טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBuller Osnat
SubjectSpecial Finite Element for the Analysis of Sandwich Panels
with a Transversly Flexible Core
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Emeritus Yeoshua Frostig


Abstract

A special finite element based on a High-Order Sandwich Panel Theory (HSAPT) (see  Frostig, 1992) has been developed for the analysis of a typical fully bonded and delaminated sandwich beam. It consists of two linear face sheets and a transversely flexible isotropic core. The field equations as well as the appropriate boundary and continuity conditions are derived via the variational principle of potential energy minimization. The main goal of the study is to provide an engineering tool for the analysis of sandwich beams with any geometry, any boundary conditions and any type of loading.

This special finite element is unique for sandwich structures and a single element include all degrees of freedom of the section although the beam consists of three different layers. The formulation uses a quadratic and cubic polynomial through the depth of the core to describe the transverse and the longitudinal displacements respectively for the derivation of the governing equations through the variational principle. The FE equations have been defined through the weak formulation approach.

 The results of the proposed special element are compared with analytical and FE results that uses commercial software. Additional results include cases where no analytical solution exist (such as various skins thickness, or various core thickness, along the longitudinal axis of the beam) that compared well with commercial FE results.