224 The Elastic Solid
(a)
(b)the strain energy function U is given by
Solution, (a) Since for linearly elastic solid 7/j = C,^/£^, therefore
therefore,
(b) From
we have
i.e.,
Changing the dummy indices, we obtain
But, CMIJ = Cijffi, therefore
Adding Eqs. (v) and (vii), we obtain