Research On Mechanical And Sound Insulation Properties Of Glass Fiber Reinforced Polypropylene Foam Sandwich Composites

Fiber reinforced polymer matrix composites have been widely used in the automobile industry as an effective way to reduce the weight of automobiles.Foam sandwich composite is a kind of structural form of advanced composite material,which has the characteristics of high specific strength,light weight,excellent sound insulation and heat insulation performance,moreover,it has good resistance to impact and energy absorption,has become one of the important research fields of lightweight materials for automobiles.In this thesis,glass fiber reinforced polypropylene(GFRP)foam sandwich composites are investigated and the effect of foamed polypropylene foam on mechanical and sound insulation properties of GFRP foam sandwich composites are studied by method of experimental and numerical analysis.Detailed contents are listed as follows:(1)The preparation process of glass fiber reinforced polypropylene foam sandwich composite material is studied according to the prepreg technology and molding process of thermoplastic composite.(2)Mechanical properties of glass fiber reinforced polypropylene foam sandwich composites are tested,the tensile properties,flexural properties and failure modes are studied.A tensile and bending model of GFRP foam sandwich composite is constructed,and its maximum tensile and bending loads and failure modes are analyzed.(3)The low speed impact model of GFRP foam sandwich composite is established by Abaqus based on the Hashin criterion and the crushable foam model,and The effect of polypropylene foam on low speed impact response of GFRP foam sandwich composite was investigated.The low velocity impact and energy absorption properties of glass fiber reinforced polypropylene foam sandwich composites are evaluated.(4)The sound insulation properties of GFRP foam sandwich composites are studied by using the method of dual microphone impedance tube and four microphone impedance tube.The sound insulation properties of GFRP foam sandwich composites are analyzed by different evaluation indexes such as acoustic impedance,reflection coefficient and transmission loss.