基于等效Mohr-Coulomb摩擦角的强度准则主应力平面表示

Expressing strength criterion in principal stress plane base on equivalent Mohr-Coulomb friction angle

定义Mohr-Coulomb(M-C)强度准则各种表达式和对应的等效M-C摩擦角,基于等效M-C摩擦角给出主应力σ1σ2关系表达式,即各种强度准则在主应力平面的表示。以Matsuoka-Nakai(M-N),Lade-Duncan(L-D)和Moji强度准则为例,演示了该方法的应用,研究3种强度准则中间主应力σ2对材料屈服时的最大主应力σ1的影响。结果表明:这种在二维主应力σ1-σ2平面中表示强度准则的新方法既适用于无黏性材料又适用于黏性材料,用于黏性材料时,通过平移坐标轴将黏性材料破坏面转换成无黏性材料破坏面,为材料强度准则研究提供了新思路。

Different expressions for the Mohr-Coulomb（M-C）criterion and the definitions of the equivalent M-C friction angle were defined. The expression about the relationship between principal stresses σ1 and σ2, derived from the equivalent M-C friction angle was given further. The strength criterion was expressed in the principal stress plane. The Matsuoka-Nakai（M-N）, Lade-Duncan（L-D） and Moji criteria were used as application examples to demonstrate the proposed method, and the influence of the intermediate principal stress σ2 to the yield strength σ1 of the material was studied. The results show that this new method is suitable for both cohesionless and cohesive materials. The failure surface for cohesive materials transforms to the failure surface for cohesionless materials through translation of the coordinates＇ system for cohesive materials, which provides a new idea for research strength criterion.