Strength and deformation of rigid polymers: the stress-strain curve in amorphous PMMA
Date
2003
Authors
Stachurski, Zbigniew
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Poly(methyl methacrylate) (PMMA) is used to model the relaxation and plastic flow mechanisms of deformation, and the characteristic stress-strain response, relating it to its structure as much as it is known. The scope of this work is to identify and quantify the micromechanisms and the corresponding stress-strain relationships, and to assemble these into a coherent and self-consistent model for the observed mechanical behaviour. Detailed relationship between relaxation strength and time constants has been derived for some of the secondary motions. It is proposed that plastic events occur when the tension in chain segments pulls the chains out of/through constriction points. The scheme for simulating the isothermal true stress-strain curve is carried out under the following limitations: (i) geometrical effects, such as elastic instability and necking, (ii) thermodynamic adiabatic effects, and (iii) structural and kinetic effects, such as may arise from quenching or annealing, are neglected. Qualitative agreement achieved here is considered satisfactory in view of the simplicity of the model and only a few adjustable parameters.
Description
Keywords
Keywords: Amorphous materials; Isotherms; Plastic deformation; Plastic flow; Reaction kinetics; Strain; Stress analysis; Micromechanisms; Polymethyl methacrylates; poly(methyl methacrylate); polymer; deformation; polymethyl methacrylate; stress-strain analysis; art Anelasticity; Mechanical model; Plasticity
Citation
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Source
Polymer
Type
Journal article