A New Type Of Plane Beam Element With2Nodes And16Degrees Of Freedom For Sandwich Structures

Sandwich structures are widely used in the fields of spacecrafts, architecture and transportation because of their outstanding performances such as excellent high strength, stiffness ratio and good sound insulation, ant-vibration and thermal insulation performance. The classic model of calculating the mechanical properties of the sandwich beam is based on the plane cross-section assumption and the transverse incompressible assumption, which limit the real response of beam. We may turn to the finite element method to overcome the deficiencies of the classic method, but one will find that the work of meshing turn to be too much or even unacceptable when processing complex systems. There hasn’t been an idea, which can not only overcome the deficiencies of the classical model but also solve the mechanical problems of sandwich structures conveniently.In this paper, a new model for solving the mechanical performance of sandwich beam is presented from the following aspects:(1) To overcome the plane cross-section assumptions and the transverse incompressibility of the classical methods, a new theoretical assumption is dished and a new sandwich beam element with2nodes and16degrees of freedom is established. Compared the results of statics of the proposed model with the Euler-Bernoulli beam model and the three-dimensional finite element method, the precision and validity of the proposed method has been verified.(2) According to the classical finite element process, the element mass matrix of the proposed model can be obtained. Basing on the Rayleigh damping, the damping matrix is obtained, and then dynamical characteristics and time-domain response problems are solved. Compared the results of characteristics of dynamics of the proposed model with the existing article model and the three-dimensional finite element method, the validity of the proposed method has been verified. (3) The two following problems have been studied:First, the total thickness of the sandwich beam is fixed, the effects of the proportion of the core on statics and characteristics of dynamics. Second, the effect of the modulus of the core on statics and characteristics of dynamics is studied. Last, the dynamical response of the model with impact load is researched.The results show that:First, the proposed model has overcome the disadvantages of the classical model, which deformation of cross-section is no longer in the same plane and transverse direction can be compressed. Second, the work of meshing is convenient, and precision is in good agreement with the three-dimensional finite element method.