We propose a geometrically nonlinear extended isogeometric analysis approach for cohesive fracture. A shifting technique is used to enforce compatibility in the direction perpendicular to the crack path, while a blending technique has been adopted to remove the effect of the discontinuity in the extension of the cohesive crack. Bézier extraction is employed to cast the formulation in a finite element datastructure. The use of a sign function instead of a Heaviside step function removes the need to make an assumption for the normal to the crack at its centreline. Examples are given to illustrate the methodology, including buckling of a delaminated structure and an assessment of the interface contribution to the tangent stiffness matrix.

我们提出了一种用于粘性断裂的几何非线性扩展等几何分析方法。使用移位技术来增强与裂纹路径垂直的方向的兼容性，而采用混合技术来消除粘性裂纹扩展中的不连续性影响。贝塞尔（Bézier）提取用于将配方转换为有限元数据结构。使用符号函数而不是Heaviside阶跃函数可以消除对裂纹中心线法线的假设。举例说明了该方法，包括分层结构的屈曲以及界面对切线刚度矩阵的贡献评估。