Finite Element Simulation And Experimental Research On Stiffness Character Of Diaphragm Air Spring Used On Some Heavy Truck

With the rapid development of high way and constant improvement in vehicleperformance, People put forward for vehicle lightweight and fast pace andcomfortable personalized requirements. Air-spring suspension has light weights,variable stiffness properties, low natural frequency, adjustable in height and gooddamping performance, etc. it can greatly improve the ride comfort andcomfortableness used in vehicles. Air spring is the core component in air thesuspension, its stiffness is the key parameter of matching suspension system andvehicle for good vehicle performance.In this paper, diaphragm air spring which installed on the rear suspension ofsome heavy truck is studied to obtain the stiffness of this air spring with graphicalmethod based on assumptions, test method and finite element method, and analysis theinfluence factors on the stiffness through the simulation. The main contents are listedas follows:(1) Introduce the working principle, structure, type and characteristics of the airsprings. The formula of calculating the vertical stiffness of air springs derived isbased on the engineering thermodynamics, and particular analysis the influencefactors on the stiffness of air springs.(2) Based on the assumption of the longitude line length and the outside diameterof rubber to remain the same, the simplified model is gained according to the structureshape parameters of air spring. The mathematics calculation formula of the effectivearea and its rate, the effective volume and its rate are obtained through the geometricrelationship of this model, and the analytical solution to the stiffness of air spring isobtained by generating them into the formulas, then the results were analyzed.(3) According to national standard GB/T130361-911in the spring characteristic,the air spring is tested for getting its static stiffness, and the test results were analyzed,while compared the analytical solution of the air spring are with the experimentalresults.(4) Analysis of the air spring the key technique in the finite element simulation,involving material nonlinearity, geometric nonlinearity and contact nonlinearity andso on, it is a multiple nonlinear problem. The theory and solution to this problem infinite element analysis software ABAQUS is given, then the finite element model ofair spring is built based on it. (5)Through the finite element simulation of the air spring to analysis its verticalstiffness, and compared the simulation results with the experiment to verify theaccuracy of the finite element model. Based on this verified models, the law of impacton the stiffness character of air spring caused by different initial pressure,differentcord parameters and different piston shape are studied, it provide certain theoreticalbasis on the design and match of air spring.