Chapter 3.8 – Prediction of laminate failure with the Rotem failure criterion*

Publisher Summary The chapter examines the mechanical behavior of four types of composite material in various laminate lay-ups by using the Rotem failure criterion. The criterion distinguishes between fiber failure and matrix failure. Only in-plane loads are considered, neglecting the possibility of inter-laminar failure. The polymeric matrix material induces nonlinear behavior on the laminate stiffness where the matrix is dominant. Mainly the effect of biaxial loading is examined, including tension, compression, and shear. Biaxial loading induces matrix failure and only unidirectional or almost unidirectional loading in a fiber direction can cause fiber failure. The criterion distinguishes between tensile and compressive stresses to account for the different strengths. By using a computer program it is easy to take all these restrictions into account. The different laminates of glass and carbon fibers, ductile and stiff matrices are analyzed and their strengths predicted.