scholarly journals Train Derailment Process Analysis on Heavy Haul Railway Bridge under Ship Impact

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2122
Author(s):  
Kai Gong ◽  
Linya Liu ◽  
Cuiying Yu ◽  
Chen Wang
Keyword(s):  
Impact Load ◽  
Lateral Displacement ◽  
Process Analysis ◽  
Great Influence ◽  
Reduction Rate ◽  
Relative Displacement ◽  
Wheel Load ◽  
Train Derailment ◽  
Spatial Vibration ◽  
The Impact

In order to research train derailment law under ship impact, the spatial vibration calculation model of a freight train-track-bridge (FTTB) system is used to establish the vibration model of the FTTB system under ship impact. Meanwhile, the calculation method of a train derailment process under ship impact is proposed based on the random analysis method of train derailment energy. Further, the train derailment process on a bridge under ship impact is calculated, and the variation law of the FTTB system spatial vibration response under different impact loads and speeds is analyzed. The results show that the ship impact load has a great influence on wheel lift value. When the impact load is greater than 15 MN, the wheel derails more easily. With the increase of impact load, the derailment coefficient, wheel load reduction rate, and lateral relative displacement of bogie and rail, the lateral displacement of the bridge increases significantly, but the limits of them make it difficult to determine whether the wheel has derailed. The lateral relative displacement of the bogie and rail considering the safety factor is calculated at the moment of derailment, which is taken as the early warning threshold of train derailment. The above conclusions can provide a reference for controlling train safety under ship impact.

Dynamic Analysis of Liquid Sloshing for Shipboard Pressure Vessel

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.

Improvement of aircraft crashworthy performance using inversion failure strut system

2017 ◽  
Vol 89 (2) ◽  
pp. 330-337 ◽  
Author(s):  
Yiru Ren ◽  
Jinwu Xiang
Keyword(s):  
Energy Absorption ◽  
Impact Load ◽  
Great Influence ◽  
Absorption Efficiency ◽  
The Novel ◽  
Content Type ◽  
Failure Behaviour ◽  
Energy Absorption Efficiency ◽  
Geometrical Factors ◽  
The Impact

Purpose The purpose of this paper is to improve the crashworthiness of aircraft by using the strut system as an energy absorption device without redesigning other components. Design/methodology/approach The novel strut system consists of metal stepped thin-walled tubes and articulated connecting hinges. The strut is suffering axial load during impact process for rotating of hinges, and the metal stepped tube has an inversion failure behaviour. Findings The metal stepped tube has lower initial impact load and more stable failure behaviour. The geometrical factors have a great influence on the impact load and energy absorption efficiency. The best length ratio between upper and lower sections is about 2:1 and 1:1 for the metal stepped circular and square tubes, respectively. Practical implications The metal stepped tube with inversion mechanism is suitable for aircraft strut system to improve crashworthiness performance. Originality/value A new strut system is provided using metal inversion failure stepped tubes and articulated connecting hinges to improve crash worthiness of aircraft.

scholarly journals Dynamic Wheel-Rail Force-Based Track-Irregularity Evaluation for Ballasted Track on Serviced Railway by Adjacent Excavation

2021 ◽  
Vol 12 (1) ◽  
pp. 375
Author(s):  
Jung-Youl Choi ◽  
Dong-Ryong Park ◽  
Jee-Seung Chung ◽  
Sun-Hee Kim
Keyword(s):  
Impact Load ◽  
Field Measurements ◽  
Interaction Force ◽  
Wheel Load ◽  
Track Geometry ◽  
Railway Line ◽  
Before And After ◽  
Track Irregularity ◽  
The Impact ◽  
Track Irregularities

This study investigates a load-based, track-irregularity-analysis technique for ballasted tracks on a serviced railway line with respect to excavation work conducted in adjacent sites. A numerical analysis and field measurements (railbed-settlement-monitoring sensor, track-geometry-measurement system, wheel-load measurements) were analyzed comparatively to demonstrate the correlation between the track irregularities and the Wheel-Rail interaction force. In this way, we highlight the necessity for load-based track-irregularity-management methods. The analyzed results show that the maximum dynamic wheel load was measured in the range of approximately 10 m before and after the location where the maximum track irregularities occurred, and that even if the maintenance criteria of track irregularities were satisfied, the design dynamic wheel load could still be exceeded depending on the train speed, thus indicating that track damage can be caused by the impact load.

scholarly journals Experimental Study and Numerical Analysis on Impact Resistance of Civil Air Defense Engineering Shear Wall

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Chenglong Shi ◽  
Jigang Zhang ◽  
Junbo Zhang ◽  
Feng Shao ◽  
Yicong Zhang ◽  
...  
Keyword(s):  
Impact Load ◽  
Impact Resistance ◽  
Great Influence ◽  
Shear Walls ◽  
Horizontal Displacement ◽  
Shear Wall ◽  
Factors Affecting ◽  
Air Defense ◽  
Impact Surface ◽  
The Impact

In order to study the impact resistance of civil air defense engineering shear wall, the impact resistance of civil air defense engineering shear wall was studied by combining finite element numerical simulation with pendulum impact test. The effects of impact height, pendulum mass, and impact times on the impact resistance of civil air defense engineering shear walls were analyzed. It was shown that when the impact height increased from 0.4 m to 2.5 m, the failure mode of civil air defense engineering shear wall tended to be local impact failure, and the horizontal displacement in the middle of the wall span increased. The concrete crushing occurred in the impact area of the back of the civil air defense engineering shear wall. The increase in the impact height is a negative factor for the impact resistance of the civil air defense engineering shear wall. With the increase of pendulum weight, the number of concrete horizontal cracks in the back of the civil air defense engineering shear wall increased, while the number of vertical cracks decreased, but the impact surface was destroyed. Through multiple impact tests on the civil air defense engineering shear wall, the civil air defense engineering shear wall had accumulated damage. The longitudinally loaded steel on the back reached the ultimate strength, and there are large cracks at the bottom and even collapses. The increase of impact times has a great influence on the impact resistance of the civil air defense engineering shear wall. Through the analysis of the factors affecting the impact resistance of civil air defense engineering shear wall, it provides guidance for civil air defense engineering shear wall to resist impact load.

Ice Pressure Prediction Based on the Probabilistic Method for Ice-Going Vessels in Inland Waterways

2018 ◽  
Author(s):  
Meng Zhang ◽  
Harsha Cheemakurthy ◽  
Sören Ehlers ◽  
R. U. Franz von Bock und Polach ◽  
Karl Garme ◽  
...  
Keyword(s):  
Impact Load ◽  
Probabilistic Method ◽  
Control Point ◽  
Great Influence ◽  
Point Of View ◽  
Design Strategies ◽  
Inland Waterways ◽  
Transport Efficiency ◽  
Ice Pressure ◽  
The Impact

With increasing need to utilize inland waterways (IWW), the design for IWW vessels gains attention both from a transport efficiency and an emission control point of view. The primarily issue is to estimate the ice pressure acting on the ship hull for inland waterways. Ice information for Lake Mälaren is extracted and analysed in this work. Since the ice properties have great influence on the impact load, they are studied based on empirical formulae and are calibrated by reference data. The ice impact is then predicted for an inland water barge. Probabilistic method is selected to derive the load based on available field test data. Several parent datasets are chosen, and different design strategies are implemented to evaluate the ice impact load and investigate the influences from exposure factors. The paper finds that the design curve of α = 0.265a−0.57 can be used for Lake Mälaren. The approach itself introduces a possible way to investigate loads on ice affected IWW.

scholarly journals Fracture Characteristics and Geometric Fractal of Damaged Sandstone under Impact Load

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hao Hu ◽  
Qiangqiang Zheng ◽  
Xin Gao ◽  
Bing Cheng ◽  
Qianqian Wang ◽  
...  
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Impact Load ◽  
Reduction Rate ◽  
Average Diameter ◽  
Rock Block ◽  
Damage Factor ◽  
Hopkinson Pressure Bar ◽  
Fracture Characteristics ◽  
Before And After ◽  
The Impact

Before the rock mass in the engineering is broken under load, it is usually in a state of varying degrees of damage. Aiming at the fracture characteristics of damaged sandstone under impact load, this paper adopts a method of the cyclic static load to cause the sandstone specimens to have varying degrees of damage. Then, the wave velocity of sandstone before and after the damage is measured using the nonmetallic acoustic velocimeter, and the change rule of damage factor is analyzed. Finally, the split Hopkinson pressure bar (SHPB) is used to test the impact dynamics of sandstone with different damage degrees. The broken rock block is screened by a vibrating screen, and the crushing characteristics are analyzed. The results show that not only the damage factor of damaged sandstone but the growth rate increases, with the raising upper limit of stress. Under the impact load of the same incident energy, the fragmentation degree of the damaged sandstone increases with the increase of the upper stress limit, while the average diameter of the broken rock block decreases gradually, and the reduction rate increases first and then decreases.

Ice Pressure Prediction Based on the Probabilistic Method for Ice-Going Vessels in Inland Waterways

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Meng Zhang ◽  
Harsha Cheemakurthy ◽  
Sören Ehlers ◽  
R. U. Franz von Bock und Polach ◽  
Karl Garme ◽  
...  
Keyword(s):  
Impact Load ◽  
Probabilistic Method ◽  
Control Point ◽  
Great Influence ◽  
Point Of View ◽  
Design Strategies ◽  
Inland Waterways ◽  
Transport Efficiency ◽  
Ice Pressure ◽  
The Impact

With increasing need to utilize inland waterways (IWW), the design of IWW vessels gains attention both from a transport efficiency and an emission control point of view. The primary challenge is to estimate the ice pressure acting on the ship hull for IWW. Ice information for Lake Mälaren is extracted and analyzed in this work. Since the ice properties have great influence on the impact load, they are studied based on empirical formulae and are calibrated by reference data. The ice impact is then predicted for an IWW barge. Probabilistic method is selected to derive the load based on available field test data. Several parent datasets are chosen, and different design strategies are implemented to evaluate the ice impact load and investigate the influence from exposure factors. The paper finds that the design curve of α=0.265a−0.57 can be used for Lake Mälaren. The approach itself introduces a possible way to investigate loads on ice-affected IWW.

Investigation of Relationship between Train Speed and Bolted Rail Joint Fatigue Life using Finite Element Analysis

2018 ◽  
Vol 2672 (10) ◽  
pp. 85-95 ◽  
Author(s):  
Hao Yin ◽  
Yu Qian ◽  
J. Riley Edwards ◽  
Kaijun Zhu
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Impact Load ◽  
Wheel Load ◽  
Joint Area ◽  
Train Speed ◽  
Stress Propagation ◽  
Speed Restrictions ◽  
The Impact ◽  
The Relationship

Reducing the allowable operating speed or imposing temporary speed restrictions are common practices to prevent further damage to rail track when defects are detected related to certain track components. However, the speeds chosen for restricted operation are typically based on past experience without considering the magnitude of the impact load around the rail joints. Due to the discontinuity of geometry and track stiffness at the bolted rail joints, an impact load always exists. Thus, slower speeds may not necessarily reduce the stresses at the critical locations around the rail joint area to a safe level. Previously, the relationship between speed and the impact load around the rail joints has not been thoroughly investigated. Recent research performed at the University of Illinois at Urbana-Champaign (UIUC) has focused on investigating the rail response to load at the joint area. A finite element model (FEM) with the capability of simulating a moving wheel load has been developed to better understand the stress propagation at the joint area under different loading scenarios and track structures. This study investigated the relationship between train speed and impact load and corresponding stress propagation around the rail joints to better understand the effectiveness of speed restrictions for bolted joint track. Preliminary results from this study indicate that the contact force at the wheel–rail interface would not change monotonically with the changing train speed. In other words, when train speed is reduced, the maximum contact force at the wheel–rail interface may not necessarily reduce commensurately.

Role of Brand experience in Fashion brands

2019 ◽  
Vol 118 (1) ◽  
pp. 57-64
Author(s):  
G. Aiswarya ◽  
Dr. Jayasree Krishnan
Keyword(s):  
Factor Analysis ◽  
Purchase Intention ◽  
Great Influence ◽  
Brand Experience ◽  
Brand Preference ◽  
Mediating Role ◽  
Confirmatory Factor ◽  
Selling Strategies ◽  
The Impact

Traditionally the products were pushed into the hands of customers by production and selling strategies; then the marketing strategy evolved which gained momentum by understanding the customer needs and developing products satisfying those needs. This strategy is most prevalent and what should be done to stand up in this most competitive scenario? The answer to this key question is to create an experience. The customers now also seek good experiences than other benefits. Brand experience has gained more attention, especially fashion brands. Previous studies demonstrate the role of the brand experience in brand equity and other consumer behavior constructs. But very little is known about the impact of brand experiences on fashion brands. The aim of this study is to develop a model which makes our understanding better about the role of Brand preference and Brand experience and its influence on purchase intention of the brand. An initial exploratory study is conducted using a focus group to generate items for the study. The items, thus generated are prepared in the form of a questionnaire and samples were collected.  Exploratory factor analysis is conducted and the reliability of the constructs is determined. These constructs are loaded onto AMOS to perform Confirmatory factor analysis. The results confirmed the scales used. We also noticed that Brand preference has a great influence on the Brand experience. Thereby the finding supports the role of the brand experience which tends to have a mediating role in influencing the purchase intention.

Impact Load Buffering Method Based on Stress Wave Attenuation Principle

2019 ◽  
Vol 11 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Lin Gan ◽  
He Zhang ◽  
Cheng Zhou ◽  
Lin Liu
Keyword(s):  
Stress Wave ◽  
Wave Attenuation ◽  
Impact Load ◽  
Dynamics Simulation ◽  
Scanning System ◽  
Isolation Method ◽  
Element Analysis ◽  
System A ◽  
High Emission ◽  
The Impact

Rotating scanning motor is the important component of synchronous scanning laser fuze. High emission overload environment in the conventional ammunition has a serious impact on the reliability of the motor. Based on the theory that the buffer pad can attenuate the impact stress wave, a new motor buffering Isolation Method is proposed. The dynamical model of the new buffering isolation structure is established by ANSYS infinite element analysis software to do the nonlinear impact dynamics simulation of rotating scanning motor. The effectiveness of Buffering Isolation using different materials is comparatively analyzed. Finally, the Macht hammer impact experiment is done, the results show that in the experience of the 70,000[Formula: see text]g impact acceleration, the new buffering Isolation method can reduce the impact load about 15 times, which can effectively alleviate the plastic deformation of rotational scanning motor and improve the reliability of synchronization scanning system. A new method and theoretical basis of anti-high overload research for Laser Fuze is presented.

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