scholarly journals Effects of under sleeper pads on dynamic responses of railway prestressed concrete sleepers subjected to high intensity impact loads

2020 ◽  
Vol 214 ◽  
pp. 110604 ◽  
Author(s):  
Chayut Ngamkhanong ◽  
Sakdirat Kaewunruen
Keyword(s):  
Prestressed Concrete ◽  
High Intensity ◽  
Dynamic Responses ◽  
Impact Loads

Behaviour of new LCR and ordinary prestressed concrete railway sleepers under repeated impact loads

2022 ◽  
Vol 319 ◽  
pp. 126151
Author(s):  
Ferhat Çeçen ◽  
Bekir Aktaş ◽  
Hakan Öztürk ◽  
M. Burhan Navdar ◽  
İrfan Ş. Öztürk
Keyword(s):  
Prestressed Concrete ◽  
Impact Loads ◽  
Repeated Impact

Dynamic Analysis of Shipping Cask Subjected to Sequential Bolt Preload and Impact Loads

2009 ◽  
Author(s):  
Tsu-te Wu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Numerical Integration ◽  
Dynamic Responses ◽  
Integration Scheme ◽  
Impact Loads ◽  
Element Mesh ◽  
Bolt Preload ◽  
Numerical Integration Scheme ◽  
Structural Responses

This paper presents an improved methodology for evaluating the dynamic responses of shipping casks subjected to the sequential HAC impact loads. The methodology utilizes the import technique of the finite-element mesh and the analytical results form one dynamic analysis using explicit numerical integration scheme into another dynamic analysis also using explicit numerical integration scheme. The new methodology presented herein has several advantages over conventional methods. An example problem is analyzed to illustrate the application of the present methodology in evaluating the structural responses of a shipping cask to the sequential HAC loading.

Analysis on the Dynamic Responses of the Broken Conductors in Transmission Lines

2011 ◽  
Vol 50-51 ◽  
pp. 511-515 ◽  
Author(s):  
Feng Li Yang ◽  
Jing Bo Yang
Keyword(s):  
Transmission Lines ◽  
Element Model ◽  
Dynamic Responses ◽  
Impact Loads ◽  
Safe Operation ◽  
Rayleigh Damping ◽  
Fea Model ◽  
Insulator Element ◽  
Reaction Forces ◽  
Short Time

Impact loads from the broken conductors are common for transmission lines, which can bring threaten to the safe operation of the transmission lines. Dynamic analysis of the conductors in transmission lines under broken load was carried out. A finite element model of seven span conductors in transmission line was established in general software ANSYS. The insulator and the phase spacer were considered in the FEA model. The broken load case can be realized by the birth-death element method in ANSYS. Stiffness of the broken conductor or insulator element was changed to be a near zero value in a very short time. Effect of the damping property of the conductors was considered by the Rayleigh damping method. Dynamic responses of displacements at the broken points and the reaction forces of the insulators were obtained. Dynamic responses for the broken conductors with different damping ratios and bundle numbers were compared.

scholarly journals Influence of Fluid Viscous Damper on the Dynamic Response of Suspension Bridge under Random Traffic Load

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Yue Zhao ◽  
Pingming Huang ◽  
Guanxu Long ◽  
Yangguang Yuan ◽  
Yamin Sun
Keyword(s):  
Dynamic Response ◽  
Traffic Flow ◽  
High Intensity ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Dynamic Responses ◽  
Traffic Load ◽  
Damping Coefficient ◽  
Suspension Bridges ◽  
Fluid Viscous Dampers

Fluid viscous dampers (FVDs) are widely used in long-span suspension bridges for earthquake resistance. To analyze efficiently the influences of FVDs on the dynamic response of a suspension bridge under high-intensity traffic flow, a bridge-vehicle coupling method optimized by isoparametric mapping and improved binary search in this work was first developed and validated. Afterwards, the traffic flow was simulated on the basis of monitored weigh-in-motion data. The dynamic responses of bridge were analyzed by the proposed method under different FVD parameters. Results showed that FVDs could positively affect bridge dynamic response under traffic flow. The maximum accumulative longitudinal girder displacement, longitudinal girder displacement, and longitudinal pylon acceleration decreased substantially, whereas the midspan girder bending moment, pylon bending moment, longitudinal pylon displacement, and suspender force were less affected. The control efficiency of maximum longitudinal girder displacement and accumulative girder displacement reached 33.67% and 57.71%, longitudinal pylon acceleration and girder bending moment reached 31.51% and 7.14%, and the pylon longitudinal displacement, pylon bending moment, and suspender force were less than 3%. The increased damping coefficient and decreased velocity exponent can reduce the bridge dynamic response. However, when the velocity exponent was 0.1, an excessive damping coefficient brought little improvement and may lead to high-intensity work under traffic flow, which will adversely affect component durability. The benefits of low velocity exponent also reduced when the damping coefficient was high enough, so if the velocity exponent has to be increased, the damping coefficient can be enlarged to fit with the velocity exponent. The installation of FVDs influences dynamic responses of bridge structures in daily operations and this issue warrants investigation. Thus, traffic load should be considered in FVD design because structural responses are perceptibly influenced by FVD parameters.

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