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Effect of Blasting Stress Wave on Dynamic Crack Propagation

Computer Modeling in Engineering & Sciences 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

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Study on boundary conditions of the natural vibrations for self-anchored cable-stayed suspension bridges

Study on boundary conditions of the natural vibrations for s...

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2013 International Conference on Mechanics and Mechatronics, ICMM 2013

作者： Huang, Hai Xin Zhang, Ying Cheng, Shou Shan Qie, Yan Hui School of Civil Engineering Hebei University of Technology Tianjin 300401 China Key Laboratory of Bridge Detection and Reinforcement Technology Ministry of Communications Beijing 100088 China

ISBN: (纸本)9783037858714

The study of the natural vibrations is the basis of risk evaluation. Based on numerical simulation technology, some influence factors such as different restriction means including the setup of vertical support or fixed connection between pylon and girder, and elastic constraint along longitude of girder, as well as whether setting the auxiliary piers, the location and the number of the auxiliary pier and the changes of the dead load are chosen in order to study in depth the effects on the first-order longitudinal frequency, first-order vertical-bending frequency, first-order transverse-bending frequency and the first-order torsional frequency of self-anchored cable-stayed suspension bridges. The results obtained here have an important guiding significance to optimize structure design and defend risk. © (2013) Trans Tech Publications, Switzerland.

关键词： Suspension bridges

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External parameters analysis of the shrinkage and creep on wide deck and curved extradosed cable-stayed bridge

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Revista de la Facultad de Ingenieria 2017年第1期32卷 316-323页

作者： Feng, Yang Song, Yifan Feng, Mingshuo School of Highway Chang'an University Xi'an710064 China Key Laboratory of Old Bridge Detection and Reinforcement Technique Ministry of Transport Xi'an710064 China Kaifeng Tongda Highway Investigation and Design Co. Ltd Kaifeng475003 China

In order to analyze the influence of the shrinkage and creep on structure performance of wide deck and curved extra-dosed cable-stayed bridge. Based on the Huanglong bridge and the finite element theory, considering the influence of relative humidity, loading age, pre-stressing force, the parameters of relative humidity selected 45%-95%, the parameters of loading age selected 3 days -14 days, the parameters of pre-stressing force selected 65%-85%, analyzes the change trend of mid-span deflection, mid-span bending moment, pounding bottom bending moment in finished bridge state, three years after the state, ten years after the state. The research results show that: in the low range of parameters,the influence of pre-stressing force on the structure is remarkable, and the linear effect is outstanding; in the higher range of parameters, the influence of relative humidity parameters on the structure is remarkable, and the nonlinear effect is outstanding; the influence of loading age on the structure has certain nonlinear effect.

关键词： Loading

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Experimental study on the sensitive parameters of non-destructive test method for the cable based on the leakage magnetic principle 2

Experimental study on the sensitive parameters of non-destru...

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2nd International Conference on Environmental Prevention and Pollution Control Technologies, EPPCT 2020

作者： Dong, Zhenhua Fan, Ping Li, Pengfei Mao, Yan Bridge and Tunnel Research Center Research Institute of Highway Science of Transport Ministry Beijing100088 China Key Laboratory of Old Bridge Inspection and Reinforcement Technology Industry Beijing100088 China

The nondestructive testing (NDT) technique of steel rope based on the leakage magnetic principle has been extensively applied to the cable. In view of the difference of geometric characteristics, structures, loading between steel rope and cable, the applicability of the leakage magnetic NDT and the sensitive parameters on detection accuracy should be studied. So a cable specimen with local defects was designed and fabricated, and then the leakage magnetic testing technique was applied. The experimental electrical signal output of the cable were compared and analyzed. The results show that the accuracy of the test results is strictly related to the geometric characteristics of the test instrument, the depth of internal defects, the height of sensor removal, the sensitivity coefficient of the magnetically sensitive element, the defect spacing, etc., and the qualitative evaluation and individual quantitative index of the cable defects are proposed. The above conclusions can provide data support for the test quantitative index and the application of nondestructive testing technique. © 2020 IOP Publishing Ltd. All rights reserved.

关键词： Magnetic leakage

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Evaluation Method of Bearing Capacity of Concrete Structure

Evaluation Method of Bearing Capacity of Concrete Structure

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2024 世界交通运输大会

作者： Junpeng Xing Zechen Zhang Yubo Wang Yugeng Xu Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation

In the process of using concrete bridge structures,due to the influence of environmental and internal material factors,with the passage of time,materials will gradually age,structural performance will deteriorate,and structures will experience damage or even *** reinforced concrete structures,the main manifestations include concrete carbonation,reinforcement corrosion,deterioration of mechanical properties of corroded reinforcements,and the appearance and development of structural *** prestressed concrete structures,the main manifestations include concrete deterioration,corrosion of prestressing tendons and ordinary reinforcement,reduction in effective prestress,degradation of mechanical properties of corroded reinforcements,weakening of bond strength between corroded reinforcements and concrete,as well as the appearance and development of structural *** determine the safety,durability,and normal functional use of bridges,it is necessary to inspect and evaluate in-service prestressed concrete *** paper summarizes existing crack detection methods and introduces evaluation methods for reinforced concrete structures based on crack statistical *** introduces performance evaluation indicators for prestressed concrete structures and explains how to use these indicators to evaluate prestressed concrete structures.

关键词： bridge engineering Highway bridges detection techniques Evaluation methods

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Calculation Method for the Cable Zone Beams of a Single Cable Plane Low-Pylon Cable-Stayed bridge with a Wide Box Girder 5

Calculation Method for the Cable Zone Beams of a Single Cabl...

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5th International Conference on transportation Engineering, ICTE 2015

作者： Zhan, Binglai Sun, Ning Li, Yang Xu, Yue Key Laboratory of Bridge Detection and Reinforcement Technology Ministry of Communication Chang'an University Xi'an Shanxi China CCCC First Highway Consultants Co. Ltd. Xi'an China

ISBN: (数字)9780784479384

ISBN: (纸本)9780784479384

The researches for cable area beams of single cable plane low-pylon cable-stayed bridge were summarized;Based on plane frame theoretical mechanics, the simplified model for cable area beams of single cable plane low-pylon cable-stayed bridge with wide box girder is elaborated;and mechanical characteristics of the cable zone beams were studied by changing the structural properties. The Conclusions has some reference value. © ASCE.

关键词： Low-pylon cable-stayed bridge Single cable plane Cable zone beam Simplified calculation modalities The mechanical characteristic Mechanical properties cable computational methods Box beams Cable stayed bridge reference value plane Platanus hybrida BEAM Beams and girders Planing

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Seismic Isolation and Energy Absorption Properties Research for a Dry Joint Segment Fabricated Pier Viaduct in a Highly Seismic Region 5

Seismic Isolation and Energy Absorption Properties Research ...

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5th International Conference on transportation Engineering, ICTE 2015

作者： Zhan, Binglai Sun, Ning Li, Yang Key Laboratory of Bridge Detection and Reinforcement Technology Ministry of Communication Chang'an University Xi'an Shanxi China CCCC First Highway Consultants Co. Ltd. Xi'an China

ISBN: (数字)9780784479384

ISBN: (纸本)9780784479384

This article proposes a bilinear stiffness plastic hinge simplified model , based on the existing experimental research on dry joints fabricated pier;Using of nonlinear time history analysis method, seismic isolation performance of combination system of dry joints fabricated pier with laminated rubber bearing is discussed in the perspective of damping isolation. Results indicate that the dry joints fabricated pier system can reduce the seismic force and energy. The conclusion has some practical significance for the applications of dry joints fabricated pier bridge in high earthquake region. © ASCE.

关键词： Seismic isolation performance Fabricated pier Time history analysis method Simplified calculation mode

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The improvement of gray system theory based on Kalman's filtering method and its application in extradosed cable-stayed bridge construction control

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C e Ca 2017年第1期42卷 82-85页

作者： Feng, Yang Feng, Mingshuo Song, Yifan School of Highway Chang'an University Xi'an710064 China Kaifeng Tongda Highway Investigation and Design Co. Ltd Kaifeng475003 China Key Laboratory of Old Bridge Detection and Reinforcement Technique Ministry of Transport Chang'an University Xi'an710064 China

In the construction of extradosed cable-stayed bridge, the measured deflection values are often different from design value. As a solution, the grey system theory was modified by Kalman's filtering method and was applied in the field deflection prediction. We analyzed the actual measurement data set and predicted the adjustment values of deflection gradually in the construction process, so as to meet the design requirements of extradosed cable-stayed bridge structure and to achieve the design requirements of flexure and internal force state. In order to verify the accuracy of the improved calculation model, the original grey system theory and the modified one using Kalman's filtering method are adopted in the deflection prediction based on the actual extra dosed cable-stayed bridge. Experimental results show that the revised grey system theory based on Kalman's filtering method can effectively reduce the deviation between predicted values and measured ones, reducing the deviation of bridge linear from the design one as well.

关键词： Cable stayed bridges

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Analysis on the capacity of old highway bridge

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2013 3rd International Symposium on Chemical Engineering and Material Properties, ISCEMP 2013

作者： Yang, Ya Xun Wang, Wei Shan Qiao, Chao Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation Chang'an University Xi'an 710064 Shaanxi China Xi'an Highway Research Institute Xi'an 710064 Shaanxi China

ISBN: (纸本)9783037858363

Most bridges show different degrees of disease in the operations many years later. Combing the bridge disease investigation, materials inspection and load test done on the background of the interchanges over Yicheng-Houma expressway, this paper will make assessment of the frequently-used box-girder bridges' bearing capacity in the expressway to provide a reference for bearing capacity assessment of the old expressway bridges. © (2013) Trans Tech Publications, Switzerland.

关键词： Bearing capacity

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Seismic response of rocking double-column bridge bents with external hysteretic dissipaters

Seismic response of rocking double-column bridge bents with ...

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2020 International Conference on Intelligent transportation, Big Data and Smart City, ICITBS 2020

作者： Zhou, Yulong Zhang, Jinquan Cheng, Shoushan He, Haifang Dong, Zhenhua Qiang, Han Key Laboratory of Old Bridge Inspection and Reinforcement Technology Industry Research Institute of Highway Science of Transport Ministry Beijing100088 China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Technology Beijing100124 China

ISBN: (纸本)9781728166971

Rocking bent is a potential alternative for seismic resistant and post-earthquake resilience of bridges. In order to study the seismic response of rocking double-column bridge bents with external hysteretic dissipaters, this paper developed an analytical model considering the impact and dissipater fracture. The benefits of dissipaters for rocking bridge bents were validated compared with the free-rocking bent. The influence of the hysteretic dissipater parameters on the seismic response of rocking bridge bent were also analyzed. The analysis considers far-field and near-field earthquake records. The study results show that the external hysteretic dissipaters have attractive benefit on the seismic response and stability of rocking double-column bridge bents. The dissipater fracture and overturning are sensitive to the distinctive pulses of near-field records, which is crucial from the design point of view. © 2020 IEEE.

关键词： Seismic response

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