Characterization and failure analysis of a polymeric clamp hanger component

This paper characterizes the failure of a polymeric clamp hanger component using finite element analysis coupled with experimental methods such as scanning electron microscopy, X-ray computed tomography, and mechanical testing. Using Fourier transform infrared spectroscopy, the material was identified as a polypropylene. Internal porosity that arose from the manufacturing procedure was determined using three dimensional X-ray computed tomography. From static mechanical experiments, the forces applied on the component were determined and used in a finite element simulation, which clearly showed the process of fracture arising from the pre-existing processing pores. The fracture surfaces were observed under a scanning electron microscope confirming the finite element simulation results illustrating that low-cycle fatigue fracture occurred in which the fatigue cracks nucleated from the manufacturing porosity.

► Fracture mechanism in hanger component was found to be low-cycle fatigue.
► Material determined to be polypropylene using FTIR.
► Fracture surfaces examined and pore sizes calculated.
► Fracture mechanics analytical treatment using material properties from experiments.
► Finite element simulations showed effects of pores on the stresses and triaxiality.