Stress Analysis And Structure Optimization Of Exhaust Manifold Catalytic Converter

Because of the complex structures and poor working environment of catalytic converter, it will cost a lot of time, manpower and financial resources through experiments to understand the flow characteristics, thermal deformation conditions and stamping forming problems. With the development of CAE technology, testing effort and the design cycle can be reduced greatly, besides it can provide structural optimization foundation for product design.The article establish a finite element analysis model for the 4G16-type catalytic converter, the flow field analysis, thermal stress analysis, and punching analysis are done for the model, based on the results of the CAE analysis, some optimization have been done for the model.Firstly, the flow analysis model is established, based on the theory of fluid dynamics, the steady state and transient analysis have been done for the manifold, make sure the structure is reasonable according to the results.Secondly, base on one type of exhaust manifold, establish the finite element analytical model, using the method of solid-fluid coupling analysis of the calculated and work out heat transfer boundary conditions, through the heat transfer analysis the temperature field of the exhaust manifold can be got and carry out thermal stress analysis under the temperature field. The thermal-stress distribute status can be got about this type exhaust manifold, give structure optimization and the revision amendments to stress concentration and stress on the largest point to avoid effectively structural damage caused by the stress concentration.Finally, the further stamping analysis have been done for the manifold, the shape of the manifold shell is irregular and complex, the phenomena such as crack, wrinkle and so on may emerge, besides the stress distribution of the pressing is analyzed to ensure it away from the material yield limit. Sheet Metal Forming CAE analysis can predict all sorts of possible defects for sheet metal forming, .analyze the causes of defects, in order to improve quality of stamping parts, short the development cycle and reduce the costs.Though the comprehensive CAE analysis for the manifold structure, including flow analysis, thermal stress analysis and stamping analysis, the main reasons have been found for the manifold cracks, at the same time combined with finite element analysis, the optimization has been done for the manifold structure to reduce the stress of structural cracks, the crack problem of the manifold structure has been solved on theory, provides the theoretical basis for the further test analysis. Besides through the paper, a comprehensive and effective finite element method has been formed for the manifold , saving the manifold development cycle.