集成竹Ⅰ型层间断裂特性试验研究与数值分析  

Experimental study and numerical simulation on mode-Ⅰ interlaminar fracture behavior of laminated bamboo

作　　者：刘燕燕 黄东升[1,2] 盛宝璐 LIU Yanyan;HUANG Dongsheng;SHENG Baolu(National Engineering Research Center of Biomaterials,Nanjing Forestry University,Nanjing 210037,China;School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学国家工程中心,江苏南京210037 [2]南京林业大学土木工程学院,江苏南京210037

出　　处：《建筑结构学报》2023年第1期280-288,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51978338)。

摘　　要：针对集成竹Ⅰ型层间断裂问题开展了双悬臂梁(DCB)断裂试验研究,并采用虚拟裂纹闭合法(VCCT)与内聚力模型(CZM)对其断裂行为进行了数值分析,通过试验验证了两种方法用于模拟集成竹Ⅰ型层间断裂行为的有效性。其中,CZM中考虑了裂纹尖端内聚力的退化,可有效模拟材料断裂过程中的非线性行为;而VCCT基于线弹性断裂力学,无法考虑断裂中的非线性,但采用VCCT的分析结果相对稳定,易收敛,适用于材料断裂非线性不明显的情况。通过CZM,进一步考察了双悬臂梁宽度对Ⅰ型断裂韧度的影响。结果表明:材料Ⅰ型断裂韧度随梁宽度增大呈现减小的趋势;宽度达到55 mm以上时,裂纹尖端应力场受平面应变状态主导,应变能释放率趋于稳定值0.539 5 N/mm。In order to verify the effectiveness of the virtual crack closure technique(VCCT) and cohesive zone modeling(CZM) methods used for simulating the interlaminar fracture behavior of laminated bamboo composites, the mode-Ⅰ interlaminar fracture behavior of laminated bamboo composites was investigated through double cantilever beam(DCB) test. And the numerical simulation was carried out using the two methods. Since the stiffness degradation of cohesive elements was considered in the CZM method, the nonlinear behavior of the load-crack opening displacement curve was predicted. The VCCT was based on linear elastic fracture mechanics and couldn’t predict the nonlinearity in fracture. However, VCCT analysis is relatively stable and easy to converge, which is suitable for the case that the fracture nonlinearity is not obvious. The effect of specimen width on the fracture toughness was further investigated using the CZM method. The toughness shows a decreasing tendency with the increasing width. When the width reaches 55 mm, the crack tip is dominated by plain strain and a constant value of 0.539 5 N/mm for fracture toughness is obtained.

关 键 词：集成竹 虚拟裂纹闭合法 内聚力模型 双悬臂梁试验 数值模拟 层间断裂特性 

分 类 号：TU366.1[建筑科学—结构工程]