Research On Lightweight,Vibration And Noise Reduction Of Automotive Based On CFRP Composites

Driven by a series of national policies to reduce energy consumption and low carbon environmental protection,many automotive companies expect to achieve the goal of energy saving and emission reduction from the field of vehicle light-weighting.Carbon Fiber Reinforced Plastic(CFRP),because of their excellent mechanical properties such as low density,high specific strength and elastic modulus,has become one of the research hotspots of automotive light-weighting materials.At the same time,consumers are increasingly demanding the comfort of automobiles,which is most affected by the car's NVH(Noise,Vibration,Harshness)ability.So,this paper focused on the design and experimental problems faced by CFRP when it applied in the field of vehicle light-weighting and vibration and noise reduction,takes a commercial vehicle cab as an example and combines with the theory of phonon crystal band gap characteristics,to explore the characteristics and rules of composite materials based on CFRP in the application field of light-weighting and vibration and noise combination.The main contents are as follows:(1)Firstly,the mechanical properties of CFRP are tested,including tensile test,shear test to obtain the elastic modulus,shear modulus and poisson ratio of CFRP.Secondly,the finite element modal analysis of CFRP plate is carried out by using the experimental data.Finally,the modal test of CFRP plate is carried out to verify the correctness of the mechanical properties parameters of CFRP.The results show that the maximum deviation between simulation and experiment is less than 6%.Considering the effect of sensor mass on modal testing,which verifies the correctness of the mechanical properties of CFRP.(2)Taking the cab of commercial vehicle as the research object,the CAE modeling and simulation of the body in white are carried out,and then combined with CFRP for light-weighting design and optimization.The simulation results show that the overall weight of the cab model decreases from 336.6 kg to 298.7 kg,and the weight loss is 37.9 kg,with a decrease of 11.3%.In addition,the dynamic mechanical properties of the cab are effectively improved,and also the first-order mode frequency is increased by 27.3%.(3)Testing the acoustic performance parameters of CFRP.Using the calculation method of absorption coefficient in engineering application field,it is concluded that the absorption coefficient of CFRP is less than 0.2 in the frequency range of 0~1000Hz,which belongs to low sound absorption material.(4)Based on the theory of phononic crystal band gap,the frequency response characteristic curve of phononic crystal plate is obtained by finite element method,aiming at the shortage of sound absorption performance of CFRP itself.On this basis,the related factors affecting the band gap of phononic crystal plate are studied.The simulation results show that the type II phononic crystal plate,in the medium and high frequency range,has good performance in reducing vibration and noise.In this paper,the innovative combination of CFRP and phononic crystals is applied to the research of vehicle light-weighting and vibration and noise reduction,which provides guidance and reference for the follow-up research based on CFRP and applied in the automotive field.