Comparison of measured and empirically predicted creep of reinforced polyphthalamide

The long-term creep properties of a commercial thermoplastic resin system were determined at test temperatures of 23 degrees C, 100 degrees C, and 150 degrees C. In addition, the applicability of using short-term stress relaxation test (SRT) results to predict long-term creep behavior was investigated. Creep strain and strain rate were empirically predicted from the SRT and quantitatively compared to measured values at two applied stresses for each test temperature. The SRT method predictions correlated well with measured creep curves at temperatures below the glass transition and in the secondary creep region. Poor correlations in other regimes are a primary result of differences in the initial deformation. (C) 1999 Elsevier Science Ltd. All rights reserved.