用于接触面模拟的三维非线性接触单元

提出了一种新的模拟结构缝或接触问题的三维非线性接触单元，在本构关系上，模型同时考虑了已被大量实验证实的接触面法向和切向的非线性特性，法向采用了考虑法向变形的双曲线模型，切向采用了考虑应变化的双曲线模型，模拟了接触面的粘结、滑移和开裂等非线性现象，相对于其它接触单元，本文模型避免了Goodman单元等只考虑缝面变形及法向、切向参数取值的任意性，计算结果常使法向应力出现波动和过量嵌入等缺点，并据此编制了有限元计算程序，利用此程序分析了3个典型算例，验证了模型的合理性和程序的计算精度。

A New Three-Dimensional Nonlinear Interface Element for Modeling Joints

A new three dimension nonlinear interface element for modeling joints is presented. Nonlinear characteristics of interface both in the normal and shear direction, which are testified by experiments are considered in the constitutive model. Hyperbola model containing normal deformation in the normal direction and strain hardening in the shear direction is applied in the model. Several working states such as bond, slip, and crack on interface are modeled. Compared with other contact elements, the advantages of the presented model are that it avoids the occurrence of normal stress fluctuation and over intrusion on the interface, and avoids the arbitrariness of parameters of normal and shear stiffness of the Goodman element. The model is implemented as an element into the finite element code, and three typical examples are presented to illustrate the good accuracy of the model.