Talebi Hossein, Askari Mohsen, Ayatollahi Majid Reza, Cicero Sergio
Fatigue and Fracture Research Laboratory, Center of Excellence in Experimental Solid Mechanics and Dynamics, School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16846, Iran.
LADICIM, Departamento de Ciencia e Ingeniería del Terreno y de los Materiales, Universidad de Cantabria, 39005 Santander, Spain.
Polymers (Basel). 2023 May 25;15(11):2454. doi: 10.3390/polym15112454.
In this research, the fracture behavior of brittle specimens weakened by V-shaped notches with end holes (VO-notches) is studied. First, an experimental investigation is conducted to evaluate the effect of VO-notches on fracture behavior. To this end, VO-notched samples of PMMA are made and exposed to pure opening mode loading, pure tearing mode loading, and some combinations of these two loading types. As part of this study, samples with end-hole radii of 1, 2, and 4 mm are prepared to determine the effect of the notch end-hole size on the fracture resistance. Second, two well-known stress-based criteria, namely the maximum tangential stress (MTS) criterion and the mean stress (MS) criterion, are developed for VO-shaped notches subjected to mixed-mode I/III loading, also determining the associated fracture limit curves. A comparison between the theoretical and the experimental critical conditions indicates that the resulting VO-MTS and VO-MS criteria predict the fracture resistance of VO-notched samples with about 92% and 90% accuracy, respectively, confirming their capacity to estimate fracture conditions.
在本研究中，对带有端孔的V形切口（VO切口）削弱的脆性试样的断裂行为进行了研究。首先，开展了一项实验研究，以评估VO切口对断裂行为的影响。为此，制作了聚甲基丙烯酸甲酯（PMMA）的VO切口试样，并使其承受纯张开模式加载、纯撕裂模式加载以及这两种加载类型的一些组合。作为本研究的一部分，制备了端孔半径为1毫米、2毫米和4毫米的试样，以确定切口端孔尺寸对抗断裂性能的影响。其次，针对承受I/III混合模式加载的VO形切口，开发了两个著名的基于应力的准则，即最大切向应力（MTS）准则和平均应力（MS）准则，同时还确定了相关的断裂极限曲线。理论临界条件与实验临界条件之间的比较表明，所得的VO-MTS和VO-MS准则分别以约92%和90%的准确度预测了VO切口试样的抗断裂性能，证实了它们估计断裂条件的能力。
