**5. Conclusions**

The present work focuses on investigating the convergence properties and accuracy of different enrichment schemes in the XFEM for modeling the cohesive crack problem. Four kinds of enrichment schemes for cohesive cracks were manufactured to examine the influences of their variations on convergence performance and accuracy level. The convergence study was conducted on a double-cantilever beam specimen with both the pure mode I problem and the mixed-mode problem, and cases of linear and exponential constitutive laws were considered. On the basis of the simulation results, our main conclusions are as follows.


**Author Contributions:** Methodology, G.L.; software, G.L.; validation, G.L., J.G. and Y.B.; writing original draft preparation, J.G. and Y.B.; writing—review and editing, G.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was funded by the National Natural Science Foundation of China (Nos. 51909153, 51108259, and 11772193). And The APC was funded by the National Natural Science Foundation of China (No. 51909153).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
