The problem of noise has always been highlighted in assembled steel structure houses.Therefore,it is necessary to use effective soundproof measures where steel beams intersect with the reserved line pipe openings,door...The problem of noise has always been highlighted in assembled steel structure houses.Therefore,it is necessary to use effective soundproof measures where steel beams intersect with the reserved line pipe openings,doors,windows,elevator shafts,and other locations.In this paper,we will investigate the areas with subpar soundproof performance in an assembled steel structure residential project and propose suitable noise control measures to address this issue.展开更多
Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is propo...Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is proposed as a substituting method.By absorbing high energy of the 1064 nm pulsed laser, the paint is vaporized quickly.The ablated debris is then collected by using a suction pump.Initial metal surface of the steel is exposed when laser beam irradiates perpendicularly and scans over it.The cleaned surface fulfills the requirements of surface preparation standards ISO 8501 of SA2.The adhesion is further characterized with pull-off test after carrying out painting with Jotamastic 87 aluminum paint.The repainting can be embedded onto the laser cleaned surface to bond much more tightly.The excellent adhesion strength of 20 MPa between repainted coating and the substrate is achieved, which is higher than what is required by shipyards applications.展开更多
Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also...Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also put forward new requirements for the quality of steel structure bridges.However,in actual design,due to the influence of many fectors,some problems are inevitable,which will affect the integrity of the design.Therefore,the designer needs to fully grasp the possible design problems,and then take efiective measures to improve the integrity of the design scheme,so as to ensure the quality of the steel structure bridge and improves the safety of the steel structure bridge from the fundamentals.This paper mainly focuses on steel structure bridges,analyzed the current status of steel structure bridge types and their selection,and proposes the integrity design strategy of steel structure bridges.展开更多
<div style="text-align:justify;"> In this paper, perlite was used as a kind of modifier to prepare waterborne fire resistive coatings for steel structure. The influence of perlite on the properties of ...<div style="text-align:justify;"> In this paper, perlite was used as a kind of modifier to prepare waterborne fire resistive coatings for steel structure. The influence of perlite on the properties of the fire resistive coatings was investigated with the help of thermogravimetric analysis (TGA), micro-scale combustion calorimetry (MCC) and fire protection test. The TGA results showed that the char residue weight of the coatings was increased when perlite was loaded and the anti-oxidation performance was enhanced as well and MCC data indicated the addition of perlite reduced the peak heat release rate and total heat release. After the fire protection test, the results confirmed that the fire resistant time of the coating coated with 5 wt% perlite increased up to 114.4 min when the temperature of the sample boards’ backside reached 500?C. </div>展开更多
Taking the construction project of the National Cybersecurity Talents and Innovation Base as an example,this paper studies the construction technology of freeform surface spatial bending-torsion steel structure based ...Taking the construction project of the National Cybersecurity Talents and Innovation Base as an example,this paper studies the construction technology of freeform surface spatial bending-torsion steel structure based on structural design model transformation,including the parametric modeling of deepening design model,computer-aided bending and torsion frame production,flexible docking in the bending-torsion combination unit,and welding stress deformation,in hope to provide reference for similar projects in the future.展开更多
Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use o...Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use of structures.The main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage assessment.However,for many shear-type structures,it is difficult to obtain accurate FEM.In order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this paper.This method only needs to measure a few low-order vibration modes of the structure.The proposed defect diagnosis method is divided into two stages.In the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after damage.In the second stage,damage severity is evaluated based on an improved frequency sensitivity equation.Themain innovations of this method lie in two aspects.The first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear structure.The second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite elementmodel.Thismethod has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear structure.Based on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element modeling.The proposed method should be a very simple and practical defect diagnosis technique in engineering practice.展开更多
Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction indu...Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.展开更多
Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic p...Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic properties of the Wuhan International Securities Building (a 68-storey super high-rise steel structure with three horizontal strengthened storeys) were evaluated in this study.Two approaches,i.e.,mode-superposition response spectrum analysis and time-history analysis,were employed to calculate the seismic response of the structure.The response spectrum analysis indicated that transition parts near the three strengthened storeys were weak zones of the structure because of the abrupt change in rigidity.In the response spectrum analysis approach,the Square Root of Sum of Square (SRSS) method was recommended when the vertical seismic effects could be ignored.However,the complete quadratic combination (CQC) method was superior to SRSS method when the vertical seismic effects should be considered.With the aid of time-history analysis,the seismic responses of the structure were obtained.The whiplash effect that spectrum analysis cannot reveal was observed through time-history analysis.This study provides references for the seismic design of super high-rise steel structures with horizontal strengthened storeys.展开更多
Input ground motions have significant impacts on the uncertainty of structural responses in time-history analysis.In this study,records were selected and scaled for the evaluation of mean structural responses accordin...Input ground motions have significant impacts on the uncertainty of structural responses in time-history analysis.In this study,records were selected and scaled for the evaluation of mean structural responses according to the target spectrum.The Newmark-Hall spectrum is closely related to seismic response of short,medium and long-period structures,so it was taken as the target spectrum here.The nonlinear time-history analyses of 9-story and 20-story steel moment-resisting frame structures were carried out as examples.They represent medium and long-period buildings,respectively.Three target spectra with risk of 50%,10%and 2%probabilities for exceedance in 50 years were calculated by the average Newmark-Hall spectrum method for three ground motion sets developed in the SAC Steel Project.The predicted structural mean responses of these Newmark-Hall spectra were compared with those calculated by the average spectral acceleration method for the same record set.It is found that both methods have similar accuracy for estimating the structural mean response.However,the method proposed herein is more effective in reducing the variability of the structural responses.Also,the proposed method is more advantageous for the time-history analysis of long-period structures or structures with more severe nonlinear responses under strong seismic excitations.展开更多
In order to study the mechanical behavior of corroded channel steel beam,experiment on five corroded channel steel beams is carried out. Test results show that the bending failures may occur under the ultimate load ca...In order to study the mechanical behavior of corroded channel steel beam,experiment on five corroded channel steel beams is carried out. Test results show that the bending failures may occur under the ultimate load carrying capacity of members,compared with the calculating results of non-corrosion channel steel beam,and the bearing capacity of corroded channel steel beam is reduced,while the deflection is increased. With the increase of shear-span ratio,the bearing capacity of corroded channel steel beam reduces and the deflection increases gradually; with the increment of heightspan ratio, the bearing capacity increases and the deflection decreases gradually; with the enhancement of width-height ratio,the bearing capacity reduces and the deflection-span ratio increases gradually. The measured results indicate that the load-deflection relationship curves of corroded channel steel beam may be divided into four sections: the exfoliated rust layer stage,the elastic stage,the yielding stage and the descending stage. The load-strain relationship curves include two sections: the elastic stage and the yielding stage. The strain measurement of web proves that the average strains agree well with the assumption of plane section. This paper could provide some scientific bases for the maintenance and reinforcement of the corroded steel structure.展开更多
The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds o...The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds of sheathings,namely,medium⁃and low⁃density calcium⁃silicate boards and oriented strand board,were selected for double⁃shear experiments on the mechanical properties of 253 screw connections at ambient and elevated temperatures.The effects of the shear direction,screw edge distance and the number of screws on the behavior of the connections were studied.The results showed that the shear direction and the screw edge distance more significantly influenced the peak deformation,while their impacts on the peak load varied with the type of sheathings.Compared with the single⁃screw connections,the peak loads of the specimens with double⁃screw connections obviously increased but did not double.Finally,a simplified load⁃displacement curve model of stud⁃to⁃sheathing connections at elevated temperature was generated first by establishing the prediction formula for characteristic parameters,such as the peak load,the peak deformation and the elastic stiffness,and then by considering whether the curves corresponded to stiffness increase phenomena.The present investigation provides basic data for future studies on the numerical modeling of CFS structures under fire conditions.展开更多
Taking the construction project of National Network Security Talents and Innovation Base Exhibition Center as an example,the application of building information model in the construction process of free-form surface s...Taking the construction project of National Network Security Talents and Innovation Base Exhibition Center as an example,the application of building information model in the construction process of free-form surface steel structure is analyzed in this paper.The results show that the application of Building Information Modeling(BIM)technology to the construction of free-form surface structure improves the work efficiency of the construction team in multi-disciplinary collaboration,surface component manufacturing,and construction process design,and subsequently improves the construction speed and construction quality.展开更多
With the rapid development of modern large-span and large-complex steel structure buildings,at present the Building Information Modeling(BIM)technology plays an important role from the design to the construction of a ...With the rapid development of modern large-span and large-complex steel structure buildings,at present the Building Information Modeling(BIM)technology plays an important role from the design to the construction of a building.This study takes the Comprehensive Gymnasium of Hubei Olympic Sports Center as the carrier and introduce the BIM technology from two aspects;The technology;and the management.Further,the optimal application of BIM technology in the complex component nodes,the technical guidance of component processing,and the correction and verification of drawings were emphatically analyzed in this paper.An engineering practice shows that the application of BIM technology has greatly improved the production efficiency,shortened the construction period,reduced unnecessary cost,and lastly laid a solid foundation for the smooth completion of the project.展开更多
A set of evaluation indicators based on corrosion ratio in theory for assessing the extent of pitting corrosion and performance reduction are proposed. In order to quantify the morphology of pitting corrosion and extr...A set of evaluation indicators based on corrosion ratio in theory for assessing the extent of pitting corrosion and performance reduction are proposed. In order to quantify the morphology of pitting corrosion and extract the evaluation indicators,the 3D profile data obtained by pitting morphology measurement are imported into a special written program to automatically determine the location of each corrosion pit and distill any desired data pertinent to the pitting morphology. The results show that this method seems to be effective to analyze the corroded surface and characterize the pitting morphology.展开更多
For the research on steel structure in fire,it is very important to determine the properties of structural steel at elevated temperature.Up to now,the high-temperature properties of material is believed to be related ...For the research on steel structure in fire,it is very important to determine the properties of structural steel at elevated temperature.Up to now,the high-temperature properties of material is believed to be related to only temperature state,which is not precise enough to simulate the behavior of steel structures under different combinations of heating,cooling,loading,and unloading.To analyze the influence of the temperature-load history on the steel properties,a series of tests were carried out under different temperature-load paths about steel Q235,which is widely used in steel structures in China.In this paper,the method to set the temperature-load paths was introduced;the variety regulation of steel properties changing with temperature was analyzed under different paths;according to experimental results,the formulas of elastic modulus and yield strength at elevated temperature were fitted,and the stress-strain-temperature 3D relationships of structural steel under different paths were presented.展开更多
On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major fai...On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major failure occurr<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ing</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on the connection between the RC column top and steel roof as well as the cracks in the RC column base w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> observed during the emergent inspection. According to the earlier studies, it was implied that the presence of the slotted hole possibly deteriorates the seismic capacity;however, the length of slotted hole was fixed at a certain value. Facing this concern, this research attempts to clarify the influence of the slotted hole length through a comprehensive parametric study by pushover and seismic response analyses. In conclusion, it has been discovered that the slotted hole deteriorates the seismic capacity for the connection failure up to almost 50% of that without slotted hole. Moreover, the discrepancy of characteristics obtained by the static and dynamic analyses is originated by means of the presence of slotted hole. This slotted hole effect should be noted by structural engineers and researchers to provide the adequate seismic diagnosis and strengthening.</span></span></span>展开更多
Work-hardening behaviour of type 316 austenitic stainless steel having difFerent initial dislocation structures introduced by swaging to various levels is analysed by a simplified Kock’s model which takes into accoun...Work-hardening behaviour of type 316 austenitic stainless steel having difFerent initial dislocation structures introduced by swaging to various levels is analysed by a simplified Kock’s model which takes into account the structural changes through the dislocation accumulation and annihilation process during deformation. The dislocation accumulation and annihilation factors show a temperature and structure dependence. The dislocation annihilation factor shows a plateau or decreasing tendency in the dynamic strain ageing (DSA) temperature range. This is attributed as either due to dislocation accumulation being more pronounced than dislocation annihilation or as due to precipitates being formed at DSA temperatures acting as obstacles to dislocation motion in the DSA temperature range.展开更多
In the city of Gdansk in Poland,in the very center of the Baltic capital,on 17th of June 2017,a new draw footbridge was ceremoniously opened to the public.The Olowianka footbridge represents the long-time much needed ...In the city of Gdansk in Poland,in the very center of the Baltic capital,on 17th of June 2017,a new draw footbridge was ceremoniously opened to the public.The Olowianka footbridge represents the long-time much needed link between the highly tourist-visited historical old town and Ołowianka Island,where further cultural,tourist and recreation facilities are located.The bridge spans a very busy navigable channel of the Motława River,leading inward towards other city channels,a harbor for many tourist ships and the Gdansk Marina.Being the main navigable entrance to the city center,the Motława is constantly under nautical traffic,so the Ołowianka footbridge operates 24/7,according to a 30-min schedule.The Ołowianka footbridge is an extraordinary acquisition for the city of Gdansk,which immediately became a new landmark and much more in the already very picturesque historic city center.Not just its design,but also its carefully chosen location and its realization at the right moment,has made this bridge indispensable to the inhabitants,visitors and the administration of the city of Gdansk,decisively contributing to further development in the Ołowianka Island area and its surroundings.展开更多
This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground motions.Seismic performance of this skeleton is t...This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground motions.Seismic performance of this skeleton is then compared to that of a bundled-tube,as a conventional and efficient load-resisting system in order to provide a better perception of the seismic behavior of a hexagrid skeleton.Two 20-story buildings with bundled-tube and hexagrid skeleton were studied.Nonlinear behavior of the structures was investigated through 3-D finite element computer models and nonlinear time history analyses by subjecting the models to seven three-component records of scaled near-field ground motions.Distribution of peak inter story drift and corner beam-column joint rotations were calculated and compared.Results indicated that by replacing the exterior columns of the bundled-tube system with inclined beam-column elements of nature-inspired hexagons,lateral stiffness of the building increased and it would tolerate less deformations before global dynamic instability is reached.The presence of inclined columns in the hexagrid skeleton helped to concentrate local nonlinearities in ring beams rather than exterior columns.展开更多
With the current rapid development of urbanization in China,people's living standards have been greatly improved.In the context of such a development background,the requirements for road traffic are getting more s...With the current rapid development of urbanization in China,people's living standards have been greatly improved.In the context of such a development background,the requirements for road traffic are getting more stringent,especially for bridge projects.The arched continuous rigid-frame bridge was developed under this social background.The advantage of the bridge lies in the design of a bridge model that integrates various functions such as transportation,landscape,and sightseeing.Based on the above,this paper first refers to the case to analyze the design and construction strategy of the arched continuous rigid-frame bridge,in hope of providing a valuable reference for relevant personnel.展开更多
文摘The problem of noise has always been highlighted in assembled steel structure houses.Therefore,it is necessary to use effective soundproof measures where steel beams intersect with the reserved line pipe openings,doors,windows,elevator shafts,and other locations.In this paper,we will investigate the areas with subpar soundproof performance in an assembled steel structure residential project and propose suitable noise control measures to address this issue.
基金supported by the National Natural Science Foundation of China (U1609209)National Natural Science Foundation of China (61605162)+2 种基金NSFC-Liaoning Province united foundation (U1608259)National Natural Science Foundation of China (51501219)the financial support from the China Scholarship Council
文摘Paint removal from steel structure is executed for shipyards of marine and offshore engineering.Due to environmental unfriendliness and unhealthy drawbacks of sand blasting technique, laser ablation technique is proposed as a substituting method.By absorbing high energy of the 1064 nm pulsed laser, the paint is vaporized quickly.The ablated debris is then collected by using a suction pump.Initial metal surface of the steel is exposed when laser beam irradiates perpendicularly and scans over it.The cleaned surface fulfills the requirements of surface preparation standards ISO 8501 of SA2.The adhesion is further characterized with pull-off test after carrying out painting with Jotamastic 87 aluminum paint.The repainting can be embedded onto the laser cleaned surface to bond much more tightly.The excellent adhesion strength of 20 MPa between repainted coating and the substrate is achieved, which is higher than what is required by shipyards applications.
文摘Nowadays,the scope of bridge construction projects in China is becoming wider,which promotes China's economic development to a large extent and also improves China's transportation system.Meanwhile,people also put forward new requirements for the quality of steel structure bridges.However,in actual design,due to the influence of many fectors,some problems are inevitable,which will affect the integrity of the design.Therefore,the designer needs to fully grasp the possible design problems,and then take efiective measures to improve the integrity of the design scheme,so as to ensure the quality of the steel structure bridge and improves the safety of the steel structure bridge from the fundamentals.This paper mainly focuses on steel structure bridges,analyzed the current status of steel structure bridge types and their selection,and proposes the integrity design strategy of steel structure bridges.
文摘<div style="text-align:justify;"> In this paper, perlite was used as a kind of modifier to prepare waterborne fire resistive coatings for steel structure. The influence of perlite on the properties of the fire resistive coatings was investigated with the help of thermogravimetric analysis (TGA), micro-scale combustion calorimetry (MCC) and fire protection test. The TGA results showed that the char residue weight of the coatings was increased when perlite was loaded and the anti-oxidation performance was enhanced as well and MCC data indicated the addition of perlite reduced the peak heat release rate and total heat release. After the fire protection test, the results confirmed that the fire resistant time of the coating coated with 5 wt% perlite increased up to 114.4 min when the temperature of the sample boards’ backside reached 500?C. </div>
基金The Hubei Provincial Building Technology Project in 2021(No.43)。
文摘Taking the construction project of the National Cybersecurity Talents and Innovation Base as an example,this paper studies the construction technology of freeform surface spatial bending-torsion steel structure based on structural design model transformation,including the parametric modeling of deepening design model,computer-aided bending and torsion frame production,flexible docking in the bending-torsion combination unit,and welding stress deformation,in hope to provide reference for similar projects in the future.
基金the Zhejiang Public Welfare Technology Application Research Project(LGF22E080021)Ningbo Natural Science Foundation Project(202003N4169)+2 种基金Natural Science Foundation of China(11202138,52008215)the Natural Science Foundation of Zhejiang Province,China(LQ20E080013)the Major Special Science and Technology Project(2019B10076)of“Ningbo Science and Technology Innovation 2025”.
文摘Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame structures.Fault diagnosis of shear-type structures is an important topic to ensure the normal use of structures.The main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage assessment.However,for many shear-type structures,it is difficult to obtain accurate FEM.In order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this paper.This method only needs to measure a few low-order vibration modes of the structure.The proposed defect diagnosis method is divided into two stages.In the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after damage.In the second stage,damage severity is evaluated based on an improved frequency sensitivity equation.Themain innovations of this method lie in two aspects.The first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear structure.The second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite elementmodel.Thismethod has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear structure.Based on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element modeling.The proposed method should be a very simple and practical defect diagnosis technique in engineering practice.
文摘Because of urbanization,land resources in China’s cities has become increasingly scarce.Therefore,modern buildings are becoming taller,making high-rise steel frame structures the new favorite of the construction industry.However,the construction of high-rise steel frame structures requires advanced technology.If the construction technology is effectively implemented and the welding techniques of the construction personnel align with the requirements for high-rise steel frame structures,it can help mitigate deformations in the steel structure,thus preserving the overall construction quality of high-rise steel frame structures.To enhance the applicability of steel frame structures in high-rise buildings,this paper focuses on analyzing the optimization path for the construction process of high-rise steel frame structures.It introduces a tailored approach to control welding-induced deformations in steel frame structures,aiming to make a valuable contribution to the advancement of China’s construction industry.
文摘Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic properties of the Wuhan International Securities Building (a 68-storey super high-rise steel structure with three horizontal strengthened storeys) were evaluated in this study.Two approaches,i.e.,mode-superposition response spectrum analysis and time-history analysis,were employed to calculate the seismic response of the structure.The response spectrum analysis indicated that transition parts near the three strengthened storeys were weak zones of the structure because of the abrupt change in rigidity.In the response spectrum analysis approach,the Square Root of Sum of Square (SRSS) method was recommended when the vertical seismic effects could be ignored.However,the complete quadratic combination (CQC) method was superior to SRSS method when the vertical seismic effects should be considered.With the aid of time-history analysis,the seismic responses of the structure were obtained.The whiplash effect that spectrum analysis cannot reveal was observed through time-history analysis.This study provides references for the seismic design of super high-rise steel structures with horizontal strengthened storeys.
基金National Natural Science Foundation of Hebei Province under Grant No.E2020202038the National Natural Science Foundation of China under Grant No.51778206。
文摘Input ground motions have significant impacts on the uncertainty of structural responses in time-history analysis.In this study,records were selected and scaled for the evaluation of mean structural responses according to the target spectrum.The Newmark-Hall spectrum is closely related to seismic response of short,medium and long-period structures,so it was taken as the target spectrum here.The nonlinear time-history analyses of 9-story and 20-story steel moment-resisting frame structures were carried out as examples.They represent medium and long-period buildings,respectively.Three target spectra with risk of 50%,10%and 2%probabilities for exceedance in 50 years were calculated by the average Newmark-Hall spectrum method for three ground motion sets developed in the SAC Steel Project.The predicted structural mean responses of these Newmark-Hall spectra were compared with those calculated by the average spectral acceleration method for the same record set.It is found that both methods have similar accuracy for estimating the structural mean response.However,the method proposed herein is more effective in reducing the variability of the structural responses.Also,the proposed method is more advantageous for the time-history analysis of long-period structures or structures with more severe nonlinear responses under strong seismic excitations.
基金National Natural Science Foundation of China(No.51578001)Natural Science Foundations of Anhui Province,China(Nos.KJ2010A046,KJ2015ZD10)the Science and Technology Item Foundation of Ma'anshan,China(Nos.2012(6),2013(79))
文摘In order to study the mechanical behavior of corroded channel steel beam,experiment on five corroded channel steel beams is carried out. Test results show that the bending failures may occur under the ultimate load carrying capacity of members,compared with the calculating results of non-corrosion channel steel beam,and the bearing capacity of corroded channel steel beam is reduced,while the deflection is increased. With the increase of shear-span ratio,the bearing capacity of corroded channel steel beam reduces and the deflection increases gradually; with the increment of heightspan ratio, the bearing capacity increases and the deflection decreases gradually; with the enhancement of width-height ratio,the bearing capacity reduces and the deflection-span ratio increases gradually. The measured results indicate that the load-deflection relationship curves of corroded channel steel beam may be divided into four sections: the exfoliated rust layer stage,the elastic stage,the yielding stage and the descending stage. The load-strain relationship curves include two sections: the elastic stage and the yielding stage. The strain measurement of web proves that the average strains agree well with the assumption of plane section. This paper could provide some scientific bases for the maintenance and reinforcement of the corroded steel structure.
基金the National Natural Science Foundation of China(Grant No.51978655)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20201347)+1 种基金the Xuzhou Science and Technology Project(Grant No.KC20175)the China Postdoctoral Science Foundation Funded Project(Grant No.2019M652007).
文摘The behavior of cold⁃formed steel(CFS)stud⁃to⁃sheathing connections at elevated temperatures is an important parameter for the fire resistance design and modeling of mid⁃rise CFS structures.In this paper,three kinds of sheathings,namely,medium⁃and low⁃density calcium⁃silicate boards and oriented strand board,were selected for double⁃shear experiments on the mechanical properties of 253 screw connections at ambient and elevated temperatures.The effects of the shear direction,screw edge distance and the number of screws on the behavior of the connections were studied.The results showed that the shear direction and the screw edge distance more significantly influenced the peak deformation,while their impacts on the peak load varied with the type of sheathings.Compared with the single⁃screw connections,the peak loads of the specimens with double⁃screw connections obviously increased but did not double.Finally,a simplified load⁃displacement curve model of stud⁃to⁃sheathing connections at elevated temperature was generated first by establishing the prediction formula for characteristic parameters,such as the peak load,the peak deformation and the elastic stiffness,and then by considering whether the curves corresponded to stiffness increase phenomena.The present investigation provides basic data for future studies on the numerical modeling of CFS structures under fire conditions.
基金The Hubei provincial building technology project in 2021(Project No:43).
文摘Taking the construction project of National Network Security Talents and Innovation Base Exhibition Center as an example,the application of building information model in the construction process of free-form surface steel structure is analyzed in this paper.The results show that the application of Building Information Modeling(BIM)technology to the construction of free-form surface structure improves the work efficiency of the construction team in multi-disciplinary collaboration,surface component manufacturing,and construction process design,and subsequently improves the construction speed and construction quality.
基金The Hubei provincial building technology project in 2021(Project No:43)。
文摘With the rapid development of modern large-span and large-complex steel structure buildings,at present the Building Information Modeling(BIM)technology plays an important role from the design to the construction of a building.This study takes the Comprehensive Gymnasium of Hubei Olympic Sports Center as the carrier and introduce the BIM technology from two aspects;The technology;and the management.Further,the optimal application of BIM technology in the complex component nodes,the technical guidance of component processing,and the correction and verification of drawings were emphatically analyzed in this paper.An engineering practice shows that the application of BIM technology has greatly improved the production efficiency,shortened the construction period,reduced unnecessary cost,and lastly laid a solid foundation for the smooth completion of the project.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51378417)Program for Changjiang Scholars and Innovative Research Team in University(IRT13089)PhD Innovation Fund of Xi'an University of Architecture and Technology
文摘A set of evaluation indicators based on corrosion ratio in theory for assessing the extent of pitting corrosion and performance reduction are proposed. In order to quantify the morphology of pitting corrosion and extract the evaluation indicators,the 3D profile data obtained by pitting morphology measurement are imported into a special written program to automatically determine the location of each corrosion pit and distill any desired data pertinent to the pitting morphology. The results show that this method seems to be effective to analyze the corroded surface and characterize the pitting morphology.
文摘For the research on steel structure in fire,it is very important to determine the properties of structural steel at elevated temperature.Up to now,the high-temperature properties of material is believed to be related to only temperature state,which is not precise enough to simulate the behavior of steel structures under different combinations of heating,cooling,loading,and unloading.To analyze the influence of the temperature-load history on the steel properties,a series of tests were carried out under different temperature-load paths about steel Q235,which is widely used in steel structures in China.In this paper,the method to set the temperature-load paths was introduced;the variety regulation of steel properties changing with temperature was analyzed under different paths;according to experimental results,the formulas of elastic modulus and yield strength at elevated temperature were fitted,and the stress-strain-temperature 3D relationships of structural steel under different paths were presented.
文摘On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major failure occurr<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ing</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> on the connection between the RC column top and steel roof as well as the cracks in the RC column base w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> observed during the emergent inspection. According to the earlier studies, it was implied that the presence of the slotted hole possibly deteriorates the seismic capacity;however, the length of slotted hole was fixed at a certain value. Facing this concern, this research attempts to clarify the influence of the slotted hole length through a comprehensive parametric study by pushover and seismic response analyses. In conclusion, it has been discovered that the slotted hole deteriorates the seismic capacity for the connection failure up to almost 50% of that without slotted hole. Moreover, the discrepancy of characteristics obtained by the static and dynamic analyses is originated by means of the presence of slotted hole. This slotted hole effect should be noted by structural engineers and researchers to provide the adequate seismic diagnosis and strengthening.</span></span></span>
文摘Work-hardening behaviour of type 316 austenitic stainless steel having difFerent initial dislocation structures introduced by swaging to various levels is analysed by a simplified Kock’s model which takes into account the structural changes through the dislocation accumulation and annihilation process during deformation. The dislocation accumulation and annihilation factors show a temperature and structure dependence. The dislocation annihilation factor shows a plateau or decreasing tendency in the dynamic strain ageing (DSA) temperature range. This is attributed as either due to dislocation accumulation being more pronounced than dislocation annihilation or as due to precipitates being formed at DSA temperatures acting as obstacles to dislocation motion in the DSA temperature range.
文摘In the city of Gdansk in Poland,in the very center of the Baltic capital,on 17th of June 2017,a new draw footbridge was ceremoniously opened to the public.The Olowianka footbridge represents the long-time much needed link between the highly tourist-visited historical old town and Ołowianka Island,where further cultural,tourist and recreation facilities are located.The bridge spans a very busy navigable channel of the Motława River,leading inward towards other city channels,a harbor for many tourist ships and the Gdansk Marina.Being the main navigable entrance to the city center,the Motława is constantly under nautical traffic,so the Ołowianka footbridge operates 24/7,according to a 30-min schedule.The Ołowianka footbridge is an extraordinary acquisition for the city of Gdansk,which immediately became a new landmark and much more in the already very picturesque historic city center.Not just its design,but also its carefully chosen location and its realization at the right moment,has made this bridge indispensable to the inhabitants,visitors and the administration of the city of Gdansk,decisively contributing to further development in the Ołowianka Island area and its surroundings.
文摘This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground motions.Seismic performance of this skeleton is then compared to that of a bundled-tube,as a conventional and efficient load-resisting system in order to provide a better perception of the seismic behavior of a hexagrid skeleton.Two 20-story buildings with bundled-tube and hexagrid skeleton were studied.Nonlinear behavior of the structures was investigated through 3-D finite element computer models and nonlinear time history analyses by subjecting the models to seven three-component records of scaled near-field ground motions.Distribution of peak inter story drift and corner beam-column joint rotations were calculated and compared.Results indicated that by replacing the exterior columns of the bundled-tube system with inclined beam-column elements of nature-inspired hexagons,lateral stiffness of the building increased and it would tolerate less deformations before global dynamic instability is reached.The presence of inclined columns in the hexagrid skeleton helped to concentrate local nonlinearities in ring beams rather than exterior columns.
文摘With the current rapid development of urbanization in China,people's living standards have been greatly improved.In the context of such a development background,the requirements for road traffic are getting more stringent,especially for bridge projects.The arched continuous rigid-frame bridge was developed under this social background.The advantage of the bridge lies in the design of a bridge model that integrates various functions such as transportation,landscape,and sightseeing.Based on the above,this paper first refers to the case to analyze the design and construction strategy of the arched continuous rigid-frame bridge,in hope of providing a valuable reference for relevant personnel.
