The double cantilever beam test applied to mode I fracture characterization of polyamide 12 processed by selective laser sintering technology

Abstract

In recent years, parts produced by Selective Laser Sintering (SLS) technology have aroused growing interest due to their valuable potential for end-use applications. However, to ensure the applicability of SLS products for advanced structural purposes, an accurate characterization of their mechanical behaviour is essential, which includes the assessment of fracture performance. Thus, cohesive zone modelling that allows mimicking damage initiation and propagation in quasi-brittle materials is used in this work to identify the cohesive laws of Polyamide 12 parts sintered by SLS with different values of energy density. This has been accomplished with success in this work for pure mode I loading employing the Double Cantilever Beam (DCB) test. In this context, experimental data is used to evaluate the critical energy release rate under quasi-static loading, by means of the Compliance-Based Beam Method (CBBM). The identification of the cohesive laws comprises finite element analysis to achieve accurate agreement with the experimental load-displacement curves obtained under quasi-static loading. The experimental protocols are duly validated for the tested conditions, which includes a developed numerical procedure combined with experimental data.