Effect of residual stress on impact damage in a dissimilar laminated plate at a biaxial bending mode

Systematic investigations have been performed on the mechanisms that lead to impact damage in a dissimilar laminated plate with a thermal residual stress at a biaxial bending mode. Glass/polymer laminated plates are often used as blast-proof safety screens, and bullet-proof windows, and in windshields in the automotive and the aerospace and aeronautical fields. Their many advantages, the development of new materials, and the need for high-performance, low-weight structures ensure that laminated plate construction will continue to be in demand. In this work, the impact damage in glass/Al alloy laminated circular plates cured at RT and 80°C was investigated using an instrumented long bar impact tester at a biaxial bending mode. A circular plate was cured at different curing temperatures to form a thermally induced residual stress at the bonding interface. To improve the damage tolerance of laminated circular plates, various geometric (thickness ratio of the inner to outer layer) and material parameters are considered by determining their effects of maximizing impact absorbed energy. The measured impact force profiles and the impulse of the force explained the impact damage behaviors induced in the laminated circular plates. We show that a compressive residual stress could reduce the initiation of radial cracks and the impact damaged area of the laminated plate in the outer layer. Greater an inner layer thickness results in smaller a damaged area. A design guideline for effective dissimilar laminated plate construction is proposed.