Internal synthesis of motion and the dynamic characteristics of external friction

Competition of modes and self-modulation instability in dynamics of coherent friction: A review

“…In the region of medium angles, the ratio t down /t roll is closer to unity, but is regularly less than unity. Unlike data of work [16], in the region of low inclination angles (tanα ~ 0.01-0.06), high dynamic friction occurs that is not related to surface contamination, defects, etc., since, in this region, the level of the AE signal is most stable and fairly high for reliable recording. We note that, in accordance with the usual rolling scheme, the value tan α s = 3.5μ = 3.5tanα cr corre sponds to the onset of contact slip (for balls).…”

“…This dependence also differs from conventional unit. Similar to work [16], the following two regions of low dynamic friction exist, i.e., one region at small (tanα ~ 0.1-0.2) and the other region at high angles α (tanα ~ 1-2). In the region of medium angles, the ratio t down /t roll is closer to unity, but is regularly less than unity.…”

“…The absence of a mechanical drive and the sin gleness of the friction contact as a whole make it pos sible to analyze coherent friction processes in the pure state and to study factors that affect their stability. The motion of rolling and sliding bodies over an inclined plane was considered in our earlier work [16]. In the context of equilibrium thermodynamics, there is no adequate explanation for the observed effects of abnormally low (negative) dynamic friction, but they agree fairly well with the autowave scheme of pulse and energy transfer.…”

“…For practical applications, the dependence of the force of friction on processes that develop both in a friction contact and in a tribosystem as a whole is the most essential conclusion that follows from this con sideration. As calculations carried out in [18] show, the difference of these results from data obtained in [16] is due to changes in the geometric dimensions of the motion plane.…”

“…The main mea surements were carried out with a bearing ball 13.5 mm in diameter used in our earlier work [16]. Rolling mainly occurred over the glass surface of a mirror 5 × 300 × 700 mm in size.…”