When Large Deformation Analysis Meets Large Deformation Phenomenon: Comparative Study and Improvement

Large deformation phenomena in rock engineering are commonly key bottlenecks impeding engineering progress. Correspondingly, large deformation analysis in rock mechanics has a widespread impact on mechanism understanding, prevention, and control guidance. Various large deformation schemes broadly categorized as hypoelastic- and hyperelastic-based models exist in the literature and software. Without an understanding of the capabilities and demerits of these schemes, the diversity in choices inadvertently leads to pitfalls, placing engineering endeavors at a disadvantage. In this work, we review and compare the most prevalent schemes (including PK2-Green, Jaumann, Green–Naghdi, Truesdell, and hyperelastic-based schemes) from perspective of rock mechanics, with an emphasis on their application in rock engineering, and further develop a hyperelastic-based large deformation scheme (marked as Cauchy-Ln scheme) based on Cauchy stress and Hencky logarithm strain. The proposed model realizes the separation of material nonlinearity and geometry nonlinearity. Several typical large deformation phenomena in rock engineering are studied. The relationships between large deformation phenomena and large deformation analyses are clarified under different circumstances. Especially under large strain conditions, the PK2-Green scheme is enfeebled, and the hypoelastic-based scheme should be used with caution. For rock material with an apparent pressure-sensitive effect, the proposed Cauchy-Ln scheme is superior.