| The bellows in automotive exhaust system plays an important role in improving the sound and vibration characteristics of the system,which leads to the bello ws is more and more concerned by the technical researcher in the related field.Thus,this paper carries out the following jobs with the method of finite element and experiment taking the double-layer bellows provided by the bellows design and manufacturing company in Wuxi:(1)The finite element analysis structure of the bellows is established by UG and other tools with the influence of the inner and outer wire sets on the performance of the bellows being neglected,since the design of the bellows is based on the double-layer corrugated tube structure.(2)The static stiffness of bellows is studied with the software ANSYS-Workbench,and the results are compared with the results calculated by the theory of static stiffness in EJMA standard as well as the test results.Finally,the differences are found out.(3)Based on the theory of single-degree-of-freedom vibration system combined with the experiment,the damping coefficient of bellows is analyzed which lays a foundation for the transient dynamics and fatigue life analysis of bellows below.(4)In the way of finite element simulation together with the fatigue test of shearing,the S-N data points of bellows' full structure is established,and the S-N curve is fitted by least squares method.(5)The fatigue analysis of bellows is finished under the shearing load and random load of 6 DOF by the commercial fatigue analysis software nCode DesignLife with the former analysis is based on the static stress field of shearing simulated by HyperMesh/Nastran and the latter is the transient stress field of the random load of 6 DOF simulated by HyperMesh/Nastran.(6)On the premise of the equal damage of bellows under the initial load and edited load,the random load of 6 DOF is compressed into an acceleration load,and the rig tests is done under edited load,the difference between each other is found out by the comparison of test result and simulation data,for further,the optimization direction of the bellows is put forward.The results show that the above research can provide much theoretical and methodological guidance for the structural design and optimization of bellows,which could shorten the period of bellows design and has a certain value in engineering... |
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