STUDY OF PARAMETERS AFFECTING FRICTION SHEAR STRESS AT TOOL-PART INTERFACE FOR AUTOCLAVE COMPOSITES PROCESSING

摘要

Tool-part interaction during autoclave processing has shown important relevance in distortionand warpage of composite parts. Due to deformation mismatch, the tool induces residual stress inthe part by means of contact friction. An experimental investigation was conducted tocharacterize the influence of different parameters such as stacking sequence, tool surfaceconditions, pressure, and tool-part displacement rate on friction-induced stress. An orthogonalarray method was implemented to optimize the number of experiments based on Taguchi'stheory of robust experiments. Tests were carried out using a customized friction rig that canreproduce autoclave processing conditions. In order to mimic the tool-part interface conditions, acarbon-epoxy prepreg (Cytec 977-2 UD) was studied in the friction rig during cure. The toolsurface conditions and normal pressure were found to be stronger contributors to friction stressthan layup configuration.