A thermo-elasto-plastic model for a fiber-metal laminated beam with interfacial damage

In this paper, a thermo-elasto-plastic model for the fiber-metal laminated (FML) beams is established and the mechanic characterization of a FML beam with interfacial damage under thermal environment is investigated. The elasto-plastic behavior of the FML beam is modeled by a macromechanical orthotropic plasticity theory, where the composite layers in the FML are assumed to be linearly elastic and the aluminum layers are taken as orthotropic elasto-plastic. Additionally, the thermal stresses in the FML beam are studied by introducing heat conduction equation. Considering the mismatch in properties of different layers, the interfacial damage is investigated based on cohesive zone model and shear-lag model, and the evolution of the interfacial damage is addressed as well. The incremental thermo-elasto-plastic governing equations for the FML beams are solved by finite difference method and iteration method. In the numerical simulations, the temperature variation, the elasto-plastic deformation and the interfacial damage evolution of the elasto-plastic FML beam are discussed in detail. The results show that mode II interfacial damage occurs at 1/4 and 3/4 length of the beam and mode I damage is most likely to happen at the center.