According to increasing development of technologies, affordable structures with high strength and stability come to public attention. Sandwich panels with a honeycomb-core are structures that have attracted a lot of attention in industries such as automotive, aerospace, and civil engineering due to their unique mechanical and thermal characteristics in recent decades. Additionally, simulation of such structures, which have complex geometry in their core section in comparison with general strucures, using commercial softwares which have function based on the finite element methods (FEM) is more sophisticated; Although FEM has been considered as a standard method in solving wide range of enginreeing problems for the past few years, current problems are more complecated in a way that this method could not deal with them solely.Therefore, attempting to find a solution to this challenge and analysing structures with different geometries, researchers introduced meshless methods. Meshless methods are relatively modern methods which due to some distinctive features like high accuracy and flexibility, higher calculation speed, and cost-effectiveness, have always been of interest in the analysis and investigation of problems with complex structures. Galerkin meshless method, developed based on deiffuse element method, is a method that a set of arbitrary nodes scattered in the geometry of the problem as well as the boundries is used to specify the domain of the problem, and Moving Least Square approximation is used to create shape functions. Convergence rate is one of the key features of this method in some problems which is significantly higher than other methods like finite element method. Due to the complex geometry of such structures, which should be considered in the modeling of the honeycomb core, the generalized method of Malek and Gibson is used to obtain the effective mechanical properties of the honeycomb core in this thesis. Also, to obtain displacement fields and relations of the problem, both Classic plate theory and First deformation theory are used individually and relations are formulated by Galerkin meshless method. Finally, the obtained parameters are eva‎luated, and the validation of these relations are confirmed by comparing the results of this study with existing articles. Simulating foregoing procedure has been done step-by-step by Matlab program then the impact of various boundary conditions, the individual layer thickness, the ratio of the dimensions and distances of the core walls on the displacement and free vibration of the panel are investigated. The obtained results are represented in the form of tables and graphs.

نسرين جعفري , سعيد صرامي

نسرين جعفري , مهدي زندي