posted December 11, 2000 07:56 PM           

Relationship between the circumferential and meridional strains of a tyre sidewall and the stress-strain state of the rubber between the cord strands.

A pneumatic tyre is a complex rubber-cord construction. The prediction of its behaviour in service on the

basis of standard tests of simple specimens under laboratory conditions does not make it possible With sulficient accuracy to indicate where the stress state is critical or to estimate the mileage before failure. The reason for this is the discrepancy between the loading conditions of the testpieces (uniaxial elongation of the rubber, pulling out of a cord strand from the rubber mass, etc.) and the loading of a real product, where the rubber-cord parts of the tyre operate under conditions of a complex stress-strain state that does not reduce to cases of simple loading of standard specimens.

In a number of studies an examination has been made of the behaviour of composites whose structure is similar to the structure of the rubber-cord carcass and breaker plies of tyres. However, the mechanical properties of such systems have been described for small strains in an approximation of Hooke's law.

Kauchuk i Rezina, 1997, 4, 3

Int. Polym. Sci. & Technol., 1998, 25[7]

4 diag.