A note on the determination of relaxation and creep data from ramp tests

The response of(linearly) viscoelastic material is approximately the same f or ramp and true step strain histories once an initial time interval of abo ut ten times the ramp-up time has passed. Because the loss of relaxation da ta during that initial time can be a substantial portion of the total (loga rithmically measured) time scale, a simple method is documented for exploit ing data obtained from the initial ramp history via a recursion formula. Co mparison of data obtained in ramp and relaxation histories are demonstrated to yield good results within the accuracy of the test method.