A Stochastic Damage Model for Bond Stress-Slip Relationship of Rebar-Concrete Interface under Monotonic Loading
A Stochastic Damage Model for Bond Stress-Slip Relationship of Rebar-Concrete Interface under Monotonic Loading
复制标题
单调荷载下钢筋-混凝土界面粘结应力-滑移关系的随机损伤模型
DOI：
10.3390/ma12193151
复制
发表时间：
2019-10-01
期刊：
影响因子：
3.4
通讯作者：
Yuan, Ju
中科院分区：
文献类型：
--
作者：
Lv, Xiaoyong;Yu, Zhiwu;Yuan, Ju
随机粘结滑移行为是钢筋-混凝土界面研究的重要课题。然而，在目前的文献中，很少有理论模型纳入随机行为可以追溯。基于细观力学方法，提出了单调加载下界面粘结应力-滑移关系的随机损伤模型。为了描述钢筋-混凝土界面的力学行为，提出了一个细观损伤模型。通过引入由平行弹簧单元、摩擦单元和开关单元组成的微单元，建立了该模型。为了反映界面微破裂对粘结应力-滑移行为的随机性，采用了一系列的弹性微单元，并将单个弹簧单元的失效门槛值设为随机变量。基于统计损伤力学理论，推导了粘结应力-滑移关系的均值和方差表达式。此外，通过利用搜索启发式全局优化算法（即，遗传算法），所提出的模型的参数能够从实验结果中识别，其中对数正态分布已被采用。实验结果验证了该预测，它表明，所提出的模型是能够捕捉的随机性质的微观结构和表征的随机行为。
The stochastic bond stress-slip behavior is an essential topic for the rebar-concrete interface. However, few theoretical models incorporating stochastic behavior in current literature can be traced. In this paper, a stochastic damage model based on micro-mechanical approach for bond stress-slip relationship of the interface under monotonic loading was proposed. In order to describe the mechanical behaviors of the rebar-concrete interface, a microscopic damage model was proposed. By introducing a micro-element consists of parallel spring element, friction element and a switch element, the model is formulated. In order to reflect the randomness of the bond stress-slip behavior contributed by the micro-fracture in the interface, a series of paralleled micro-elements are adopted with the failure threshold of individual spring element is set as a random variable. The expression of both mean and variance for the bond stress-slip relationship was derived based on statistical damage mechanics. Furthermore, by utilizing a search heuristic global optimization algorithm (i.e., a genetic algorithm), parameters of the proposed model are able to be identified from experimental results, which a lognormal distribution has adopted. The prediction was verified against experimental results, and it reveals that the proposed model is capable of capturing the random nature of the micro-structure and characterizing the stochastic behavior.