Analysis and experiment of the optimum shrink range between chain plate and bush for agricultural machinery chain by using finite element method

Selecting suitably the shrink range between chain plate and bush can effectively decrease the stress and the factor of stress concentration, and increase the fatigue strength of chain. But the traditional method is unfitted for the non-axisymmetric structure of chain plate. A finite element method(FEM) model was set up based on the condition of equivalence on the fitted surface. Then a program is put forward by simulating the shrink range from the continuous displacement on the fitted surface. It is confirmed that the program has a high reliability and degree of accuracy by means of comparing the calculated results with the theoretical stress pattern of thick shell cylinder. The results of the FEM analysis and the fatigue test for Type 16A chain all indicate that the stress scope reduces with the shrink range increasing. The optimum shrink range value could be obtained when the shrink range increases while the stress remains unchanged. The reasonable shrink range should be within the certain range just beyond the optimum shrink point. It is obtained that the reasonable shrink range for Type 16A chain is from 0.06 mm to 0.08 mm. The fatigue strength at this value increases by 40% to 50% compared with that of no shrink range.