Load Path Optimization and U* Structural Analysis for Passenger Car Compartments under Frontal Collision

2003 ◽  
Author(s):  
Toshiaki Sakurai ◽  
Junichi Tanaka ◽  
Akinori Otani ◽  
Changjun Zhang ◽  
Kunihiro Takahashi
Keyword(s):  
Structural Analysis ◽  
Path Optimization ◽  
Load Path ◽  
Passenger Car ◽  
Frontal Collision

scholarly journals Crippling Test of a Budd Pioneer Passenger Car

2012 ◽  
Author(s):  
Michael Carolan ◽  
Benjamin Perlman ◽  
David Tyrell
Keyword(s):  
Research Program ◽  
Task Force ◽  
Alternative Methods ◽  
Fe Model ◽  
Load Path ◽  
Passenger Car ◽  
Test Configuration ◽  
Passenger Rail ◽  
Alternative Methodology ◽  
Displacement Transducers

This research program was sponsored by the Federal Railroad Administration (FRA) Office of Research and Development in support of the advancement of improved safety standards for passenger rail vehicles. FRA and the Volpe National Transportation Systems Center (Volpe Center) have conducted a research program to develop alternative methods for demonstrating occupied volume integrity (OVI) of passenger rail cars using a combination of testing and analysis. Previous publications have addressed the planning and progress of a series of tests intended to examine the collision load path through the occupant volume of passenger cars equipped with crash energy management (CEM) systems. This program has included an elastic 800-kip buff strength test, two quasi-static tests that loaded a passenger car to its ultimate (crippling) capacity, and corresponding finite element (FE) analyses of each test. This paper discusses the two crippling tests and the companion FE analyses. One alternative method for evaluating OVI moves the applied loads from the line of draft to the collision load path. This alternative methodology also permits a combination of testing and analysis to be used to demonstrate the car’s OVI, in contrast to the conventional methodology (as prescribed in existing FRA regulations) which only permits testing. The alternative methodology was adopted as the recommendations developed by the Railroad Safety Advisory Committee’s (RSAC) Engineering Task Force (ETF) in its “Technical Criteria and Procedures for Evaluating the Crashworthiness and Occupant Protection Performance of Alternatively-Designed Passenger Rail Equipment for Use in Tier I Service.” The research program was undertaken to verify the efficacy of using a combination of elastic testing and plastic analysis to evaluate the OVI of a passenger car loaded along its collision load path as prescribed in the ETF report. Earlier in this research program an elastic test of a Budd Pioneer car was used to validate an FE model of the car, per the ETF’s procedures. This model was then modified to reflect the condition of the car in its crippling test configuration. The model was used to simulate the crippling behavior of the car, following the ETF’s procedures. Two Pioneer cars were then tested to crippling to provide additional data to validate the FE model and the proposed alternative OVI evaluation. Because the test cars used in this research program were equipped with CEM systems, the alternative evaluation loads were placed at the locations where the energy-absorbing components attached to the occupant volume. During both crippling tests, loads were measured at each energy-absorber support location on the live and restrained ends of the car. Additional instrumentation used in the second crippling test included strain gages on the major longitudinal structural members, displacement transducers at each load location, and vertical, lateral, and longitudinal displacement transducers on the underframe of the car. The results of the FE analysis compare favorably with the results of the crippling tests. In particular, the crippling loads are consistent between the tests and analysis: crippling loads for the first and second cars tested were 1.15 and 1.19 million pounds respectively, and the pre-test FEA estimated a crippling load of 1.19 million pounds. The research program has established a technical basis for the alternative OVI requirements and methodology.

scholarly journals Occupied Volume Integrity Testing: Elastic Test Results and Analyses

2011 ◽  
Author(s):  
Michael Carolan ◽  
Michelle Muhlanger ◽  
Benjamin Perlman ◽  
David Tyrell
Keyword(s):  
Research And Development ◽  
Development Program ◽  
Full Scale ◽  
Fe Model ◽  
Test Model ◽  
Test Results ◽  
Load Path ◽  
Passenger Car ◽  
Post Test ◽  
Railroad Safety

The Office of Research and Development of the Federal Railroad Administration (FRA) and the Volpe Center have been conducting research into developing an alternative method of demonstrating the occupied volume integrity (OVI) of passenger rail equipment through a combination of testing and analysis. This research has been performed as a part of FRA Office of Research and Development’s Railroad Safety Research and Development program, which provides technical data to support safety rulemaking and enforcement programs of the FRA Office of Railroad Safety. Previous works have been published on a series of full-scale, quasi-static tests intended to examine the load path through the occupant volume of conventional passenger cars retrofitted with crash energy management (CEM) systems. This paper reports on the most recent testing and analysis results. Before performing any tests of proposed alternative loading techniques, an elastic test of the passenger car under study was conducted. The elastic test served both to aid in validating the finite element (FE) model and to verify the suitability of the test car to further loading. In January, 2011, an 800,000 pound conventional buff strength test was performed on Budd Pioneer 244. This test featured arrays of vertical, lateral, and longitudinal displacement transducers to better distinguish between the deformation modes and rigid body motions of the passenger car. Pre-test car repairs included straightening a dent in one side sill and installing patches over cracks found in the side sills. Additionally, lateral restraints were added to the test frame due to concerns in previous tests associated with lateral shift in the frame. As a part of this testing program, a future test of a passenger car is planned to examine an alternative load path through the occupied volume. In the case of Pioneer 244, this load path places load on the floor and roof energy absorber support structures. Loading the occupant volume in this manner more closely simulates the loading the car would experience during a collision. FE analysis was used in conjunction with full-scale testing in this research effort. An FE model of the Pioneer car was constructed and the 800-kip test was analyzed. The 800-kip test results were then compared to the analysis results and the model was adjusted post-test so that satisfactory agreement was reached between the test and the model. In particular, the boundary conditions at the loading and reaction locations required careful attention to appropriately simulate the support conditions in the test. Because the 800-kip load was applied at the line of draft, this test results in significant bending as well as axial load on the car. To ensure that both the axial and bending behaviors are captured in the model, the key results that were compared between test and model are the longitudinal force-displacement behavior and the vertical deflections at various points along the car. The post-test model exhibited good agreement with the compared test results. The validated model will be used to examine the behavior of the occupant volume when loaded along the alternative load path.

Frontal Offset Crash: Smart Structure Solution

2001 ◽  
Author(s):  
Saad A. Jawad ◽  
Mohamed Ridha Baccouche
Keyword(s):  
High Speed ◽  
Injury Risk ◽  
Degrees Of Freedom ◽  
Smart Structures ◽  
Smart Structure ◽  
Load Path ◽  
Front End ◽  
Frontal Collision ◽  
Partial Overlap ◽  
Overlap Ratio

Abstract The majority of real world frontal collisions involve partial overlap of the vehicle front. Excessive, intrusion is usually generated on the impacted side subjecting occupants to higher contact injury risk compared with full frontal collision. The problem encountered by the front end design engineer is to address conflicting requirements of keeping the G-level in the full frontal crash within its permitted values, and minimizing intrusions in offset crash. Traditional solutions to this problem focus on the use of three forked and cross members to ensure continuity of the load path into the passenger compartment. The ideal structure for offset crash is to stiffen the impacted side of the structure, and transfer part of the load to the non-impacted side to even out the load on both sides. Smart hydraulic structure is proposed to meet these ideal requirements. Sample hydraulic “Smart Structures” were designed and tested for feasibility of crash under high-pressure and high-speed impact conditions. This research is attempting to find a solution to the design trade off faced by the designer for offset crash. A novel system of “Smart Structures” is introduced to support the function of the existing passive structure. The proposed “Smart Structures” consist of two independently controlled hydraulic cylinders integrated with the front-end rails. A ten-degrees of freedom, two-dimensional spring-mass-damper simulation model has been developed to study the dynamics of crash between two vehicles in head-on collisions. The model inputs mass, speed of both colliding vehicles, overlap ratio and deformation characteristics of both passive and “smart” structures. The model assumes that the two colliding structures geometrically interact with each other. Full simulations of various scenarios of offset crashes were investigated using “Smart Structures” integrated with the front rail members. Deployable “Smart Structures” have not been considered in this paper as this scenario was covered in previous publication (9). “Smart Structures” proved superior to the traditional passive structures by absorbing more energy for the same crush zone distance, stiffening the impacted side and stiffening the structure at high-speed impacts. The results are reduced intrusion for offset crashes while maintaining the permitted G-level in both full and offset crashes.

Investigation on Design and Analysis of Passenger Car Body Crash-Worthiness in Frontal Impact Using Radioss

2020 ◽  
Keyword(s):  
Passenger Car ◽  
Automobile Safety ◽  
Automotive Components ◽  
Frontal Collision ◽  
Passenger Safety ◽  
Occupant Injuries ◽  
Lightweight Metals ◽  
Frontal Crashes ◽  
Safety Features ◽  
Dynamic Structural Analysis

Increasing advancement in automotive technologies ensures that many more lightweight metals become added to the automotive components for the purpose of light weighting and passenger safety. The accidents are unexpected incidents most drivers cannot be avoided that trouble situation. Crash studies are among the most essential methods for enhancing automobile safety features. Crash simulations are attempting to replicate the circumstances of the initial crash. Frontal crashes are responsible for occupant injuries and fatalities 42% of accidents occur on frontal crash. This paper aims at studying the frontal collision of a passenger car frame for frontal crashes based on numerical simulation of a 35 MPH. The structure has been designed to replicate a frontal collision into some kind of inflexible shield at a speed of 15.6 m/s (56 km/h). The vehicle’s exterior body is designed by CATIA V5 R20 along with two material properties to our design. The existing Aluminum alloy 6061 series is compared with carbon fiber IM8 material. The simulation is being carried out by us in the “Radioss” available in “Hyper mesh 17.0” software. The energy conservation and momentum energy absorption are carried out from this dynamic structural analysis.

Forging Process Design of Al Rotating Arm Holder by FE Analysis

2007 ◽  
Vol 26-28 ◽  
pp. 99-102
Author(s):  
Kwan Do Hur ◽  
Hyo Young Lee ◽  
Hong Tae Yeo
Keyword(s):  
Structural Analysis ◽  
Safety Factor ◽  
Effective Stress ◽  
Process Design ◽  
Aluminium Alloys ◽  
Fuel Efficiency ◽  
Effective Strain ◽  
Fe Analysis ◽  
Passenger Car ◽  
Forging Process

Aluminium alloys have been widely used in the structure of aircraft and passenger car because of its lightweight. It is also interested in the lightweight products to improve the fuel efficiency. In this research, forging design of Al rotating arm holder has been studied by FE analysis. Structural analysis of the model was performed at first. From the results of the analysis, effective stress, effective strain and safety factor acting on the component were obtained.

scholarly journals Load Path U* Analysis in Passenger Car Body Structures and Load Transfer Balance in Structural Components

2012 ◽  
Vol 78 (794) ◽  
pp. 1462-1472
Author(s):  
Yasuyuki KUMAZAWA ◽  
Satoru KUWAHARA ◽  
Masaki OMIYA ◽  
Kunihiro TAKAHASHI
Keyword(s):  
Load Transfer ◽  
Structural Components ◽  
Load Path ◽  
Passenger Car ◽  
Car Body

Multi Level Boarding Bi-Level Commuter Car for North American Market

Joint Rail ◽  
2004 ◽  
Author(s):  
Radovan Sarunac ◽  
Terry B. Soesbee ◽  
Shin-Ichiro Ohta
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
North American ◽  
Engineering Practice ◽  
Load Path ◽  
Worst Case ◽  
The North ◽  
North American Market ◽  
The One ◽  
Tier I

A multilevel boarding version (low and high level platform boarding) of the bi-level commuter car for the North American market has been developed. The major challenge of the bi-level carbody design with the high and lower boarding access, i.e., passenger doors, is the side sill interruption at the lower level. The side sill is the main structural member (beside the center sill) that transmits the longitudinal load from the one end of the car to the other end. Since the side sill is interrupted by placing lower level passenger doors the alternative load path had to be designed. Originally, a solution similar to the one used on the California bi-level car was considered. However, due to major differences in the equipment arrangement and seating plan, an alternative design was developed. Consequently, the LIRR carbody type was chosen, with the exception that the lower body section between bolsters, “fish belly” was similar to the MARC III section. The specific goal and the first step were to study and confirm the feasibility of the concept. As a good engineering practice, prior to the initiation of any major carbody design, a preliminary structural analysis was provided. The worst-case structural scenarios regarding door and window locations were considered. Preliminary structural analysis included linear, static, finite element carbody analysis for various loads and loads requirements defined. This study summarizes the results of the analyses for each load case. The study also comprises the investigation and applicability of the relevant laws and requirements for Tier-I passenger equipment with specific emphasis to the Bi-level car. The applicability of the Code of Federal Regulations, 49 CFR, Transportation, Parts 200 to 399 and American Public Transit Association (APTA) Manual of Standards and Recommended Practices for Rail Passenger Equipment was investigated in detail. Relevant laws, standards, and requirements for Tier-I passenger equipment were identified, categorized and prioritized. Based on the relevant standards, feasibility analysis was performed for the most demanding design. Stress contour and deflection plots from the finite element analyses are provided only for the worst-case direction for a given loading scenario. Floor and seating plans accommodating the multilevel boarding options were developed.

Design of CASTonCAST shell structures based on load path network method

2017 ◽  
Vol 32 (3-4) ◽  
pp. 216-225
Author(s):  
Lluís Enrique Monzó ◽  
Joseph Schwartz
Keyword(s):  
Structural Analysis ◽  
Geometric Modeling ◽  
Shell Structures ◽  
Load Path ◽  
Load Bearing ◽  
Modeling Process ◽  
Network Method ◽  
Structural Aspects

The CASTonCAST system consists in designing and producing architectural freeform shapes from precast stackable components. This allows fabricating and constructing curved shapes in concrete in an efficient and sustainable manner. Currently, the geometric modeling process of the system does not ensure that the shapes are load-bearing. This article introduces a method for the design of shell structures from stackable components based on the CASTonCAST system. In this research, the structural analysis is conducted using load path network method since this method helps integrating design, realization, and structural aspects.

scholarly journals Load path optimization in tube hydroforming

2015 ◽  
pp. 1-8
Author(s):  
S. Mojarad ◽  
H. Champliaud ◽  
J. Gholipour ◽  
J. Savoie ◽  
P. Wanjara
Keyword(s):  
Tube Hydroforming ◽  
Path Optimization ◽  
Load Path
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