Quantifying the influence of elliptical ring geometry on the degree of restraint in a ring test
Quantifying the influence of elliptical ring geometry on the degree of restraint in a ring test
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DOI：
10.1016/j.compstruc.2017.08.002
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发表时间：
2017-08
影响因子：
4.7
通讯作者：
W. Dong;Xiangming Zhou;Zhimin Wu;H. Luo;G. Kastiukas
中科院分区：
文献类型：
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作者：
W. Dong;Xiangming Zhou;Zhimin Wu;H. Luo;G. Kastiukas
提出了一种新的椭圆环试验方法来取代传统的圆形环试验方法，以缩短评估混凝土开裂倾向的试验时间，更方便地检测混凝土环内的裂缝演变。为了进一步探索这种新测试方法的机理，建立了一个数值模型来分析混凝土环中的应力发展和裂缝萌生，其中一个虚构的温度场模拟混凝土收缩对混凝土产生相同应变的外部力学效应。提出的数值模型与实验结果进行了验证，然后用于评估环几何形状对混凝土约束程度的影响。此外，通过一系列数值实验推导了椭圆环约束度的表达式。通过对混凝土性能和环几何约束度的误差分析，验证了该表达式的正确性，可用于计算内钢圈提供的约束度。根据推导出的表达式，可以设计约束椭圆环试验，更准确地定量模拟工程结构中混凝土的使用状况。
A novel elliptical ring test method has been proposed to replace the traditional circular ring test method for the purpose of shortening test duration for assessing cracking tendency of concrete and more conveniently examining crack evolution in concrete rings. To further explore the mechanism of this new test method, a numerical model was established to analyse stress development and crack initiation in concrete rings in which a fictitious temperature field simulated the externally applied mechanical effects of concrete shrinkage on concrete causing the same strain as shrinkage does. The proposed numerical model was validated against experimental results and was then used to evaluate the effects of ring geometry on the degree of restraint to concrete. Moreover, a series of numerical experiments were conducted to derive the expression of the degree of restraint to elliptical rings. Through the error analysis of the degree of restraint on concrete properties and ring geometry, the expression was verified so that it can be used to calculate the degree of restraint provided by the internal steel ring. According to the derived expression, the restrained elliptical ring test can be designed to quantitatively simulate the service condition of concrete in an engineering structure more accurately.