Evaluation of viscoelastic characteristics of polymer by using indentation method

Five-step indentation test is used to evaluate viscoelastic characteristic of acrylonitrile butadiene styrene resin, ABS resin. Five-step indentation test consists of two indentation cycles and the creep compliance is evaluated from the second indentation cycle, because the measured penetration depth in second cycle is unaffected by plastic deformation. The creep compliance is evaluated by the indentation theory for an axisymmetric conical indenter and elastic-viscoelastic correspondence principle. Furthermore, in order to evaluate the creep compliance, FEM is used to analyze the indentation problem, in which the conical indenter is impressed on an impression. The results show that creep compliance evaluated by FEM are comparable to that by tensile test. This result means that the creep compliance of polymer can be evaluated by 5-step indentation test.