In manufacturing operations, numerous parts and components are formed into different shapes by applying external forces to the workpiece, typically by means of various tools and dies. Common examples of such operations are forging, extruding, drawing and rolling. Forming operations may be carried out at room temperature or at elevated temperatures, and at a low or a high rate of deformation. These operations are also used in forming and shaping non-metallic materials such as plastics and ceramics. However, the processes of working of polymers in a solid state are affected by phenomena of plastic instabilities. These phenomena are interpreters on the basis of intrinsic law of behavior of the material which express the influence of the deformation and the rate of deformation on the plastic yield stress. This law directly reflects the structural modifications undergone by material under the conditions of the test. In addition, she gives the necessary information to the modeling of instabilities using techniques of calculation such as the finite element method.
Amorphous Polymer, Damage, Mechanical Behavior, Modeling
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