ABSTRACT

CHAPTER 2

KINEMATICS OF DEFORMATION

2.1. Material and Spatial Description of Motion

The locations of material points of a three-dimensional body in its initial,

undeformed conguration are specied by vectors X. Their locations in

deformed conguration at time t are specied by vectors x, such that

x = x(X; t): (2.1.1)

The one-to-one deformation mapping from X to x is assumed to be twice

continuously dierentiable. The components of X are the material coordi-

nates of the particle, while those of x are the spatial coordinates. They can

be referred to the same or dierent bases. For example, if the orthonormal

base vectors in the undeformed conguration are e

J

, and those in the de-

formed conguration are e

i

, then X = X

J

e

J

and x = x

i

e

i

. Often, the same

basis is used for both congurations (common frame).