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论文类型：期刊论文

发表时间：2017-05-01

发表刊物：ENGINEERING FAILURE ANALYSIS

收录刊物：SCIE、EI

卷号：75

页面范围：54-70

ISSN号：1350-6307

关键字：Concrete; Mixed mode fracture; Fracture process zone; Digital image correlation; Numerical simulation

摘要：Digital image correlation (DIC) technique is applied to study the evolution of fracture process zone (FPZ) of mixed mode fracture in concrete. By testing a series of beams of various sizes under four-point shearing, the opening and sliding displacements on the crack surfaces are derived using the DIC technique. Meanwhile, a numerical method is employed to simulate the fracture process by introducing a crack propagation criterion. The opening and sliding displacements on the crack surfaces obtained from numerical analysis exhibit a reasonable agreement with the experimental results, which verifies the DIC technique presented in the study. By combining experimental observations with numerical simulations, the evolution of the FPZ during the whole crack propagation process of mix mode fracture is investigated and elaborated in depth. The results indicate that the ratio of crack opening to sliding displacement remains approximately constant as crack propagates before reaching a peak load. Meanwhile, the FPZ evolution during the complete fracture process is influenced by the specimen ligament length and the ratio of mode I to II stress intensity factor component. With the decrease of ligament length and the ratio of mode I to II stress intensity factor component, the full FPZ length decreases. However, when the ligament length is less than 63 mm or ratio of mode I to II stress intensity factor component is less than 0.11, the FPZ cannot fully develop, but keeps increasing as crack propagates. (C) 2017 Elsevier Ltd. All rights reserved.