TY - JOUR

T1 - Prediction of tearing energy in mode III for filled elastomers

AU - El Yaagoubi, Mohammed

AU - Juhre, Daniel

AU - Meier, Jens

AU - Alshuth, Thomas

AU - Giese, Ulrich

PY - 2017/4

Y1 - 2017/4

N2 - Elastomers composites are viscoelastic materials and show a complex behaviour due to their non-linear response to external load, characterised in general by energy dissipation, residual set and material softening. For production reasons defects like micro-cracks and pores may be contained. A micro crack in a filled elastomer can occur between polymer-polymer, filler-polymer or filler-filler interfaces. Such a crack grows when the energy flux at the crack tip exceeds a critical value. Energy considerations at the crack shows that the energy released during the crack growth is not the total dissipated energy. The remaining energy is dissipated in the rest of the elastomer composite. In this study three different fracture criteria are compared: the tearing energy (Rivlin and Thomas, 1953), energy release rate (Groß and Seelig, 2011) and the J-integral (Rice, 1968). Tearing energy and energy release rate are based on the global energetic consideration and J-integral is based on the local energy observation. As a global criterion the tearing energy can be determined experimentally and numerically, whereas the J-integral is a local criterion at the crack tip and can be evaluated only numerically. The importance of local calculations lies in the determination of actually required tearing energy as well as the description of inelastic effects of elastomers at the crack tip. The analytical evaluation of the energy release rate allows for the prediction of the driving force at the crack tip without carrying out experiments for the determination of the tearing energy. Stumpf and Le (1990) have applied the variational principle to determine the energy flux at the mode I crack tip for a hyperelastic body. In this work only the trouser-sample is analysed. The load on this sample corresponds to the presented mode III from linear fracture mechanics. Here, the Ogden model is chosen (ABAQUS, 1998) as hyperelastic material model. The analytical determination of the energy release rate is calculated from the energy density function of this model. Results obtained from the experiments, simulations and analytical calculations are compared, where the analytical energy release rate turned out to be in closer accordance with the experimentally evaluated tearing energy than the J-Integral.

AB - Elastomers composites are viscoelastic materials and show a complex behaviour due to their non-linear response to external load, characterised in general by energy dissipation, residual set and material softening. For production reasons defects like micro-cracks and pores may be contained. A micro crack in a filled elastomer can occur between polymer-polymer, filler-polymer or filler-filler interfaces. Such a crack grows when the energy flux at the crack tip exceeds a critical value. Energy considerations at the crack shows that the energy released during the crack growth is not the total dissipated energy. The remaining energy is dissipated in the rest of the elastomer composite. In this study three different fracture criteria are compared: the tearing energy (Rivlin and Thomas, 1953), energy release rate (Groß and Seelig, 2011) and the J-integral (Rice, 1968). Tearing energy and energy release rate are based on the global energetic consideration and J-integral is based on the local energy observation. As a global criterion the tearing energy can be determined experimentally and numerically, whereas the J-integral is a local criterion at the crack tip and can be evaluated only numerically. The importance of local calculations lies in the determination of actually required tearing energy as well as the description of inelastic effects of elastomers at the crack tip. The analytical evaluation of the energy release rate allows for the prediction of the driving force at the crack tip without carrying out experiments for the determination of the tearing energy. Stumpf and Le (1990) have applied the variational principle to determine the energy flux at the mode I crack tip for a hyperelastic body. In this work only the trouser-sample is analysed. The load on this sample corresponds to the presented mode III from linear fracture mechanics. Here, the Ogden model is chosen (ABAQUS, 1998) as hyperelastic material model. The analytical determination of the energy release rate is calculated from the energy density function of this model. Results obtained from the experiments, simulations and analytical calculations are compared, where the analytical energy release rate turned out to be in closer accordance with the experimentally evaluated tearing energy than the J-Integral.

KW - Crack growth

KW - Energy release rate

KW - J-integral

KW - Tearing energy

KW - Trouser specimen

UR - http://www.scopus.com/inward/record.url?scp=85007529885&partnerID=8YFLogxK

U2 - 10.1016/j.tafmec.2016.11.006

DO - 10.1016/j.tafmec.2016.11.006

M3 - Article

AN - SCOPUS:85007529885

VL - 88

SP - 31

EP - 38

JO - Theoretical and Applied Fracture Mechanics

JF - Theoretical and Applied Fracture Mechanics

SN - 0167-8442

ER -