关闭×


  《北京工业大学学报》是北京工业大学主办的理工科综合性学术刊物,主要刊登光学工程、机械工程、电子信息与控制工程、计算机与软件工程、土木工程、交通工程、环境与能源工程、材料科学与工程、生物医学工程、应用数学等方面的学术论文。主要任务是反映校内外最新科研成果,促进教学和科研水平的提升,发现和培养人才,开展国内外学术交流。为中文核心期刊,已被国内外多家著名数据库收录。国内外公开发行,月刊,彩色印刷,全国各地邮局订购,邮发代号2-86。现任主编为聂祚仁教授。..... 更多>>
15 August 2020, Volume 46 Issue 8 Previous Issue   
Articles
Numerical Study on Behavior of Double-superimposed RC Shear Wall Under Axial Compression and Bending Combination
CUI Yao, WANG Jingqiu, YU Yinquan, XIAO Ming, ZHAO Zuozhou
2020, 46 (8):  851-860.  doi: 10.11936/bjutxb2019030017
Abstract ( 9 )   PDF (5675KB) ( 4 )  
Double-superimposed reinforced concrete shear wall (DRCSW) is a semi prefabricated shear wall structure, which is constituted by two prefabricated panels and cast-in-situ concrete layer. These three parts of concrete are connected by truss. To study the behavior of DRCSWs under axial compression and bending combination, ABAQUS has been used in this paper. Some tested specimens of DRCSW have been predicted to calibrate the numerical modelling method adopted and parameter studies have been carried out. The parameters considered include concrete strength, axial force ratio, boundary elements construction method, overlapped reinforcement bar area and stirrup layout in boundary elements. It has been concluded that increasing axial compression ratio will increase the peak load of the wall and lateral stiffness before peak load while decrease the deformation capacity of the wall. The change of concrete strength on the DRCSW under high axial compression ratio is more obvious than that under low axial compression ratio. The peak load and deformation capacity of the walls are almost the same no matter the boundary element is precast or cast-in-site. The DRCSW with prefabricated boundary elements is more favorable for structure industrial manufacture. Increasing the overlapped reinforcement bar area in the wall boundary elements will slightly improve the bearing capacity of the wall but increase the capacity degradation ratio after the peak load and the damage zone will transfer from the wall bottom to the upper end area of the overlapped reinforcement bar. Increasing the stirrup ratio can improve the deformation capability of the DRCSW.
References | Related Articles | Metrics
Strain Variation Inside Steel Bars Embedded in Concrete Beams and Its Correlation With Loads
LIU Simeng, BAI Yu, WU Caixing
2020, 46 (8):  861-867.  doi: 10.11936/bjutxb2019100008
Abstract ( 6 )   PDF (3883KB) ( 2 )  
In order to investigate the influence of the strain gradient of the reinforcement with the change of load, the theoretical analysis method was used to study the strain distribution on the reinforced concrete section, and the formula of the strain difference of the reinforcement was derived. For the reinforced concrete beam, a finite element analysis and model tests were carried out in this study. Theoretical analysis shows that the strain difference between the upper and lower edges of the reinforcement is related to the section curvature and the diameter of the reinforcement, and the section curvature is related to the load. The analysis of the test data demonstrates that during the loading process, the strain difference between the upper and lower edges of the steel bar increases with the increase of the load. The relationship between the strain difference of the compressed steel bar and the load is clearer. The strain difference ratio can be as high as 50%. The research results show that when measuring the strain of steel bars in concrete structures, the influence of the strain gradient inside the steel bars needs to be fully considered.
References | Related Articles | Metrics
Experimental Research on the Seismic Response of a Continuous Rigid Frame Bridge With High Piers Under Near-fault Pulse-like Ground Motions
YAN Weiming, LUO Zhenyuan, XU Weibing, CHEN Yanjiang, WANG Jin
2020, 46 (8):  868-878.  doi: 10.11936/bjutxb2019040012
Abstract ( 3 )   PDF (8861KB) ( 0 )  
To study the effects of near-fault pulse-type (NFPT) ground motions on seismic response of a continuous rigid frame bridges with high piers (CRFB-HP), a 1/15-scale model was designed and fabricated. Then series of shaking table tests were carried out to study the seismic response of the model under the far field ground motions and NFPT ground motions, respectively. The effects of the velocity pulse number (VPN) were mainly discussed. Results show that the first-order vibration frequencies of the model bridge along the longitudinal and transverse directions are relatively small. The seismic response of the model is mainly low frequency response. The seismic response of the bridge model under the NFPT ground motions is greater than that of twice of it under the far-field ground motions. However, the dynamic response of the bridge model under the no-pulse near-fault ground motions is slightly smaller than (0.76-0.95 times as large as) that of the far-field ground motions. The velocity pulse causes instantaneously large displacement response of the model, the peak value is up to 54.8 m. In this sense, the collision between the abutment and the girder or the bearing damage may occur. The VPN has a significant influence on the seismic response of the bridge model, and the influence coefficient of the VPN (AF<i>w) is between 1.46-5.54. The multi-pulse ground motions may cause larger dynamic response of the model than the others. The double-pulse ground motion has much smaller influence on the dynamic responses of the model bridge. The parameters influence of the NFPT ground motions on the seismic response of the long-period bridges should be considered.
References | Related Articles | Metrics
Seismic Experiment and Design Suggestion for BRB-Concrete Frame Bent Structure
HUANG Jin, GAO Xiangyu, ZHOU Jianjun, WANG Yongqiang, ZENG Zhenjie, WANG Fumin
2020, 46 (8):  879-891.  doi: 10.11936/bjutxb2019030015
Abstract ( 4 )   PDF (10566KB) ( 0 )  
In order to study the seismic performance of buckling-restrained brace (BRB)-reinforced concrete frame bent (RCFB) structure, a four-story BRB-RCFB structure specimen was designed and manufactured, based on the prototype of the main workshop of a concrete reinforced thermal power plant consisting of a double-span frame and bent. The crack development and damage mechanism, hysteresis hoop, stiffness degradation law, deformation capacity of structure and energy dissipation capacity of BRB were studied by static cycle loading test. Results show that the system has plump hysteresis hoop, the BRB and RCFB can effectively work together to resist lateral force, terefore, the energy dissipation mechanism of this system can be realized. The measured axial force-axial displacement curve of the BRB shows that its energy dissipation effect is remarkable and the damping ratio of the structure increases. Suggestions are put forward for the shear structural design of the deaerator room and the two layers at the bottom of the coal-bunker room, the design of the weak parts of the rigid layer (it is composed of steel beams, steel braces and concrete beams) in coal-bunker room, the form of BRB and the model design test of a single structure.
References | Related Articles | Metrics
Reliability Analysis of Nuclear Power Plants Under Random Earthquake Based on Extreme Value Theory
QIN Miaojun, ZHAO Yangang, LU Zhaohui
2020, 46 (8):  892-899.  doi: 10.11936/bjutxb2019070017
Abstract ( 3 )   PDF (3795KB) ( 7 )  
To solve the problem of dynamic reliability of nuclear power plants under random ground motion excitation, a dynamic reliability analysis method was developed, with the extreme value distribution of the maximum response evaluated based on linear moments(L-moment). First, according to the target response spectrum, the corresponding time-history of ground motion samples were generated. Combined with the nuclear power structure finite element model, the time-domain explicit method was used in the random vibration analysis to obtain the node displacement response time-history sample. Then, the maximum displacement response time-history samples were estimated to determine the first three L-moment of the maximum response, and the three-parameter of maximum response distribution was determined according to the L-moment matching. Finally, based on the maximum response distribution, the reliability under different thresholds was estimated. Results show that when the peak value of seismic acceleration is 0.3 g, the containment structure has good reliability with slight damage as the boundary, and still has certain reliability with medium damage. The dynamic reliability analysis of the nuclear power plant shows that compared with the Monte Carlo method, this method greatly reduces the minimum sample size and improves the computational efficiency of the simulated tail while ensuring the calculation accuracy. At the same time, it has wide applicability for solving the problem of dynamic reliability of other structures.
References | Related Articles | Metrics
Influences of Bond Pattern on Compressive Properties of Earth Brick Masonry
LAN Guanqi, WANG Yihong, NIU Dongdong, ZENG Guiyuan
2020, 46 (8):  900-907.  doi: 10.11936/bjutxb2019050009
Abstract ( 4 )   PDF (2022KB) ( 1 )  
To study the influence of different bond patterns on the uniaxial compressive performance of the earth block masonry prism and to determine the bond pattern of specimen for measuring the compressive strength of earth block masonry prism, two kinds of traditional adobe and two new types of earth brick were selected to build masonry prisms. The uniaxial compression tests were performed on three kinds of masonry to analyze the influences of bond pattern on masonry compressive properties from failure mode, compressive strength, elastic modulus and Poisson's ratio, respectively. Based on the analytic hierarchy process, the optimum specimen bond pattern for measuring the compressive strength of earth brick masonry was determined. It is shown that local failure and splitting failure occurred in stacked specimens and penetration failure caused by vertical cracks occurred in the specimens with vertical joints. The compressive strength, elastic modulus and Poisson's ratio of all kinds of masonry show the same variation regularity: compressive strength and elastic modulus in order from strength to weakness are stack bond, stretcher bond, flemish bond and inbond, and the Poisson's ratios in descending order are inbond, flemish bond, stretcher bond and stack bond. Because of the superiority of stretcher bond in applicability, operability, data variation, specimen failure mode, and reproducibility, it was suggested to use this bond pattern as the standard bond pattern for testing the compressive strength of earth brick masonry.
References | Related Articles | Metrics
Experimental Research and Theoretical Analysis of Mechanical Behavior of Pre-embedded Anchor Bolts
ZHAI Chuanming, ZHANG Chao, WANG Juanjuan, ZHAO Jiping, XU Jianyun
2020, 46 (8):  908-917.  doi: 10.11936/bjutxb2019060013
Abstract ( 3 )   PDF (7141KB) ( 2 )  
Considering the effect of concrete strength, cover depth and edge distance, 24 specimens were carried to research the mechanical property including failure mode and ultimate bearing capacity on pre-embedded anchor bolt that is applied for the lifting and supporting of precast element. Results show that the failure mode of concrete includes cone failure and blow-out under axial tension. For the concrete cone failure, the angle of cone failure is about 40°. Under shearing force, the failure mode of concrete is cuneiform failure. Based on the experimental results and twin shear stress three-parameter criterion and ACI standard, theoretical formula for different failure modes was derived. It shows that the calculation results agree well with those of the test results, which can be applied to giving a reference for engineering design.
References | Related Articles | Metrics
Finite Element Analysis of Circular Concrete-filled Double Steel Tubular Short Columns Under Axial Compression
CI Junchang, YAN Weiming, JIA Hong
2020, 46 (8):  918-928.  doi: 10.11936/bjutxb2019100005
Abstract ( 2 )   PDF (4059KB) ( 0 )  
Based on the finite element software ABAQUS, a finite element model of concrete-filled double steel tubular (CFDST) columns under axial compression was established. Two constitutive models of core concrete were adopted for the case that core concrete is confined by both internal and external steel tubes. At the same time, the simulation results of the two constitutive models were compared with the experimental results of predecessors, which verifies the correctness of the model, and the constitutive models suitable for sandwich concrete, core concrete and steel tube were proposed. On this basis, ABAQUS broadens the scope of parameter study, and the force analysis of circular CFDST short columns under different parameters was carried out.
References | Related Articles | Metrics
Analysis of Influencing Factors of Seismic Response of Connected Parallel Subway Stations
HAN Xuechuan, TAO Lianjin, LIU Chunxiao, AN Shao, WU Xiaowa
2020, 46 (8):  929-939.  doi: 10.11936/bjutxb2019070020
Abstract ( 3 )   PDF (8261KB) ( 0 )  
Based on ABAQUS software, a three-dimensional finite element numerical model of connected parallel subway station structures with large openings was established. Considering the spectral characteristics of near-far field seismic waves, the influence of concrete plastic deformation and damage, the difference of nonlinear seismic response characteristics of connected parallel subway station structures under different earthquake types was simulated. Results show that the spectral characteristics of seismic waves have a great influence on the dynamic response and damage of connected parallel subway station structures. The closer the main frequency of seismic waves and the natural frequency of structures are, the more serious the damage is. Tensile and compressive damage distribution of the connected parallel subway station structure is left-right symmetrical, with the floor and center pillar of the structure in the 45 sector range at the top and bottom of the side wall with openings and both sides of the openings being the most seriously damaged. When the opening ratio of the side wall of the connected parallel subway station structure is less than 1/3, the displacement change rate of the opening layer is the largest, which has significant spatial effect. Seismic response analysis should be carried out according to the spatial problem. When the opening ratio of the side wall is greater than 2/3, the displacement change rate of the opening layer is unchanged, which can be treated approximately according to the plane strain problem. The research results provide reasonable reference and guidance for improving the seismic performance of such subway station structures.
References | Related Articles | Metrics
Analysis Model for Relaxation Effect of Pulling Force of Prestressed Anchor Cables Used in Reinforcing Rock Mass
XIAO Shiguo, CAO Shunli, ZHAO Linzhi
2020, 46 (8):  940-947.  doi: 10.11936/bjutxb2019070018
Abstract ( 2 )   PDF (2778KB) ( 0 )  
Based on the interaction mechanism between an anchor cable and rock mass, a series of models that one Hooke body of describing the anchor cable connects in series with one Kelvin-Hooke body of describing the rock mass was proposed to solve the relaxation problem of pulling force of prestressed anchor cables. In light of the model reflecting coupling relation between the anchor cable and rock mass, a formula corresponding to the relaxation effect of the pulling force was derived. It reveals quantitatively the influences of the spacing between the adjacent two anchor holes, elastic modulus of the anchor cable, rheological parameters of rock mass, and diameter of the anchor cable, and initial pulling force on the long-term pulling force. Analysis results of one laboratory and in-situ test example show that the predicted pulling force using the proposed model is identical with the observed one. The maximum error of final pulling force of the prestressed cables between the calculation and observation value is 7%. The proposed model is reasonable. Spacing between the adjacent two anchor holes, diameter of the anchor cable, and rheological parameters of the rock mass have obviously nonlinear influences on the relaxation effect of the cable.
References | Related Articles | Metrics
Experimental Study on Preparation and Mechanical Properties of MPC Concrete
XIE Jian, LI Ming, BAI Weiliang
2020, 46 (8):  948-955.  doi: 10.11936/bjutxb2019110004
Abstract ( 3 )   PDF (5887KB) ( 0 )  
To solve the problems of long construction period of existing reinforcement materials and poor adhesion with old concrete structures, three kinds of magnesium phosphate cement (MPC) concrete were prepared by modified magnesium phosphate cement, the difference of mechanical properties between MPC and the ordinary portland cement (OPC) concrete and the influence of different aggregates were studied. Contrasting with OPC concrete, MPC concrete prismatic specimens were prepared for uniaxial compression test. The experimental findings show that the peak strain of MPC concrete is obviously higher than that of OPC concrete, and with adding lightweight aggregate, the peak strain of MPC concrete increases further. Its modulus of elasticity is obviously lower than that of OPC concrete, besides, the modulus of elasticity reduces further due to lightweight aggregate added. The Poisson ratio is about 0.2 at the elastic phase, but the Poisson ratio of MPC concrete is higher than that of OPC concrete at high stress. After the inelastic phase, there are more internal cracks, and the final failure phenomenon is more abrupt and looser after failure. MPC concrete shows stronger brittleness than OPC concrete.
References | Related Articles | Metrics
Segregation Experiment of Ice Melting and Salt-containing Ceramsite Concrete
HOU Ziyi, LI Hongcheng, ZHENG Shaopeng, LI Sili, CHENG Zhihao
2020, 46 (8):  956-962.  doi: 10.11936/bjutxb2018070006
Abstract ( 3 )   PDF (4846KB) ( 0 )  
To ensure good deicing and snow melting durability of salt-containing ceramsite concrete pavement and eliminate the adverse effects of stratification of salt-containing ceramsite on concrete performance the factors that influence the homogeneity of salt-containing ceramsite concrete were analyzed through segregation experiments. Results show that reasonable sand ratio can effectively improve the viscosity of cement mortar in concrete mixture. When the sand ratio is 36%, the anti-delamination and anti-segregation performance of salt-containing ceramsite concrete is the best. The replacement of fly ash to cement can reduce the density difference between cement mortar and salt-containing ceramsite, which can improve the workability of concrete mixture and effectively reduce the floatation of salt-containing ceramsite. With a certain vibration time it can make the cementitious material of concrete fully contact with water, the viscosity coefficient of concrete mixture obviously increases, and excessive vibration leads a large amount of salt-containing ceramsite floating. By optimizing the material composition and strictly controlling the vibrating time of salt-containing ceramsite concrete, it is possible to ensure that the distribution of salt-containing ceramsite is in line with the proportion of aggregate replacement.
References | Related Articles | Metrics
Influence Factor and Early Cohesion Force of Emulsified Asphalt Cold Recycling Mixture
WANG Decai, HAO Peiwen
2020, 46 (8):  963-970.  doi: 10.11936/bjutxb2018070021
Abstract ( 5 )   PDF (4334KB) ( 1 )  
To study the construction quality problems of emulsified asphalt cold recycling mixture caused at least in part by lack of early cohesive force index,the influence rule of different mixing time, characteristics and dosage of emulsified asphalt, reclaimed asphalt pavement (RAP) content and mixing water content for the cohesive force was systematically investigated by the HVEEN cohesive force test. Meanwhile, the significance of four influencing factors was analyzed by statistical product and service solutions (SPSS). According to the test results,the requirement for early cohesion force specification was recommended. Finally, technical measures for improving cohesive force were discussed in this paper. Results show that the cohesive force of the emulsified asphalt cold recycled mixture first increases and then decreases with the increase of the mixing time, dosage of emulsified asphalt and mixing water content,increases with the increase of the RAP content,and there is a maximum cohesive force when the workability of cold recycled mixture is good.The smaller the average particle size of emulsified asphalt is, the greater the cohesion force is not. The test of cohesion force is in good agreement with the indirect tensile test for optimum mixing water content.There is a significant impact on the cohesive force of emulsified asphalt cold recycling mixture including emulsified asphalt content,mixing water content,characteristics of emulsified asphalt and content of RAP,and there is a significant improvement of cohesive force when adding Buton rock asphalt (BRA), regenerating agent (RA) to the emulsified asphalt cold recycling mixture and using SBR modified emulsion asphalt, however, the cohesion force is slightly reduced with adding basalt fiber (BF).
References | Related Articles | Metrics
Status Problems and Copying Strategies in Self-service Ticket Space of Railway Passenger Station
WANG Bingbing, DUAN Jinfang, WANG Shan
2020, 46 (8):  971-978.  doi: 10.11936/bjutxb2018070019
Abstract ( 3 )   PDF (7610KB) ( 1 )  
At present, self-service equipment is not easy to find and spaces are crowded in the self-service ticket space of railway passenger stations, which affects the efficiency of station use and reduces the comfort of passengers. To solve these problems, this paper conducts a systematic study on the self-service ticket space of railway passenger stations. First, three railway passenger stations in Beijing were researched. By using the method of observation, the location, quantity, failure of self-service ticket equipment, layout of self-service ticket space and guiding signs as well as the use and management were observed and recorded. Second, three problems were sorted out in equipment setting, space layout along with use and management, and deep reasons causing the problems were analyzed. Finally, the coping strategies were put forward in turn to solve the three problems.The research results can be used as a basis for the space design, transformation, use and management of self-service ticket space of railway passenger stations.
References | Related Articles | Metrics