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2015-04-14
Collection
The pedestrian and cyclist safety session focuses on research and development efforts aimed at protecting pedestrians and cyclists in the event of vehicle impact. Papers covern injury biomechanics, vehicle design, dummy and impactor development, computational modeling, regulations and consumer assessment testing, active safety and collision avoidance.
2015-04-14
Collection
The Occupant Restraints technical paper collection highlights papers that document new research on the restraint topics of airbags, seat belts, inflatable bolsters/seat belts, knee bolsters, Child Restraint Systems (CRS) and other related areas. These papers could include several of the following: technology description, occupant performance considerations, field data studies, development/validation methodology / results, CAE/Finite Element methods/results, packaging, and implementation / performance challenges.
2015-04-14
Journal Article
2015-01-0740
John Patalak, Thomas Gideon, John W. Melvin, Mike Rains
Abstract Throughout the first decade of the twenty first century, large improvements in occupant safety have been made in NASCAR®'s (National Association for Stock Car Auto Racing, Inc) race series. Enhancements to the occupant restraint system include the development and implementation of head and neck restraints, minimum performance requirements for belts and seats and the introduction of energy absorbing foam are a few highlights, among others. This paper discusses nineteen sled tests used to analyze hypothesized improvements to restraint system mounting geometry. The testing matrix included three sled acceleration profiles, three impact orientations, two Anthropomorphic Test Device (ATD) sizes as well as the restraint system design variables.
2015-04-14
Technical Paper
2015-01-0739
John Patalak, Thomas Gideon
Abstract Over the last decade large safety improvements have been made in crash protection for motorsports drivers. It has been well established that in side and rear impacts the driver seat provides the primary source for occupant retention and restraint. Beginning in the 2015 season, NASCAR®'s (National Association for Stock Car Auto Racing, Inc) Sprint Cup Series will require driver seats which have all seat belt restraint system anchorage locations integrated internally to the seat with a minimum of seven anchorage locations. This paper describes the development of the quasi-static test for the seat integrated seat belt restraint system portion of the NASCAR Seat Submission and Test Protocol Criteria. It reviews the methodology used to develop the testing including the developmental dynamic sled tests.
2015-04-14
Technical Paper
2015-01-1330
Yoshiyuki Tosa, Hiroyuki Mae
Abstract The objective of this study is to accurately predict the dynamic strain on the windshield caused by the deployment of the airbag in a short term without vehicle tests. The following assumption is made as to the dynamic pressure distribution on the windshield: The deployment of the airbag is fast enough to ignore spatial difference in the patterns of the pressure time histories. Given this assumption, significant parameters of the dynamic pressure distribution are as follows: 1) the distribution of the maximum pressure during contact between the airbag and the windshield, and 2) the characteristic of the force time histories applied to the windshield by the deploying airbag. In this study, the prediction method consists of a simplified airbag deployment test and an FE simulation. The simple deployment test was conducted to measure the peak pressure distribution between the airbag and a flat panel simulating the windshield.
2015-04-14
Technical Paper
2015-01-1341
Hisaki Sugaya, Yoshiyuki Tosa, Kazuo Imura, Hiroyuki Mae
Abstract The explicit methods analysis solver LS-DYNA was used to create technology for simulating airbag deployment and plastic airbag lid tear-away in the front passenger seat. The present study clarified the mechanical properties and the transitions in fracture pattern of the material at low temperature plastic this way, an appropriate modeling method was developed and the prediction accuracy of the simulation of airbag lid tear-away on deployment was increased. Tensile testing of the material was carried out where there were differences in thickness of the tear-away section and the fracture characteristics were determined. A material model was created by analyzing changes in fracture characteristics and collapse patterns, taking into consideration the effects of strain and strain rate localization on fracture strain as well as ductile-brittle fracture transition. Next, airbags were subjected to the impactor testing.
2015-04-14
Technical Paper
2015-01-1443
Morteza Seidi, Marzieh Hajiaghamemar, James Ferguson, Vincent Caccese
Abstract Falls in the elderly population is an important concern to individuals and in the healthcare industry. When the head is left unprotected, head impact levels can reach upwards of 500 g (gravitational acceleration), which is a level that can cause serious injury or death. A protective system for a fall injury needs to be designed with specific criteria in mind including energy protection level, thickness, stiffness, and weight among others. The current study quantifies the performance of a protective head gear design for persons prone to falls. The main objective of this paper is to evaluate the injury mitigation of head protection gear made from a patented system of polyurethane honeycomb and dilatant materials. To that end, a twin wire fall system equipped with a drop arm that includes a Hybrid-III head/neck assembly was used. The head was instrumented with an accelerometer array.
2015-04-14
Technical Paper
2015-01-1451
Anand Sai Gudlur, Theresa Atkinson
Abstract The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years. Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to seek factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants.
2015-04-14
Technical Paper
2015-01-1452
Kathleen DeSantis Klinich, Kyle Boyle, Laura Malik, Miriam Manary, Jingwen Hu
This study documented the position and orientation of child restraint systems (CRS) installed in the second rows of vehicles, creating a database of 486 installations. Thirty-one different CRS were evaluated, selected to provide a range of manufacturers, sizes, types, and weight limits. Eleven CRS were rear-facing only, fourteen were convertibles, five were combination restraints, and one was a booster. Ten top-selling vehicles were selected to provide a range of manufacturers and body styles: four sedans, four SUVS, one minivan, and one wagon. CRS were marked with three reference points on each moving component. The contours and landmarks of each CRS were first measured in the laboratory. Vehicle interior contours, belt anchors, and LATCH anchors were measured using a similar process. Then each CRS was installed in a vehicle using LATCH according to manufacturers' directions, and the reference points of each CRS component were measured to document the installed orientation.
2015-04-14
Technical Paper
2015-01-1453
Jingwen Hu, Kurt Fischer, Paul Lange, Angelo Adler
Abstract In this study, two sled series were conducted with a sled buck representing a compact vehicle. The first series of tests focused on the effects of crash pulse, impact angle, occupant size, and front seat location on rear seat occupant restraint with a generic rear-seat belt system without pre-tensioner or load limiter. The second series of tests focused on investigating the benefit of using advanced features for rear-seat occupant restraint in the most severe crash condition in the first sled series. The first series of tests include 16 test conditions with two impact angles (0° and 15°), two sled pulse (soft and severe), and four ATD sizes (HIII 6YO, HIII 5th female, HIII 95th male, and THOR-NT) with two ATDs in each test. The driver seat was located at the mid position, while the front passenger seat was positioned such that a constant distance between the ATD knee and the front seat is achieved.
2015-04-14
Technical Paper
2015-01-1455
Kenshi Torikai, Hitoshi Higuchi, Kazuhiro Seki
Abstract The reaction force of a traditional passenger airbag tends to reduce after the initial inflation and before contact with the occupant, since the vent structure discharging the internal gas is always open. A potential means to prevent this drop in the airbag reaction force includes the addition of a variable vent structure which keeps the vent hole closed until occupant contact to maintain the airbag internal pressure and then opens to vent gas after the contact. However, variable vent structures may involve issues from a complicated structure due to additional parts in its construction. The goal of this study was to develop a simplified variable vent structure. A slit-type vent structure was investigated. This structure incorporates no additional parts to a conventional airbag with a hole-type vent. Static deployment tests and impactor tests were conducted to measure the effect of the slit-type vent structure and to compare it with the conventional airbag.
2015-04-14
Technical Paper
2015-01-1456
Mani Ayyakannu, Latha Subbiah, Mohammed Syed
Abstract Automotive knee bolster requirements have changed substantially in recent years due to expanded safety requirements. A three-piece cellular structural knee bolster assembly has been evolved to meet this matrix of requirements while being extremely lightweight (as low as 0.7 Kg), low in cost and easily tunable to work in various car/truck programs. The energy absorber is the primary component of this assembly and allows for a range of occupant sizes and weights to be restrained (from 50 Kg/152 cm 5th percentile female to 100 Kg/188cm 95th percentile male occupants). The evolution of this knee bolster assembly design is described using crush analysis, component testing to validate the crush analysis, instrument panel assembly level analysis with occupant models and sled tests. Steel and aluminum versions of this knee bolster are compared - in terms of weight, cost, design tunability for various crash conditions, structural stiffness etc.
2015-04-14
Technical Paper
2015-01-1457
Aditya Belwadi, Richard Hanna, Audrey Eagle, Daniel Martinez, Julie Kleinert, Eric Dahle
Abstract Automotive interior design optimization must balance the design of the vehicle seat and occupant space for safety, comfort and aesthetics with the accommodation of add-on restraint products such as child restraint systems (CRS). It is important to understand the range of CRS dimensions so that this balance can be successfully negotiated. CRS design is constantly changing. In particular, the introduction of side impact protection for CRS as well as emphasis on ease of CRS installation has likely changed key design points of many child restraints. This ever-changing target creates a challenge for vehicle manufacturers to assure their vehicle seats and occupant spaces are compatible with the range of CRS on the market. To date, there is no accepted method for quantifying the geometry of child seats such that new designs can be catalogued in a simple, straightforward way.
2015-04-14
Technical Paper
2015-01-1459
Lotta Jakobsson, Magnus Björklund, Anders Axelson
Abstract Vertical loading can cause thoracic and lumbar spine injuries to a car occupant. Crashes potentially causing occupant vertical loads include; rollover events or free flying events when the car lands on its wheels, and run off road events when the car goes into the ditch and collides with an embankment. To date, there is no standardized test method evaluating this occupant loading mechanism. The aim of this study was to develop test methods addressing vertical occupant loading for car occupants and to evaluate countermeasures for reduction of such loads. Based on real world run off road crashes, representative test track methods were developed. These complete vehicle test track methods were used to provide input to a simplified and repeatable rig test method. The rig test method comprises a dummy positioned in a seat attached to a frame and exposed to a vertical acceleration. Vertical pelvis acceleration is monitored, as an indication of potential loads through the spine.
2015-04-14
Technical Paper
2015-01-1460
Massoud Tavakoli, Janet Brelin-Fornari
Abstract This study was conducted to explore the effect of various combinations of seatbelt-related safety components (namely, retractor pretensioners and load limiting retractors) on the adult rear passenger involved in a frontal collision. The study was conducted on a 50th Male and a 5th Female Hybrid III ATD in the rear seat of a mid-sized sedan. Each ATD was seated in an outboard position with 3-point continuous lap-shoulder belts. On these belts were combinations of pretensioners and load limiters. Since the main objective of this test series was to cross-compare the seatbelt configurations, front seats were not included in the buck in order to avoid uncontrollable variables that would have affected the comparison study if the possibility of contact with the front seat were allowed. Nevertheless, there was a short barrier devised to act as a foot-stop for both ATDs.
2015-04-14
Technical Paper
2015-01-1488
Adam G. M. Cook, Moustafa El-Gindy, David Critchley
Abstract This work investigates a multi-objective optimization approach for minimizing design parameters for Front Underride Protection Devices (FUPDs). FUPDs are a structural element for heavy vehicles to improve crashworthiness and prevent underride in head-on collision with another vehicle. The developed dsFUPD F9 design for a Volvo VNL was subjected to modified ECE R93 testing with results utilized in the optimization process. The optimization function utilized varying member thickness to minimize deformation and system mass. Enhancements to the function were investigated by introducing variable materials and objectifying material cost. Alternative approaches for optimization was also needed to be explored. Metamodel-based and Direct simulation optimization strategies were compared to observe there performance and optimal designs.
2015-04-14
Technical Paper
2015-01-1492
Kazunobu Ogaki, Takayuki Kawabuchi, Satoshi Takizawa
Abstract The National Highway Traffic Safety Administration (NHTSA) has developed moving deformable barriers for vehicle crash test procedures to assess vehicle and occupant response in partial overlap vehicle crashes. For this paper, based on the NHTSA Oblique Test procedure, a mid-size sedan was tested. The intent of this research was to provide insight into possible design changes to enhance the oblique collision performance of vehicles. The test results predicted high injury risk for BrIC, chest deflection, and the lower extremities. In this particular study, reducing lower extremity injuries has been focused on. Traditionally, lower extremity injuries have been reduced by limiting the intrusion of the lower region of the cabin's toe-board. In this study, it is assumed that increasing the energy absorbed within the engine compartment is more efficient than reinforcing the passenger compartment as a method to reduce lower extremity injuries.
2015-04-14
Technical Paper
2015-01-1490
Tony R. Laituri, Scott Henry, Kaye Sullivan
Abstract Injury distributions of belted drivers in 1998-2013 model-year light passenger cars/trucks in various types of real-world frontal crashes were studied. The basis of the analysis was field data from the National Automotive Sampling System (NASS). The studied variables were injury severity (n=2), occupant body region (n=8), and crash type (n=8). The two levels of injury were moderate-to-fatal (AIS2+) and serious-to-fatal (AIS3+). The eight body regions ranged from head/face to foot/ankle. The eight crash types were based on a previously-published Frontal Impact Taxonomy (FIT). The results of the study provided insights into the field data. For example, for the AIS2+ upper-body-injured drivers, (a) head and chest injury yield similar contributions, and (b) about 60% of all the upper-body injured drivers were from the combination of the Full-Engagement and Offset crashes.
2015-04-14
Technical Paper
2015-01-1756
Daniel E. Toomey, Debora R. Marth, William G. Ballard, Jamel E. Belwafa, Roger Burnett, Robert W. McCoy
Abstract For more than 30 years, field research and laboratory testing have consistently demonstrated that properly wearing a seat belt dramatically reduces the risk of occupant death or serious injury in motor vehicle crashes. In severe rollover crashes, deformation to vehicle body structures can relocate body-mounted seat belt anchors altering seat belt geometry. In particular, roof pillar mounted shoulder belt anchors (“D-rings”) are subject to vertical and lateral deformation in the vehicle coordinate system. The ROllover Component test System (ROCS) test device was utilized to evaluate seat belt system performance in simulated severe rollover roof-to-ground impacts. A mechanical actuator was designed to dynamically relocate the D-ring assembly during a roof-to-ground impact event in an otherwise rigid test vehicle fixture. Anthropomorphic test device (ATD) kinematics and kinetics and seat belt tensions were compared between tests with and without D-ring relocation.
2015-04-14
Technical Paper
2015-01-1476
P Selvakumar, Arun Mahajan, R Murasolimaran, C Elango
Abstract Roll-over protective structures (ROPS) are safety devices which provide a safe environment for the tractor operator during an accidental rollover. The ROPS must pass either a dynamic or static testing sequence or both in accordance with SAE J2194. These tests examine the performance of ROPS to withstand a sequence of loadings and to see if the clearance zone around the operator station remains intact in the event of an overturn. In order to shorten the time and reduce the cost of new product development, non-linear finite element (FE) analysis is practiced routinely in ROPS design and development. By correlating the simulation with the results obtained from testing a prototype validates the CAE model and its assumptions. The FE analysis follows SAE procedure J2194 for testing the performance of ROPS. The Abaqus version 6.12 finite element software is used in the analysis, which includes the geometric, contact and material nonlinear options.
2015-04-14
Technical Paper
2015-01-1473
Kalu Uduma, Dipu Purushothaman, Darshan Subhash Pawargi, Sukhbir Bilkhu, Brian Beaudet
Abstract NHTSA issued the FMVSS 226 ruling in 2011. It established test procedures to evaluate countermeasures that can minimize the likelihood of a complete or partial ejection of vehicle occupants through the side windows during rollover or side impact events. One of the countermeasures that may be used for compliance of this safety ruling is the Side Airbag Inflatable Curtain (SABIC). This paper discusses how three key phases of the optimization strategy in the Design for Six Sigma (DFSS), namely, Identify; Optimize and Verify (I_OV), were implemented in CAE to develop an optimized concept SABIC with respect to the FMVSS 226 test requirements. The simulated SABIC is intended for a generic SUV and potentially also for a generic Truck type vehicle. The improved performance included: minimization of the test results variability and the optimization of the ejection mitigation performance of the SABIC.
2015-04-14
Technical Paper
2015-01-1480
Seung Kwon Cha, Jong Heon Lee, Un Ko, Tae Hoon Song, HangChul Ko, YangGi Lee
Abstract Recently, the wagon for European has been developed. The characteristic of this vehicle is to have a capability of large luggage space. Therefore the passenger needs to be protected from injuries by sudden inflow of baggage from luggage room. This is also a requirement of EU regulation (ECE R-17[4]). Barrier Net[1, 2, 3] to small size wagon has been adopted for the first time based on advanced foreign supplier's technology. This reality still gives us the burden of high cost and royalty expenditure. The objective of this study is to overcome these restrictions, especially for patent circumvention and secure the new design concept which is entirely independent of the present system in addition to cost effectiveness.
2015-04-14
Technical Paper
2015-01-1484
Daniel E. Toomey, Eric S. Winkel, Ram Krishnaswami
Abstract Since their inception, the design of airbag sensing systems has continued to evolve. The evolution of air bag sensing system design has been rapid. Electromechanical sensors used in earlier front air bag applications have been replaced by multi-point electronic sensors used to discriminate collision mechanics for potential air bag deployment in front, side and rollover accidents. In addition to multipoint electronic sensors, advanced air bag systems incorporate a variety of state sensors such as seat belt use status, seat track location, and occupant size classification that are taken into consideration by air bag system algorithms and occupant protection deployment strategies. Electronic sensing systems have allowed for the advent of event data recorders (EDRs), which over the past decade, have provided increasingly more information related to air bag deployment events in the field.
2015-04-14
Technical Paper
2015-01-1485
Jiri Kral, Theresa Kondel, Mark Morra, Stephen Cassatta, Peter Bidolli, Patrick Stebbins, Vikas Joshi
Abstract A new apparatus for testing modern safety belt systems was developed. The apparatus design, dynamic behavior and test procedure are described. A number of tests have been conducted using this apparatus. These tests allowed identification of key performance parameters of pretensioners and load limiting retractors which are relevant to occupant protection in a crash environment. Good test repeatability was observed, which allowed comparison of different safety belt designs. The apparatus may be used for better specification and verification of safety belt properties on a subsystem level as well as for the validation of CAE models of safety belts used in simulations of occupant response to crash events.
2015-04-14
Technical Paper
2015-01-1483
Anindya Deb, N Shivakumar, Clifford Chou
Abstract Rigid polyurethane (PU) foam finds wide applications as a lightweight material in impact safety design such as improving occupant safety in vehicle crashes. The two principal reacting compounds for formulating such foam are variants of polyol and isocyanate. In the present study, an alternative mechanical engineering-based approach for determining, with confidence, the desirable ratio of reacting compounds for formulation of a rigid/crushable PU foam for mechanical applications is demonstrated. According to the present approach, PU foam samples are prepared by varying the mixing ratio over a wide range. The desirable mixing ratio is shown to be the one that optimizes key mechanical properties under compression such as total absorbed energy, specific absorbed energy and energy absorption efficiency.
2015-04-14
Technical Paper
2015-01-0407
Timothy W. Skszek, Matthew Zaluzec, Jeff Conklin, David Wagner
Abstract The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance, occupant safety and utility of the baseline production vehicle. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The MMLV vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine, resulting in a significant environmental benefit and fuel reduction. This paper includes details associated with the MMLV project approach, mass reduction and environmental impact.
2015-04-14
Technical Paper
2015-01-1472
Roberto Arienti, Carlo Cantoni, Massimiliano Gobbi, Giampiero Mastinu, Mario Pennati, Giorgio Previati
Abstract The lightweight seat of a high performance car is designed taking into account a rear impact, i.e. the crash due to an impulse applied from the rear. The basic parameters of the seat structure are derived resorting to simulations of a crash with a test dummy positioned on the seat. The simulations provide the forces acting at the seat structure, in particular the forces applied at the joint between the seat cushion and the seat backrest are taken into account. Such a joint is simulated as a plastic hinge and dissipates some of the crash energy. The simulations are validated by means of indoor tests with satisfactory results. A tool has been developed for the preliminary design of lightweight seats for high performance cars.
2015-04-14
Collection
This technical paper collection focuses on the latest research related to methods and techniques for reconstructing vehicular crashes involving wheeled and tracked vehicles, pedestrians, and roadside features. Emphasis is placed on experimental data and theoretical methods that will enable reconstructionists to identify, interpret and analyze physical evidence from vehicular crashes
2015-04-09
Standard
J1538_201504
The terms included in the Glossary are general in nature and may not apply to all manufacturers' systems. All terms in Section 3 apply to automotive inflatable restraint systems in general which are initiated by an electric or mechanical stimulus upon receipt of a signal from a sensor. These terms are intended to reflect existing designs and the Glossary will be updated as information on other types of systems becomes available. Appendix A is included to identify terminology that is no longer in common use or specifically applicable to inflatable restraint systems, but was published in the December 2001 version of SAE J1538.
2015-04-01
Journal Article
2015-01-9151
Eric S. Winkel, Daniel E. Toomey, Robert Taylor
Abstract Thoracolumbar vertebral fractures are most commonly due to compressive loading modes and associated with falls from height. Two injury metrics are generally referenced for assessing the potential for compressive thoracolumbar injury; the Dynamic Response Index (DRI) and the compressive load measured between the pelvis and lumbar spine using the Code of Federal Regulations (CFR) title 49 part 572 subpart B anthropomorphic test device (ATD). This study utilizes an ATD to investigate the injury mitigation potential of a variety of seat cushions during vertical impact in an unrestrained seated posture. ATD responses and DRI are reported for 65 vertical impacts with and without cushions from heights between 4 and 80 inches. The cushions investigated reduced ATD peak pelvic acceleration 63 +/− 11% and compressive lumbar load 42 +/− 9% on average.
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