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Viewing 151 to 180 of 16638
2016-04-05
Journal Article
2016-01-0404
Qianqian Du
Abstract Crashworthiness is one of the most important performances of vehicles, and the front rails are the main crash energy absorption parts during the frontal crashing process. In this paper, the front rail was simplified to a thin-walled beam with a cross section of single-hat which was made of steel and aluminum. And the two boards of it were connected by riveting without rivets. In order to optimize its crashworthiness, the thickness (t), radius (R) and the rivet spacing (d) were selected as three design variables, and its specific energy absorption was the objective while the average impact force was the constraint. Considering the error of manufacturing and measurements, the parameters σs and Et of the steel were selected as the uncertainty variables to improve the design reliability. The algorithm IP-GA and the approximate model-RBF (Radial Basis Function) were applied in this nonlinear uncertainty optimization.
2016-04-05
Technical Paper
2016-01-0221
Roberto Monforte, Fabrizio Mattiello, Andrea Perosino, Fabrizio Porta, Susanna Paz, Pablo Lopez del Rincón
Abstract The adoption of a low-GWP refrigerant gas in MAC systems is mandatory from January 1st, 2017 according to the European Directive 2006/40/EC requirements for all new passenger cars, in order to gain their registration in the EU28 market. Following the work carried out in 2008 to support the FCA choice for the new types development, a further step was accomplished to evaluate the risk involved by the adoption of the low-GWP refrigerant gas R-1234yf in the MAC systems. This paper is focused on the activities held to enhance the 3D CFD method and its validation. In certain concentrations, R-1234yf could present a safety hazard to the vehicle occupants and, according to the ISO Standard Risk Scenario evaluation, 3D CFD tools are adopted to evaluate the ignition event associated with small or large leak in the passenger compartment. The method validation has been supported by both a simplified control volume “dummy cabin compartment” and an actual FCA vehicle.
2016-04-05
Technical Paper
2016-01-0456
Zhaozhong Zhang, Dongpu Cao
Abstract One main objective is to find out how these parameters interact and optimal driver control gain and driver preview time are obtained. Some steps further, neuromuscular dynamics is considered and the system becomes different from the simplified driver-vehicle system studied before. New optimal driver control gain and driver preview time could be obtained for both tensed and relaxed muscle state. Final step aims at analysing the full system considering driver, neuromuscular, steer-by-wire and vehicle models. The steer-by-wire system could potentially have a significant influence on the vehicle when the driver is at impaired state, which could be represented by setting higher response delay time or smaller preview time. Vehicle's stability and active safety could also be improved by introducing the steer-by-wire system.
2016-04-05
Journal Article
2016-01-0497
Brian Falzon, Wei Tan
Abstract The development of the latest generation of wide-body carbon-fibre composite passenger aircraft has heralded a new era in the utilisation of these materials. The premise of superior specific strength and stiffness, corrosion and fatigue resistance, is tempered by high development costs, slow production rates and lengthy and expensive certification programmes. Substantial effort is currently being directed towards the development of new modelling and simulation tools, at all levels of the development cycle, to mitigate these shortcomings. One of the primary challenges is to reduce the extent of physical testing, in the certification process, by adopting a ‘certification by simulation’ approach. In essence, this aspirational objective requires the ability to reliably predict the evolution and progression of damage in composites. The aerospace industry has been at the forefront of developing advanced composites modelling tools.
2016-04-05
Journal Article
2016-01-0519
Xiaoqing Xu, Bohan Liu, Yan Wang, Yibing Li
Abstract The mechanical behavior of polyvinyl butyral (PVB) film plays an important role in windshield crashworthiness and pedestrian protection and should be depth study. In this article, the uniaxial tension tests of PVB film at various strain rates (0.001 s-1, 0.01 s-1, 0.1 s-1, 1 s-1) and temperatures (-10°C, 0°C, 10°C, 23°C, 40°C, 55°C, 70°C) are conducted to investigate its mechanical behavior. Then, temperature and strain rate dependent viscoelastic characteristics of PVB are systematically studied. The results show that PVB is a kind of temperature and strain rate sensitive thermal viscoelastic material. Temperature increase and strain rate decrease have the same influence on mechanical properties of PVB. Besides, the mechanical characteristics of PVB change non-linearly with temperature and strain rate.
2016-04-05
Technical Paper
2016-01-1335
Abhishek Sinha, Kamlesh Yadav, Rajdeep Singh Khurana
Abstract The biggest challenge in vehicle BIW design today is to make a light, cost effective and energy absorbing structure. With the increasing competition as well as increasing customer awareness, today’s vehicle has to satisfy several aesthetic and functional requirements besides the mandatory regulatory requirements. Working on global platform is challenging in order to comply with both pedestrian protection and low speed bumper impact (ECE-R42) and, at the same time, to meet the styling intent of reducing the front overhang. Pedestrian lower leg compliance demands space between bumper member and bumper: a condition that reduces the space available for energy absorption during low speed impact (ECE-R42). Therefore, reduction in front overhang poses a problem in meeting both the requirements with limited space.
2016-04-05
Technical Paper
2016-01-0150
Felix Pistorius, Andreas Lauber, Johannes Pfau, Alexander Klimm, Juergen Becker
Abstract Various algorithms such as emergency brake or crash warning using V2X communication have been published recently. For such systems hard real-time constraints have to be satisfied. Therefore latency needs to be minimized to keep the message processing delay below a certain threshold. Existing V2X systems based on the IEEE 1609 and SAE J2735 standards implement most message processing in software. This means the latency of these systems strongly depends on the CPU load as well as the number of incoming messages per time. According to safety constraints all messages of nearby vehicles have to be processed, whereby no prediction of the message importance can be given without analyzing the message content. Regarding the aforementioned requirements we propose a novel architecture that optimizes latency to satisfy the hard real-time constraints for V2X messages.
2016-04-05
Technical Paper
2016-01-1472
Dietmar Otte, Martin Urban, Heiko Johannsen
Abstract Estimating the potential benefit of advanced safety systems by simulation has become increasingly important during the last years. All over the world OEMs and suppliers carry out benefit estimations by simulations via computer models. Such simulations should, of course, be based on real world scenario such as the pre-crash phase of real world accidents. Several methodologies for building up accident scenarios have been developed in the past. This paper shows a new method for generating pre-crash scenarios directly from the reconstruction of the accident by using the software PC-Crash1. The new method was developed by the Medical University Hannover (MHH) and the Fraunhofer Institute for Transportation Dresden (Fraunhofer IVI). It is based on transferring all information (participant-, vehicle-, environment- and motion-data) from the reconstruction file into a scenario-database.
2016-04-05
Journal Article
2016-01-0050
Huafeng Yu, Chung-Wei Lin, BaekGyu Kim
Abstract Modern vehicles can have millions of lines of software, for vehicle control, infotainment, etc. The correctness and quality of the software play a key role in the safety of whole vehicles. In order to assure the safety, engineers give an effort to prove correctness of individual subsystems or their integration using testing or verification methods. One needs to eventually certify that the developed vehicle as a whole is indeed safe using the artifacts and evidences produced throughout the development cycle. Such a certification process helps to increase the safety confidence of the developed software and reduce OEM’s liability. However, software certification in automotive domain is not yet well established, compared to other safety-critical domains, such as avionics and medical devices. At the same time, safety-relevant standards and techniques, including ISO 26262 and assurance cases, have been well adopted.
2016-04-05
Technical Paper
2016-01-1470
Nathan A. Rose, Neal Carter, Gray Beauchamp
Abstract Calculating the speed of a yawing and braked vehicle often requires an estimate of the vehicle deceleration. During a steering induced yaw, the rotational velocity of the vehicle will typically be small enough that it will not make up a significant portion of the vehicle’s energy. However, when a yaw is impact induced and the resulting yaw velocity is high, the rotational component of the vehicle’s kinetic energy can be significant relative to the translational component. In such cases, the rotational velocity can have a meaningful effect on the deceleration, since there is additional energy that needs dissipated and since the vehicle tires can travel a substantially different distance than the vehicle center of gravity. In addition to the effects of rotational energy on the deceleration, high yaw velocities can also cause steering angles to develop at the front tires. This too can affect the deceleration since it will influence the slip angles at the front tires.
2016-04-05
Technical Paper
2016-01-1530
Yury Chudnovsky, Justin Stocks-Smith, Jeya Padmanaban, Joe Marsh
Abstract NASS/CDS data (1993-2013) was used to examine serious injury rates and injury sources for belted drivers in near- and far-side impacts. Frequency and severity of near- and far-side impacts by crash severity (delta-V) were compared for older (1994-2007 MY) and newer (2008-2013 MY) vehicles. For 2008-2013 MY, individual cases were examined for serious thorax injury in far-side impacts. Results show that, for newer passenger cars, about 92% of side impacts have a delta-V under 15 mph and, for older cars, the percentage is about 86%. The rate of serious injury is higher for nearside compared to far-side crashes for both older and newer models, and the near-side injury rate is much lower for newer models. Safety features, including side airbags, are effective in reducing injuries to near-side belted drivers in newer models. The serious injury rate for near-side belted drivers in older cars is 5.5% for near-side crashes and 1.2% for far-side crashes.
2016-04-05
Technical Paper
2016-01-0056
Bjoern Steurich, Klaus Scheibert, Axel Freiwald, Martin Klimke
Abstract Vehicle manufacturers are challenged by rising costs for vehicle recalls. A major part of the costs are caused by software updates. This paper describes a feasibility study on how to implement software update over the air (SOTA) in light vehicles. The differences and special challenges in the automotive environment in comparison to the cellular industry will be explained. Three key requirements focus on the drivers’ acceptance and thus are crucial for the vehicle manufacturers: SOTA must be protected against malicious attacks. SOTA shall interfere as little as possible with the availability of a vehicle. Long update processes with long vehicle downtimes or even complete fails must be avoided. The functional safety of the vehicle during operation may not be limited in any way The study gives options how those objectives can be achieved.
2016-04-05
Technical Paper
2016-01-1491
Eunjoo Hwang, Jason Hallman, Katelyn Klein, Jonathan Rupp, Matthew Reed, Jingwen Hu
Abstract Current finite element (FE) human body models (HBMs) generally only represent young and mid-size male occupants and do not account for body shape and composition variations among the population. Because it generally takes several years to build a whole-body HBM, a method to rapidly develop HBMs with a wide range of human attributes (size, age, obesity level, etc.) is critically needed. Therefore, the objective of this study was to evaluate the feasibility of using a mesh morphing method to rapidly generate skeleton and whole-body HBMs based on statistical geometry targets developed previously. THUMS V4.01 mid-size male model jointly developed by Toyota Motor Corporation and Toyota Central R&D Labs was used in this study as the baseline HBM to be morphed. Radial basis function (RBF) was used to morph the baseline model into the target geometries.
2016-04-05
Technical Paper
2016-01-1506
David Poulard, Huipeng Chen, Matthew Panzer
Abstract Pedestrian finite element models (PFEM) are used to investigate and predict the injury outcomes from vehicle-pedestrian impact. As postmortem human surrogates (PMHS) differ in anthropometry across subjects, it is believed that the biofidelity of PFEM cannot be properly evaluated by comparing a generic anthropometry model against the specific PMHS test data. Global geometric personalization can scale the PFEM geometry to match the height and weight of a specific PMHS, while local geometric personalization via morphing can modify the PFEM geometry to match specific PMHS anatomy. The goal of the current study was to evaluate the benefit of morphed PFEM compared to globally-scaled and generic PFEM by comparing the kinematics against PMHS test results. The AM50 THUMS PFEM (v4.01) was used as a baseline for anthropometry, and personalized PFEM were created to the anthropometric specifications of two obese PMHS used in a previous pedestrian impact study using a mid-size sedan.
2016-04-05
Technical Paper
2016-01-1489
Logan Miller, James Gaewsky, Ashley Weaver, Joel Stitzel, Nicholas White
Abstract Crash reconstructions using finite element (FE) vehicle and human body models (HBMs) allow researchers to investigate injury mechanisms, predict injury risk, and evaluate the effectiveness of injury mitigation systems, ultimately leading to a reduced risk of fatal and severe injury in motor vehicle crashes (MVCs). To predict injuries, regional-level injury metrics were implemented into the Total Human Model for Safety (THUMS) full body HBM. THUMS was virtually instrumented with cross-sectional planes to measure forces and moments in the femurs, upper and lower tibias, ankles, pelvis (pubic symphysis, ilium, ischium, sacrum, ischial tuberosity, and inferior and superior pubic ramus), and the cervical, thoracic, and lumbar vertebrae and intervertebral discs. To measure accelerations, virtual accelerometers were implemented in the head, thoracic vertebrae, sternum, ribs, and pelvis.
2016-04-05
Journal Article
2016-01-1507
Jisi Tang, Qing Zhou, Bingbing Nie, Tsuyoshi Yasuki, Yuichi Kitagawa
Abstract Lower extremities are the most frequently injured body regions in vehicle-to-pedestrian collisions and such injuries usually lead to long-term loss of health or permanent disability. However, influence of pre-impact posture on the resultant impact response has not been understood well. This study aims to investigate the effects of preimpact pedestrian posture on the loading and the kinematics of the lower extremity when struck laterally by vehicle. THUMS pedestrian model was modified to consider both standing and mid-stance walking postures. Impact simulations were conducted under three severities, including 25, 33 and 40 kph impact for both postures. Global kinematics of pedestrian was studied. Rotation of the knee joint about the three axes was calculated and pelvic translational and rotational motions were analyzed.
2016-04-05
Technical Paper
2016-01-1521
Masaaki Kuwahara, Tsuyoshi Yasuki, Takeki Tanoue, Ryosuke Chikazawa
Abstract This paper describes impact kinematics and injury values of Hybrid III AM50, THOR AM50 and THUMS AM50 in simulated oblique frontal impact conditions. A comparison was made among them in driver and passenger seat positions of a midsize sedan car finite element (FE) model. The simulation results indicated that the impact kinematics of THOR was close to that of THUMS compared to that of the Hybrid III. Both THOR and THUMS showed z-axis rotation of the rib cage, while Hybrid III did not. It was considered that the rib cage rotation was due primarily to the oblique impact but was allowed by flexibility of the lumbar spine in THOR and THUMS. Lateral head displacement observed in both THOR and THUMS was mostly induced by that rotation in both driver seat and passenger seat positions. The BrIC, thorax and abdominal injury values were close to each other between THOR and THUMS, while HIC15 and Acetabulum force values were different.
2016-04-05
Technical Paper
2016-01-0136
Deepak Gangadharan, Oleg Sokolsky, Insup Lee, BaekGyu Kim, Chung-Wei Lin, Shinichi Shiraishi
Abstract Optional software-based features (for example, to provide active safety, infotainment, etc.) are increasingly becoming a significant cost driver in automotive systems. In state-of-the-art production techniques, these optional features are built into the vehicle during assembly. This does not give the customer the flexibility to choose the specific set of features as per their requirement. They either have to buy a pre-bundled option that may or may not satisfy their preferences or are unable to find an exact combination of features from the inventory provided by a dealership. Alternatively, they have to pre-order a car from the manufacturer, which could result in a substantial delay. Therefore, it is important to improve the flexibility of delivering the optional features to customers. Towards this objective, the vehicle could be configured with the desired options at the dealership, when the customer requires them.
2016-04-04
Standard
ARP1836C
This SAE Aerospace Recommended Practice (ARP) outlines the functional and design requirements for a b self-propelled belt conveyor for handling baggage and cargo at aircraft bulk cargo holds. Additional considerations and requirements may legally apply in other countries. As an example, for operation in Europe (E.U. and E.F.T.A.), the applicable EN standards shall be complied with.
2016-04-04
Standard
AIR6894
This document describes laser wire stripping technologies and recommendations to strip electrical single conductor and shielded cables intended for aerospace applications. These recommendations include: - Laser stripping safety guidelines - Laser stripping quality - Tool qualification - Tool inspection - User health and safety
2016-04-01
Magazine
Electronic Warfare Next Generation FPGAs for Electronic Warfare Systems Materials: Composites Managing the Impact of Nanomaterials in Aerospace Manufacturing Aerospace Materials/Manufacturing Turbine Flow Meters Alternative Power Sources Designing a Power Generation System for a More-Electric Aircraft
2016-03-30
WIP Standard
J2194
Any ROPS meeting the performance requirement of ISO 5700 (Static ROPS Test Standard) or ISO 3463 (Dynamic ROPS Test Standard) meets the performance requirements of this SAE Standard if the ROPS temperature/material and seat belt requirements of this document are also met. Fulfillment of the intended purpose requires testing as follows: A temperature-material requirement (6.9). This can be satisfied by using the appropriate materials or by performing any of the structural performance tests (Sections 7, 8, or 9) at -18 °C. A laboratory test, under repeatable and controlled loading, to permit analysis of the ROPS for compliance with the performance requirements of this document. Either the static test sequence (Section 7) or the impact test sequence (Section 8 ) shall be conducted. See Figure 1. A seat belt anchorage test (Section 10). The test procedures and performance requirements outlined in this document are based on currently available engineering data.
2016-03-30
WIP Standard
J1194
Fulfillment of the intended purpose requires testing as follows: A laboratory test, under repeatable and controlled loading, to permit analysis of the ROPS for compliance with the performance requirements of this SAE Standard. Either the static test (6.1) or the dynamic test (6.2) shall be conducted. A crush test to verify the effectiveness of the deformed ROPS in supporting the tractor in an upset attitude. A field upset test under reasonably controlled conditions, both to the rear and side, to verify the effectiveness of the protective system under actual dynamic conditions. (See 6.4.1.1 for requirements for the omission of this test). In addition to the laboratory and field loading requirements, there is a temperature-material requirement. (See 7.1.2.) The test procedures and performance requirements outlined in this document are based on currently available engineering data.
2016-03-27
Article
Self-driving car project CEO John Krafcik discussed Google's work underway toward fully autonomous vehicles, at a recent NY forum. First likely market: the elderly and impaired.
2016-03-27
Technical Paper
2016-01-1710
Ek-u thammakornbunjut, Sutee Olarnrithinun
In general, the automotive chassis will be subjected to a combination of dynamic loads. The important one of these loads is an impact load which will be occurred when a vehicle crash to another vehicle or infrastructures. This paper aims to investigate the axial impact strength of a C-shape straight beam reinforced with dented rectangular plates. Only spherical shape of the dent is considered in this study. The effects of dent diameter, dent depth, and number of dented plates are analyzed using nonlinear finite element method. The possibility to use this type of reinforcement is discussed.
2016-03-27
Technical Paper
2016-01-1737
Thitsadee Ngernsukphaiboon, Sunhapos Chantranuwathana, Nuksit Noomwongs, Angkee Sripakagorn, Solaphat Hemrungrojn MD
Abstract The world is aging rapidly. Many countries can already be categorized as aging or aged societies while a few are becoming super-aged societies. In Thailand as well as in other countries, traffic accidents caused by elderly drivers will continue to rise as a significant percentage of elderly people still prefer to drive. Accidents may be prevented with driving tests and screening methods for elderly drivers. However, it is also necessary to understand the effect of aging on driving ability. With this understanding, driver training, driver assistant systems, and improvements on infrastructure may be designed accordingly. Among various physical changes, cognitive ability of the brain is one of the most significant factors affecting driving ability. In this paper, correlation between various cognitive functions of the brain and car following skill of drivers are considered.
2016-03-27
Technical Paper
2016-01-1738
Natt Winitthumkul, Peerapat Phondeenana, Nuksit Noomwongs
Abstract According to the recent study, Thailand has the 2nd most dangerous road in the world. Based on many researches, the driver is the main influencers of the traffic fatalities. Since the more dangerous the driver drive, the more chance of accident become. Therefore, driver’s monitoring system become one of the solutions that acceptable and reliable, especially for fleet management and public transportation. This paper’s goal is to find an algorithm that can distinguish driving behaviour based on cars’ acceleration and velocity, calling it as Risk Driving Score (RDS). The algorithm was tested by driving test by volunteers on highways with observers, who were told to rank the drivers in terms of driving risk from the 1-5 point. Meanwhile, the drivers were asked to drive in 3 different styles, normal, safety, and hurry. All drives were recorded by satellite and video data then filtered and used for the algorithm calculation.
2016-03-25
WIP Standard
AIR5661A
This report provides data and general analysis methods for calculation of internal and external, pressurized and unpressurized airplane compartment pressures during rapid discharge of cabin pressure. References to the applicable current FAA and EASA rules and advisory material are provided. While rules and interpretations can be expected to evolve, numerous airplanes have been approved under current and past rules that will have a continuing need for analysis of production and field modifications, alterations and repairs. The data and basic principles provided by this report are adaptable to any compartment decompression analysis requirement.
2016-03-23
Standard
J175_201603
The SAE Recommended Practice establishes minimum performance requirements and related uniform laboratory test procedures for evaluating lateral (curb) impact collision resistance of all wheels intended for use on passenger cars and light trucks.
2016-03-17
WIP Standard
ARP6412
The scope of the Landing Gear Integrity Programs (LGIP) Aerospace Recommended Practice (ARP) is intended to assist in the safe-life structural integrity management of the landing gear system and subsystems components. In addition, component reliability, availability, and maintainability is included in a holistic LGIP.
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