Crack initiation and propagation in circular rubber bearings subjected to cyclic compression

Abstract

ABSTRACT:The fatigue failure mechanism of rubber bearings under cyclic compression is important in evaluating their fatigue lives and thus is analyzed theoretically and numerically here. At first, the stress distributions in a bonded rubber cylinder derived from three different existing models were utilized to calculate the cracking energy densities within it. Next, the location of fatigue crack initiation and the direction of subsequent crack propagation in circular rubber bearings were consecutively determined. Furthermore, finite element numerical results were compared to those obtained theoretically from the three models to check their validity in predicting the fatigue crack initiation and propagation in circular rubber bearings. Based on the quasi-statically theoretical and numerical results, it is found that the fatigue cracks initiate first at the outermost boundary between rubber and steel plates and propagate later inwards to the center of circular rubber bearings. The corresponding fatigue failure mechanism obtained theoretically and numerically is consistent with experimental findings reported previously.

Fatigue life prediction for circular rubber bearings subjected to cyclic compression

“…The fatigue crack in bonded rubber cylinders thus initiates at the point with the maximum cracking energy density, and then propagates along the direction with the lowest cracking energy density. On the basis of Horton's theory, the curves which describe the crack initiation and propagation in bonded rubber cylinders with various shape factors under cyclic compression were determined, and these were also consistent with the experimental observations and the simulations of quasi‐static finite element numerical analyses 19. It is found that the fatigue cracks initiate at the outermost boundary ( r/R = 1) between rubber and steel plates and propagate inward to the center of circular rubber bearings.…”

“…To calculate the fatigue lives of circular rubber bearings, Chou and Huang 19 proposed a fatigue failure mechanism using a quasi statically numerical methods with three assumptions. First, intrinsic flaws with a uniform size distribute randomly in rubber.…”

“…On the basis of Horton's theory, the curves which describe the crack initiation and propagation in bonded rubber cylinders with various shape factors under cyclic compression were determined, and these were also consistent with the experimental observations and the simulations of quasi-static finite element numerical analyses. 19 It is found that the fatigue cracks initiate at the outermost boundary (r/R ¼ 1) between rubber and steel plates and propagate inward to the center of circular rubber bearings. Figure 3 shows the normalized curves of crack propagation in bonded rubber cylinders with different shape factors of S ¼ 0.1, 1.0, 2.5, and 10, respectively, derived numerically from Horton's approach.…”

“…Consequently, the fatigue crack initiates at the point with maximum cracking energy density from the accumulation of intrinsic flaws in rubber, subsequently propagates along a direction perpendicular to the maximum tensile principal stress. In the paper, we aim to theoretically estimate the fatigue life of circular rubber bearings under cyclic compression, based on the results of crack initiation and propagation obtained by quasi‐static analysis 19. First, the energy release rate which depends on the cracking energy density and crack length in bonded rubber cylinders under quasi‐static compression is calculated.…”

“…In the paper, we aim to theoretically estimate the fatigue life of circular rubber bearings under cyclic compression, based on the results of crack initiation and propagation obtained by quasi-static analysis. 19 First, the energy release rate which depends on the cracking energy density and crack length in bonded rubber cylinders under quasi-static compression is calculated. Then, their fatigue behaviors, such as crack growth rate and fatigue life, are determined.…”