The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Safety belts
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental Rattle Source Characterization Using Matrix Inversion on a Reception Plate

Virtual Vehicle-Eugene Nijman, Bernhard Zeller
Virtual Vehicle Research Center-Josef Girstmair
  • Technical Paper
  • 2020-01-1541
To be published on 2020-06-03 by SAE International in United States
Minimising rattle noises is becoming increasingly important for hybrid and electrical vehicles as masking from the IC engine is missing and in view of the functional requirements of the office-like interiors of next generation automated vehicles. Rattle shall therefore be considered in the design phase of component systems. One hurdle is the modelling of the excitation mechanisms and its experimental validation. In this work we focus on excitation by loose parts having functional clearances such as gear systems or ball sensors in safety belt retractors. These parts are excited by relatively large low frequency displacements such as road-induced movements of the car body or low order rigid body engine vibrations generating multiple impacts with broad band frequency content. Direct measurement of the impact forces is in many cases not possible. An experimental procedure to measure the multi-DOF rattle impact forces in component systems is presented based on a reception plate transfer matrix inversion. The investigated component is mounted on the reception plate and rattle is induced by direct low frequency rigid body excitation of the…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

3D Audio Reproduction via Headrest equipped with Loudspeakers – Investigations on Acoustical Design Criteria

Manuel Brandner
AUDIO MOBIL Elektronik GmbH-Thomas Hatheier
  • Technical Paper
  • 2020-01-1567
To be published on 2020-06-03 by SAE International in United States
This paper focuses on the analysis and evaluation of acoustical design criteria to produce a plausible 3D sound field solely via headrest with integrated loudspeakers at the driver/passenger seats in the car cabin. Existing audio systems in cars utilize several distributed loudspeakers to support passengers with sound. Such configurations suffer from individual 3D audio information at each position. Therefore, we present a convincing minimal setup focusing sound solely at the passenger’s ears. The design itself plays a critical role for the optimal reproduction and control of a sound field for a specific 3D audio application. Moreover, the design facilitates the 3D audio reproduction of common channel-based, scene-based, and object-based audio formats. In addition, 3D audio reproduction enables to represent warnings regarding monitoring of the vehicle status (e.g.: seat belts, direction indicator, open doors, luggage compartment) in spatial accordance. Furthermore, individual sound zones enable superior in-car communication between seats regardless of the current driving situation. An often overlooked topic is the acoustical privacy of in-car systems towards the exterior especially during telephony which is also tackled…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Evaluation of Near- and Far-Side Occupant Loading in Low- to Moderate-Speed Side Impact Motor Vehicle Collisions

Exponent Inc.-Megan Toney-Bolger, Sarah Sherman, Jessica Isaacs, Christina Garman, Alan Dibb
  • Technical Paper
  • 2020-01-1218
To be published on 2020-04-14 by SAE International in United States
Many side-impact collisions occur at speeds much lower than tests conducted by the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS). In fact, nearly half of all occupants in side-impact collisions experience a change in velocity (delta-V) below 15 kph (9.3 mph). However, studies of occupant loading in collisions of low- to moderate-severity, representative of many real-world collisions, is limited. While prior research has measured occupant responses using both human volunteers and anthropometric test devices (ATDs), these tests have been conducted at relatively low speeds (<10 kph [<6.2 mph] delta-V). This study evaluated near- and far-side occupant response and loading during two side impacts with delta-V of 6.1 kph and 14.0 kph (3.8 mph and 8.7 mph). In each crash test, a Non-Deformable Moving Barrier (NDMB) impacted the side of a late-model, mid-sized sedan in a configuration consistent with the IIHS side-impact crash-test protocol. Two instrumented Hybrid III 50th-percentile male ATDs were positioned in the vehicle, one in the driver's seat and one in the right, front passenger seat.…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Evaluation of Laminated Side Glazing and Curtain Airbags for Occupant Containment in Rollover

Exponent Inc.-Bruce Miller, Janine Smedley, Michael Carhart, Sarah Sharpe
Ford Motor Company-Ram Krishnaswami
  • Technical Paper
  • 2020-01-0976
To be published on 2020-04-14 by SAE International in United States
By their nature as chaotic, high-energy events, rollovers pose an injury risk to occupants, in particular through exposure to perimeter contact and ejection. While seatbelts have long been accepted as a highly effective means of retaining occupants, it has been suggested that technologies such as laminated safety glazing or rollover curtain airbags could alternatively provide effective occupant containment during rollovers. In this study, a full-scale dolly rollover crash test was performed to assess the occupant containment capacity of laminated side glazing and rollover curtain airbags in a high-severity rollover. This allowed for the analysis of unrestrained occupant kinematics during interaction with laminated side glazing and rollover curtain airbags and evaluation of failure modes and limitations of laminated glazing and rollover curtain airbags as they relate to partial and complete ejection of unrestrained occupants. The dolly rollover was performed with a 2010 Chevrolet Express at a nominal speed of 43 mph, with unbelted anthropomorphic test devices (ATDs) positioned in the driver, right front passenger, and designated third, fourth, and fifth row seating positions. Vehicle dynamics and…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigation of Fracture Behavior of Deep Drawn Automotive Part affected by Thinning with Shell Finite Elements

General Motors LLC-Hwawon Lee, Shengjian li, Hui-Min (Emmy) Huang, Parvath Police
  • Technical Paper
  • 2020-01-0208
To be published on 2020-04-14 by SAE International in United States
In the recent decades, tremendous effort has been made in automotive industry to reduce vehicle mass and development costs for the purpose of improving fuel economy and building safer vehicles that previous generations of vehicles cannot match.An accurate modeling approach of sheet metal fracture behavior under plastic deformation is one of the key parameters affecting optimal vehicle development process. FLD (Forming Limit Diagram) approach, which plays an important role in judging forming severity, has been widely used in forming industry, and localized necking is the dominant mechanism leading to fracture in sheet metal forming and crash events.FLD is limited only to deal with the onset of localized necking and could not predict shear fracture. Therefore, it is essential to develop accurate fracture criteria beyond FLD for vehicle development. To enhance the accuracy of crash simulations, forming results from stamping process are generally introduced to consider work hardening and thinning/thickening of a stamped part during the simulations. However, fracture criteria are only applied to the original design thickness, not the change in the gage thickness after…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Determination of Seatbelt Use Following a Crash

DJS Associates-John R. Yannaccone
  • Technical Paper
  • 2020-01-0643
To be published on 2020-04-14 by SAE International in United States
When investigating a vehicle crash, the issue of seatbelt usage is frequently part of the information needed to perform an occupant kinematics or injury analysis. A physical inspection of the vehicle is the preferred method to investigate seatbelt usage. However, if the vehicle is no longer available, or the condition has changed since the time of the crash, preventing analysis of seatbelt usage by an occupant, the investigators must rely on other available evidence to assess occupant seatbelt usage. This would typically include a review of the police report, scene or early photographs of the vehicle, physical marks on the occupant in medical records and statements from witnesses. More recently, event data recorders (EDR) can provide data regarding seatbelt status for front seat occupants, and occasionally, rear seat occupants. However, the EDR data must have been previously recovered or the vehicle must be available.In cases where the available data is limited or includes only subjective data such as a police report or statements of occupants, some investigators have used the post-crash seatbelt position to determine…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Assessment of Collision Markings on Non-Used Vehicle Seat Belt Restraint Systems

Design Research Engineering-Richard H. Gregg
Explico Engineering-Karla J. Petroskey
  • Technical Paper
  • 2020-01-0975
To be published on 2020-04-14 by SAE International in United States
Forensic investigators of automobile collisions are commonly tasked with determining whether physical evidence observed on restraint systems is consistent with the occupant’s use or non-use of the seat belt restraint. The characteristics of collision-induced markings generated on seat belt systems are not solely dependent on the belted status of the occupant, but also the technological features incorporated in the seat belt assembly. As the state-of-the-art for seat belt assemblies has changed over time, so has the constellation of physical evidence typically created on seat belt restraint systems. Pretensioner deployment can leave physical evidence on restraint system hardware in the absence of occupant loading. This study presents examples of physical evidence collected from seat belt systems involved in real-world collisions, which were initially alleged to affirm proper belt use, but were ultimately proven to be evidence of non-use. Several laboratory demonstrations were conducted to investigate physical evidence created on restraint system hardware as a result of pretensioner deployments of non-used seat belts in a variety of incompletely stowed conditions. The demonstrations show the initial positions of…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The roles of vehicle seat cushion stiffness and length in child restraint system (CRS) performance

Ohio State University-Julie Mansfield, Yun-Seok Kang
Transportation Research Center Inc.-HyunJung Kwon
  • Technical Paper
  • 2020-01-0977
To be published on 2020-04-14 by SAE International in United States
The objective is to determine whether responses and injury risks for pediatric occupants in child restraint systems (CRS) are affected by vehicle seat cushion stiffness and fore/aft length. Eighteen sled tests were conducted using the FMVSS 213 frontal pulse (48 km/h). Seats from a recent model year vehicle were customized by the manufacturer with three different levels of cushion stiffness: compliant, mid-range, and stiff. Each stiffness level was quantified using ASTM D 3574-08 and all were within the realistic range of modern production seats. The usable length of each seat cushion was manipulated using foam spacers provided by the manufacturer. Two different seat lengths were examined: short (34.0 cm) and long (43.5 cm). Three different types of CRS were tested with size-appropriate anthropomorphic test devices (ATDs): rear-facing (RF) CRS with 12-month-old CRABI, forward-facing (FF) CRS with Hybrid III 3-year-old, and high-back booster with Hybrid III 6-year-old. Each CRS, vehicle seat (including cushion and frame), seat belt webbing and buckle were replaced after every test. ATD kinematic and kinetic data were compared across seat cushion lengths…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

An Optimization Study of Occupant Restraint System for Different BMI Senior Women in Vehicle Frontal Impact

Chongqing University-Guan Lin, Zhenfei Zhan, Huijie Xu, Yue Fu, Ling Jiang, Yunlei Yin
State Key Lab of Vehicle NVH & Safety Technology-Ruyi Chen
  • Technical Paper
  • 2020-01-0981
To be published on 2020-04-14 by SAE International in United States
Accident statistics have shown that older and obese occupants are less adaptable to existing vehicle occupant restraint systems than ordinary middle-aged male occupants, and tend to have higher risk of death and injury in vehicle crashes.However, the current research on the mechanism of injury in vehicle frontal impact for aging and obese occupants is scarce. This paper mainly focuses on the optimization design method of occupant constraint system parameters for specific body type characteristics. The damage attributes of vehicle crash on elderly female with different BMI (body mass index) was analyzed. The design variables in the constraint system were screened for DOE analysis. We selected five parameters for optimization, namely the force limiter force limit value of the seat belt, the pretensioner preload of the seat belt, the preload time of the seat belt, the ignition time of the airbag, the proportionality coefficient of the mass flow rate of the airbag. The objective of this study is to minimize the risk of comprehensive injuries, and the constraints are that indicator values for head injury, neck…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Load Distribution Optimization of Seatbelt Using Validated Finite Element Approach

Joyson Safety Systems-Anshul Satija, Priyanshu Mishra, Ravi Gaurav, Virender Singh
  • Technical Paper
  • 2019-28-2575
Published 2019-11-21 by SAE International in United States
The seat belt system is one of most important component of the safety instrument family in a vehicle. The main purpose of seat belt is to minimize the injuries by preventing the occupant from impacting hard on interior parts of the vehicle and also the passenger from being thrown-out from the vehicle in case of rollover accidents. The standard three-point belt is mounted in the vehicle at three locations namely Anchor, D-ring and Buckle. The position of anchorages is very important to distribute the impact load evenly to the occupants. Very high load in any of these locations could cause breakage of the mountings and also concentrated loading on the occupant chest of pelvis. Current study mainly focuses on the seatbelt assembly performance improvement against UNECE-R16 sled test. The sled test was carried out first using 28g peak acceleration pulse and measurement of forces at shoulder and anchor position was measured using the load cell. FE (Finite Element) model of the complete seatbelt assembly was developed including Buckle, Retractor and Anchor plate. The simulation was…
Annotation ability available