Thermo-mechanical load interactions in foam cored axi-symmetric sandwich circular plates – High-order and FE models

This work presents analytical and finite element analysis (FEA) results of the thermo mechanical non linear response of an axi symmetric circular sandwich plates with a compliant foam core. The study investigates the load thermal interaction response of a sandwich panel where the properties of the core are temperature dependent and degrade as the temperatures are raised. It presents briefly the governing equations for a sandwich plate based on the principles of the high order sandwich panel theory (HSAPT) which incorporates the effects of the vertical flexibility of the core material as well as the effects of tem perature independent/dependent mechanical properties of the foam core. The effects of the thermal deg radation of core material on the thermo mechanical non linear response of a simply supported circular sandwich plate are studied through the analytical and FE models. The difficulties involved in non linear geometrical FE modeling of sandwich panels with a compliant ‘‘soft” core with temperature dependent mechanical properties are discussed. The HSAPT model predictions are compared very well with FE result. An important conclusion of the study is that the interaction between mechanical loads, tempera ture induced deformations, and degradation of the mechanical properties due to elevated temperatures, may seriously affect the structural integrity of foam cored sandwich plates.This work presented in this paper was conducted during the stays of Dr. Carlos Santiuste and the visit of Professor Yeoshua Fro stig with the Department of Mechanical and Manufacturing Engineering at Aalborg University. The stay of Dr. Santiuste was sponsored by the Department of Continuum Mechanics and Structural Analysis, University Carlos III of Madrid, Spain. The visiting professorship of Professor Frostig was sponsored by the US Navy, Office of Naval Research (ONR), Award N000140710227, "Influence of local effects in sandwich structures under general loading conditions and ballistic impact on advanced composite and sandwich structures”, where the pro grammer manager was Dr. Yapa D.S. Rajapakse and by the Ashtrom Engineering Company, which supports Frostig’s professorial chair at Technion Israel Institute of Technology. The financial support received is gratefully acknowledged.Publicad