9 - Experimental study of delamination in cross-ply laminates

Abstract

Publisher Summary Fiber-Reinforced Polymer-matrix [“FRP―] laminates made of a stack of plies or layers are labeled cross-ply, if fiber orientation from one ply or layer to the next alternates in the 0° and 90° direction, respectively. In cross-ply, as for all FRP laminates, constituents (fiber and matrix material, additives) and their content, stacking sequence (symmetric or asymmetric with respect to the midplane), number of plies or layers, and layer thickness or number of plies per layer with the same fiber orientation can be varied. Depending on the application, various shapes and sizes (e.g., thickness reduction requiring ply-drop off), modifications (e.g., machining of holes) of the cross-ply laminate and combination with other components are possible. Together with the processing conditions, a specific choice from the above selections will yield a cross-ply laminate specimen or element whose delamination behavior can be assessed experimentally. With respect to formation of delaminations, their stable propagation or unstable growth in cross-ply laminates, the effects of load-type (e.g., tensile, compressive, biaxial), the rate of load-application (e.g., monotonic or quasistatic, high-rate or impact, fatigue, combined), and of environmental conditions (e.g., constant or varying, elevated or low temperature, exposure to humidity or other gaseous or fluid media) can be investigated.