Finite Element Modeling And Analysis On The Compressive And Shear Performance Of Ceramic Fibrous Termal Insulation Tiles

Rigid ceramic fibrous insulation tiles,reusable,are widely used in the large-area surface thermal protection structure of Reusable Launch Vehicle(RLV)due to their lightweight,low thermal conductivity,ablation resistance,high strength,and both load-bearing and heat-insulating ability.In this paper,the compressive and shear performance of ceramic fibrous insulation tiles are studied by combining experimental,theoretical and simulation methods.Firstly,an experimental method is independently designed to mearure the shear performance of the ceramic fibrous insulation tiles,and the compressive and shear mechanical properties are obtained via experiments.Results close to reality and the influences of fibre modulus Ef,the shape and size of the model on the macro modulus are obtained through theoretical analysis.Secondly,a finite element model(FEM)for 3D brittle stochastic fibrous network material is established using MATLAB software.Stress-strain curves consistent with the experimental results are obtained through finite element analysis(FEA),and the damage evolution processes and failure reasons of the model are also learned.It is found that fibre failure is predominant in the compressive case while connection and buckling failure matters more in the shear situation.Unit failure merges in the elastic phase in both loading models,which is an important factor affecting the service life of the material.Finally,the effects of connections,apparent density,fibre orientation,fibre diameter,fibre strength dispersion,and delamination on the properties of the material are analyzed through simulation.In general,the stronger the connection,the better the mechanical properties of the material;the effect of fibre orientation on the compressive and shear performance all conform the logistic regression model;the increase in fibre diameter also increases the dispersion of material performance;both fibre strength fluctuation and delamination will obviously harm the material performance.