Wrinkling of sandwich polymer matrix composite panels under transverse thermal gradients

This paper studies the effect of transverse thermal gradients on the wrinkling load of sandwich polymer matrix composite panels. Analytical solution of wrinkling load is obtained for the sandwich panels with continuous material property variations along the transverse direction induced by the transverse thermal gradients in fire damage. The wrinkling load is presented in terms of a single parameter that measures the geometrical lengths of the panel, the degraded material properties and material gradients at elevated temperature. The effects of the thickness of the core and the material gradients on wrinkling load are discussed. An alternative approach to use upper bound temperature fields in wrinkling analysis is discussed. The solution provides insights toward the development of a quantitative methodology for structural integrity in fire.