| In this paper,the thermal coupling behaviors of 3D 4-directional carbon/epoxy resin braided composites are studied and explored.Based on the experimental study,the thermal physical properties and mechanical properties of 3D 4-directional braided composite material were analyzed from two aspects.And the mechanical properties of 3D 4-directional braided composites under thermal environment are calculated by numerical simulation.It has certain theoretical significance and practical value.As a new type of textile structural material,3D braided composite has better mechanical properties,structural designability,higher strength,difficulty in layering and better overall performance than traditional materials.First of all,the thermal expansion coefficient,thermal conductivity,specific heat and thermal diffusivity of 3D 4-directional carbon/epoxy resin braided composites and fiber bundles under thermal environment were studied experimentally.The purpose of this paper is to obtain the thermophysical properties and distribution characteristics of composites in the thermal environment,and to provide the corresponding material parameters for the numerical calculation of thermodynamic coupling behavior of 3D 4-directional braided composites.Secondly,the axial compression and tensile strength of 3D four-direction carbon/epoxy resin braided composites with different braiding angles were studied experimentally,and the main mechanical properties and some preliminary conclusions were obtained.Finally,according to the braided structure of 3D 4-direcational braided composites,the geometric model of spiral monocyte of 3D 4-direcational braided composites is established.Based on the helical geometrical model of 3D 4-direcational braided composites with different angles,numerical analysis of the mechanical behavior of the composite material under thermal loading and mechanical interaction is carried out.The thermal coupled stress field and displacement field of 3D 4-directional composites are obtained. |
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