Modeling of thermo-elastic properties of composite material in stability problems of multilayered shells

Thin-walled structures, the elements of which are plates and shells made of composite materials, are increasingly used in various industries. The growing needs of practice and the introduction of new composite materials require further improvement of the calculation methods of shell structures of inhomogeneous structure. Therefore, the problem of developing an adequate method of analyzing the behavior of shells made of composite materials with a multilayer structure is relevant. The work is devoted to the application of the developed method of finite elements for the analysis of geometrically nonlinear deformation and stability of elastic shells to the problem of the study of shells, the layer materials of which are composites of a fibrous structure. The method of structuring materials through the shell thickness and plan by using a universal 3D finite element is applied to model the thermoelastic properties of a ingomogeneous material. Determination of the effective characteristics of the composite material is realized by the structural micromechanical parameters of its components based on known methods of predicting elastic constants for this model of the composite material. The multilayer finite element, created within the framework of the developed approach, can be exploited to the problems of calculating thin elastic shells from both traditional and composite materials. The results of investigation of a multilayer composite panel using various micromechanical techniques are presented. The results of the study of a multilayer composite panel obtained by various micromechanical methods are given. These results are consistent with those obtained using the NASTRAN software. The new modification of the developed finite element makes it possible to analyze the stress-strain state and stability of multi-layer shells made of fibrous composite materials reliably, with accuracy acceptable for engineering calculations.