Preparation And Mechanical Property Prediction Of Hollow Glass Bubble/Epoxy Light Composite

Recently, composites of hollow glass bubble filled epoxy were widely used in aerospaceand ocean detecting industry, due to their low density, high strength and other property. Andthe mechanical property is always the concern of people, which is determined by their macroperformance. So it is of great importance to establishe the prediction model of this material’smechanical property from macro structure.In this paper, the composite samples of different HGB volume fraction weremanufactured with glass bubble filled E-51epoxy and harder594, through stir casting process.The microballoons were modified using silane coupling agent.Then the composite’scompressive property and failure model were studied through mechanical analysis andscanning eleetron microscope(SEM). Meanwhile, the elastic and strength prediction modelwere deduced through differential method and finite element method(FEM).The results show that the composite’s density decrease, porosity increases, as themicroballoons volume fraction increases. The introduction of bubble enhances strength ofcomposite, but reduces the moduli. And the compressive failure is related to themicroballoons volume fraction. The composites with fraction below55%fail through shearyielding of the matrix. When the fraction is above55%, composites fail due to the interactiveinfluence of matrix’s shear yielding and microballoons’ crushing.The prediction model of elastic property is deduced, using differential scheme, which iseffective when microballoon volume fraction is below63%. It is found that theoreticalpredictions are in agreement with the experimental results, with the error within10%.The stress distribution of composite’s unit cell model is analysized. It is showed thatthere is great stress concentration in the composite’s inner, and the maximum stress in themicroballoon is ten times the load. Then the strength of composite is analysized through thestress distribution contour. The theoretical results are well in agreement with experiment data,with the error bellow10.2%.In this research,the prediction methods of HGB/epoxy composite’s elastic and strengthproperty were established, which can reveal the relationship between the micro mechanicalproperty and macro structure，and service as the guide of formulation design and mechanicalproperty’s study.