Tensile behaviour of polymers

The elastic modulus is the slope of the tangent at the origin of the stress/strain curve. The tensile or compression modulus is often called Young s modulus whereas the torsion modulus is often called shear modulus or Coulomb s modulus. 

The yield point is the first point of the stress/strain curve for which there is an increase in the strain without an increase in the stress. Parts must always operate well below this point during service. 

Stress and strain at yield are the values of the stress and strain corresponding to the yield point. 

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For the investigation of the time and the temperature dependence of the fibre strength it is necessary to have a theoretical description of the viscoelastic tensile behaviour of polymer fibres. Baltussen has shown that the yielding phenomenon, the viscoelastic and the plastic creep of a polymer fibre, can be described by the Eyring reduced time (ERT) model [10]. The shear deformation of a domain brings about a mutual displacement of adjacent chains, the... 

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