COMPARISON OF VISCOELASTIC MODELS IN SIMULATING THE TRANSIENT-RESPONSE OF A SLEWING POLYMER ARM

In this paper, we analyze the transient behavior of a polymethylmethac rylate (PMMA) slewing beam. Experimental data shows that the Young's m odulus of PMMA varies considerably between 0 and 50 Hz. For accurate s imulation, this variation must be modeled. Traditional stress-strain m odels such as the Voigt-Kelvin and the standard linear solid models ar e examined and shown to have only limited abilities. Models involving fractional derivatives, which are derivatives of an order between 0 an d 1, give better results. An integration algorithm based on the Newmar k family is described to compute the dynamic equations,with a function al derivative.