The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechni...The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechnical materials.However,there is lack of effective quantitative analysis method for the complex evolution mechanism of threedimensional shear bands.In this work,we used X-ray computed tomography(CT)to reconstruct volume images and used the digital volume correlation(DVC)method to calculate the three-dimensional strain fields of granite residual soil samples at different loading stages.The trend of the failure surface of the shear bands was obtained by the planar fitting method,and the connectivity index was constructed according to the projection characteristics of the shear bands on the failure trend surface.The results support the following findings:the connectivity index of the shear band increases rapidly and then slowly with increasing axial strain,which is characterized by a near'S'curve.As the stress reaches the peak value,the connectivity index of the shear bands almost exceeds 0.7.The contribution of the new shear band volume to the connectivity of the shear bands becomes increasingly small with increasing axial loading.Affected by quartz grains and stress at the initial stage,the dip angle gradually and finally approaches the included angle of the maximum shear stress from the discrete state with increasing axial loading.The tendency and dip angle of the resulting shear bands are dynamic,and the tendency slightly deflects with increasing loading.展开更多
During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil d...During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.展开更多
In order to increase use ratio of steel slag solid waste,the concrete containing steel slag powder and zeolite powder as admixtures was prepared by using the orthogonal test method.The effects of water-binder ratio,s...In order to increase use ratio of steel slag solid waste,the concrete containing steel slag powder and zeolite powder as admixtures was prepared by using the orthogonal test method.The effects of water-binder ratio,sand ratio,steel slag powder content and zeolite powder on working properties,mechanical strength and chloride ion permeability of the concrete was studied.It was found that the early strength of the concrete had a decrease with the mixing of steel slag and zeolite powders,but its later strength approached to pure concrete.Moreover,the physical filling and pozzolanic activity of the admixtures increased the density of the concrete,resulting in the improvement of the durability of the concrete by the migration speed of Cl−reducing.The optimum mix ratio of C40 steel slag powder-zeolite powder concrete is obtained,and which had the slump of 220 mm,the 3 d,7 d and 28 d compressive strengths of 27.8 MPa,37.5 MPa and 48.4 MPa,the 6 h electric flux of 950 C and the diffusion coefficient of 1.65×10−12 m2/s.展开更多
To determine structure and parameters of a rheological constitutive model for rocks,a new method based on differential evolution(DE) algorithm combined with FLAC3D(a numerical code for geotechnical engineering) was pr...To determine structure and parameters of a rheological constitutive model for rocks,a new method based on differential evolution(DE) algorithm combined with FLAC3D(a numerical code for geotechnical engineering) was proposed for identification of the global optimum coupled of model structure and its parameters.At first,stochastic coupled mode was initialized,the difference in displacement between the numerical value and in-situ measurements was regarded as fitness value to evaluate quality of the coupled mode.Then the coupled-mode was updated continually using DE rule until the optimal parameters were found.Thus,coupled-mode was identified adaptively during back analysis process.The results of applications to Jinping tunnels in China show that the method is feasible and efficient for identifying the coupled-mode of constitutive structure and its parameters.The method overcomes the limitation of the traditional method and improves significantly precision and speed of displacement back analysis process.展开更多
A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility.However,their use for damage detection should be...A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility.However,their use for damage detection should be performed with special attention,particularly in operational and environmental conditions subjected to temperature changes.Beams in construction industries experience different loading types,such as temperature changes leading to crack initiation and propagation.Changed physical and dynamic properties such as natural frequencies and mode shapes indicate that damage has occurred within the structures.In this study,vibration analysis of cantilever and cantilever simply supported beams has been carried out on intact and damaged beams to investigate the coupled effect of temperature changes and damage depth on natural frequencies.A numerical analysis of beams is completed using ANSYS software.The results of numerical simulation are validated using two other studies from literature.Numerical results revealed that in order to perform a successful damage assessment using the frequency shift,the vibration modes should be selected properly.In addition,an increase in temperature results in a decrease in structural frequencies.The assessment of the effect of damage depth on natural frequencies also confirms that when damage depth is increased,there is a significant decrease in natural frequency responses.展开更多
The problem of seismic response of buried pipeline aimed at the interaction of soil around the pipeline and the complicated calculation model was considered, and the various simplified finite element model was calcula...The problem of seismic response of buried pipeline aimed at the interaction of soil around the pipeline and the complicated calculation model was considered, and the various simplified finite element model was calculated, and it was analyzed. Firstly, the ADINA finite element analysis software was used. The four nodes in shell unit were used by tube. The spring unit was used by soil spring. The analysis model of buried pipeline finite element numerical based on tension and compression spring was established. Seismic wave was input. The response to the simple boundary, viscoelastic boundary earthquake were calculated and analyzed by the finite element numerical simulation. The pipeline’s earthquake ground motion response was obtained, and was compared with the real soil model, and the most suitable simplified calculation model for numerical analysis of buried pipeline was found, which was the numerical analysis model of buried pipeline pressure spring tension finite element based on the viscoelastic boundary, and the theory basis for the seismic design of pipeline was provided.展开更多
Applying recycled concrete for engineered projects not only protects the ecological environment but also improves the utilization rate of waste concrete to satisfy sustainable development requirements.However,the mech...Applying recycled concrete for engineered projects not only protects the ecological environment but also improves the utilization rate of waste concrete to satisfy sustainable development requirements.However,the mechanical properties of recycled concrete are not as good as those of ordinary concrete.To enhance the former’s performance and increase its popularity and application in engineeringfields,notable advances have been made by using steel,synthetic,plant,and mineralfiber materials.These materials are added to recycled concrete to improve its mechanical properties.Studies have shown that(1)steelfibers have a distinct reinforcing effect and improve the strength,toughness,and elastic modulus of recycled concrete;(2)the addition of syntheticfibers can improve the tension,crack resistance,and durability of concrete,but the size effect needs to be further explored and elaborated;(3)plantfiber concrete is lightweight and environmentally friendly and provides high toughness and good thermal insulation,but thefibers corrode in alkaline environments;in addition,plantfibers have high water absorption capacity,which leads to wet expansion and dry shrinkage phenomena,which need to be further studied;and(4)the cost of basaltfiber,a mineralfiber,is relatively low,and a suitable basalt content can improve the mechanical properties of recycled concrete to a certain extent.展开更多
Three-dimensional rock fracture induced by blasting is a highly complex problem and has received considerable attention in geotechnical engineering.The material point method is firstly applied to treat this challengin...Three-dimensional rock fracture induced by blasting is a highly complex problem and has received considerable attention in geotechnical engineering.The material point method is firstly applied to treat this challenging task.Some inherent weaknesses can be overcome by coupling the generalized interpolation material point(GIMP)and the convected particle domain interpolation technique(CPDI).For the media in the borehole,unchanged GIMP-type particles are used to guarantee a homogenous blast pressure.CPDITetrahedron type particles are employed to avoid the fake numerical fracture near the borehole for the rock material.A blasting experiment using three-dimensional single-borehole rock was simulated to examine the applicability of the coupled model under realistic loading and boundary conditions.A good agreement was achieved between the simulation and experimental results.Moreover,the mechanism of three-dimensional rock fracture was analyzed.It was concluded that rock particle size and material parameters play an important role in rock damage.The reflected tensile waves cause severe damage in the lower part of the model.Rayleigh waves occur on the top face of the rock model to induce a hoop failure band.展开更多
Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse ...Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers on combustion characteristics of asphalt mortar by thermogravimetric and kinetic analysis. It is shown that the combustion of asphalt mortar is not just a linear superposition of asphalt and limestone. The limestone will increase the ignition point and the activation energy of the primary volatile release, and will catalyze the char formation from the primary volatile release. Kinetic analysis shows that the primary volatile release stage of asphalt mortar combustion can be explained by a three-dimensional diffusion model, the secondary volatile release and char combustion stage can be explained by a model under the assumption of random nucleation and nuclei growth, whereas the limestone decomposition stage appears to follow the one-dimensional phase boundary model.展开更多
Digital twin(DT)can achieve real-time information fusion and interactive feedback between virtual space and physical space.This technology involves a digital model,real-time information management,comprehensive intell...Digital twin(DT)can achieve real-time information fusion and interactive feedback between virtual space and physical space.This technology involves a digital model,real-time information management,comprehensive intelligent perception networks,etc.,and it can drive the rapid conceptual development of intelligent construction(IC)such as smart factories,smart cities,and smart medical care.Nevertheless,the actual use of DT in IC is partially pending,with numerous scientific factors still not clarified.An overall survey on pending issues and unsolved scientific factors is needed for the development of DT-driven IC.To this end,this study aims to provide a comprehensive review of the state of the art and state of the use of DT-driven IC.The use of DT in planning,design,manufacturing,operation,and maintenance management of IC is demonstrated and analyzed,following which the driving functions of DT in IC are detailed from four aspects:information perception and analysis,data mining and modeling,state assessment and prediction,intelligent optimization and decision-making.Furthermore,the future direction of research,using DT in IC,is presented with some comments and suggestions.This work will help researchers gain in-depth and systematic understanding of the use of DT,and help practitioners to better promote its implementation in IC.展开更多
With the aid of non-contact measurements of vibrating surfaces through laser scanning,operating deflection shapes(ODSs)with high spatial resolutions can be used to graphically characterize damage in plane structures.A...With the aid of non-contact measurements of vibrating surfaces through laser scanning,operating deflection shapes(ODSs)with high spatial resolutions can be used to graphically characterize damage in plane structures.Although numerous damage identification approaches relying on laser-measured ODSs have been developed for plate-type structures,they cannot be directly applied to circular cylinders due to the gap between equations of motions of plates and circular cylinders.To fill this gap,a novel approach is proposed in this study for damage identification of circular cylinders.Damage-induced discontinuities of the derivatives of ODSs can be used to gra-phically manifest the occurrence of the damage,and characterize the location and size of the damage.The approach is experimentally validated on a specimen of the circular cylinder component,whose out-of-plane ODSs in an inspection region are acquired through laser scanning using a scanning laser vibrometer.The results suggest that the occurrence,location,and size of the internal damage of the circular cylinder can be identified.展开更多
基金supported by the Building Fund for the Academic Innovation Team of Shantou University (CN)(NTF21017)the Special Fund for Science and Technology of Guangdong Province in2021 (STKJ2021181)the National Natural Science Foundation of China (Grant nos.12272394)
文摘The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechnical materials.However,there is lack of effective quantitative analysis method for the complex evolution mechanism of threedimensional shear bands.In this work,we used X-ray computed tomography(CT)to reconstruct volume images and used the digital volume correlation(DVC)method to calculate the three-dimensional strain fields of granite residual soil samples at different loading stages.The trend of the failure surface of the shear bands was obtained by the planar fitting method,and the connectivity index was constructed according to the projection characteristics of the shear bands on the failure trend surface.The results support the following findings:the connectivity index of the shear band increases rapidly and then slowly with increasing axial strain,which is characterized by a near'S'curve.As the stress reaches the peak value,the connectivity index of the shear bands almost exceeds 0.7.The contribution of the new shear band volume to the connectivity of the shear bands becomes increasingly small with increasing axial loading.Affected by quartz grains and stress at the initial stage,the dip angle gradually and finally approaches the included angle of the maximum shear stress from the discrete state with increasing axial loading.The tendency and dip angle of the resulting shear bands are dynamic,and the tendency slightly deflects with increasing loading.
基金financial supports for this research project by the National Natural Science Foundation of China(Nos.41602308,41967037)supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LY20E080005+1 种基金funded by National Key Research and Development Projects of China(No.2019YFC507502)Guangxi Science and Technology Plan Project(No.RZ2100000161).
文摘During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.
基金This work was supported by the Gui Ke Neng(19-J-21-7 and 19-J-21-12).
文摘In order to increase use ratio of steel slag solid waste,the concrete containing steel slag powder and zeolite powder as admixtures was prepared by using the orthogonal test method.The effects of water-binder ratio,sand ratio,steel slag powder content and zeolite powder on working properties,mechanical strength and chloride ion permeability of the concrete was studied.It was found that the early strength of the concrete had a decrease with the mixing of steel slag and zeolite powders,but its later strength approached to pure concrete.Moreover,the physical filling and pozzolanic activity of the admixtures increased the density of the concrete,resulting in the improvement of the durability of the concrete by the migration speed of Cl−reducing.The optimum mix ratio of C40 steel slag powder-zeolite powder concrete is obtained,and which had the slump of 220 mm,the 3 d,7 d and 28 d compressive strengths of 27.8 MPa,37.5 MPa and 48.4 MPa,the 6 h electric flux of 950 C and the diffusion coefficient of 1.65×10−12 m2/s.
基金Project (50809017) supported by the National Natural Science Foundation of China
文摘To determine structure and parameters of a rheological constitutive model for rocks,a new method based on differential evolution(DE) algorithm combined with FLAC3D(a numerical code for geotechnical engineering) was proposed for identification of the global optimum coupled of model structure and its parameters.At first,stochastic coupled mode was initialized,the difference in displacement between the numerical value and in-situ measurements was regarded as fitness value to evaluate quality of the coupled mode.Then the coupled-mode was updated continually using DE rule until the optimal parameters were found.Thus,coupled-mode was identified adaptively during back analysis process.The results of applications to Jinping tunnels in China show that the method is feasible and efficient for identifying the coupled-mode of constitutive structure and its parameters.The method overcomes the limitation of the traditional method and improves significantly precision and speed of displacement back analysis process.
基金This work is partially supported by the Anhui Provincial International Joint Research Center of Data Diagnosis and Smart Maintenance on Bridge Structures(No.2021AHGHZD01)the Nanjing Science and Technology Project(No.202002014)the Nantong Science and Technology Opening Cooperation Project in 2021(No.BW2021001).
文摘A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility.However,their use for damage detection should be performed with special attention,particularly in operational and environmental conditions subjected to temperature changes.Beams in construction industries experience different loading types,such as temperature changes leading to crack initiation and propagation.Changed physical and dynamic properties such as natural frequencies and mode shapes indicate that damage has occurred within the structures.In this study,vibration analysis of cantilever and cantilever simply supported beams has been carried out on intact and damaged beams to investigate the coupled effect of temperature changes and damage depth on natural frequencies.A numerical analysis of beams is completed using ANSYS software.The results of numerical simulation are validated using two other studies from literature.Numerical results revealed that in order to perform a successful damage assessment using the frequency shift,the vibration modes should be selected properly.In addition,an increase in temperature results in a decrease in structural frequencies.The assessment of the effect of damage depth on natural frequencies also confirms that when damage depth is increased,there is a significant decrease in natural frequency responses.
文摘The problem of seismic response of buried pipeline aimed at the interaction of soil around the pipeline and the complicated calculation model was considered, and the various simplified finite element model was calculated, and it was analyzed. Firstly, the ADINA finite element analysis software was used. The four nodes in shell unit were used by tube. The spring unit was used by soil spring. The analysis model of buried pipeline finite element numerical based on tension and compression spring was established. Seismic wave was input. The response to the simple boundary, viscoelastic boundary earthquake were calculated and analyzed by the finite element numerical simulation. The pipeline’s earthquake ground motion response was obtained, and was compared with the real soil model, and the most suitable simplified calculation model for numerical analysis of buried pipeline was found, which was the numerical analysis model of buried pipeline pressure spring tension finite element based on the viscoelastic boundary, and the theory basis for the seismic design of pipeline was provided.
基金supported by the Open Fund of Engineering Research Center of Underground Mine Construction,Ministry of Education(Anhui University of Science and Technology)(Grant No.JYBGCZX2020210)Anhui International Joint Research Center of Data Diagnosis and Smart Maintenance on Bridge Structures(Grant No.2022AHGHYB09)Scientific Research Program of Anhui Province(Grant No.2022AH051092).
文摘Applying recycled concrete for engineered projects not only protects the ecological environment but also improves the utilization rate of waste concrete to satisfy sustainable development requirements.However,the mechanical properties of recycled concrete are not as good as those of ordinary concrete.To enhance the former’s performance and increase its popularity and application in engineeringfields,notable advances have been made by using steel,synthetic,plant,and mineralfiber materials.These materials are added to recycled concrete to improve its mechanical properties.Studies have shown that(1)steelfibers have a distinct reinforcing effect and improve the strength,toughness,and elastic modulus of recycled concrete;(2)the addition of syntheticfibers can improve the tension,crack resistance,and durability of concrete,but the size effect needs to be further explored and elaborated;(3)plantfiber concrete is lightweight and environmentally friendly and provides high toughness and good thermal insulation,but thefibers corrode in alkaline environments;in addition,plantfibers have high water absorption capacity,which leads to wet expansion and dry shrinkage phenomena,which need to be further studied;and(4)the cost of basaltfiber,a mineralfiber,is relatively low,and a suitable basalt content can improve the mechanical properties of recycled concrete to a certain extent.
基金This research was funded by the Natural Science Foundation of Sichuan,China(No.2022NSFSC1915)the National Natural Science Foundation of China(No.U19A2098)+1 种基金State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,Jianghan University(No.PBSKL2022B06)the Fundamental Research Funds for the Central Universities。
文摘Three-dimensional rock fracture induced by blasting is a highly complex problem and has received considerable attention in geotechnical engineering.The material point method is firstly applied to treat this challenging task.Some inherent weaknesses can be overcome by coupling the generalized interpolation material point(GIMP)and the convected particle domain interpolation technique(CPDI).For the media in the borehole,unchanged GIMP-type particles are used to guarantee a homogenous blast pressure.CPDITetrahedron type particles are employed to avoid the fake numerical fracture near the borehole for the rock material.A blasting experiment using three-dimensional single-borehole rock was simulated to examine the applicability of the coupled model under realistic loading and boundary conditions.A good agreement was achieved between the simulation and experimental results.Moreover,the mechanism of three-dimensional rock fracture was analyzed.It was concluded that rock particle size and material parameters play an important role in rock damage.The reflected tensile waves cause severe damage in the lower part of the model.Rayleigh waves occur on the top face of the rock model to induce a hoop failure band.
基金supported by the Natural Science Foundation of Zhejiang Province,China(Grant No.LY14E080014)the National Natural Science Foundation ofChina(Grant Nos.61154002 and 51078331)
文摘Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers on combustion characteristics of asphalt mortar by thermogravimetric and kinetic analysis. It is shown that the combustion of asphalt mortar is not just a linear superposition of asphalt and limestone. The limestone will increase the ignition point and the activation energy of the primary volatile release, and will catalyze the char formation from the primary volatile release. Kinetic analysis shows that the primary volatile release stage of asphalt mortar combustion can be explained by a three-dimensional diffusion model, the secondary volatile release and char combustion stage can be explained by a model under the assumption of random nucleation and nuclei growth, whereas the limestone decomposition stage appears to follow the one-dimensional phase boundary model.
基金the financial support partially provided by The Quality Engineering Project of Anhui Province(2019sjjd58,2020sxzx36)The Ministry of Education Cooperative Education Project(201901119016)+1 种基金The Chinese(Jiangsu)-Czech Bilateral Co-funding R&D Project(SBZ2018000220)the Key R&D Project of Anhui Science and Technology Department(202004b11020026).
文摘Digital twin(DT)can achieve real-time information fusion and interactive feedback between virtual space and physical space.This technology involves a digital model,real-time information management,comprehensive intelligent perception networks,etc.,and it can drive the rapid conceptual development of intelligent construction(IC)such as smart factories,smart cities,and smart medical care.Nevertheless,the actual use of DT in IC is partially pending,with numerous scientific factors still not clarified.An overall survey on pending issues and unsolved scientific factors is needed for the development of DT-driven IC.To this end,this study aims to provide a comprehensive review of the state of the art and state of the use of DT-driven IC.The use of DT in planning,design,manufacturing,operation,and maintenance management of IC is demonstrated and analyzed,following which the driving functions of DT in IC are detailed from four aspects:information perception and analysis,data mining and modeling,state assessment and prediction,intelligent optimization and decision-making.Furthermore,the future direction of research,using DT in IC,is presented with some comments and suggestions.This work will help researchers gain in-depth and systematic understanding of the use of DT,and help practitioners to better promote its implementation in IC.
基金The authors are grateful for the supports from the Changzhou Policy Guidance Plan-International Science and Technology Cooperation(No.CZ20200003)the Anhui International Joint Research Center of Data Diagnosis and Smart Maintenance on Bridge Structures(No.2021AHGHYB01)+1 种基金the Nantong Science and Technology Opening Cooperation Project in 2021(No.BW2021001)the Key R&D Project of Anhui Science and Technology Department(202004b11020026).
文摘With the aid of non-contact measurements of vibrating surfaces through laser scanning,operating deflection shapes(ODSs)with high spatial resolutions can be used to graphically characterize damage in plane structures.Although numerous damage identification approaches relying on laser-measured ODSs have been developed for plate-type structures,they cannot be directly applied to circular cylinders due to the gap between equations of motions of plates and circular cylinders.To fill this gap,a novel approach is proposed in this study for damage identification of circular cylinders.Damage-induced discontinuities of the derivatives of ODSs can be used to gra-phically manifest the occurrence of the damage,and characterize the location and size of the damage.The approach is experimentally validated on a specimen of the circular cylinder component,whose out-of-plane ODSs in an inspection region are acquired through laser scanning using a scanning laser vibrometer.The results suggest that the occurrence,location,and size of the internal damage of the circular cylinder can be identified.
