Mechanical Behavior of Rubber at High Strain Rates

Abstract

Methods to obtain the mechanical response of rubber at high rates of strain are reviewed. These techniques include the extrapolation of low strain, low strain rate data, the limitations of which are discussed, extrapolations to elevated hydrostatic pressure, and direct determinations using split Hopkinson bar and drop weight testers, as well as miscellaneous methods. Some applications involving rubber at strain rates sufficient to induce a transition to the glassy state are described.

High Strain Rate Mechanics of Polymers: A Review

“…Materials which have been well-studied in the literature are silicone elastomers [13,66,151], plasticized PVC [152,153] and polyureas [39,40,72,[154][155][156][157][158][159] and polyurethanes [160][161][162]. The rate dependence of these materials depends strongly on the glass transition, and in particular whether this transition affects the room temperature response at strain rates of interest.…”

“…In addition, it is necessary to overcome the effects of the inertia of the apparatus, so that high speed deformations can be applied after a very short period of acceleration. Hydraulic machines are often used; however, systems based on dropping weights [39][40][41][42][43][44][45][46][47][48], fly wheel systems [49,50], expanding ring [51], cam plastometer [52], very long Hopkinson bars [53], or the 'wedge bar' [54] have also been applied successfully. Accurate experiments in this strain rate regime are key because molecular mobility transitions often become activated between 1 and 1000 s -1 .…”

Mechanical response of polycarbonate nanocomposites to high velocity impact

“…However, the nano-reinforcement effect was also achieved even though for the PC containing higher percentage of 2 wt% clay at highest strain rate. For most polymeric materials it is common to find that high temperature levels can be rapidly induced when the material is being deformed at a higher strain rate, where the test is performed quickly [26]. Heat will be generated by converting the plastic energy through irreversible thermodynamic processes.…”

Comparison of the transient stress–strain response of rubber to its linear dynamic behavior

“…5,6 However, material characterizations are usually limited to only one of these conditionsslow straining to the point of failure or rapid displacements of small amplitude. Consequently, the mechanical response for many applications is often predicted by extrapolating linear dynamic data, with the assumption that strain and rate effects are separable, [7][8][9][10][11][12][13][14] and that the time-superposition principle is valid.…”

“…The segmental dynamics have quite different properties than the global chain motions probed at longer times and higher temperatures. 5,16,36 To address this issue, we obtained stress-strain data at ambient temperature for three rubbers, networks of 1,2-and 1,4-polybutadienes (1,2-PB and 1,4-PB, respectively) and a linear styrene-butadiene copolymer (SBR), using a novel instrument to access large strains over a wide range of strain rates. At the highest rates encroachment of the local segmental dynamics becomes apparent, to a degree dependent on the polymer T g .…”