CREEP COMPLIANCE OF VISCOELASTIC MATERIALS AT CONSTANT TEPERATURE

Abstract

Experiments were carried out to investigate the separate roles of the hydrostatic and deviatoric components of stress tensor (using the first and the second invariant  and The results were expressed in term of stress dependent shear compliance  in the time temperature region of the tests (up to seconds at  of the Relaxation).

was found to increase in magnitude with increasing both hydrostatic and deviatoric  components of stress.  caused a shift in the magnitude of  and  caused an increase in  with time. The difference between the shear compliance in creep and recovery was found to decrease with  and increase with .

All the different effects mentioned above could be rationalized by the idea of the time dependent free volume. If the free volume increases with time by increasing  this could explain the difference in the effect of   and on  and explain why creep is less than recovery