Train Energy and Dynamics Simulator (TEDS): A State-of-the-Art Longitudinal Train Dynamics Simulator

2012 ◽  
Author(s):  
David R. Andersen ◽  
Graydon F. Booth ◽  
Anand R. Vithani ◽  
Som P. Singh ◽  
Anand Prabhakaran ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Simulation Software ◽  
System Level ◽  
Test Results ◽  
Dynamic Representation ◽  
Draft Gear ◽  
Train Dynamics ◽  
Air Brake System ◽  
And Performance ◽  
Dynamic Braking

Train safety and operational efficiency are enhanced by the ability to understand the behavior of trains under varying conditions. Under the direction of the Federal Railroad Administration (FRA), a longitudinal train dynamics and operation simulation software — Train Energy and Dynamics Simulator (TEDS) — has been developed. TEDS is capable of modeling modern train operations and equipment, and is an effective tool for studying train operations safety and performance as affected by equipment, train makeup, train handling, track conditions, operating practices and environmental conditions. TEDS simulates the dynamics of longitudinal train action and incorporates the dynamic effects of various different types of draft gears and end-of-car cushioning units including mismatched devices coupled together, the transient response of locomotive tractive and dynamic braking effort, as well as a fluid dynamic representation of the air brake system with the capability to model conventional pneumatic and ECP brake systems. The capabilities of TEDS are described and demonstrated with several examples. The validation effort undertaken is described at both the component and system level. Comparisons of TEDS simulations of impact tests with the test results are shown to verify the draft gear and end-of-car cushioning unit models. The air brake model predictions are verified by comparing brake rack test results to TEDS simulations of braking behavior.

Design and Performance of High-Pressure Blowoff Silencers

1971 ◽  
Vol 93 (2) ◽  
pp. 695-702 ◽  
Author(s):  
Cecil R. Sparks ◽  
D. E. Lindgren
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Field Data ◽  
Fluid Dynamic ◽  
Gas Pipeline ◽  
Noise Generation ◽  
Test Results ◽  
Natural Gas Pipeline ◽  
And Performance

Through the application of fluid dynamic and acoustic theory, the noise generation of a high pressure blowoff can be approximated. The effects of silencer configurations can likewise be predicted through the application of pertinent field data taken to define performance of the silencer components. This paper describes recent test results and their application to improved silencer design for natural gas pipeline applications.

Effects of Nonlinear Friction Wedge Damping on Freight Train Dynamics

2010 ◽  
Author(s):  
Leonardo B. Baruffaldi ◽  
Auteliano A. dos Santos
Keyword(s):  
Simulation Software ◽  
Nonlinear Characteristics ◽  
Freight Train ◽  
Simulation Tools ◽  
Suspension Systems ◽  
Numerical Simulation Methods ◽  
Force Element ◽  
Train Dynamics ◽  
And Performance ◽  
Multi Body

Engineers pay great attention to comfort and performance issues, which are related to passenger trains suspension systems. Complex active shock-absorbing devices are developed and modern simulation tools are employed to determine car body vibrations and ride behavior. Freight train suspensions, however, were not given the same focus, presenting the same basic design for about 70 years now. Recent increases in pay-loads and train lines speed, and growing pressures to decrease maintenance costs, are slowly changing this scenario in such a way that numerical simulation methods are being more and more used. Most commercially available simulation software used by train manufacturers to address full vehicle behavior treats the friction wedge — the main damping element in the three-piecetruck suspension — as a weightless unidirectional force element like springs and dampers, which connects the wheel frames to the bolster that supports carbody load. This paper uses an improved friction wedge model to emphasize the importance of considering nonlinear characteristics of friction damping to vertical and longitudinal dynamics of a freight truck wagon modeled with multi-body dynamics.

Framework and performance analysis of college English testing system based on data mining technology

2021 ◽  
pp. 1-11
Author(s):  
Liu Narengerile ◽  
Li Di ◽  
Keyword(s):  
Data Mining ◽  
Test System ◽  
Test Time ◽  
Testing System ◽  
Test Results ◽  
System Software ◽  
Examination System ◽  
Mining Technology ◽  
College English ◽  
And Performance

At present, the college English testing system has become an indispensable system in many universities. However, the English test system is not highly humanized due to problems such as unreasonable framework structure. This paper combines data mining technology to build a college English test framework. The college English test system software based on data mining mainly realizes the computer program to automatically generate test papers, set the test time to automatically judge the test takers’ test results, and give out results on the spot. The test takers log in to complete the test through the test system software. The examination system software solves the functions of printing test papers, arranging invigilation classrooms, invigilating teachers, invigilating process, collecting test papers, scoring and analyzing test papers in traditional examinations. Finally, this paper analyzes the performance of this paper through experimental research. The research results show that the system constructed in this paper has certain practical effects.

Physical and performance characteristics related to starter status, position, and division in Japanese collegiate American-football players

2021 ◽  
pp. 1-8
Author(s):  
Junta Iguchi ◽  
Minoru Matsunami ◽  
Tatsuya Hojo ◽  
Yoshihiko Fujisawa ◽  
Kenji Kuzuhara ◽  
...  
Keyword(s):  
Performance Test ◽  
Vertical Jump ◽  
American Football ◽  
Football Players ◽  
Jump Height ◽  
Test Results ◽  
Repetition Maximum ◽  
Vertical Jump Height ◽  
Division 1 ◽  
And Performance

BACKGROUND: Few studies have investigated the variations in body composition and performance in Japanese collegiate American-football players. OBJECTIVE: To clarify what characterizes competitors at the highest levels – in the top division or on the starting lineup – we compared players’ body compositions and performance test results. METHODS: This study included 172 players. Each player’s body composition and performance (one-repetition maximum bench press, one-repetition maximum back squat, and vertical jump height) were measured; power was estimated from vertical jump height and body weight. Players were compared according to status (starter vs. non-starter), position (skill vs. linemen), and division (1 vs. 2). Regression analysis was performed to determine characteristics for being a starter. RESULTS: Players in higher divisions and who were starters were stronger and had more power, greater body size, and better performance test results. Players in skill positions were relatively stronger than those in linemen positions. Vertical jump height was a significant predictor of being a starter in Division 1. CONCLUSION: Power and vertical jump may be a deciding factor for playing as a starter or in a higher division.

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