Prediction of stress distribution in press-fit process of interference fit with a new theoretical model

Abstract

Interference fit is widely used in many industrial fields for its high ability to transmit an axial force or torque between a shaft and hub. But the performance of interference fits during their life in service is limited by stress concentrations and surface wear. Nowadays, theoretical methods based on thick-walled cylinder theory become increasingly abundant. However, the prediction results of stress distribution in press-fit process are not accurate for ignoring the stress concentrations. Since the stress distribution is significant for analysis of surface wear and assembly quality, especially for precision assembly of small parts, the purpose of this study is to build a new theoretical model to predict the stress distribution. The stress distribution equation was deduced based on a simplified model that a nonuniform linear load acts on a portion of semi-infinite plane. Finally, the stress distribution in the press-fit process was analyzed by the theoretical model, as well as the stress distribution of different material pairs (Ni36CrTiAl–50Ni-50Fe, AISI 1045–AISI 1045) under full contact condition. The comparison between theoretical and numerical results shows that the new theoretical model has high accuracy in predicting stress distribution and maximum stress, and the relative error is less than 17%. Therefore, the new theoretical model can give more reasonable results and provide a more reliable approach for design of interference fits. Furthermore, the model provides a method for the optimization of interference analysis under different structures and working conditions, and gives a theoretical basis for real-time estimation of assembly quality.

Multiobjective Intelligent Cooperative Design for the Multilayer Interference Fit

“…Taking the Kriging model as the prediction method of the response surface, comparing with NSGA-II, MOSA, and MOPSO, NSGA-II is proved to be the optimal algorithm for multilayer interference fit design. Mathematical Problems in Engineering (iii) Using the equivalent stress as the evaluation index of the stress concentration problem, the design defects due to stress concentration in traditional design can be avoided [7]. Comparing finite element analysis and mechanical calculation, the maximum equivalent stress on the shrink disk is less than the yield strength of the material, and at the same time, the transmission torque is increased and the weight is reduced, ultimately the optimization goal of the MOICD method is achieved.…”

“…Strozzi et al [1] addressed the stress concentrations developed from the static press-fit of the shaft-hub interference fit, and various design charts have been compiled that report the elastic stress concentrations within the hub versus the proposed normalizing parameter, including fillet radius, shaft radius, and interference. Wang et al [7] deduced the stress distribution equation of the interference fit based on the stress concentration problem, and a new theoretical model of stress distribution prediction was established. Most of the above research was aimed at single-layer interference fit, but with the actual needs of engineering, many use double or multilayer interference fit structure to achieve load transfer.…”

“…According to the main causes of the interference fit failure such as insufficient load transfer and the maximum equivalent stress exceeding the material yield limit [7], the multiobjective model of the shrink disk first meets the requirements of torque and yield strength, and then meets the minimum mass. e mathematical expression of the multiobjective model is as follows:…”

Increasing the strength of fixed units of wheeled and tracked machines through the use of cylindrical fits with contour connection of parts

“…Решение данных задач можно выполнить с использованием неподвижных цилиндрических посадок с контурным соединением деталей [3][4][5][6][7].…”

Investigation of insert-hole interference fit influence on downhole drilling bit failure

“…A quantitative analysis of the insertion force history, non-uniform hole expansion, protuberance and residual stresses of the interference fit was presented. 10 A new theoretical model to predict the stress distribution in interference fits was proposed by Wang et al 11 In this simplified model, it was assumed that the problem was plane strain and a non-uniform linear load acted on a semi-infinite plane. Stress distributions of different material pairs under full contact conditions were also analyzed.…”