scholarly journals Experimental Analysis of Bending Stiffness Characteristics of Grouted Double Mortise-Tenon Joint for Prefabricated Metro Station Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xiuren Yang ◽  
Fang Lin ◽  
Meiqun Huang
Keyword(s):  
Variable Stiffness ◽  
Bending Stiffness ◽  
Bending Moments ◽  
Underground Structures ◽  
Axial Loads ◽  
Characteristic Analysis ◽  
Metro Station ◽  
Prototype Test ◽  
Stiffness Characteristics ◽  
Station Structure

The grouted mortise-tenon joint, invented as the connection between the large prefabricated components, is the key to the prefabricated underground structures, and the double-tenon joint is most widely used in the prefabricated metro station structure. This paper conducts characteristic analysis of bending stiffness with a 1 : 1 prototype test in key working direction of different joint types for grouted double mortise-tenon joint. The results show that the double-tenon joint is characteristic of variable stiffness under different loads. Change laws of double-tenon joint bending stiffness without and with auxiliary pretightening device in tension side and compression side are also discussed. The correlations for calculating double-tenon joint bending stiffness with various axial loads and bending moments are derived at last, which offers the theory foreshadowing of similar joints.

scholarly journals Experimental Research on Bending Bearing Capability of Grouted Double Mortise-Tenon Joint for Prefabricated Metro Station Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiuren Yang ◽  
Fang Lin ◽  
Meiqun Huang
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Characteristic Curve ◽  
Test Results ◽  
Underground Structures ◽  
Metro Station ◽  
Prototype Test ◽  
Resistance Moment ◽  
Ultimate Failure ◽  
Bearing Characteristic

The grouted mortise-tenon joint, invented as the connection between the large prefabricated elements, is the most important component in the prefabricated underground structures. This paper conducts analysis of load-carrying capacity performance and failure mode with 1 : 1 prototype test in key working direction of different double mortise-tenon joint types for the prefabricated metro station. The resistance moment is developed and used to analyze the bending bearing characteristic curve, and the corresponding test results of each stage of the characteristic curve are described in detail. In addition, the bending bearing performance of different types of double-tenon joints under different load conditions is compared. The test results clarify the ultimate failure mode of double-tenon joint and the variable bearing capacity characteristics of the joint with the increase in axial load and explain the bearing performance of each stage. It is also found the auxiliary pretightening device is helpful to delay the appearance of cracks and improve the bearing capacity, especially when it is set on the tension side. The research results have important application value for the joint design of prefabricated metro station structures.

Three Dimensional Seismic Response Analysis of Complicated Metro Station with Shallow Depth

2014 ◽  
Vol 638-640 ◽  
pp. 1905-1910
Author(s):  
Hong Lin ◽  
Xin Pan
Keyword(s):  
Three Dimensional ◽  
Calculation Model ◽  
Shallow Depth ◽  
Response Analysis ◽  
Concept Design ◽  
Underground Structures ◽  
Metro Station ◽  
Seismic Motion ◽  
Main Station ◽  
Station Structure

Focusing on a complicated metro station with shallow depth, its three-dimensional calculation model was established, which includes not only the main station structure, but also includes the subsidiary structure such as the entrances and detailed structures such as the holes in the floor. The Davidenkov model was employed to simulate the nonlinear characteristics of the soil. The three-dimensional nonlinear seismic responses were analyzed. it can be shown from the calculation that: (1) the metro station structure can satisfy the demand under given seismic motion; (2) it is more important for structural concept design and structural measures design than the strength and deformation design for complicated underground structures.

scholarly journals Seismic Response Study of Tunnels Running underneath a Subway Station in Parallel

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Fuxue Sun ◽  
Guo-bo Wang ◽  
Xiang-jun Peng ◽  
Zhou-zhou Jin ◽  
Xiao-chun Li ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Underground Structure ◽  
Internal Force ◽  
Underground Structures ◽  
Plane Model ◽  
Metro Station ◽  
Soil Response ◽  
The Impact ◽  
Station Structure ◽  
Range Of Influence

A tunnel passing below a metro station is taken as the object of our study, and a two-dimensional plane model is established to study the effects of their dynamic interaction to seismic excitation. Comparative analysis is used to obtain the influence law between the underground structures and on the soil. The results show that (1) the influence of the underground structure on the soil response is related to structure depth. The range of influence of the station structure on the surface is approximately five times the width of the station, and the surface response is obviously significant within this range. (2) The existence of the tunnel is conducive to reducing the acceleration of the column in the station. It increases the displacement difference between the stations, but the impact on the internal force of the station is not significant. (3) The influence of the station on the dynamic response of the tunnel is consistent with regard to tunnel acceleration, difference in displacement between the top and bottom of the tunnel, and internal force. The presence of the station will reduce the dynamic response of the tunnel.

The Analysis of Test of the Seismic Response for the Metro Station Structure Considering Soil-Structure Interaction

2012 ◽  
Vol 204-208 ◽  
pp. 2600-2604
Author(s):  
Ying Ming Zhou ◽  
Shu Wei Wang ◽  
Peng Wang ◽  
Li Na Yao
Keyword(s):  
Seismic Response ◽  
Large Scale ◽  
Underground Structure ◽  
Three Dimensional ◽  
Earth Pressure ◽  
Shaking Table ◽  
Underground Structures ◽  
Metro Station ◽  
General Law ◽  
Station Structure

In this paper, the subway station structure seismic response of large-scale three-dimensional shaking table model test is analysis, the model system acceleration response time, the stress response of the model structure of the schedule and structure of the surface of the earth pressure time is obtained, which has been the subway underground structure seismic response of the general law, the conclusion can provide a reliable basis and guidance for the seismic design of the MTR underground structures in the general venue.

Theoretical and Numerical Analysis on the Seismic Response of Underground Structures in Existence of Isolators

2011 ◽  
Vol 368-373 ◽  
pp. 710-714
Author(s):  
Jin Chun Liu ◽  
Yi Huan
Keyword(s):  
Dynamic Response ◽  
Analytical Procedure ◽  
Axial Loading ◽  
Seismic Loading ◽  
Underground Structures ◽  
Structural Dynamic ◽  
Metro Station ◽  
Single Degree Of Freedom ◽  
Theoretical And Numerical Analysis ◽  
Elastically Supported

In this paper, an analytical method of the beam with springs and dampers fixed at the ends was proposed based on equivalent single degree of freedom (SDOF) system and secondary Lagrange’s dynamic equations, in order to develop a new effective method to enhance the aseismic capability of underground structures. The dynamic response of elastically supported and damply supported beams subjected to both seismic loading and static axial loading was analyzed by the proposed analytical procedure. The theoretical results were validated by the numerical simulation. In order to further investigate the effects of springs and dampers fixed at the ends of the columns in nonlinear response situation, the 3D nonlinear seismic responses of the Dakai metro station structure with and without the isolators were analyzed by ABAQUS respectively. It is demonstrated that: (1) the proposed analytical procedure can predict the dynamic response of beams with elastic and damper supports subjected to both seismic loading and axial loading. (2) Setting isolators at the supports of the column could enhance the aseismic capability of the structure effectively. (3) The axial static loading induced by the gravity of the soil and structure provide the constraint on the column, and therefore could not be neglected in the structural dynamic analysis.

Experimental Analysis of Static Stiffness for Vehicle Body in White

2012 ◽  
Vol 248 ◽  
pp. 69-73 ◽  
Author(s):  
Shu Ming Chen ◽  
Xue Wei Song ◽  
Chuan Liang Shen ◽  
Deng Feng Wang ◽  
Wei Li
Keyword(s):  
Test Bench ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Vehicle Body ◽  
Torsional Angle ◽  
Static Stiffness ◽  
Torsional Deformation ◽  
Automotive Body ◽  
Body In White ◽  
Stiffness Characteristics

In order to know the static stiffness characteristics of the vehicle body in white, the bending stiffness and torsional stiffness of an automotive body in white were tested on a test bench of the static stiffness of an automotive BIW. The bending stiffness and bending deformation of the bottom of the BIW were determined. Also, the torsional stiffness and torsional deformation of the bottom of the BIW were obtained. The fitting curves and equations between loading torque and torsional angle were acquired at clockwise and counterclockwise loading, respectively.

Effect of membrane bending stiffness on the deformation of capsules in simple shear flow

2001 ◽  
Vol 440 ◽  
pp. 269-291 ◽  
Author(s):  
C. POZRIKIDIS
Keyword(s):  
Curvature Tensor ◽  
Deformation Gradient ◽  
Bending Stiffness ◽  
Boundary Element Methods ◽  
Simple Shear Flow ◽  
Normal Vector ◽  
Membrane Thickness ◽  
Bending Moments ◽  
Balance Equations ◽  
Capsule Deformation

The effect of interfacial bending stiffness on the deformation of liquid capsules enclosed by elastic membranes is discussed and investigated by numerical simulation. Flow-induced deformation causes the development of in-plane elastic tensions and bending moments accompanied by transverse shear tensions due to the non-infinitesimal membrane thickness or to a preferred configuration of an interfacial molecular network. To facilitate the implementation of the interfacial force and torque balance equations involving the hydrodynamic traction exerted on either side of the interface and the interfacial tensions and bending moments developing in the plane of the interface, a formulation in global Cartesian coordinates is developed. The balance equations involve the Cartesian curvature tensor defined in terms of the gradient of the normal vector extended off the plane of the interface in an appropriate fashion. The elastic tensions are related to the surface deformation gradient by constitutive equations derived by previous authors, and the bending moments for membranes whose unstressed shape has uniform curvature, including the sphere and a planar sheet, arise from a constitutive equation that involves the instantaneous Cartesian curvature tensor and the curvature of the resting configuration. A numerical procedure is developed for computing the capsule deformation in Stokes flow based on standard boundary-element methods. Results for spherical and biconcave resting shapes resembling red blood cells illustrate the effect of the bending modulus on the transient and asymptotic capsule deformation and on the membrane tank-treading motion.

scholarly journals Spring Effects on Workspace and Stiffness of a Symmetrical Cable-Driven Hybrid Joint

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 101 ◽  
Author(s):  
Shan Zhang ◽  
Zheng Sun ◽  
Jili Lu ◽  
Lei Li ◽  
Chunlei Yu ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Robotic Manipulator ◽  
Spring Model ◽  
Cable Tension ◽  
Stiffness Analysis ◽  
Hybrid Joint ◽  
Compression Spring ◽  
Spring Force ◽  
Basic Parameters ◽  
Stiffness Characteristics

This paper aims to investigate how to determine the basic parameters of the helical compression spring which supports a symmetrical cable-driven hybrid joint (CDHJ) towards the elbow joint of wheelchair-mounted robotic manipulator. The joint design of wheelchair-mounted robotic manipulator needs to consider lightweight but robust, workspace requirements, and variable stiffness elements, so we propose a CDHJ which becomes a variable stiffness joint due the spring under bending and compression provides nonlinear stiffness characteristics. Intuitively, different springs will make the workspace and stiffness of CDHJ different, so we focus on studying the spring effects on workspace and stiffness of CDHJ for its preliminary design. The key to workspace and stiffness analysis of CDHJ is the cable tension, the key to calculate the cable tension is the lateral bending and compression spring model. The spring model is based on Castigliano’s theorem to obtain the relationship between spring force and displacement. The simulation results verify the correctness of the proposed spring model, and show that the spring, with properly chosen parameters, can increase the workspace of CDHJ whose stiffness also can be adjusted to meet the specified design requirements. Then, the modelling method can be extended to other cable-driven mechanism with a flexible compression spring.

End moments in open web steel joists

1980 ◽  
Vol 7 (1) ◽  
pp. 114-124
Author(s):  
S. C. Shrivastava ◽  
R. G. Redwood ◽  
P. J. Harris ◽  
A. A. Ettehadieh
Keyword(s):  
Significant Influence ◽  
The Other ◽  
Bending Moments ◽  
Axial Loads ◽  
Simply Supported ◽  
Gravity Load ◽  
Negative Bending

A study is made of the behaviour of open web steel joists having both top and bottom chords connected to a column when the end is subjected to negative bending moments. Six tests are described, three of which examine the behaviour with typical standard connections as detailed and supplied by manufacturers; the other three involve modifications to these connections in an attempt to minimize connection eccentricity. It is shown that the eccentricities inherent in the standard connections examined can have a significant influence on the behaviour and strength of a joist, whereas if the eccentricities are eliminated, reasonably predictable behaviour, based upon the member resistances under axial loads, can be achieved. These results are examined in relation to tie joists, which are designed to be simply supported under gravity load but have the bottom chord extended and attached to a column, and also in relation to joists designed as framing members.

scholarly journals Conceptual mechanical design of antagonistic variable stiffness joint based on equivalent quadratic torsion spring

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042094129
Author(s):  
Jishu Guo
Keyword(s):  
Degrees Of Freedom ◽  
Modular Design ◽  
Angular Displacement ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Design Calculation ◽  
Robot Arm ◽  
Compact Structure ◽  
Torsion Spring ◽  
Stiffness Characteristics

The variable stiffness joint is a kind of flexible actuator with variable stiffness characteristics suitable for physical human–robot interaction applications. In the existing variable stiffness joints, the antagonistic variable stiffness joint has the advantages of simple implementation of variable stiffness mechanism and easy modular design of the nonlinear elastic element. The variable stiffness characteristics of antagonistic variable stiffness joints are realized by the antagonistic actuation of two nonlinear springs. A novel design scheme of the equivalent nonlinear torsion spring with compact structure, large angular displacement range, and desired stiffness characteristics is presented in this article. The design calculation for the equivalent quadratic torsion spring is given as an example, and the actuation characteristics of the antagonistic variable stiffness joint based on the equivalent quadratic torsion spring are illustrated. Based on the design idea of constructing the antagonistic variable stiffness joint with compact structure and high compliance, as well as the different design requirements of the joints at different positions of the multi–degrees of freedom robot arm, nine types of mechanical schemes of antagonistic variable stiffness joint with the open design concept are proposed in this article. Finally, the conceptual joint configuration schemes of the robot arm based on the antagonistic variable stiffness joint show the application scheme of the designed antagonistic variable stiffness joint in the multi–degrees of freedom robot.

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