Mixed-mode (I/II) rupture assessment of rubber-like materials weakened by cracks using the averaged strain energy density criterion

In the present study, the application of the averaged strain energy density (ASED) criterion is extended from pure mode-I to mixed-mode (I/II) loading for hyperelastic materials. Indeed, the use of a recently proposed method by the present authors for determination of the critical values of strain energy density and radius of control volume in mode-I loading has been generalized to the mixed-mode loading conditions. The key point in the generalization is the almost uniaxial state of stress fields near the crack tip in rubber-like materials. To validate the accuracy of the criterion in mixed-mode (I/II) loading, a new set of experiments on rubbers weakened by cracks has been carried out. The experimental results confirm the accuracy of the ASED criterion in the case of cracked rubbers under mixed-mode (I/II) loading.submittedVersionThis is a submitted manuscript of an article published by Elsevier Ltd in Theoretical and applied fracture mechanics, 25 May 2017

Rupture analysis of rubber in the presence of a sharp V-shape notch under pure mode-I loading

The rupture behavior of styrene-butadiene rubbers (SBR) in the presence of a V-shape notch is investigated for the first time both experimentally and theoretically. In the experiments, V-notched samples of SBR are tested under tensile loading and their rupture displacements are determined. Afterwards and in the analytical field, the rupture loads of tested rubbers are predicted using the averaged strain energy density (ASED) criterion. The key idea of this criterion (i.e. the almost uniaxial state of stress field near the notch tip) is verified through non-linear finite element modeling. It is shown that good agreement exists between the predictions of the ASED criterion and the experimental results obtained for SBR. Moreover, the microscopic study of the ruptured surfaces of the notched SBR demonstrates its high roughness which can be attributed to the resistance of the rubber chains against the crack growth

Mixed-mode (I/II) rupture assessment of rubber-like materials weakened by cracks using the averaged strain energy density criterion

In the present study, the application of the averaged strain energy density (ASED) criterion is extended from pure mode-I to mixed-mode (I/II) loading for hyperelastic materials. Indeed, the use of a recently proposed method by the present authors for determination of the critical values of strain energy density and radius of control volume in mode-I loading has been generalized to the mixed-mode loading conditions. The key point in the generalization is the almost uniaxial state of stress fields near the crack tip in rubber-like materials. To validate the accuracy of the criterion in mixed-mode (I/II) loading, a new set of experiments on rubbers weakened by cracks has been carried out. The experimental results confirm the accuracy of the ASED criterion in the case of cracked rubbers under mixed-mode (I/II) loading

Rupture analysis of rubber in the presence of a sharp V-shape notch under pure mode-I loading

The rupture behavior of styrene-butadiene rubbers (SBR) in the presence of a V-shape notch is investigated for the first time both experimentally and theoretically. In the experiments, V-notched samples of SBR are tested under tensile loading and their rupture displacements are determined. Afterwards and in the analytical field, the rupture loads of tested rubbers are predicted using the averaged strain energy density (ASED) criterion. The key idea of this criterion (i.e. the almost uniaxial state of stress field near the notch tip) is verified through non-linear finite element modeling. It is shown that good agreement exists between the predictions of the ASED criterion and the experimental results obtained for SBR. Moreover, the microscopic study of the ruptured surfaces of the notched SBR demonstrates its high roughness which can be attributed to the resistance of the rubber chains against the crack growth.submittedVersionThis is a submitted manuscript of an article published by Elsevier Ltd in International Journal of Mechanical Sciences, 13 August 2018

Mixed-mode fracture in EPDM/SBR/nanoclay rubber composites: An experimental and theoretical investigation

Fracture analysis of rubber nanocomposites weakened by a crack and loaded in mixed-mode (I/II) condition is investigated in the current research for the first time. In fact, no study was devoted in the past to investigate the fracture of rubbers reinforced with nanoparticles and subjected to mixed-mode loading, neither experimentally nor theoretically. To fill this gap, in the experimental phase of study, ethylene–propylene-diene monomer (EPDM)/styrene-butadiene rubber (SBR) blends reinforced with CLOISITE 15 nanoclay are prepared and some uniaxial tensile experiments and fracture tests are conducted. In the theoretical field of contribution, due to the undeniable importance of presentation of a fracture criterion, an energy-based criterion, namely averaged strain energy density (ASED), is adopted to predict the rupture of tested rubber/nanoclay composites. To apply the criterion, some non-linear finite element analyses considering the Ogden hyperelastic material model are also performed. The results highlight the success of this criterion to assess the fracture of nano-reinforced rubbers containing a mixed-mode crack

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