Accelerated ratcheting testing of polycarbonate using the time-temperature-stress equivalence method

Continuum approach for modeling fatigue in amorphous glassy polymers. Applications to the investigation of damage-ratcheting interaction in polycarbonate

“…Since fatigue tests are both costly and time consuming, an accelerated life testing with a high mean stress has been applied, Lesser (2002); Maxwell et al (2005); Lu and Kim (2007); Zhang et al (2015). In the referred test, see Janssen et al (2008b), the stress waveform is sinusoidal, and the maximum stress is allowed Table 2: Fatigue model parameters for PC.…”

“…This behavior is known as ratchetting (cyclic creep) which closely contributes to the fatigue of polymers under cyclic loadings, i.e. rapidly growing ratcheting strain (cyclic creep strain) reduces fatigue life, Liu et al (2008); Zhang et al (2015). Xi et al (2015) conducted experiments on polycarbonate (PC) polymers and showed that the polymers with large molecular weights are more prone to ratcheting than those with lower weights.…”

“…Xi et al (2015) conducted experiments on polycarbonate (PC) polymers and showed that the polymers with large molecular weights are more prone to ratcheting than those with lower weights. Loading conditions, such as mean stress, amplitude, and temperature, influence also ratcheting development, Kang (2008); Zhang et al (2015); Lu et al (2016). Although a lot of approaches are proposed for the simulation of ratcheting behavior, they are rarely aimed at amorphous polymer materials or require modeling of hysteresis loop action leading to a large number of material parameters to be defined, Liu et al (2008).…”

Experimental Observation on the Pure Torsional Ratchetting of Polycarbonate Polymer at Room Temperature

“…In recent years, due to the more and more extensive applications of polymeric materials in engineering, many researchers began to pay attention to the study of cyclic deformation behavior of these materials; for example, Chen et al [7] investigated the influence of humidity on cyclic deformation behavior and cyclic heat generation of polyamide-6 polymer. e results show that the change of humidity will not change the inherent cyclic softening/ hardening features of the material but obviously affects the degree of cyclic softening/hardening of the material; Liu et al [8] discussed the effects of stress cycling on the physical aging of polycarbonate polymer; Holopainen et al [9] proposed a model to simulate the ratchetting and fatigue interaction behavior of polycarbonate polymer in the framework of continuum mechanics; Hughes et al [10] experimentally studied the fatigue behavior of polycarbonate polymers and proposed a multistage fatigue model to evaluate the crack evolution; Zhang et al [11] proposed a method to accelerate ratchetting testing based on the time-temperature equivalence principle and verified the effectiveness of the proposed method with the uniaxial ratchetting test of polycarbonate polymer; Li et al [12] studied the effect of cyclic deformation on the mechanical properties of polycarbonate polymer. e results reveal that, during the initiation of fatigue damage, the fracture toughness of the material decreases with the increasing number of cyclic loadings significantly, while the yield strength is almost unaffected; Fang et al [13] conducted cyclic deformation experiments on polycarbonate (PC) and polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) and discussed the effects of cyclic loading on the uniaxial tensile properties of the two kinds of materials.…”

Accelerated aging test of hydrogenated nitrile butadiene rubber using the time–temperature–strain superposition principle

“…27 Zhu et al discussed the possible mechanisms of accelerated aging of polymers under applied stress. 28 A time-temperature-stress superposition principle, 29 borrowing the idea from accelerating studies of long-term creep, [30][31][32][33][34][35][36][37] has been successfully proposed to study the acceleration effect of applied stress on the aging of polycarbonate. While little work can be found in the literature concerning the effect of applied strain on the aging process, many rubber components are actually subjected to a prescribed strain rather than stress for certain applications, for example as seals and gaskets.…”