Optimization Design And Experimental Study Of Blue Brand Commercial Vehicle Composite Front Plate Spring

With the development of social economy,energy and environmental issues have been paid more and more attention.Meanwhile,relevant national regulations have been implemented,and automotive lightweight technology can not only reduce weight,but also improve fuel economy and reduce environmental pollution.Therefore,automotive lightweight technology develops rapidly in recent years.At present,the newly published regulations of blue brand light trucks generally exceed the limit of 200 kg,resulting in difficulties in new car registration and annual vehicle inspection.Therefore,this paper chooses blue brand light trucks as the research object.The leaf spring is an important part of the suspension system,accounting for about 30%-40% of the unsprung mass,and the weight reduction space is obvious.Therefore,this paper takes the leaf spring of blue brand light truck as the research object,uses glass fiber composite material as the raw material to design the composite leaf spring to realize the equivalent replacement of leaf spring,and optimizes it on the basis of traditional design.Specific research work has the following parts:According to the technical parameters of the leaf spring of the target vehicle type,the preliminary structure of the composite leaf spring was determined.By comparing different joint structures,the spring body was connected to the joint by means of mechanical connection and cementation,and finally a three-dimensional solid model of the composite leaf spring was established.By comparing the mechanical properties of various composite materials,it is determined that the raw material for the spring design is E glass fiber/epoxy resin,and the mechanical properties parameters of laminates are obtained through the mechanical properties test,which provides data sources for material parameters acquisition in CAE analysis.A fine modeling method of composite plate spring is proposed.In the cosimulation of Hypermesh and Abaqus,the concrete flow of simulation design of composite plate spring is described in detail.Based on this model,several layering schemes are compared and analyzed,and finally the layering design scheme with the ratio of 0° to 45° is adopted.By comparing the processing technology of four kinds of composite plate springs,the molding process is selected for trial production of the sample.The test results show that the stiffness of the composite spring is 146N/mm,and the design error is 2.6% or less than 5%,which is within the allowable range of error.The simulation value is compared with the experimental value,and the error is 3.08%,which verifies the accuracy of the model.The fatigue life reaches 30 W times,the same life as the car,and no fatigue failure occurs.An optimization model suitable for the design of composite plate springs is established.The secondary development of Abaqus based on Python language realized the automation of the simulation process of composite spring,and combined with Isight software to extract the optimization parameters of the simulation script,realizing the continuous iteration of the layup parameters.At the same time,multi-island genetic algorithm is used to optimize the composite plate spring,taking the layup length,layup Angle and total thickness as design variables,stiffness and strength as constraints,and minimum spring body mass as design objectives.After optimization,the weight of the spring is reduced by 23.4%,and the stiffness and strength of the spring meet the design requirements.