Internal friction 4 Mechanical testing 4 Strain 4 Strain rate 4 Stresses 4 Thermal effects 4 Activation volume 2 Amplitude dependent dynamical behavior 2 Damping 2 Dynamic mechanical behavior 2 Dynamic mechanical testing 2 Dynamics 2 Effective stress 2 Elastic moduli 2 Hyperbolic sine stress 2 Hyperbolic sine stress dependence 2 Loss factor 2 Loss tangent 2 Mechanical variables measurement 2 Poly(methyl methacrylate) 2 Polymethyl methacrylates 2 Polyvinyl chlorides 2 Relaxation processes 2 Storage Young modulus 2 Storage Young's modulus 2 Storage young’s modulus 2 Strain amplitude 2 Strain amplitude dependence 2 Strain amplitude-dependent damping and modulus 2 Viscoelasticity 2