scholarly journals Dynamic Response and Robustness Evaluation of Cable-Supported Arch Bridges Subjected to Cable Breaking

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Guotao Shao ◽  
Hui Jin ◽  
Ruinian Jiang ◽  
Yue Xu
Keyword(s):  
Dynamic Response ◽  
Evaluation Method ◽  
Progressive Collapse ◽  
Bending Moment ◽  
Simulation Method ◽  
Dynamic Amplification Factor ◽  
Cable System ◽  
Evaluation Indexes ◽  
Dynamic Amplification ◽  
Arch Bridges

Cable-supported arch bridges have had many cable break accidents, which led to dramatic deck damage and even progressive collapse. To investigate the dynamic response and robustness of cable-supported arch bridges subjected to cable breaking, numerical simulation methods were developed, compared, and analyzed, and an effective and accurate simulation method was presented. Then, the cable fracture of a prototype bridge was simulated, and the dynamic response of the cable system, deck, and arch rib was illustrated. Finally, the robustness evaluation indexes of the cable system, deck, and arch rib were constructed, and their robustness was evaluated. The results show that the dynamic response of the adjacent cables is proportional to the length of the broken cable, while the dynamic response of the deck is inversely proportional to the length of the broken cable. The dynamic amplification factor of the cable tension and deck displacement is within 2.0, while that of the arch rib bending moment exceeds 2.0. The break of a single cable will not trigger progressive collapse. When subjected to cable breaking, the deck system has the least robustness. The proposed cable break simulation procedure and the robustness evaluation method are applicable to both existing and new cable-supported bridges.

Dynamic response of bridges under travelling loads

1993 ◽  
Vol 20 (2) ◽  
pp. 287-298 ◽  
Author(s):  
J. L. Humar ◽  
A. M. Kashif
Keyword(s):  
Dynamic Response ◽  
Rational Design ◽  
Weight Ratio ◽  
Experimental Investigations ◽  
Speed Ratio ◽  
Force Model ◽  
Beam Model ◽  
Dynamic Amplification Factor ◽  
Design Procedures ◽  
Dynamic Amplification

In spite of a number of analytical and experimental investigations on the dynamic response of bridges to moving vehicle loads, the controlling parameters that govern the response have not been clearly identified. This has, in turn, inhibited the development of rational design procedures. Based on an analytical investigation of the response of a simplified beam model traversed by a moving mass, the present study identifies the governing parameters. The results clearly show why attempts to correlate the response to a single parameter, either the span length or the fundamental frequency, are unsuccessful. Simple design procedures are developed based on relationships between the speed ratio, the weight ratio, and the dynamic amplification factors; and a set of design curves are provided. Key words: dynamic response of bridges, vehicle–bridge interaction, moving force model, moving sprung mass model, dynamic amplification factor.

Estimation Method of Cable Tension Based on Iterative Algorithm and Optimization Algorithm

2013 ◽  
Vol 353-356 ◽  
pp. 3202-3206
Author(s):  
Yong Hui Huang ◽  
De Quan Luo ◽  
Rui Rao
Keyword(s):  
Iterative Algorithm ◽  
Optimization Algorithm ◽  
Evaluation Method ◽  
Estimation Method ◽  
Empirical Formulas ◽  
Cable System ◽  
Cable Tension ◽  
Application Range ◽  
Taut String ◽  
Arch Bridges

The vibration method is usually used for field measurement of cable tension of cable system bridges. The cable tension evaluation method is mostly based on the simple taut string theory. However, the simple theory may cause unacceptable errors in many applications especially for the cables with big bending stiffness and two ends fixed boundary conditions. In this paper a cable tension estimation method based on iterative algorithm and optimization algorithm is presented and implemented using finite element method and ANSYS soft ware. Compared with the analytical method and empirical formulas the method presented in this paper is more convenient and the application range is more extensive. The accuracy of the method has been verified by a set of test. In the end, the method is used to estimate the cable tension of a tied-arch bridges suspenders.

scholarly journals Nonlinear behaviour of reinforced concrete flat slabs after a column loss event

2018 ◽  
Vol 21 (14) ◽  
pp. 2169-2183 ◽  
Author(s):  
Justin M Russell ◽  
John S Owen ◽  
Iman Hajirasouliha
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Nonlinear Behaviour ◽  
Dynamic Amplification Factor ◽  
Element Analysis ◽  
Flat Slab ◽  
Standard Design ◽  
Loss Event ◽  
Dynamic Amplification

Previous studies have demonstrated that reinforced concrete flat slab structures could be vulnerable to progressive collapse. Although such events are dynamic, simplified static analyses using the sudden column loss scenario are often used to gain an indication into the robustness of the structure. In this study, finite element analysis is used to replicate column loss scenarios on a range of reinforced concrete flat slab floor models. The model was validated against the results of scaled-slab experiments and then used to investigate the influence of different geometric and material variables, within standard design ranges, on the response of the structure. The results demonstrate that slab elements are able to effectively redistribute loading after a column loss event and therefore prevent a progressive collapse. However, the shear forces to the remaining columns were 159% of their fully supported condition and increased to 300% when a dynamic amplification factor of 2.0 was applied. It is shown that this can potentially lead to a punching shear failure in some of the slab elements.

scholarly journals BOUT THE PROBLEM OF ANALYSIS RESISTANCE BEARING SYSTEMS IN FAILURE OF A STRUCTURAL ELEMENT

2018 ◽  
Vol 14 (3) ◽  
pp. 103-113 ◽  
Author(s):  
Anatoly V. Perelmuter ◽  
Oleg V. Kabantsev
Keyword(s):  
Progressive Collapse ◽  
Universal Method ◽  
Dynamic Amplification Factor ◽  
Dynamic Calculation ◽  
Structural Element ◽  
Load Bearing ◽  
Static Calculation ◽  
Dynamic Amplification ◽  
Bearing Structure ◽  
Bearing System

This paper focuses on the methods of calculating load-bearing systems in the case of a failure of a structural element. This kind of failure makes it necessary to assess further behavior of the structure with a possibility of the progressive collapse development. The stress-strain state analysis of a load-bearing system in the case of a failure of a structure is carried out by two main methods – static and dynamic calculation. It is shown that the static calculation (quasi-static analysis using the dynamic amplification factor) is not a universal method. This paper justifies the application of the direct dynamic calculation in the mode of direct integration of motion for the design analysis of load-bearing systems with high rigidity stories (protection structures for a load-bearing system). It also gives recommendations for selecting parameters of the direct dynamic calculation in the case of a failure analysis of a bearing structure.

scholarly journals Damped dynamic response of strengthened beams by composite coats under moving force by FEM

2018 ◽  
Vol 106 (2) ◽  
pp. 206
Author(s):  
Abdennacer Chemami ◽  
Youcef Khadri ◽  
Sabiha Tekili ◽  
El Mostafa Daya ◽  
Ali Daouadji ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Numerical Study ◽  
Moving Load ◽  
Damping Ratio ◽  
Time Integration ◽  
Superposition Method ◽  
Dynamic Amplification Factor ◽  
Aluminum Composite ◽  
Strengthened Beam ◽  
Dynamic Amplification

This paper presents a numerical study of the free and damped forced vibration of simply-supported beams with composite coats subjected to a moving load by use of finite elements method. Three types of beam configurations, aluminum, composite and strengthened beam are investigated. The equation of motion of the beam is solved using the modal superposition method and integrated by applying the Newmark time integration procedure. Good agreements were achieved between the FEM and analytical solutions. The damped dynamic response, critical velocities and the dynamic amplification factor of the beam are calculated for different parameters such as the thickness ratio, the fiber orientation of the coat and damping ratio.

Dynamic Response of High Steep Rock Slopes Based on Wenchuan Near-Field Seismic Motion Characteristics

2010 ◽  
Vol 168-170 ◽  
pp. 1090-1097
Author(s):  
Shi Guo Xiao ◽  
Wen Kai Feng
Keyword(s):  
Numerical Analysis ◽  
Dynamic Response ◽  
Amplification Factor ◽  
Near Field ◽  
Seismic Load ◽  
Rock Slopes ◽  
Dynamic Amplification Factor ◽  
Seismic Motion ◽  
Dynamic Amplification ◽  
Motion Characteristics

Near-field seismic motion characteristics are analyzed in accordance with records of the 2008 Ms8.0 Wenchuan Earthquake measured at Wolong Station, upon which the determination of seismic load is introduced. Dynamic response features, such as acceleration, displacement and stress, of high steep rock slopes on the banks of Zipingpu Reservoir at a variety of locations resulting from horizontal seismic force are analyzed with a numerical analysis routine. The dynamic amplification factor on the slope top is determined, leading to a characterization of the mode of failure of the high steep slope. Analyses show that the dynamic amplification factor at the top of the slopes is about 1.34; however, dynamic response deformation features and stress state at different positions on the slope vary. Earthquake damage of the high steep rock slopes consists mainly of partial avalanche of the rock mass at the top of the slopes by joint cutting. Field investigations after the earthquake have partially confirmed the numerical analysis results presented in this paper.

Dynamic Behaviour of Minimum Platforms Under Random Seas

2003 ◽  
Author(s):  
Micaela Pilotto ◽  
Beverley F. Ronalds
Keyword(s):  
Dynamic Response ◽  
Dynamic Behaviour ◽  
Amplification Factor ◽  
Finite Element Models ◽  
Dynamic Amplification Factor ◽  
Maximum Value ◽  
Random Seas ◽  
Exponential Stretching ◽  
Structural Configurations ◽  
Dynamic Amplification

This paper describes the dynamic response of minimum facilities with different structural configurations which are subjected to random seas. The finite element models are kept simple with the aim of focusing on the physics of the phenomena involved. The response is studied in terms of the dynamic amplification factor (DAF), representing the ratio between the dynamic and the static response. Two different formulations of the DAF under random seas are compared. The first is defined in terms of standard deviation (DAF1), the second in terms of the most probable maximum value (DAF2). Ringing is observed to be a relevant feature of the dynamic response and to affect primarily the braced monopod configurations. Ringing is detected using DAF2. The paper also addresses the importance of the kinematic representation above the still water level. Different methods of stretching the velocity field in the wave zone (delta, Wheeler and exponential stretching) are shown to have a significant impact on the dynamic response of the platforms.

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