Mooney-Rivlin solid
= Mooney-Rivlin solid
{c}
{wiki=Mooney–Rivlin_solid}
An incompressible <Mooney-Rivlin solid> has <strain energy density> $W=C_1(I_1-3)+C_2(I_2-3)$, with <right Cauchy-Green deformation tensor> $C=F^TF$, $I_1=\operatorname{tr}C$ and $I_2=\operatorname{tr}C^{-1}$ when $\det C=1$. It extends the <neo-Hookean solid> by a second invariant. A convention $W=\mu_1(I_1-3)/2-\mu_2(I_2-3)/2$ means $C_1=\mu_1/2$, $C_2=-\mu_2/2$; the minus sign must be retained when comparing material constants.