Estimating static/dynamic strength of notched unreinforced concrete under mixed-mode I/II loading
Estimating static/dynamic strength of notched unreinforced concrete under mixed-mode I/II loading
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DOI：
10.1016/j.engfracmech.2020.107329
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发表时间：
2020-09
影响因子：
5.4
通讯作者：
N. Alanazi;L. Susmel
中科院分区：
文献类型：
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作者：
N. Alanazi;L. Susmel
临界距离理论(TCD)是一种强大的设计工具，能够估计缺口/裂纹材料的强度，这是通过在评估应力提升器之前直接后处理线弹性应力场来实现的。在本研究中，设计了一种改进的TCD公式，专门用于预测I/II混合模式加载下无筋缺口混凝土的静力和动强度。根据含有不同锐度缺口的素混凝土的大量试验结果，检验了所提出的设计方法的可靠性和准确性，这些试验不仅在不同的模式混合度下进行，而且在不同的名义位移速率值(即在0.002-35 mm/S范围内)下进行。TCD的这一高级版本所作的预测被认为主要落在1%±230%的误差区间内，即在与表征校准数据的本征散射的频带一样宽的误差范围内。这表明，TCD原理也可以有效地扩展到在役静/动态混合加载下的缺口素混凝土的评估，相关的应力场可以通过将混凝土建模为线弹性、均匀和各向同性材料来确定。
The Theory of Critical Distances (TCD) is a powerful design tool capable of estimating the strength of notched/cracked materials, with this being done by directly post-processing the linear-elastic stress fields ahead of the stress raisers being assessed. In the present study, an advanced formulation of the TCD is devised to specifically predict static and dynamic strength of notched unreinforced concrete subjected to Mixed-Mode I/II loading. The reliability and accuracy of the design approach being proposed was checked against a large number of experimental results generated by testing plain concrete containing notches of different sharpness, with these experiments being run not only under various degrees of Mode mixity, but also under different values of the nominal displacement rate (i.e., in the range 0.002–35 mm/s). The predictions made by this advanced version of the TCD were seen to fall mainly within an error interval of ± 30%, that is, within an error band as wide as the band characterizing the intrinsic scattering of the calibration data. This suggests that that the TCD philosophy can effectively be extended also to the assessment of notched plain concrete subjected to in-service static/dynamic Mixed-Mode loading, with the relevant stress fields being determined by modelling concrete as a linear-elastic, homogeneous and isotropic material.