Analysis On Mechanical Properties Of Carbon/Carbon Composite Material Plate With Bolt Hole Pulled-through

C/C composite material have been increasingly widely used in aerospacetechnology, although with the development science and technology, the demand ofcomponent with large size and complicated structure has become more and more urgent.Subject to the conditions of preparation technology, direct preparation of C/C compositematerials component with large size and complex shape are difficult. Therefore, usingthe simple component with small size for secondary connection is an effective approachto solve the problem. C/C composite material is a kind composite material whosemechanical properties is very stable in high temperature so that completing theconnection of the material by melting in high temperature is not feasible, the moststraightforward method is achieving mechanical connection by mechanical fastenerssuch as bolts, screws. But it must punch on composite material structure to use themechanical connection, punching can destroy the microstructure of composite materialitself, and it is likely to produce stress concentration phenomenon on the edge of thehole leading to the damaged component under low load. In this paper, C/C compositematerial plate with bolt hole pulled-through mechanical properties were studied throughexperimental analysis combined with finite element simulation method.Firstly, the related theory knowledge of composite material mechanics includingsome basic formulas, strength criterion and finite element theory has been introduced tobe a theory bedding. Then the C/C composite material plate with countersunk bolt holeand straight bolt hole pulled-through experimental analysis have been conducted, andacquired the pull-off strength of typical text piece. The C/C composite material platewith the two kinds of bolt hole pulled off outside the flat surface numerical simulationanalysis has been proceeded on the basis of the experiments results, and compared theresults of the numerical simulation with them of the experiments to prove the accuracyof numerical simulation analysis.In addition, further using finite element simulation software to composite materialplate stress distribution around the hole has been finished; meanwhile, the influence ruleof geometric parameters of the components to the limit load of C/C composite materialplate with bolt hole pulled-through was given. To the plate with countersunk bolt hole,the influence of the distance constrained on the plate by the fixture and angle ofcountersunk has been studied, and to the plate with straight bolt hole, the influence ofdistance constrained on the plate by the fixture and bolt head radius has been studied,and the relationship between the geometric parameters and limit load was provided.