Dynamic analysis of CRTS III slab track-subgrade system under impact load

With the increasing popularity of high-speed railway, more and more bridges are being constructed in Western China where debris flows are very common. A debris flow with moderate intensity may endanger a high-speed train traveling on a bridge, since its direct impact leads to adverse dynamic responses of the bridge and the track structure. In order to address this issue, a dynamic analysis model is established for studying vibrations of coupled train–track–bridge system subjected to debris flow impact, in which a model of debris flow impact load in time domain is proposed and applied on bridge piers as external excitation. In addition, a six-span simply supported box girder bridge is considered as a case study. The dynamic responses of the bridge and the running safety indices such as derailment factor, offload factor, and lateral wheel–rail force of the train are investigated. Some influencing factors are then discussed based on parametric studies. The results show that both bridge responses and running safety indices are greatly amplified due to debris flow impact loads as compared with that without debris flow impact. With respect to the debris flow impact load, the boulder collision has a more negative impact on the dynamic responses of the bridge and train than the dynamic slurry pressure. Both the debris flow impact intensity and train speed determine the running safety indices, and the debris flow occurrence time should be also carefully considered to investigate the worst scenario.

Download Full-text

Dynamic Analysis of Liquid Sloshing for Shipboard Pressure Vessel

Volume 3: Design and Analysis ◽

10.1115/pvp2020-21183 ◽

2020 ◽

Author(s):

Qi Li ◽

Hui Tang ◽

Fujun Zhang ◽

Zhijian Wang ◽

Qianyu Shi

Keyword(s):

Dynamic Analysis ◽

Pressure Vessel ◽

Impact Load ◽

Great Influence ◽

Liquid Sloshing ◽

Pressure Curve ◽

Operation Condition ◽

Device Structure ◽

Safety Operation ◽

The Impact

Abstract With the development of pressure vessel industry in China, more and more pressure vessel is widely used in the aerospace, automobile, marine project and other fields. The liquid sloshing in the device could bring adverse effect on the safety operation of the pressure vessel under the extrinsic excitation, such as the impact load results in the failure of device structure. Thus, dynamic analysis of liquid sloshing for the shipboard pressure vessel is significant. According to the little research on the design criteria and the method of the shipboard pressure vessel, this paper focuses on the research of the transient sloshing of the internal liquid in the shipboard pressure vessel. In this paper, during analyzing the liquid sloshing dynamic of the shipboard pressure vessel, an obvious cycle is got. Considering the operation condition of lateral inclination, longitudinal inclination and heave in the complex marine environment, the liquid sloshing character is obtained and compared through the liquid surface height curve and the wall sloshing pressure curve, which has great influence on the piping layout of the pressure vessel. Moreover, it is beneficial to restrain sloshing through installing baffle inside the pressure vessel. This may provide a project reference to liquid sloshing design of the shipboard pressure vessel.

Download Full-text

Study on Dynamics Characteristics of Concrete Floating Slab Track in Urban Track

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.302-303.700 ◽

2006 ◽

Vol 302-303 ◽

pp. 700-705 ◽

Cited By ~ 3

Author(s):

Gao Liang ◽

Ke Ming Yin ◽

Ge Yan Zhang

Keyword(s):

Finite Element ◽

Dynamic Analysis ◽

Dynamic Responses ◽

Finite Element Analyses ◽

Analysis Model ◽

Slab Track ◽

Stiffness And Damping

In this paper, in order to do research on the characteristics of reducing vibration and declining noise of concrete floating slab track, the vertical dynamic analysis model of vehiclefloating slab track is established with the use of finite element analyses method. By using this model, dynamic responses of floating slab track are studied under different conditions of train’s speed, stiffness and damping of infrastructure, structure size, etc. On the basis of this research, some suggestions for design of floating slab track are put forward.

Download Full-text