沉积岩折曲带形成的弹塑性相变模型

为了揭示岩石折曲带的形成机理，建立了沉积岩折曲带形成的弹塑性相变分析模型．考虑到跨越折曲带界面变形梯度和应力的不连续，强加了跨越界面的力的连续性和相变Maxwell条件．应用基于Drucker-Prager屈服准则的沉积岩的弹塑性本构方程，建立了平面应变下沉积岩挤压折曲形成的控制方程模型．该模型可以预测折曲带形成时的挤压应力、折曲带内外的应力和应变、折曲带倾角和折曲角等．数值求解表明，预测结果和实验结果一致．

Model of Elastoplastic Phase Transformation of Kink Bands in Sedimentary Rocks

An elastoplastic phase transformation model for the formation of kink bands in sedimentary rocks was put forward to reveal its formation mechanism. Considering the discontinuity of deformation gradient and stress across the interface between kink bands and un-kinked areas, the continuity of traction across the interface and Maxwell relation were imposed. Using the elastoplastic constitutive equation for sedimentary rocks based on Drucker-Prager yield criteria, the control equations for the formation of kink bands in sedimentary rocks under plane strain state were deduced. The compressive stress for the formation of kink bands, the stress and strain inside and outside kink band, the inclination angle of kink band, and the kink angle could be predicted. The results were consistent with experimental data.