Nonlinear elasto-dynamic analysis of bi-material composite members subjected to explosion

Composite members that are composed of two or more elements connected together by elastic shear connection are frequently found in many areas of engineering practice. Evaluation and subsequent strengthening of new and existing types of these members for extreme loading cases, such as explosion or blast, require a realistic and pragmatic design approach to be formulated and for which there is a significant dearth of scientific data in the literature. This paper therefore addresses, in generic form, an innovative mechanical-based formulation for the nonlinear elasto-dynamic response of an isolated bi-material composite element under a blast loading, which importantly incorporates the partial shear interaction which occurs at the interface of the two components. The formulation is based on a non-discretisation semi-analytical method, in which the second order effects in the strain-displacement field are taken into account so that the axial force developed is quantified correctly. The bi-material composite member is restrained at its ends by translational and rotational springs, which simulate a semi-rigid connection in a steel-concrete composite frame. The generic technique that is developed is shown to agree with solutions obtained from the finite element method, and it provides a structural model for the dynamic response of bi-material composite members with the potential for inclusion in prescriptive code rules.

► An innovative formulation for dynamic response of composite element is addressed.
► The element is subjected to explosion.
► Partial shear interaction at the interface of components is considered.
► The formulation is based on a non-discretisation semi-analytical method.
► The generic technique has the potential for inclusion in prescriptive code rules.