Design And Fabrication Of Carbon Fiber Reinforced Plastic Semi-trailer Axle Based On Bending Stiffness

Semi-trailer is the main force of motor transport,and bear more than 85%of the cargo in the entire motor transport.For the semi-trailer,the weight of the axle accounted for more than one third of the weight of the semi-trailer.Reducing the quality of the axle can not only increase the smoothness of the vehicle,but also can reduce the weight of the semi-trailer and improve revenue.Carbon fiber reinforced plastic?CFRP?is a carbon fiber reinforced,resin-based composite material.Compared with the metal materials,the density of CFRP is about1/5 of steel,1/2 of aluminum alloy.However,its specific strength is 3-8 times than the two metal materials,and the specific stiffness is 2-3 times.In addition,it is easy to design.In recent years,aerospace,rail transportation and automotive are widely use of CFRP.Therefore,in order to achieve the effect of weight loss and the better strength and stiffness performance,it is possible to design semi-trailer axle with CFRP.The semi-trailer axle is a non-drive shaft,which is mainly subjected to the vertical load,and its main deformation is bending deformation.Therefore,it is very important to study the bending performance of semi-trailer axle.In this paper,theoretical analysis,finite element simulation analysis and test were studied in turn.Through the above three methods,the semi-trailer metal axle and the CFRP semi-trailer axle are analyzed respectively.This article applies three-dimensional mapping in the semi-trailer metal axle using PowerScan-Pro 2.0M three-dimensional scanner.And the three-dimensional model of the metal axle was established using UG software.According to the load condition of the metal axle,the deflection curve formula of the metal axle is obtained.And the maximum deformation of the metal axle calculated under the rated load is1.53mm/m.The three-dimensional model of the metal axle is imported into the Abaqus for simulation analysis,and the simulation results of the maximum deformation under the rated load is 1.34mm/m.The semi-trailer metal axle samples were tested on the bench,and the maximum deformation of the three samples under the rated load was 1.97mm/m,1.67mm/m and 1.80mm/m respectively.The result of the bench test are larger than those of the theoretical calculation.On the one hand,there is a test error.On the other hand,the variable cross section of the metal axle is simplified in the theoretical analysis,resulting in the bending stiffness of metal axle is too large in the theoretical calculation,so the deformation of the theoretical calculation result is too small compared with the test results.Finally,the equivalent bending stiffness of the semi-trailer metal axle sample at the variable cross section is calculated using the test results.In this paper,CFRP semi-trailer axle is made of CFRP square-section tube and metal parts.Based on the bending stiffness analysis of the CFRP square-section tube,the laying scheme of the CFRP square-section tube was determined as{[0°]₄±15°[0°]₄[90°]₂}₁₁.And the maximum deformation of the CFRP semi-trailer axle calculated under the rated load is 2.16mm/m.Secondly,the three-dimensional model of the CFRP semi-trailer axle is established,and the stiffness of the CFRP semi-trailer axle was obtained by simulation using Abaqus.The simulation result is1.51mm/m,and the error is 30.1%compared with the theoretical calculation value.In the simulation analysis,the equivalent stiffness of the variable cross section will be greater than the equivalent stiffness of the variable cross section used in the theoretical calculation,so the result of the simulation analysis will be less than the theoretical calculation result.Finally,the sample of the CFRP semi-trailer axle was prepared by bag moulding process and bonding process.The weight of the CFRP semi-trailer axle sample is 83.7kg,which is 23.2%lighter than the semi-trailer metal axle.Test showed that the stiffness of the sample was 2.85mm/m,and the error is30.9%compared with the theoretical calculation value.On the one hand,there is a test error.On the other hand,CFRP square-section tube has a serious stratification phenomenon in the molding process,resulting in the bending stiffness of the CFRP semi-trailer axle is small than the theoretical calculation value.Therefore,the deformation of the CFRP semi-trailer axle is too large.