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Inner damage identification and residual strength assessment of a 3D printed tunnel with marble-like cementitious materials using piezoelectric transducers

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 838-851页

作者： Guowei Ma Chen Huang Junfei Zhang School of Civil and Transportation Engineering Hebei University of TechnologyTianjin300401China College of Architecture and Civil Engineering Beijing University of TechnologyBeijing100124China

Quantitative damage identification of surrounding rock is important to assess the current condition and residual strength of underground tunnels.In this work,an underground tunnel model with marble-like cementitious materials was first fabricated using the three-dimensional(3D)printing technique and then loaded to simulate its failure mode in the laboratory.Lead zirconate titanate piezoelectric(PZT)transducers were embedded in the surrounding rock around the tunnel in the process of 3D printing.A 3D monitoring network was formed to locate damage areas and evaluate damage extent during loading.Results show that as the load increased,main cracks firstly appeared above the tunnel roof and below the floor,and then they coalesced into the tunnel boundary.Finally,the tunnel model was broken into several parts.The resonant frequency and the peak of the conductance signature firstly shifted rightwards with loading due to the sealing of microcracks,and then shifted backwards after new cracks appeared.An overall increase in the root-mean-square deviation(RMSD)calculated from conductance signatures of all the PZT transducers was observed as the load(damage)increased.Damage-dependent equivalent stiffness parameters(ESPs)were calculated from the real and imaginary signatures of each PZT at different damage states.Satisfactory agreement between equivalent and experimental ESP values was achieved.Also,the relationship between the change of the ESP and the residual strength was obtained.The method paves the way for damage identification and residual strength estimation of other 3D printed structures in civil engineering.

关键词： Piezoelectric(PZT)transducers Three-dimensional(3D)printed tunnel Electro-mechanical impedance(EMI) method Equivalent stiffness parameter(ESP) residual strength

Numerical Analysis of residual strength in the Perforated Casing of Ultra Deep Wells

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Fluid Dynamics & Materials Processing 2023年第1期19卷 261-271页

作者： Yanxian Wu Shouming Zhong Zhigang Guan Lin Song Kun Li Jiarui Sun Yuqiang Xu Maochuan Tu Chaobin Fan Jinbin Yang Engineering Technology Research Institute of Petro China Xinjiang Oilfield Company Karamay834000China School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580China SINOPEC Xinan Oilfield Service Corporation Deyang618000China SINOPEC Southwest China Oil&Gas Company Chengdu610041China

A three-dimensional model for the numerical simulation of casing-cement behavior is used to investigate residual strength in the perforated casing of ultra deep wells.The influence of the hole diameter,hole density and phase angle on the residual strength of the casing under non-uniform stress and fracturing conditions is revealed through the consideration of different perforation parameters.It is shown that the residual strength of the casing increases with the hole diameter and periodically changes with the hole density;the phase angle is the main factor that affects the residual strength of the perforated casing,and the perforation should be avoided in the direction of the minimum principal stress to reduce stress concentration at the perforation hole.Moreover,as shown by a companion orthogonal experiment,the descending order of influence of the different influential parameters is:phase angle,hole diameter,hole density and the thickness of casing.

关键词： Perforated casing non-uniform stress residual strength orthogonal experiment

A Model for the Determination of Semi-Circular Spot Corrosion Damage and residual strength in Oil Pipes

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Fluid Dynamics & Materials Processing 2023年第6期19卷 1709-1720页

作者： Hongtao Liu Maoxian Xiong Bo Zhang Junfeng Xie Jinrui Deng MifengZhao Ruijing Jiang Yushan Zheng Research Institute of Oil and Gas Engineering Tarim Oilfield Company PetroChinaKorla841000China CNPC Research Institute of Safety and Environment Technology Beijing102206China

Pitting corrosion often occurs due to the presence of various corrosive substances,such as CO_(2) and H_(2)S,in the pipe service environment.As a result of this process,the residual strength of oil pipes is reduced and this can compromise the integrity of the entire pipe string.In the present work,a model is introduced on the basis of the API579 standard to determine the so-called stress concentration coefficient.The model accounts for pitting corrosion shapes such as shallow semi-circles,semi-circles,and deep semi-circles.The relationship between the corrosion pit depth and opening diameter and the residual strength of the oil casing is obtained.The results show that the influence of the pit opening diameter on the stress concentration coefficient is smaller than that of the pit depth.For a constant pit opening diameter,the coefficient increases gradually with increasing the pit depth.The compressive strength and internal pressure strength of the carbon steel oil casing decrease accordingly.When the depth of the corrosion pit is relatively small,the growth of the coefficient is slower;when the depth of the corrosion pit increases to a certain value,the increase in stress concentration coefficient becomes obvious.

关键词： Pitting corrosion residual strength stress concentration coefficient

residual strength AND FATIGUE LIFE OF 2-D AND 3-D CARBON FABRIC COMPOSITES

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Chinese Journal of Aeronautics 1999年第2期12卷 19-24页

作者：燕瑛北京航空航天大学飞机设计所北京

The fatigue behavior and damage mechanisms of 2 D and 3 D carbon/epoxy composites with approximately the same 51% fiber volume fraction were investigated. A test program was conducted on fatigue residual strength and fatigue life under constant amplitude tensile fatigue loading. Equations of predicting the fatigue life for both 2 D and 3 D composites were provided. Comparison of the 2 D and 3 D composites indicated that due to the through thickness reinforcement, the 3 D composite has considerably better fatigue performance. Comparison of experimental data with calculation results shows good agreement, thus confirming the usefulness of the predictions.

关键词： D and 3 D composites residual strength fatigue life

residual strength model for composite laminates

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Journal of Harbin Institute of Technology(New Series) 2010年第3期17卷 424-426页

作者：边文凤郭景哲杜善义 Postdoctoral Flow Station of Materials Science and Engineering Harbin Institute of Technology School of Civil Engineering Harbin Institute of Technology at Weihai

To research the approach of predicting composites fatigue life,the cumulative fatigue damage of fiber-reinforced plastic laminates(FRP) was investigated,and based on the complex exponential function,the residual strength model was obtained. This model can accurately describe the propagation of cumulative fatigue damage of FRP in three stages,especially in the initial stage and the ceasing stage. Applying this model in the experiment with two loading cycles,it can be found that the prediction result has good coincidence with experimental data. So a reliable residual strength model can be provided for studying the cumulative fatigue damage of FRP.

关键词： composite material residual strength fatigue life cumulative damage

Determining effects of impact loading on residual strength of fiber-metal laminates with grid-characteristic numerical method

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Chinese Journal of Aeronautics 2021年第7期34卷 1-12页

作者： Katerina BEKLEMYSHEVA Vasily GOLUBEV Igor PETROV Alexey VASYUKOV Moscow Institute of Physics and Technology DolgoprudniyRussia

The Grid-Characteristic numerical Method(GCM)that is quite common in solving aero and hydrodynamic problems can also be applied for mechanics of solids.It allows to implement complex border and contact conditions,including the non-reflecting border and the destructible contact.Both this conditions are very important for the precise and effective modeling of LowVelocity Impacts(LVI)on fiber and Fiber-Metal Laminates(FML)and the resulting Barely Visible Impact Damage(BVID)that influences the residual strength of a composite aircraft part.BVID is the type of damage that is not visible by the naked eye and can be hardly detected by a standard ultrasound equipment that is used for regular maintenance.It can appear during any weak impacts like bird strike or hail.Determining its influence on the residual strength of the part is very important to define the priorities of development of ultrasound diagnostics.In this paper,the GCM was applied for a full cycle of loading of an FML aircraft cover part.The FML consisted of a Carbon Fiber Reinforced Polymer(CFRP)and a single titanium layer on the upper surface.The cycle of loading in a single calculation consisted of an LVI caused by a small striker and a comparatively slow compressive in-plane loading.Three-dimensional patterns of velocity and stress distributions over the time of calculation are given.Destruction patterns,obtained via the Hashin failure criterion are given and analyzed.

关键词： Fiber-metal laminate Grid-characteristic method Low-velocity impact Numerical modeling residual strength

Corrosion damage evolution and residual strength of corroded aluminum alloys

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Journal of University of Science and Technology Beijing 2008年第4期15卷 430-433页

作者： Youhong Zhang Guozhi Lv Hui Wang Bomei Si Yueliang Cheng The Second Artillery Engineering College Xi＇an 710025 China School of Aeronautics Northwest Polytechnical University Xi＇an 710072 China Naval Aeronautical Engineering Academy Qingdao Branch Qingdao 266041 China

The LY12CZ aluminum alloy specimens were corroded under the conditions of different test temperatures and exposure durations. After corrosion exposure, fatigue tests were performed. Scanning electron microscopy and optical microscope analyses on corrosion damage were carried out. The definition of surface corrosion damage ratio was provided to describe the extent of surface corrosion damage. On the basis of the measured data sets of the corrosion damage ratio, the probabilistic model of corrosion damage evolution was built. The corrosion damage decreased the fatigue life by a factor of about 1.25 to 2.38 and the prediction method of residual strength of the corroded structure was presented.

关键词： aluminum alloy corrosion damage fatigue statistical analysis residual strength

An analytical method to assess the damage and predict the residual strength of a ship in a shoal grounding accident scenario

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Journal of Ocean Engineering and Science 2016年第2期1卷 167-179页

作者： Sun Bin Hu Zhiqiang Wang Jin Yu Zhaolong State Key Lab of Ocean Engineering Shanghai Jiao Tong UniversityShanghaiChina COTEC USA HoustonUSA Dept.of Marine Technology Norwegian University of Science and TechnologyTrondheimNorway

In this paper,a simplified analytical method used to predict the residual ultimate strength of a ship hull after a shoal grounding accident is proposed.Shoal grounding accidents always lead to severe denting,though not tearing,of the ship bottom structure,which may threaten the global hull girder resistance and result in even worse consequences,such as hull collapse.Here,the degree of damage of the bottom structure is predicted by a series of analytical methods based on the plastic-elastic deformation mechanism.The energy dissipation of a ship bottom structure is obtained from individual components to determine the sliding distance of the seabed obstruction.Then,a new approach to assess the residual strength of the damaged ship subjected to shoal grounding is proposed based on the improved Smith’s method.This analytical method is verified by comparing the results of the proposed method and those generated by numerical simulation using the software ABAQUS.The proposed analytical method can be used to assess the safety of a ship with a double bottom during its design phase and predict the residual ultimate strength of a ship after a shoal grounding accident occurs.

关键词： Shoal grounding residual strength Simplified analytical method Numerical simulation Damage analysis

Prediction of the residual strength of clay using functional networks

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Geoscience Frontiers 2016年第1期7卷 67-74页

作者： S.Z.Khan Shakti Suman M.Pavani S.K.Das Civil Engineering Department BIETBPUT Civil Engineering Department National Institute of Technology Rourkela

Landslides are common natural hazards occurring in most parts of the world and have considerable adverse economic effects. residual shear strength of clay is one of the most important factors in the determination of stability of slopes or landslides. This effect is more pronounced in sensitive clays which show large changes in shear strength from peak to residual states. This study analyses the prediction of the residual strength of clay based on a new prediction model, functional networks（FN） using data available in the literature. The performance of FN was compared with support vector machine（SVM） and artificial neural network（ANN） based on statistical parameters like correlation coefficient（R）, Nash–Sutcliff coefficient of efficiency（E）, absolute average error（AAE）, maximum average error（MAE） and root mean square error（RMSE）. Based on R and E parameters, FN is found to be a better prediction tool than ANN for the given data. However, the R and E values for FN are less than SVM. A prediction equation is presented that can be used by practicing geotechnical engineers. A sensitivity analysis is carried out to ascertain the importance of various inputs in the prediction of the output.

关键词： Landslides residual strength Index properties Prediction model Functional networks