Last. Tinh Quoc Bui(TITech: Tokyo Institute of Technology)H-Index: 45
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Abstract The objective of this article is to simulate crack growth of complex Mindlin–Reissner plates by developing an adaptive multi-patch extended isogeometric analysis (XIGA). Nitsche’s method is used to treat continuity between multi-patches or the coupling of non-conforming meshes, exactly describing the geometry of complex plates. The computational meshes in XIGA are independent of the cracks by introducing some enrichment functions into the displacement approximation based on the partitio...
Abstract The municipal water distribution systems across the world include a significant amount of cast-iron pipes. Many of the buried cast-iron pipes are over fifty years old and require rehabilitation. Municipalities decide on a rehabilitation solution between the replacement and re-use of the existing pipes based on the remaining strengths of the pipes. Fracture mechanics has appeared as the most viable tool for remaining strength assessment of the deteriorating pipes. However, a method of as...
Last. Peter K. Liaw(UT: University of Tennessee)H-Index: 77
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Abstract High total strain-controlled creep-fatigue tests of 1.8% were performed for a directionally-solidified Ni-based superalloy, DZ445, at 900 °C in air. Dwell times of 0, 2, and 5 min. were introduced at the tensile peak strain for each cycle. Experimental results show a decrease in fatigue life with increasing dwell time. The significant cyclic softening is observed after the application of the dwell time. The mean compressive stress and large plastic-strain accumulation are produced due t...
Last. Haojie Lian(TUT: Taiyuan University of Technology)H-Index: 12
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Abstract In this technical paper, large-scale true triaxial tests were conducted with sandstone specimens to investigate several factors that determine whether hydraulic fractures can propagate from the tips of axial prefabricated cracks (pre-cracks). Specifically, we investigated the influence of pre-crack inclination angles on hydraulic fracture initiation locations and how the critical pre-crack angle varies with different confining stresses, fluid viscosities, and leak-off effects. The exper...
Abstract In this study, a systematic three-dimensional finite element analyses (3D FEA) are performed to evaluate the Mode II stress intensity factor (SIF) for circumferential through-wall cracked pipe under torsion moment. A wide range of crack lengths and pipe radius over thickness ratios are considered. Empirical solution of the mid-thickness Mode II SIF is developed as functions of crack lengths and pipe sizes. The deviating angle and the effective SIF regarding a through-wall crack (TWC) un...
#1Xiaoran Wang(CUMT: China University of Mining and Technology)
#2Pouyan Asem(UMN: University of Minnesota)H-Index: 4
Last. Joseph F. Labuz(UMN: University of Minnesota)H-Index: 29
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Abstract Acoustic emission (AE) and digital image correlation were used to monitor mode I fracture in center notch and smooth boundary specimens. The AE source was characterized as a microcrack and represented by the moment tensor, which was obtained by minimizing the error between displacements calculated from an elastodynamic solution and those measured, subjected to the constraint of a microcrack source. Results showed that microcracking was locally mixed-mode dominant because of oblique micr...
Abstract Microwave assisted mechanical rock breaking is a hybrid rock breaking method that combines microwave heating and mechanical rock breaking technologies and is proven to have potential applications in mineral processing, mining, and geotechnical engineering. It is, thus, important to understand the effect of microwave-induced damage on rock fracture characteristics. In this study, granite specimens of the Cracked Straight Through Brazilian Disc (CSTBD) were used to carry out the mode I fr...
Last. Xiaojing Gong(University of Toulouse)H-Index: 1
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Abstract Strain energy release rate (SERR) along a linear crack front of a multidirectional composite DCB specimen shows an obviously non-uniform distribution, which causes the fracture toughness GIavg measured by experiments smaller than the real GIC, and so leading to a lower estimation of fracture toughness. In this study, based on the numerical model a novel semi-empirical closed-form formula was proposed for determination of pure mode I fracture toughness of a multidirectional composite DCB...
Last. Thomas Keller(EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 37
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Abstract The two-dimensional (2D) delamination growth in fiber-reinforced polymer (FRP) laminates with in-plane isotropy under Mode I loading condition was numerically investigated using finite element analyses. Two sizes of plate models were developed, focusing on different fracture stages. Cohesive elements were employed to simulate the fracture behavior in the presence of large-scale bridging (LSB). The influences of the pre-crack shape/area, loading zone shape/area and fracture resistance we...