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Investigation of crack segmentation and fast evaluation of crack propagation, based on deep learning

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 516-535页

作者： Than V.TRAN H.NGUYEN-XUAN Xiaoying ZHUANG Institute of Photonics Leibniz University HannoverHannover 30167Germany CIRTech Institute HUTECH UniversityHo Chi Minh City 700000Vietnam College of Civil Engineering Tongji UniversityShanghai 200092China

Identifying crack and predicting crack propagation are critical processes for the risk assessment of engineering *** traditional approaches to crack modeling are faced with issues of high computational costs and excessive computing *** address this issue,we explore the potential of deep learning(DL)to increase the efficiency of crack detection and forecasting crack ***,there is no single algorithm that can fit all data sets well or can apply in all cases since specific tasks *** the paper,we present DL models for identifying cracks,especially on concrete surface images,and for predicting crack ***,SegNet and U-Net networks are used to identify concrete *** gradient descent(SGD)and adaptive moment estimation(Adam)algorithms are applied to minimize loss function during ***,time series algorithms including gated recurrent unit(GRU)and long short-term memory(LSTM)are used to predict crack *** experimental findings indicate that the U-Net is more robust and efficient than the SegNet for identifying crack segmentation and achieves the most outstanding *** evaluation of crack propagation,GRU and LSTM are used as DL models and results show good agreement with the experimental data.

关键词： deep learning crack segmentation crack propagation encoder−decoder recurrent neural network

Particle Discontinuous Deformation Analysis of Static and Dynamic crack propagation in Brittle Material

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2215-2236页

作者： Zediao Chen Feng Liu State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin300072China

crack propagation in brittle material is not only crucial for structural safety evaluation,but also has a wideranging impact on material design,damage assessment,resource extraction,and scientific research.A thorough investigation into the behavior of crack propagation contributes to a better understanding and control of the properties of brittle materials,thereby enhancing the reliability and safety of both materials and *** an implicit discrete elementmethod,the Discontinuous Deformation Analysis(DDA)has gained significant attention for its developments and applications in recent *** these developments,the particle DDA equipped with the bonded particle model is a powerful tool for predicting the whole process of material from continuity to *** primary objective of this research is to develop and utilize the particle DDAtomodel and understand the complex behavior of cracks in brittle materials under both static and dynamic *** particle DDA is applied to several classical crack propagation problems,including the crack branching,compact tensile test,Kalthoff impact experiment,and tensile test of a rectangular plate with a *** evolutions of cracks under various stress or geometrical conditions are carefully *** simulated results are compared with the experiments and other numerical *** is found that the crack propagation patterns,including crack branching and the formation of secondary cracks,can be well *** results show that the particle DDA is a qualified method for crack propagation problems,providing valuable insights into the fracture mechanism of brittle materials.

关键词： Discontinuous deformation analysis particle DDA crack propagation crack branching brittle materials

Fatigue crack propagation Law of Corroded Steel Box Girders in Long Span Bridges

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 201-227页

作者： Ying Wang Longxiao Chao Jun Chen Songbai Jiang Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education School of Civil EngineeringSoutheast UniversityNanjing211189China Jiangsu Provincial Engineering Construction Standard Station Nanjing210036China

In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks,this study realizes the simulation of the welding process through elastic-plastic finite element theory,thermal-structural sequential coupling,and the birth-death element *** simulated welding residual stresses are introduced into the multiscale finite element model of the bridge as the initial ***,the study explores the impact of residual stress on crack propagation in the fatigue-vulnerable components of the corroded steel box *** results indicate that fatigue cracks at the weld toe of the top deck,the weld root of the top deck,and the opening of the transverse diaphragm will not propagate under the action of a standard vehicle ***,the inclusion of residual stress leads to the propagation of these *** considering residual stress,the fatigue crack propagation paths at the weld toe of the transverse diaphragm and the U-rib weld toe align with those observed in actual *** the absence of residual stress,the cracks at the toe of the transverse diaphragm with a 15%mass loss rate are categorized as type I ***,when residual stress is considered,these cracks become I-II composite *** stress significantly alters the cumulative energy release rate of the three ***,incorporating the influence of residual stress is essential when assessing the fatigue performance of corroded steel box girders in long-span bridges.

关键词： Residual stress crack propagation corroded steel box girder cumulative energy release rate

Effect of Blasting Stress Wave on Dynamic crack propagation

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工程与科学中的计算机建模(英文) 2024年第1期138卷 349-368页

作者： Huizhen Liu Duanying Wan Meng Wang Zheming Zhu Liyun Yang Key Laboratory for Old Bridge Detection&Reinforcement Technology of the Ministry of Transportation Beijing100088China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China MOE Key Laboratory of Deep Underground Science and Engineering School of Architecture and EnvironmentSichuan UniversityChengdu610065China

Stress waves affect the stress field at the crack tip and dominate the dynamic crack ***,evaluating the influence of blasting stress waves on the crack propagation behavior and the mechanical characteristics of crack propagation is of great significance for engineering *** this study,ANSYS/LS-DYNA was used for blasting numerical simulation,in which the propagation characteristics of blasting stress waves and stress field distribution at the crack tip were closely ***,ABAQUS was applied for simulating the crack propagation path and calculating dynamic stress intensity factors(DSIFs).The universal function was calculated by the *** results show that:the compressive wave causes the crack to close and the reflected tensile wave drives the crack to initiate and propagate,and failure mode is mainly tensile *** crack propagation velocity varies with time,which increases at first and then decreases,and the crack arrest occurs due to the attenuation of stress waves and dissipation of the blasting *** addition,crack arrest toughness is smaller than the crack initiation toughness,applied pressure waveforms(such as the peak pressure,duration,waveforms,wavelengths and loading rates)have a great influence on *** is conducive to our deep understanding or the study of blasting stress waves dominated fracture,suggesting a broad reference for the further development of rock blasting in engineering practice.

关键词： crack propagation blasting stress wave dynamic stress intensity factor pressure waveform numerical simulation

Fatigue crack Initiation and propagation Dominated by Crystallographic Factors in TiB/near α-Ti Composite

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 763-776页

作者： Fanchao Meng Rui Zhang Shuai Wang Fengbo Sun Run Chen Lujun Huang Lin Geng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Waikato Centre for Advanced Materials and Manufacturing School of EngineeringUniversity of WaikatoHamilton 3240New Zealand State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Discontinuously reinforced titanium matrix composites(DRTMCs)with a network structure have been extensively researched due to their superior combination of strength and ***,their fatigue performance has remained *** order to elucidate the fatigue behavior of DRTMCs,a tension-tension fatigue test was performed on a TiB/nearα-Ti composite with network *** results showed that the variability of fatigue lifetime increased as the stress level *** analysis indicated that fatigue crack initiation was associated with facet formation,while the subsequent propagation was hindered by the network structure comprising TiB whiskers and *** characterization further revealed that facets formed due to a combination of shear and normal *** reduction in fatigue lifetime was attributed to an increase in the effective slip length,which was influenced by the orientation of grains near the crack-initiation sites toward basal slip in the life-limiting *** in situ observation suggested that the crack initiation was facilitated by both basal and prismatic slip ofα-Ti as well as fracture of *** propagation was found to be associated with basal and prismatic slip systems with high Schmid factors,regardless of whether the crack was intergranular or intragranular.

关键词： Titanium matrix composite TiBw Fatigue lifetime variability crack initiation crack propagation

Fatigue crack propagation in fine-grained magnesium under low temperature tension-tension cyclic loading

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Journal of Magnesium and Alloys 2023年第12期11卷 4420-4430页

作者： Qizhen Li School of Mechanical and Materials Engineering Washington State UniversityPullmanWAUSA

Fine-grained magnesium was tested under stress-controlled tension-tension cyclic loading at -30 ℃ and the tested sample was observed using scanning electron microscope and electron backscatter diffraction to explore the fatigue behavior and crack propagation. The fatigue data showed that the material experienced cyclic softening followed by cyclic hardening before the final fracture failure. The microscopic observations demonstrated that the cracks were almost perpendicular to the loading direction with some zigzags and the cracks progressed along both small angle grain boundaries and large angle grain boundaries. Although the cracks were mainly propagated along large angle grain boundaries, the value of grain boundary angle was not the primary factor to determine the crack propagation direction. The local residual strain from the rolling process was released due to the crack propagation and there was more strain relaxation at regions closer to the cracks.

关键词： Fine-grained magnesium Fatigue properties Tension crack propagation Low temperatures

Theoretical Analysis of crack propagation Measurement for Brittle Materials Based on Virtual Principal Strain Field

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Acta Mechanica Solida Sinica 2022年第5期35卷 842-850页

作者： Liuning Gu Xinxing Shao Department of Engineering Mechanics School of Civil EngineeringSoutheast UniversityNanjing211189China

The measurement of crack propagation is crucial for revealing the fracture mechanical properties of materials and *** on the virtual principal strain field and Steger’s algorithm,an accurate and automatic method has been proposed for measuring the geometric parameters of crack *** measured geometric parameters of crack propagation include the width,length,and tip location of each *** mechanism of the crack-induced virtual principal strain field and the effects of subset,step,and strain window size are analyzed and discussed *** effectiveness of the derived theoretical equations is verified by the simulation *** to the theoretical equations,it is determined that the distribution of the virtual principal strain field near the crack is similar to the grayscale distribution of the laser fringe image with optimized calculation *** are further conducted to validate the effectiveness of the derived *** the optimized calculation parameters,the minimum crack that can be measured is approximately 0.0362 pixel in the laboratory environment,while the measurement error of the crack width is less than 0.025 pixel for two-dimensional digital image correlation(DIC)and 0.020 pixel for three-dimensional DIC.

关键词： crack propagation Brittle materials Digital image correlation Virtual principal strain Steger’s algorithm

Atomistic simulation of{0001}<1210>crack propagation with Nb precipitates inα-Zr

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Rare Metals 2023年第5期42卷 1663-1669页

作者： Hua Ji Jian Yin Guo Wei Wen-Sheng Lai Bai-Xin Liu Jian-Bo Liu Suzhou Nuclear Power Research Institute Suzhou215004China School of Physics and Technology Center for Ion Beam Applicationand Hubei Nuclear Solid Physics Key LaboratoryWuhan UniversityWuhan430072China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing100084China

The fracture characteristics of Zr alloys significantly impact the performance of fuel cladding tubes in pressurized water reactors of nuclear power *** this study,molecular dynamics(MD)simulations were performed to investigate the{0001}(1210)crack propagation inα-*** influence of temperature and Nb precipitates on the crack propagation was investigated.A total of 469tensile simulations were *** innovative approach to study the interaction between crack propagation and second-phase particles in the crystals was adopted,which could effectively capture the interaction of secondphase particles with dislocations and twins generated during crack *** the simulation,{1126}and{1012}twins were observed during crack propagation with Nb precipitates in the *** simulation results revealed that the Nb precipitates further resisted crack propagation,especially those with a radius of approximately 2 *** addition,the Nb precipitates in the extension direction of the{1026}twin exhibited higher resistance to crack propagation than those at other locations.

关键词： Zirconium alloys crack propagation Twinning Nb precipitates Molecular dynamic(MD)simulation

Kernel broken smooth particle hydrodynamics method for crack propagation simulation applied in layered rock cells and tunnels

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Underground Space 2023年第3期10卷 55-75页

作者： Chengzhi Xia Zhenming Shi Hongchao Zheng Xiaohan Wu School of Civil Engineering Tongji UniversityShanghai 200092China College of Environmental Science and Engineering Tongji UniversityShanghai 200092China

Understanding the cracking process of layered tunnels requires a high-fidelity *** smooth particle hydrodynamics(SPH),termed kernel broken SPH(KBSPH),was implemented to simulate the crack propagation and deformation of layered rock cells and field layered tunnels with dip angles of 0°–90°,and the results were compared with those of the laboratory *** attempts,including the bedding angle,interlayer distance,and lateral pressure coefficient,were made to investigate the crack propagation and deformation of layered ***,the pros and cons of the KBSPH method applied in the rock field were compared with those of other *** results indicate that the KBSPH can explicitly reproduce crack propagation by improving the kernel function with a totally damaged symbol,and the deformation responses have been captured *** infer that this method is effective and rapid in crack propagation and large deformation simulation for other types of rock tunnels.

关键词： Smooth particle hydrodynamics Kernel broken Layered rock tunnel crack propagation