| Glass fiber reinforced composites in automobile field are difficult to recycle,resulting in huge pollution to ecological environment.So the development of natural fiber composites to replace glass fiber reinforced composites has become the hot topic in research.At present,the main research on bast fiber composites is to optimize the mechanical properties of bast fiber composites by changing the reinforcement morphology and improving the interface compatibility,and finally used in the field of automotive interior decoration.However,problems,such as single structure,poor designability and inadequate mechanical properties,limit the application of bast fiber composites in automobile interior decoration.In order to solve these problems,the jute/polypropylene composite(JPC)molding process was optimized through response surface design.Than leno mesh fabric(LMF)was woven and used as the reinforced rib to prepare leno mesh fabric reinforced jute/polypropylene composite(LRJPC).Finally,the influence of the parameters of LRJPC on its mechanical properties was studied by finite element method,which reflected its internal stress trend.The research content is as follows:The three-factor and three-level experiment was designed by Box-Behnken response surface design,which made the temperature,pressure and holding time as influencing factors,and made tensile strength,flexural strength,and shear strength as response values.The compression molding parameters of JPC were optimized.The results show that when the molding temperature is 185°C,the molding pressure is14MPa,and the pressure holding time is 11 minutes,the comprehensive mechanical properties of JPC are the best.Jute roving yarn and polypropylene yarn were used as raw materials to woven(Plain mesh fabric,PMF)and LMF.The PMF or LMF were used to combine with jute/polypropylene non-woven material(JPN),and the plain mesh fabric reinforced jute/polypropylene composite(PRJPC)and LRJPC were prepared.The tensile,flexural,impact and dynamic mechanical properties of composites were tested.The results show that LRJPC has better tensile properties,flexural properties and impact properties than PRJPC,which has potential applications in the field of automotive interiors.The effects of different grid sizes of LMF,different layers of JPN and different plied positions of LMF with JPN on the mechanical properties of LRJPC were studied.The results show that when the LMF grid size is 5mm×5mm,JPN is 8 layers,and the LMF is plied on the upper surface,the mechanical properties of LRJPC are the best.In that composite with the optimal parameters,the tensile strength is 43.09MPa,the flexural strength is 71.13MPa,and the impact strength is 61.64KJ/m~2.The finite element simulation software was used to research the effect of different plied positions of LMF with JPN on flexural property of LRJPC.The results show that the displacement-load curve obtained by the experimental test is extremely consistent with the curve obtained by simulation.In addition,when the LMF is on the upper,middle and lower positions,the relative errors of stress values between experiment and simulation by the finite element software are 4.03%,2.74%,and6.81%,respectively. |
