Ice in which deformation processes are actively occurring; hence the ice is a potential impediment or danger to ship ping.
Related Terms 
PLASTICOVISCOSITY
Plasticity in which the rate of deformation of a body subjected to stresses greater than the yield stress is a linear function of the stress.

PLASTIC COLLISION
A collision in which one or both of the colliding bodies suffers plastic deformation and mechanical energy is dissipated.

PERMANENT SET
Permanent plastic deformation of a structure or a test piece after removal of the applied load. Also known as set.

MUSKHELISHVILI'S METHOD
A method of solving problems concerning the elastic deformation of a planar body that involves using methods from the theory of functions of a complex variable to calculate analytic functions which determine the plane strain of the body.

MOIRE INTERFEROMETRY
An optical technique that measures the components of deformation of a specimen surface in the plane of the surface by superposing a reference grating and a diffraction grating that is applied to, and deforms with, the surface.

MODULUS OF ELASTICITY IN SHEAR
A measure of a material's resistance to shearing stress, equal to the shearing stress divided by the resultant angle of deformation expressed in radians. Also known as coefficient of rigidity; modulus of rigidity; rigidity modulus; shear modulus.

MAGNETOSTRICTIVE LOUDSPEAKER
[ENG ACOUS] Loudspeaker in which the mechanical forces result from the deformation of a material having magnetostrictive properties.

KELVIN BODY
An ideal body whose shearing (tangential) stress is the sum of a term proportional to its deformation and a term proportional to the rate of change of its deformation with time. Also known as Voigt body.

INELASTIC
Not capable of sustaining a deformation without permanent change in size or shape.

HOOKEAN DEFORMATION
Deformation of a substance which is proportional to the force applied to it.
