2 Reformulate the free energy functions W(λ1, λ2, λ3) for the Neo-Hookean, MooneyRivlin, and Fung materials in Table 1 in terms of the invariants of b as W(Ib 1 , I b 2 , I b 3). Remember that for an incompressible material, J = 1, and thus λ3 = 1/(λ1λ2). 3 For the free energy functions W(Ib 1 , I b 2 , I b 3) of the Neo-Hookean, Mooney-Rivlin, and Fung materials (from 2), calculate the derivat...
