ON THE REALIZATION OF GHM MODELS IN VISCOELASTICITY

A useful method of modeling viscoelastic effects in structures for tra nsient response analysis is to treat the frequency dependence of the u sual damping model through the introduction of extra dissipation co-or dinates. These new co-ordinates require a curve fit to loss factor dat a over a range of frequencies. One such method called the Golla-Hughes McTavish method, or GHM method, is examined here. The standard GHM ap proach has only three parameters per second order term in the approxim ation to the material properties, whereas the four parameters used in this paper gives the most general curve fit. Thus, for the same number of extra degrees of freedom, more accurate predictions from a finite element model with viscoelastic components is possible. This paper als o reformulates the series used in the GHM modeling in terms of the hig h Frequency stiffness, rather than the standard low frequency stiffnes s.