describing the properties of welds of polymers, and the special requirements for the testing and evaluation method, have been introduced. The mechanical heterogeneity H representing the ratio of the local strain differences and the integral strain has proven to be a good indicator for the evaluation of welding quality. The information got by means of this testing method was then compared to results obtained conventionally.