Abstract
A stress-strain relation, f={G-B(1-1/α)+C(αα2-1)}(α-1/αα2), was used to analyse the large deformation behavior of styrene-butadiene rubber (SBR) with various concentrations of oil ranging from 0 to 40 PHR. In the above relation, f denotes nominal stress at extension ratio α, G corresponds to rigidity, B and C are coefficients. The theoretical character of this relation will be discussed in another paper5) by one of the authors. The present results can be summarized as follows; The value of G is proportional to the crosslink density νe, but larger than those calculated from νekT. The value of B is almost unaffected by νe and shows almost same tendencies as G against oil concentration υ1 and strain rate ε. The value of C is about 1/100 of those of G and B, and had the maximum against νe and ε.
