We formulate an efficient numerical algorithm based on finite-difference ap
proximations and inspired by algorithms from gas dynamics to treat the quas
ilinear wave equation
w(11) = [alpha (w(x)(2) + w(y)(2))w(x)](x) + [alpha (w(x)(2) + w(y)(2))w(y)
](y).
governing antiplane motions of incompressible, isotropic nonlinearly elasti
c bodies in two-dimensions. In particular, we are concerned with the treatm
ent of focusing and shocks for bodies whose material response differs marke
dly from that of linear elasticity. We carefully validate our method by com
paring our results with those of the axisymmetric version of this equation
in polar coordinates. (C) 2001 Academic Press.