北京大学学报（自然科学版）2026，Vol.62Issue(3)：571-580,10.DOI:10.13209/j.0479-8023.2025.034
基于弹塑性梁模型的最大有效力矩准则单元边长定量研究
Quantitative Study on Unit Length of Maximum Effective Moment Criterion Based on Elastoplastic Beam Model
摘要
Abstract
Aiming at the lack of quantitative interpretation of the operational scale of the maximum effective moment criterion,this study is carried out based on an elastoplastic beam model.First,using the analytical solution for the normal stress distribution in a homogeneous elastoplastic beam under pure bending,the unit length of the criterion is derived to be approximately equal to the beam height.Subsequently,the bending and yielding process of double-and triple-layer elastoplastic beams are simulated using COMSOL multiphysics software.The results confirm that the above theoretical relationship is also valid for laminated beams(representing sedimentary strata).Finally,by analyzing the geometric scaling relationship of the kink band-like plastic deformation zones in beams and com-bining with the measurement of kink band width in field outcrops,the thickness of strata governed by this cri-terion is quantitatively estimated,thereby achieving the quantification of the unit length in the maximum effective moment criterion.The results provide a theoretical basis for reconstructing stress-strain fields and analyzing defor-mation processes in related geological structures.关键词
最大有效力矩准则/弹塑性梁/膝折带/有限元方法/COMSOLKey words
maximum effective moment criterion/elastoplastic beam/kink band/finite element method/COMSOL引用本文复制引用
刘天乐,何涛..基于弹塑性梁模型的最大有效力矩准则单元边长定量研究[J].北京大学学报（自然科学版）,2026,62(3):571-580,10.基金项目
国家自然科学基金(42174133)资助 （42174133）
