Averaged strain energy density criterion for rupture assessment of cracked rubbers: A novel method for determination of critical SED

In the present study, the application of averaged strain energy density (ASED) criterion has been extended to hyperelastic materials. Because of the material and geometry nonlinearities, commonly known for rubber-like materials, the use of conventional relations for determining the criterion parameters is no longer allowable. Therefore, by taking the advantage of a simple uniaxial state of stress field ahead of the crack tip in hyperelastic materials, a novel method has been proposed for determining the critical value of strain energy density. The sound agreement between the theoretical estimates based on the employed ASED criterion and the experimental data, taken from the literature, confirms the suitability of the proposed method

Fracture analysis of V‐notched rubbers: An experimental and theoretical study

In this study, the rupture load in rubbers weakened by sharp V‐notch is investigated under mode I loading. To this end, first, mode I fracture tests are performed on V‐notched samples made of styrene‐butadiene rubbers and the corresponding rupture loads are obtained. Then, the effective stretch (ES) criterion, which was recently developed by the present authors for rupture assessment of cracked rubber parts, is extended and used for the V‐notched rubbers. It is shown that similar to cracked rubbers, the state of stress near the notch tip is also nearly uniaxial. By employing the ES criterion, the critical displacements corresponding to the rupture in the tested samples are calculated. Finally, the predictions of the criterion are compared with the corresponding experimental values, and good consistency is shown to exist.submittedVersionThis is the pre-peer reviewed version of an article, which has been published in final form at [https://doi.org/10.1111/ffe.12947]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

A New Criterion for Rupture Assessment of Rubber-Like Materials under Mode-I Crack Loading: The Effective Stretch Criterion

A new criterion is presented for fracture assessment of rubber-like materials weakened by a mode I crack. The criterion is based on two main assumptions: the existence of a damage zone around the crack tip and the dominant uniaxial nature of the stress field near the crack in rubber-like materials. Considering these key features and employing the concepts of well-known eight-chain model, first, a failure criterion called the "Effective Stretch Criterion" has been proposed. Then, a procedure has been elaborated to calibrate the material parameters in the criterion. The criterion, finally, has been validated by using two sets of experimental data available in the literature

Rupture assessment of rubber/clay nanocomposites containing a crack by means of an energy-based fracture criterion

Due to the growing use of nanotechnology in the modern era, the application of nanomaterials in elastomers has also been increased. Although some limited experiments are available in the previous studies regarding the fracture behavior of rubber nanocomposites containing a crack, no criteria have been presented so far. To fill this gap, the current research is devoted to develop a criterion for rupture assessment of rubber nanocomposites weakened by a crack. First, some fracture tests are performed on cracked rubber/clay nanocomposites. The prepared nanocomposites are made of ethylene–propylene-diene monomer/styrene-butadiene rubber/CLOISITE 15. Afterwards, the averaged strain energy density (ASED) criterion, as one of the most used energy-based criteria, is extended and utilized in nano-reinforced hyperelastic materials. The nearly uniaxial state of stress field next to the crack tip in rubber nanocomposites, which is the main prerequisite for the criterion extension, is proved by means of non-linear finite element modelling. Finally, the estimations of the criterion is compared with the corresponding experimental data and good agreement is achieved which reveals the high performance of the ASED criterion in the case of cracked rubbers filled with nanoparticles

Low-velocity Impact Response of a Nanocomposite Beam Using an Analytical Model

AbstractLow-velocity impact of a nanocomposite beam made of glass/epoxy reinforced with multi-wall carbon nanotubes and clay nanoparticles is investigated in this study. Exerting modified rule of mixture (MROM), the mechanical properties of nanocomposite including matrix, nanoparticles or multi-wall carbon nanotubes (MWCNT), and fiber are attained. In order to analyze the low-velocity impact, Euler-Bernoulli beam theory and Hertz's contact law are simultaneously employed to govern the equations of motion. Using Ritz's variational approximation method, a set of nonlinear equations in time domain are obtained, which are solved using a fourth order Runge-Kutta method. The effect of different parameters such as adding nanoparticles or MWCNT's on maximum contact force and energy absorption, stacking sequence, geometrical dimensions (i.e., length, width and height), and initial velocity of the impactor have been studied comprehensively on dynamic behavior of the nanocomposite beam. In addition, the result of analytical model is compared with Finite Element Modeling (FEM).The results reveal that the effect of nanoparticles on energy absorption is more considerable at higher impact energies