scholarly journals Development and Fabrication of State-of-the-Art End Structures for Budd M1 Cars

2008 ◽  
Author(s):  
Richard Stringfellow ◽  
Christopher Paetsch ◽  
Gabriel Amar
Keyword(s):  
Energy Absorption ◽  
Public Transportation ◽  
Dynamic Test ◽  
Test Method ◽  
Detailed Design ◽  
Static Tests ◽  
Car Body ◽  
Fea Model ◽  
Final Design ◽  
Active Research

The Volpe Center and the Federal Railroad Administration are engaged in active research aimed at improving rail vehicle crashworthiness. One component of this research is focused on improving the performance of passenger train cab cars during collisions with heavy objects at grade crossings. New standards have been approved by the American Public Transportation Association that increase the strength requirements for cab car end structures and impose further requirements on their ability to absorb energy during a collision. The FRA has issued a notice of proposed rulemaking (NPRM) to include these new standards in 49CFR238.211. These standards include requirements for demonstration of energy absorption through either quasi-static or dynamic tests. The intent of each test method is to demonstrate a minimum level of energy absorption—120,000 ft-lbs for a corner post load and 135,000 ft-lbs for a collision post load—while limiting occupied volume intrusion to less than 10 inches. To aid in the development of these new standards, the FRA and Volpe Center are conducting a set of three tests: quasi-static loading of both the collision and corner posts, and dynamic loading of the collision post only. (A dynamic test of the corner post was conducted as part of an earlier program). These tests were developed to illustrate testing methodologies and to demonstrate the feasibility of the new energy absorption and large deformation requirements. In+ each test, the post is loaded 30 inches above the underframe by a proxy object that is 36-inches wide, with a 48-inch diameter cylindrical face. In support of this testing program, the research reported here focused on the design and fabrication of end frames suitable for retrofitting onto the cab end of a Budd M1 cab car. The design of an end frame for retrofit onto the cab end of a Budd Pioneer cab car was modified to account for differences between the two car designs. In addition, reinforcements to the M1 car body and connections from the end frame to the car body were designed and fabricated. An FEA model of the end frame retrofit onto the M1 cab car was developed based upon the detailed design. A series of linear and nonlinear static, quasi-static, and dynamic FEAs were performed to evaluate the performance of the design. Preliminary analyses revealed the need for a few minor modifications to the connections in order to meet design requirements; these were incorporated into the final design for manufacture. Components for the end frame, connections between the end frame and the car body, and reinforcements to the car body were fabricated based on detailed design drawings and then assembled and connected to the reinforced M1 Car, from which the original end frame had been cut off. A successful dynamic test was completed in April, 2008; quasi-static tests are scheduled for summer 2008. The results of FEA model predictions are compared with the results of the dynamic test.

scholarly journals Dynamic and Quasi-Static Grade Crossing Collision Tests

2009 ◽  
Author(s):  
Michelle Mu¨hlanger ◽  
Patricia Llana ◽  
David Tyrell
Keyword(s):  
Energy Absorption ◽  
Impact Load ◽  
Dynamic Test ◽  
Full Scale ◽  
Structural Deformation ◽  
Longitudinal Deformation ◽  
Static Tests ◽  
Static Test ◽  
Grade Crossing ◽  
The Impact

To support the development of a proposed rule [1], a full-scale dynamic test and two full-scale quasi-static tests have been performed on the posts of a state-of-the-art (SOA) end frame. These tests were designed to evaluate the dynamic and quasi-static methods for demonstrating energy absorption of the collision and corner posts. The tests focused on the collision and corner posts individually because of their critical positions in protecting the operator and passengers in a collision where only the superstructure, not the underframe, is loaded. There are many examples of collisions where only the superstructure is loaded. For the dynamic test, a 14,000-lb cart impacted a standing cab car at a speed of 18.7 mph. The cart had a rigid striking surface in the shape of a coil mounted on the leading end that concentrated the impact load on the collision post. During the dynamic test the collision post deformed approximately 7.5 inches, and absorbed approximately 137,000 ft-lbs of energy. The SOA collision post was successful in preserving space for the operators and the passengers. For the quasi-static test of the collision post, the collision post was loaded in the same location and with the same fixture as the dynamic test. The post absorbed approximately 110,000 ft-lb of energy in 10 inches of permanent, longitudinal deformation. For the quasi-static test of the corner post, the post was loaded at the same height as the collision post, with the same fixture. The corner post absorbed 136,000 ft-lb of energy in 10 inches of permanent, longitudinal deformation. The series of tests was designed to compare the dynamic and quasi-static methods for measuring collision energy absorption during structural deformation as a measure of crashworthiness. When properly implemented, either a dynamic or quasi-static test can demonstrate the crashworthiness of an end frame.

scholarly journals Quasi-Static and Dynamic Sled Testing of Prototype Commuter Rail Passenger Seats

2008 ◽  
Author(s):  
Kristine Severson ◽  
A. Benjamin Perlman ◽  
Richard Stringfellow
Keyword(s):  
Public Transportation ◽  
Dynamic Test ◽  
Static Tests ◽  
Occupant Protection ◽  
Injury Criteria ◽  
Commuter Rail ◽  
Seat Cushions ◽  
Hybrid Iii ◽  
Male Hybrid ◽  
Test Requirements

In support of the Federal Railroad Administration’s (FRA) Railroad Equipment Safety Program, tests have been conducted on prototype commuter rail passenger seats which have been designed for improved occupant protection during commuter train accidents. Quasi-static tests were conducted to evaluate the moment versus rotation behavior of the seat back and to improve the fidelity of the finite element seat model. Dynamic sled tests were conducted with instrumented Hybrid III anthropomorphic test devices (ATDs) to evaluate occupant protection under collision conditions and to improve the fidelity of seat/occupant computer models. The three-passenger prototype seats were designed to meet the following dynamic test requirements: 1. Seats must remain attached to the test fixture. 2. Occupants must be compartmentalized between seat rows. 3. Injury criteria for the head, chest, neck and femur must be within tolerance thresholds specified by the automotive industry. 4. All seat components, including seat cushions, must remain attached. Test conditions were specified for two dynamic sled tests as follows: three forward-facing 50th percentile male Hybrid III ATDs subjected to an 8G, 250 millisecond triangular crash pulse; and three rear-facing 50th percentile male Hybrid III ATDs subjected to a 12G, 250 millisecond triangular crash pulse. The 8G crash pulse is specified in the existing American Public Transportation Association (APTA) Standard for Row-to-Row Seating in Commuter Rail Cars [1] and in the Federal Code of Regulations 49 CFR 238.233 [2], and represents nominal collision conditions. The 12G crash pulse represents the collision environment measured in the cab car during a previous full-scale train-to-train impact test of passenger rail cars incorporating crash energy management [3, 4]. The final test results indicate that all test requirements were met: the seats remained attached to the test sled; the ATDs were compartmentalized; all the injury criteria were within accepted tolerance thresholds; and all the seat cushions remained attached.

The structural characteristics of microengineered bridges

2000 ◽  
Vol 214 (2) ◽  
pp. 351-357
Author(s):  
J S Burdess ◽  
A J Harris ◽  
D Wood ◽  
R Pitcher
Keyword(s):  
Internal Stress ◽  
Young’S Modulus ◽  
Dynamic Testing ◽  
Young's Modulus ◽  
Structural Characteristics ◽  
Dynamic Test ◽  
Test Method ◽  
Laser Vibrometer ◽  
Test Procedures ◽  
Static Tests

The paper considers the measurement of Young's modulus and internal stress in micro-engineered bridge structures. Values determined from the results of static tests, obtained from the measurement of compliance using a nanoindenter, are compared with values derived from natural frequency measurements obtained from dynamic testing using a laser vibrometer. Both test procedures use mathematical models ‘fitted’ to experimental data to estimate Young's modulus and internal stress. For the case of boron-doped silicon bridges the dynamic test method is shown to produce the superior estimates.

scholarly journals Dynamic ROPS Test for Tractors over 6,000 Kilograms

2018 ◽  
Vol 61 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Caleb M. Lindhorst ◽  
Roger M. Hoy ◽  
Santosh K. Pitla ◽  
Michael F. Kocher
Keyword(s):  
Dynamic Testing ◽  
Dynamic Test ◽  
Strength Properties ◽  
Technical Note ◽  
Test Method ◽  
Cold Weather ◽  
Drop Height ◽  
Static Tests ◽  
Static Test ◽  
Protective Structures

Abstract. OECD static tests (Codes 4, 6, 7, and 8) for agricultural rollover protective structures (ROPS) have become accepted standards for evaluating the ability of these structures to protect the operator during tractor rollover events. The strength properties of some materials typically used in ROPS change because of cold weather embrittlement at low temperatures. The static ROPS tests lack the ability to evaluate the strength of these structures during cold weather. The use of the dynamic ROPS test is well noted as a means for proving cold weather embrittlement resistance properties. Unfortunately, application of the OECD dynamic ROPS test (Code 3) is restricted to tractors with unballasted mass greater than 600 kg and generally less than 6,000 kg. The analyses presented in this technical note were undertaken to evaluate the extension of the OECD Code 3 dynamic ROPS test to tractors with unballasted mass of 6,000 kg or more. Tractor unballasted mass and wheelbase data from 47 wheeled tractors tested at the Nebraska Tractor Test Lab from 2014 to 2016 were used to explore the possibility of using a dynamic test method for evaluating the ability of ROPS on tractors with unballasted mass greater than 6,000 kg to meet the safety requirements of agricultural tractor ROPS. The data were graphed and analyzed to determine the required pendulum drop height and energy values to be applied to the ROPS by extending the existing equations to tractors over 6,000 kg. For tractors over 6,000 kg mass, it was determined that pendulum drop heights were too great for practical use. Three pendulum masses were proposed for the dynamic ROPS test: a 2,000 kg pendulum for tractors with mass less than 7,000 kg, a 4,000 kg pendulum for tractors with mass of 7,000 kg or more and less than 14,000 kg, and a 6,000 kg pendulum for tractors with mass of 14,000 kg or more and less than 23,000 kg. Alternate equations were developed for the drop height of each pendulum to meet the energy requirements that are expected to provide similar permanent deflections as those obtained when using the static ROPS test when considering the effect of strain rates on material properties. Tests should be conducted to determine how the results (permanent deflections) from the proposed dynamic ROPS test compare with results from the accepted static ROPS tests. It is further proposed that dynamic testing be conducted with the tractor rigidly restrained in a manner similar to the static test to better account for the wide variety of available tires and mountings for each tractor model. Keywords: Energy, Impact test, Pendulum, Reference mass, ROPS, Tractors.

scholarly journals Concept and Realization of a Novel Test Method Using a Dynamic Test Stand for Detecting Persons by Sensor Systems on Autonomous Agricultural Robotics

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2315
Author(s):  
Christian Meltebrink ◽  
Tom Ströer ◽  
Benjamin Wegmann ◽  
Cornelia Weltzien ◽  
Arno Ruckelshausen
Keyword(s):  
Environmental Conditions ◽  
Dynamic Test ◽  
Test Methods ◽  
Test Stand ◽  
Human Detection ◽  
Test Method ◽  
Sensor Systems ◽  
Functional Safety ◽  
Agricultural Robots ◽  
Agricultural Robotics

As an essential part for the development of autonomous agricultural robotics, the functional safety of autonomous agricultural machines is largely based on the functionality and robustness of non-contact sensor systems for human protection. This article presents a new step in the development of autonomous agricultural machine with a concept and the realization of a novel test method using a dynamic test stand on an agricultural farm in outdoor areas. With this test method, commercially available sensor systems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This test is determined by the naturally occurring environmental conditions. This fact corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. The focus of the developed test methods is on creating own real environment detection areas (REDAs) for each sensor system, which can be used to compare and evaluate the autonomous human detection of the sensor systems for the functional safety of autonomous agricultural robots with a humanoid test target. Sensor manufacturers from industry and the automotive sector provide their sensor systems to have their sensors tested in cooperation with the TÜV.

Dynamic Axial Compression of Square CFRP/Aluminium Tubes

2019 ◽  
Vol 794 ◽  
pp. 202-207
Author(s):  
Rafea Dakhil Hussein ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Jeong Whan Yoon ◽  
Zhan Yuan Gao
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Fibre Composite ◽  
Dynamic Tests ◽  
Carbon Fibre Composite ◽  
Specific Energy Absorption ◽  
Static Tests ◽  
Crushing Force ◽  
Cfrp Tubes ◽  
The Impact

Carbon fibre composite tubes have high strength to weight ratios and outstanding performance under axial crushing. In this paper, square CFRP tubes and aluminium sheet-wrapped CFRP tubes were impacted by a drop mass to investigate the effect of loading velocity on the energy absorption of CFRP/aluminium tubes. A comparison of the quasi-static and dynamic crushing behaviours of tubes was made in terms of deformation mode, peak crushing force, mean crushing force, energy absorption and specific energy absorption. The influence of the number of aluminium layers that wrapped square CFRP tubes on the crushing performance of tubes under axial impact was also examined. Experimental results manifested similar deformation modes of tubes in both quasi-static and dynamic tests. The dynamic peak crushing force was higher than the quasi-static counterpart, while mean crushing force, energy absorption and specific energy absorption were lower in dynamic tests than those in quasi-static tests. The mean crushing force and energy absorption decreased with the crushing velocity and increased with the number of aluminium layers. The impact stroke (when the force starts to drop) decreased with the number of aluminium layers.

scholarly journals Evaluation of Energy Absorption Capabilities of Polyethylene Foam under Impact Deformation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3613
Author(s):  
Baohui Yang ◽  
Yangjie Zuo ◽  
Zhengping Chang
Keyword(s):  
Energy Absorption ◽  
Failure Modes ◽  
High Strain ◽  
Early Stage ◽  
High Energy ◽  
Test Method ◽  
Test Theory ◽  
Strain Rates ◽  
Impact Properties ◽  
The Impact

Foams are widely used in protective applications requiring high energy absorption under impact, and evaluating impact properties of foams is vital. Therefore, a novel test method based on a shock tube was developed to investigate the impact properties of closed-cell polyethylene (PE) foams at strain rates over 6000 s−1, and the test theory is presented. Based on the test method, the failure progress and final failure modes of PE foams are discussed. Moreover, energy absorption capabilities of PE foams were assessed under both quasi-static and high strain rate loading conditions. The results showed that the foam exhibited a nonuniform deformation along the specimen length under high strain rates. The energy absorption rate of PE foam increased with the increasing of strain rates. The specimen energy absorption varied linearly in the early stage and then increased rapidly, corresponding to a uniform compression process. However, in the shock wave deformation process, the energy absorption capacity of the foam maintained a good stability and exhibited the best energy absorption state when the speed was higher than 26 m/s. This stable energy absorption state disappeared until the speed was lower than 1.3 m/s. The loading speed exhibited an obvious influence on energy density.

Comportement de pieux d'essais instrumentés sous charge horizontale

1993 ◽  
Vol 30 (1) ◽  
pp. 1-11
Author(s):  
R. Frank ◽  
H. Zervogiannis ◽  
S. Christoulas ◽  
V. Papadopoulos ◽  
N. Kalteziotis
Keyword(s):  
Pile Foundation ◽  
Bending Moment ◽  
Standard Penetration Test ◽  
American Petroleum Institute ◽  
Full Scale ◽  
Test Method ◽  
Cohesionless Soil ◽  
Penetration Test ◽  
Cohesionless Soils ◽  
Final Design

This paper describes the behaviour of two test piles (one bored and postgrouted and one simply bored, both 31.7 m long and 0.75 m in diameter) subjected to horizontal loads. These full-scale pile tests were carried out for the actual design of the pile foundation of a pier of the Evripos cable-stayed bridge. This bridge will link the Euboea Island to mainland Greece. The two piles have already been subjected to bearing capacity tests under axial loadings. The inclinometer measurements, taken during the present tests, yielded, in particular, the deformed shape of the piles as well as the bending moments. Conclusions could be drawn for the final design of the pile foundation with respect to horizontal loadings. Furthermore, various calculation methods using p–y reaction curves for cohesionless soils have been checked: the Ménard pressuremeter method, the method of the American Petroleum Institute recommendations, and the Standard penetration test method of Christoulas. These pile tests show that simple measurements, taken on construction sites, can yield interesting results on the actual behaviour of horizontally loaded piles. Key words : pile, horizontal loading, full-scale test, horizontal loads, bending moment, subgrade reaction modulus, p–y curve, cohesionless soil, Standard penetration test, pressuremeter test.

scholarly journals Determining the correlation between daytime and night-time road markings visibility

2016 ◽  
Vol 11 (4) ◽  
pp. 283-290 ◽  
Author(s):  
Dario Babić ◽  
Anđelko Ščukanec ◽  
Darko Babić
Keyword(s):  
Dynamic Test ◽  
Measuring Method ◽  
Objective Evaluation ◽  
Test Method ◽  
Night Time ◽  
Road Section ◽  
Minimum Requirements ◽  
Dynamic Measuring ◽  
The Republic ◽  
The Relationship

Road markings quality control implies conducting several different tests, of which the most significant are visibility tests comprising daytime and night-time visibility measurements by applying the static or the dynamic measuring method. Although the dynamic test method allows measuring the visibility along the entire road section and thus provides a more complete and objective evaluation of road markings quality compared to the static method, it does not measure daytime visibility, for which both the European and the national directives define the minimum requirements. The purpose of this paper is to examine the correlation between daytime and night-time visibility based on static measurements conducted on state roads in the Republic of Croatia. The correlation analysis determined that the strength of relationship between daytime and night-time visibility, is relatively weak. Despite being relatively weak, the relationship still exists, which was the reason for conducting a further analysis. In the analysis, a unique coefficient was obtained through the ratio of retroreflection value and daytime visibility value for all the measurements. The unique coefficient was basis for development of a model that will be able to calculate the daytime visibility based on the results of the dynamic measurements of road markings night-time visibility. The authors evaluated the model with a t-test and concluded that the accuracy of the model is statistically satisfactory.

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