In situ and real-time optical investigation of junction growth in spherical elastic–plastic contact

Elastic–Plastic Spherical Contact Modeling Including Roughness Effects

“…On the other hand, if P* is much larger than P t * , the contribution of the asperities can be neglected. A similar roughness effect on static friction coefficient and junction growth of a rough spherical contact was recently observed experimentally by Ovcharenko et al [15,16], and predicted theoretically by Cohen et al [9]. In all these studies, the effect of surface roughness was found to diminish with an increase in the normal load above a threshold value.…”

Unloading of an elastic–plastic spherical contact under stick contact condition

“…perfect slip contact condition). This assumption may be invalid in dry contact of dissimilar materials as was shown experimentally by McGuiggan (2008) and more recently by Ovcharenko et al (2008). Brizmer et al (2006a) studied the effect of full stick contact condition on the elasticity terminus of a spherical contact and found increasing differences compared to the case of perfect slip condition at decreasing Poisson's ratios.…”

The Effect of Dwell Time on the Static Friction in Creeping Elastic–Plastic Polymer Spherical Contact

“…At the same time, stress relaxation reduces the maximum stress in the material, and in cases where P was larger than L c , the plastic zone shrinks or may even vanish completely making the contact elastic. Finally, when the tangential load is applied in step III and increased to the point of sliding inception, it results in additional interference increase along with junction growth and reappearing plastic zone [18][19][20]. At sliding inception, the interference and the contact area reach their maximum values x max and A max ; respectively.…”

“…The tangential loading described in [18] caused an increase in the initial contact area produced by the normal preload alone. The mechanism of this phenomenon, which was termed ''junction growth'' by Tabor in 1959 [15], was recently explained theoretically in a model by Brizmer et al [19] and validated by the experiments of Ovcharenko et al [20]. The model described in [18] was developed for noncreeping materials ignoring creep and stress relaxation effects.…”