Seminarium Instytutowego Seminarium Mechaniki im. W. Olszaka i A. Sawczuka

Nonlinear Thermomechanical Behaviour of Polymer Foam Cored Sandwich Structures

prof. Ole Thybo Thomsen, prof. Janice Dulieu-Barton

poniedziałek, 18 kwietnia 2011, godz. 10:00, sala Aula (II p.)

Polymer foam cored sandwich structures are being used increasingly for a variety of applications including wind turbine blades, boat hulls and ship structures to mention a few. Sandwich structures are often subjected to aggressive service conditions which may include elevated temperatures. The material properties of foam cored sandwich structures depend on the temperature field imposed, and this is usually ignored in engineering analysis and design. Polymer foam core materials are particularly sensitive to elevated temperatures, and a significant reduction of the mechanical properties may occur well within the operating range of temperatures. Moreover, significant reduction of the properties occurs at much lower temperatures than the temperatures where a complete loss of stiffness and strength is experienced. Previous research has shown that thermal degradation (softening) of polymer foam core materials exert a significant influence on the performance of sandwich structures. More specifically, the degradation of the core properties with rising temperature lowers the buckling resistance. In addition, when external mechanical loads act simultaneously with thermal loads, the material degradation may shift the response from being linear and stable into being nonlinear and unstable. This is especially pronounced when thermal gradients are present across the sandwich panel thickness, and when the heated (warmest) face sheet is subject to compressive loading/stresses. Professor Thomsen&