ABSTRACT The plastic zone at the crack front of an adhesively bonded double cantilever beam (DCB) specimen is analytically expressed considering the deformation of the adhesive layer. The plastic zone length and strain during the crack propagation are obtained, and the effect of the traction–separation profile on the DCB test results is investigated. The fracture energy is given by the area under the traction–separation curve and is not affected by the curve profile. However, the crack length of the DCB specimen is strongly affected by the adhesive deformation, leading to a calculation error in the fracture energy. Therefore, several crack length correction methods have been proposed. An analytical approach to describe the plastic zone at the crack front would help better understand DCB tests for adhesives. In this study, an analytical solution for a DCB test is discussed assuming that the adhesive layer undergoes an elastic–plastic deformation. The elastic zone of the specimen is replaced with a beam on an elastic foundation and the plastic zone with a beam having a uniformly distributed load. Influence of the plastic zone at the crack front in the DCB tests is analytically described by assuming an elastic–perfectly plastic material.

中文翻译：

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考虑弹塑性变形的胶粘双悬臂梁试验胶层变形分析测定

摘要考虑粘合剂层的变形，对粘合剂粘合的双悬臂梁 (DCB) 试样裂纹前沿的塑性区进行了分析。获得了裂纹扩展过程中的塑性区长度和应变，并研究了牵引-分离剖面对 DCB 测试结果的影响。断裂能由牵引-分离曲线下的面积给出，不受曲线轮廓的影响。然而，DCB 试样的裂纹长度受粘附变形的影响很大，导致断裂能的计算错误。因此，已经提出了几种裂纹长度校正方法。描述裂纹前沿塑性区的分析方法将有助于更好地理解粘合剂的 DCB 测试。在这项研究中，假设粘合剂层经历弹塑性变形，讨论了 DCB 测试的解析解。试件的弹性区用弹性基础上的梁代替，塑性区用载荷均匀分布的梁代替。DCB 试验中裂纹前缘塑性区的影响通过假设完全弹性塑性材料进行分析描述。