Research Of Numerical Simulation On Hydroforming Process For Automobile Rear Axle Housing

Facing the serious challenge of resource and environment, to promote low energy consumption, make vehicle weight down and protect the environment in the automotive industry is an important research topic needed to be urgently addressed. Last decade the technology of application of tube hydroforming process to product lightweight components of motor vehicles has been developed. Because of the complex shaped cross section of the automobile rear axle housing and a complex mechanical processing in combining with hydroforming, eventually the quality of parts not only with the pipe material properties are closely related, while the choice of load force, fluid pressure and the assemble of these processing parameters will have an impact on the quality of parts. Traditional method of trial and error has been unable to meet modern processing efficient, highquality production requirements. Method based on the theory of modern design and new product development is needed to research.This article use non-linear finite element method to simulate a certain model of automobile rear axle housing hydroforming process. The article analyzed the volume of process parameters of internal pressure and axial feed on the forming of the matching effect, given the stress, strain and thickness distribution of a successful tube bulging. And used the forming limit diagram (FLD) to analysis of the forming of the automobile rear axle housing. Simulated under different loading paths tube deformation results, and analysis of the specific reasons for defects, give a simple breakdown criterion, analysis of the characteristics of tangential corners'formation.The simulation results compared with the results of a typical experiment, after the first step in tube hydroforming, the diameter of the maximum expansion is 146.26mm, the error is 0.87%. the diameter of the middle bulging part is 131.68mm and the error is 1.7%. After the success hydroforming of the second step, the minimum shell thickness of the rear axle housing is 3.28mm, the error is 3.5% compared with the experimental results. These are all in allowed range and the results proved the modeling and simulation method is feasible.The results of this study have an important reference value to shorten the development cycle, reduce the development costs and improve product quality in the processing of hydroforming such as the rear axle housing.