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Laminated glass consisting of two soda lime glass plies adhered by a polyvinyl butyral interlayer (PVB) is used for automotive glazing. This paper describes the application of a dynamic, nonlinear finite element method to investigate the failure modes of a laminated glass subjected to low-velocity impact with a spherical headform. Crack type, crack location and crack initiation time are evaluated using the maximum principal stress and J-integral criterion. Failure occurred due to flexural stresses and not bearing stresses. The first crack always initiated at the center of the outer impacted ply and PVB interface, and later on the exterior surface of the inner ply. The PVB thickness and velocity of impact had little or no effect on the first crack initiation.

A dynamic, nonlinear finite element method is applied to investigate the mechanical behavior of a human being head normally impacting on laminated glass plates. The human being head is modeled as a solid aluminum sphere covered with a viscoelastic skin. Both aluminum sphere and viscoelastic are deformable. Resultant accelerations in the head and maximum principal stresses in laminated glass plates are computed under various impact speeds and laminated glass configurations. The effect of impact speed and laminated glass configuration on the maximum resultant head acceleration before the failure of the laminated glass plate is studied.

In the design and use of large composite panels in structures such as aircraft and space vehicles a major concern is the ability of the panel to function after being damaged. One technique that has evolved from the stringer reinforced metallic panel is the buffer strip or hybrid panel. The present study considers a method of analysis capable of predicting accurately the stress concentration at a rectangular cutout in a unidirectional composite laminate containing symmetrically placed buffer strips. The analysis is based on a materials modelling approach by using the classical shear lag assumption to describe the stress transfer between fibers. Explicit fiber and matrix properties of the main panel and the buffer strips are retained and changes in the stress concentration as a function of the relative material properties and buffer strip width are presented. A substantial reduction in stress concentration is achieved by using soft buffer strips.