STUDY ON ELASTOPLASTIC FRICTIONAL CONTACT PROBLEM IN INTERFERENCE FITS OF COMPRESSORS

The FE parametric quadratic programming (PQP) method which was developed based on the parametric variational principle (PVP) was used for the analysis of stress distribution of 3-D elastoplastic frictional contact of impeller-shaft sleeve-shaft. A locomotive-type turbocharger compressor with 24 blades under combined centrifugal and interference-fit loading was considered in the numerical analysis. The solution of elastoplastic frictional contact problems belongs to the unspecified boundary problems where the interaction between two kinds of nonlinearities should occur. To save the time cost in the numerical computation, multi-substructure technique was adopted in the structural modeling. The effect of fit tolerance, wall thickness of shaft sleeve and rotational speed on the contact stress was discussed in detail in the numerical computation. To reduce the difficulty in the assembling process and make sure the safety of the working state, the amount of interference between the shaft sleeve and shaft by press-fitting should be controlled strictly to avoid the rapid increase of the contact stress. The numerical results show the high accuracy and good convergence of the algorithm presented here. The study plays a referenced role in deciding the proper fit tolerance and improving design and manufacturing technology of compressor impellers.