Title:
Anchoring of Bearings by Friction
Author(s):
lngo Schrage
Publication:
Symposium Paper
Volume:
70
Issue:
Appears on pages(s):
197-215
Keywords:
anchorage (structural); bearings; friction; loads (forces); rubber; strains.
DOI:
10.14359/17410
Date:
1/1/1981
Abstract:
A review of slip resistance values is given for the interaction between several materials common in bearings for civil engineering. Friction between rubber and concrete is emphazised. Recent test results on bearing pads (plain rubber-bearings) and on specimens representing the outer layer of laminated bearings (reinforced rubber-bearings) are communicated. Those tests have been initiated in order to verify the assumption, that non-anchored rubber-bearings are appropriate to transfer short term tangential life loads without slip. Reinforced bearings follow some essentials of Coulomb's friction laws. As for friction coefficient vs. normal stress and vs. slip velocity rubber behaves unlike rigid solids. From the engineering point of view these statements are also good for bearing pads within the investigated range, though there are fundamental differences between those two kinds of bearing as far as response to lateral forces is concerned. There are only few national codes of practice for the "anchoring" of non-anchored rubber-bearings by the effects of friction. Among them the nowadays building regulations in Germany may serve as an approach to this aim. Nevertheless these regulations might become less restrict with regard to reinforced bearings on concrete, whereas frictional attachement of rubber to other materials should be handled with caution. Plain bearings need a new formulation of the slip criterion. Influences by the strain rate and by ambient temperature should be taken into account too.