Research Article Effect of T-Stress on Crack-Tip Stress Field and Crack Propagation of Concrete Shaoqing Zhou and Limin Li Hunan University of Science and Engineering, Yongzhou, Hunan 425199, China CorrespondenceshouldbeaddressedtoShaoqingZhou;[email protected] Received 30 September 2022; Revised 29 December 2022; Accepted 30 December 2022; Published 6 January 2023 AcademicEditor:LinshengHuo Copyright © 2023 Shaoqing Zhou and Limin Li. Tis is an open access article distributed under the Creative Commons AttributionLicense,whichpermitsunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkis properly cited. Inordertopredictthefracturetoughnessandpropagationofthemixedmodefractureofconcrete,themodifedMTS(maximum tangentialstress)criterioncombinedwithT-stresswaspresented. TemodifedMTScriterionusesatwo-parametermodel(stress intensity factor K and T-stress) to describe the concrete’s fracture. Trough calculation, it is found that T-stress can afect the maximumtangentialstress,especiallywhenT-stressisnegative.T-stressisnottakenintoaccountinthetraditionalMTScriterion, whichwillleadtoerrorsincalculatingthemaximumcircumferentialstress.Teresultofthespecimenisnotconsistentwiththe predictedresultofthetraditionalMTS. Temodifedcriterioncanprovideaccuratepredictions fortheexperimentalresults.Tis provides a basis for the simulation of concrete’s fracture. 1. Introduction Concrete is a widely used material in engineering, and its mechanical properties and fracture characteristics are an importantbasisforconcreteanditsstructuraldesign.Some scholars [1–3] believed that concrete fracture is due to a variety of potential defects and that its fracture process is actually the process of microcrack initiation, propagation, and penetration until macroscopic cracks lead to concrete fracture.Howtostudythiscomplexmechanicalproblemhas alwaysbeenadifcultandhotspotinthe feldofmechanics and material science. After the emergence of fracture me- chanics,academiccirclessetofanupsurgeinusing fracture mechanics to study concrete. Researchers have carried out manyfracturetestsonconcretetoobtainparameterssuchas fracture toughness. At present, studies [4, 5] have realized many advantages of studying the macroscopic damage and fractureprocessofconcretefromthemesoscaleofconcrete. Somescholars[6,7]thoughtthatconcretecouldberegarded asathree-phasecompositematerial,withcementmortaras the basic phase, coarse aggregate as the second, and the adhesive tape between them as the dispersed phase. In the research on concrete fracture, some researchers [8, 9] studied the problem of crack path selection under the in- fuenceofnearbyaggregates.Teyproposedthetheoretically andexperimentallyjudgmentcriterionofcrackpropagation path. However, the stress feld at the tip of the crack is afectedbythenearbyaggregate.Tecrackwillrechoosethe propagation path and show a complex failure process. Ueda [10] performed the experiments by using poly- methyl-methacrylate(PMMA)withaslantedinternalcrack and found that there exists a diference in crack initiation angles between the MTS criterion and their experiments. Tey observed that the elastic T-stress, which is the non- singularterminWilliams’seriesexpansionofstresses,hasa signifcantinfuenceonthecrackinitiationangle.Prokopyev et al. [11] believed that the T-stress had an impact on the plastic zone size and shape of the crack tip under loading. Rice[12]usedthefniteelementmethodtostudythecrack tip stress feld about compact tension, bending, and crack center under small-scale yielding condition. Rice found there were 10–20% diferences between the fnite element and the test results, and if the second crack-tip parameter T-stresswasintroduced,suchdiferencescanbeeliminated. Weietal.[13]carriedoutmodeIfracturetestsontwokinds of rocks using a new V-notch short rod bending (VNSRB) Hindawi Mathematical Problems in Engineering Volume 2023, Article ID 4139387, 7 pages https://doi.org/10.1155/2023/4139387
Effect of T-Stress on Crack-Tip Stress Field and Crack Propagation of Concrete
May 21, 2023
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