ABSTRACT

CHAPTER 6

RATE-TYPE ELASTICITY

6.1. Elastic Moduli Tensors

The rate-type constitutive equation for nite deformation elasticity is ob-

tained by dierentiating Eq. (5.1.2) with respect to a time-like monotoni-

cally increasing parameter t. This gives

_

T

(n)

=

(n)

:

_

E

(n)

;

(n)

=

@

E

(n)

@E

(n)

@E

(n)

: (6.1.1)

The fourth-order tensor

(n)

is the tensor of elastic moduli (or tensor of

elasticities) associated with a conjugate pair of material tensors

E

(n)

;T

(n)

.

Its representation in an orthonormal basis in the undeformed conguration

is