On nonlinear wave dissipation in polymers

Abstract

Different polymeric materials are widely used in various technological and manufacturing processes and products for vibration isolation due to their properties to reduce the elastic waves magnitude. However, this property of polymers to efficiently damp elastic waves is valid for linear waves only. Nonlinear waves (for example, strain solitary waves) on the contrary can propagate in polymer waveguides, having proper characteristics, for long distances with very little loss of amplitude (we proved that in numerous experiments in waveguides made of polystyrene and PMMA). The phenomenon of existence and propagation for long distances of this new type of waves in polymer materials can be of considerable importance in engineering regarding to the potential generation of such waves in elastic constructions, that was not considered before in calculations of their strength, plasticity and damage threshold. On the other hand it allows to obtain quantitative data on nonlinear wave dissipation in these materials. We report our recent experiments on soliton propagation in waveguides made of polystyrene and PMMA, long enough to cause noticeable changes of wave shape and amplitude. Basing on these data we estimate dissipation decrements for nonlinear waves in these materials.

Longitudinal Strain Solitary Wave in a Two‐Layered Polymeric Bar

“…Previous theoretical and experimental research has been devoted to the generation and subsequent propagation of bulk strain solitary waves in various polymeric (made of polystyrene, PS and plexiglas, PMMA) wave guides, see Refs [14,[20][21][22] and references therein]. Strain solitons have been successfully generated in rods, bars and plates.…”

“…The evolution of a soliton in lengthy wave guides made of PMMA was first reported in Ref. [14]. Interferograms recorded in different areas of the wave guide allowed us to visualise the processes of soliton formation and propagation along the wave guide.…”

“…The results of this study have shown the sensitivity of a nonlinear wave to the length of the delamination zone, and have indicated that bulk nonlinear waves are potentially applicable to the detection of delamination zones in layered structures, inviting further detailed analytical and experimental studies. Such investigations are especially interesting due to the recent experiments showing that longitudinal strain bulk solitary waves can propagate for long distances without any significant decay [14]. The latter will be discussed in more detail in the next section.…”

Holographic approach to detection of delamination areas in layered polymeric waveguides by means of strain solitons

“…While the shock wave has a classical shape with the thin compression zone followed by a more extended rarefaction zone, the soliton looks like a rather long-length symmetrical bell-shaped longitudinal wave, which is not followed by any tensile wave. As reported in [8] the soliton propagates in a uniform waveguide for a long distance showing very low decay. …”

“…Bulk strain soliton is a long non-linear localized traveling wave, which, under certain conditions, can be formed in a solid waveguide from an initial pulse. Being formed, the soliton propagates along the homogeneous wave guide with almost no change of amplitude, shape and velocity (see [8] for details). In inhomogeneous waveguides soliton parameters vary depending upon the nature and characteristics of inhomogeneities ( [9][10][11]).…”