scholarly journals Full-Scale Train-to-Train Impact Test and Multi-Body Dynamic Simulation Analysis

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 297
Author(s):  
Hui Zhao ◽  
Ping Xu ◽  
Benhuai Li ◽  
Shuguang Yao ◽  
Chengxing Yang ◽  
...  

When a train crashes with another train at a high speed, it will lead to significant financial losses and societal costs. Carrying out a train-to-train crash test is of great significance to reproducing the collision response and assessing the safety performance of trains. To ensure the testability and safety of the train collision test, it is necessary to analyze and predict the dynamic behavior of the train in the whole test process before the test. This paper presents a study of the dynamic response of the train in each test stage during the train-to-train crash test under different conditions. In this study, a 1D/3D co-simulation dynamics model of the train under various load conditions of driving, collision and braking has been established based on the MotionView dynamic simulation software. The accuracy of the numerical model is verified by comparing with a five-vehicle formations train-to-train crash test data. Sensitivities of several key influencing parameters, such as the train formation, impact velocity and the vehicle mass, are reported in detail as well. The results show that the increase in the impact velocity has an increasing effect on the movement displacement of the vehicle in each process. However, increasing the vehicle mass and train formation has almost no effect on the running displacement of the braking process of the traction train. By sorting the variables in descending order of sensitivity, it can be obtained that impact speed > train formation > vehicle mass. The polynomial response surface method (PRSM) is used to construct the fitting relationship between the parameters and the responses.

2014 ◽  
Vol 971-973 ◽  
pp. 827-832
Author(s):  
Yan Jin Qin ◽  
Zhang Yong Wu ◽  
Zi Yong Mo ◽  
Xian Wang ◽  
Juan Wang

To establish the mathematical model of the system of high speed switch valve control the cartridge valve based on analyzing the working principle of the system,and then to analyze the impact of selecting different input signal of high speed solenoid valve and different duty cycle of PWM pulse width modulated signal through simulation software AMSEsim. The results obtained in the high-frequency performance is not very satisfactory, but in the low signal and moderate duty cycle, high-speed switch valve can be good linear control of the cartridge valve.


Soft Matter ◽  
2021 ◽  
Author(s):  
Siqi Zheng ◽  
Sam Dillavou ◽  
John M. Kolinski

When a soft elastic body impacts upon a smooth solid surface, the intervening air fails to drain, deforming the impactor. High-speed imaging with the VFT reveal rich dynamics and sensitivity to the impactor's elastic properties and the impact velocity.


Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.


Author(s):  
Bin Yu ◽  
Miyi Wu ◽  
Shuyi Wang ◽  
Wen Zhou

Connected vehicles (CVs) exchange a variety of information instantly with surrounding vehicles and traffic facilities, which could smooth traffic flow significantly. The objective of this paper is to analyze the effect of CVs on running speed. This study compared the delay time, travel time, and running speed in the normal and the connected states, respectively, through VISSIM (a traffic simulation software developed by PTV company in German). The optimization speed model was established to simulate the decision-makings of CVs in MATLAB, considering the parameters of vehicle distance, average speed, and acceleration, etc. After the simulation, the vehicle information including speed, travel time, and delay time under the normal and the connected states were compared and evaluated, and the influence of different CV rates on the results was analyzed. In a two-lane arterial road, running speed in the connected state increase by 4 km/h, and the total travel time and delay time decrease by 5.34% and 16.76%, respectively, compared to those in the normal state. The optimal CV market penetration rate related to running speed and delay time is 60%. This simulation-based study applies user-defined lane change and lateral behavior rules, and takes different CV rates into consideration, which is more reliable and practical to estimate the impact of CV on road traffic characteristics.


1983 ◽  
Vol 105 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ian V. Lau

The effects of impact timing during the cardiac cycle on the sensitivity of the heart to impact-induced rupture was investigated in an open-chest animal model. Direct mechanical impacts were applied to two adjacent sites on the exposed left ventricular surface at the end of systole or diastole. Impacts at 5 m/s and a contact stroke of 5 cm at the end of systole resulted in no cardiac rupture in seven animals, whereas similar impacts at the end of diastole resulted in six cardiac ruptures. Direct impact at 15 m/s and a contact stroke of 2 cm at the end of either systole or diastole resulted in perforationlike cardiac rupture in all attempts. At low-impact velocity the heart was observed in high-speed movie to bounce away from the impact interface during a systolic impact, but deform around the impactor during a diastolic impact. The heart generally remained motionless during the downward impact stroke at high-impact velocity in either a systolic or diastolic impact. The lower ventricular pressure, reduced muscle stiffness, thinner myocardial wall and larger mass of the filled ventricle probably contributed to a greater sensitivity of the heart to rupture in diastole at low-impact velocity. However, the same factors had no role at high-impact velocity.


2015 ◽  
Author(s):  
Ali Mohtat ◽  
Ravi Challa ◽  
Solomon C. Yim ◽  
Carolyn Q. Judge

Numerical simulation and prediction of short duration hydrodynamic impact loading on a generic wedge impacting a water free-surface is investigated. The fluid field is modeled using a finite element (FE) based arbitrary Lagrangian-Eulerian (ALE) formulation and the structure is modeled using a standard Lagrangian FE approximation. Validation of the numerical method against experimental test data and closed form analytical solutions shows that the ALE-FE/FE continuum approach captures the impact behavior accurately. A detailed sensitivity analysis is conducted to study the role of air compressibility, deadrise angle, and impact velocity in estimation of maximum impact pressures. The pressure field is found to be insensitive to air compressibility effect for a wide range of impact velocities and deadrise angles. A semi-analytical prediction model is developed for estimation of maximum impact pressures that correlates deadrise angle, impact velocity, and a nonlinear interaction term that couples hydrodynamic effects between these parameters. The numerical method is also used to examine the intrinsic physics of water impact on a high-speed planing hull with the goal of predicting slamming loads and resulting motions.


2015 ◽  
Vol 789-790 ◽  
pp. 362-367
Author(s):  
Mei Li Song ◽  
Xiao Ming Wang ◽  
Wen Bin Li

Penetration efficiency reflects high speed projectile penetration ability with the impact velocity (>800m/s) variation. To further study the penetration efficiency engineering model, the physical and mechanical parameters that affect the penetration efficiency of high-speed projectiles penetrating into concrete target are analyzed, penetration efficiency dimensionless quantities are determined, such as projectile’s length to diameter ratio, projectile and target strength ratio, etc. The dimensionless equation of penetration efficiency is got by using the homogeneous principles of the laws of physics dimensionless. According to experimental data, a function of dimensionless penetration efficiency and dimensionless projectile speed is fitted. Finally, the model is verified by test, and the model calculations and experiment results agree well. The model obtained in this paper can estimate the projectile’s impact velocity when the penetration efficiency reaches the maximum, it would be a theoretical guidance for high speed penetration effects experiments.


2012 ◽  
Vol 184-185 ◽  
pp. 780-783
Author(s):  
Long Bo Sheng ◽  
Ji Sheng Ma ◽  
He Yang Sun ◽  
Tao Li

Based on the braking system of a tracked vehicle, a method for co-simulation is introduced with dynamic simulation software ADAMS and multidisciplinary dynamic simulation software EASY5. By designing software interface, dynamic data exchange between the two models is achieved, and the simulation is carried out about the impact on a tracked vehicle brake performance with accumulator volume and gas-filled pressure. The simulation result shows that a seamless connection between the virtual prototype model and hydraulic system model is realized.


2011 ◽  
Vol 328-330 ◽  
pp. 2203-2206
Author(s):  
Yue Fang Wang ◽  
Xiao Rui Dong

In this paper, the wheeled vehicle is regard as a multi-rigid-body system and simulation model of the vehicle is established firstly by using dynamics simulation software of mechanical system ADAMS which is used most widely in the world. Secondly, through setting the initial condition and inputting various parameters, simulation analysis of skid-steer during the unilateral braking process and swerving braking process that the vehicle runs roundly in constant speed of 10km/h and 20km/h respectively is performed. In addition, vehicle velocity curves are recorded, vehicle yaw angular velocity curve are showed, Side accelerated speed curve is seen, the turning track curve of centre is drawn and the results are contrasted. Finally, some conclusions are reached that the vehicle minimum turning track radius decrease immensely than the radius which does not adopt unilateral braking and vehicle velocity could be controlled in a small velocity rage when vehicle is steering braking.


2010 ◽  
Vol 156-157 ◽  
pp. 293-297
Author(s):  
Tian Han ◽  
Jie Bai ◽  
Zhong Jun Yin

The complex nonlinear dynamics of a rotor-rolling bearing system with crack is built by dynamic simulation software ADAMS. The transverse vibration response and swing response of rotor are studied on the basis of considering both the nonlinear contact force of rolling bearing and the impact of stiffness caused by crack. Furthermore, the influence factors of transverse vibration response are researched including speed, crack depth, crack angle and eccentricity. The simulation analysis demonstrated that it is an effective method to solve nonlinear dynamics of rotor-rolling bearing system with crack based on virtual prototyping technology. It provides a new method of feasibility study for fault diagnosis in the future.


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