Design criterion for rubbery parts under biaxial loading

• To prevent the failure of the rubbery parts, a relevant criterion, is required for engineers designing.
• We have developed some fracture criteria for vulcanizates and thermoplastic elastomers subjected to quasi-static biaxial loadings.
• The comparison of the experimental results with the theoretical predictions shows that the proposed models are not quite satisfactory for all the considered loading modes.
• In this study, we have continued the investigation using our experimental data and the one from the literature.
• An original concept has been developed and a relevant design criterion is identified.
• The designing criterion expressed with an equivalent strain, using polar coordinates in the trisectrix plan, is defined by two material parameters.
• When comparing the failure experimental data with the prediction of our criterion good agreement is highlighted.
• The proposed approach gives better results when it is compared with those of literature.

No relevant criterion exists for designing elastomer parts under biaxial loading. Thus, in this work, we attempt to derive a design criterion for rubber-like materials under quasi-static plane stress loading. A set of experimental data published elsewhere is used, obtained from tests including various loading modes and performed on four materials.In this study, we developed a theoretical approach based on a reference axis change principle, introduced earlier for solid composite propergol and elastomers. The designing criterion based upon equivalent elongation, evaluated in a polar coordinates system, is expressed as function of two parameters. The comparison of the failure experimental data with the prediction of our criterion, for several tested elastomers, shows a good agreement.