Browse Topic: Protective systems

Items (2,295)
The Crashworthy and Escape Systems Branch at NAWCAD has been developing an integrated restraint harness concept for several years, with the intent of developing a novel method of providing improved occupant protection in a crash scenario. A series of tests was conducted on the Horizontal Accelerator at NAS Patuxent River to evaluate the performance of the prototype integrated-restraint system under MIL-STD-58095 conditions with the 50th percentile male Hybrid III Anthropomorphic Test Device (ATD). While occupant flail was the primary metric being analyzed in this effort, ATD instrumentation was also captured, showing that the integrated restraint system demonstrated a significant reduction in head flail compared to five-point restraints while maintaining injury criteria within acceptable levels.
Anderson, EricMinnich, Shannon
ABSTRACT The performance of ground vehicles during a rollover event is an important safety and occupant protection requirement for military vehicles. Modeling and simulation is a very useful tool in study and investigation of vehicle rollover characteristics and countermeasure concepts. This study presents two methods of simulating the rollover events. The first one uses Full System Method (FSM), where all the components are modelled as is and are evaluated. The second method is a reduced order modelling method (ROMM) using integration of the resulted kinematics data from FSM into the vehicle model with occupant & restraints. The FSM & ROMM methods were applied to simulate two HMMMV rollover events, and the results from both methods show that simulation and test data agreed fairly well. Computational time reduced by the ROMM was about 53% of that of the FSM. ROMM approach not only saves significant computational time but also increases robustness of the simulation. Citation: V. Babu, J. Kang, S. Kankanalapalli, J. Sheng, M. Vunnam, S. K. Karwaczynski, C. Jessup, M. Duncan, K. Paulson, “REDUCED ORDER MODELLING METHOD (ROMM) FOR GROUND VEHICLE ROLLOVER PROTECTION M&S”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 10-12, 2021.
Babu, V.Kang, J.Kankanalapalli, S.Sheng, J.Vunnam, M.Karwaczynski, S. K.Jessup, C.Duncan, M.Paulson, K.
Pilots and crew of rotary-wing aircraft can be exposed to inertial and task position stressors that generate pain. Repeated painful exposures with or without tissue damage are precursors to pain sensitization and chronic pain. Chronic pain leads to reduced operational readiness and long-term medical treatment. This study investigated protection orthosis for unrecoverable effects on the cervical spine by heavy helmets and accessories. A user-customized product has been developed and customization has been intended to be done with multi-body dynamic modeling and testing. Although there are many biomechanical models of the human cervical spine in the literature, their analysis capabilities to perform modal analysis and frequency response analysis are limited. Especially for Rotary-wing applications, models with such capabilities will play an essential role in diagnosing and rehabilitating musculoskeletal disorders and designing engineering devices to prevent and heal cervical spine injuries. Therefore, a detailed head-cervical spine model is developed in which frequency domain analysis is possible. Alternative design solutions have been investigated to support helmets to decrease the load exerted on the neck periphery. Finally, tests have been performed to correlate analysis with a real helicopter environment. At the end of the study, a customizable neck orthosis has been developed and verified with the tests that it reduces the adverse effects of heavy helmets on the cervical spine periphery.
Isci, HakanHeidari, Nimaünal, RamazanŞendur, PolatGezegen, Damla
The AW609 tiltrotor features a unique high-mounted wing with rotatable nacelles positioned at the wing tips, it is capable of operating both in airplane and vertical flight mode. To achieve suited protection of the occupants during emergency landing, the wing - which is particularly stiff in order to sustain the heavy weights at the tips, where rotors, engines and transmissions are positioned - implements a controlled failure mechanism at root, so that during emergency landings it breaks and unloads the fuselage of the weight of wingbox and nacelles, thus avoiding catastrophic collapse. As the effectiveness of such mechanism was never demonstrated under impact conditions, certification agencies requested an empirical validation through experimental testing. The test was carried out July 2022 at Polytechnic of Milan, Italy; the present work details the Test activity, from its preliminary phases to the Test Day, to the analyses of its outcomes.
Colamartino, IvanCavalera, DavideTurconi, FabrizioAnghileri, MarcoDi Renzo, Andrea
ABSTRACT
Richards, Marv
This document applies to webbing used on occupant restraint systems in service on 14 CFR/CS part 23, part 25, part 27, and part 29 aircraft applications. The guidelines presented within this document are intended to be supplemental to the requirements supplied by the OEM in the CMM, ICA, or like document. In cases of conflict between this ARP and the OEM’s requirements, the requirements of the OEM shall be followed. The objective of this document is to establish practical guidelines to help operators in the determining if restraint webbing has reached the end of its service life. The recommendations contained herein are based on test data from in service restraint systems and the continued airworthiness guidelines recommended by restraint system OEMs.
Aircraft SEAT Committee
This SAE Aerospace Standard (AS) defines the performance requirements for equipment to be used by untrained cabin occupants for protection from toxic and irritant atmospheres while on board and during evacuation of an aircraft.
A-10 Aircraft Oxygen Equipment Committee
This Standard specifies the Habitability processes throughout planning, design, development, test, production, use and disposal of a system. Depending on contract phase and/or complexity of the program, tailoring of this standard may be applied. The primary goals of a contractor Habitability program include: Ensuring that the system design complies with the customer Habitability requirements and that discrepancies are reported to management and the customer. Identifying, coordinating, tracking, prioritizing, and resolving Habitability risks and issues and ensuring that they are: ○ Reflected in the contractor proposal, budgets, and plans ○ Raised at design, management, and program reviews ○ Debated in Working Group meetings ○ Coordinated with Training, Logistics, and the other HSI disciplines ○ Included appropriately in documentation and deliverable data items Ensuring that Habitability requirements are applied to all personnel environments, including operators, maintainers, trainers, and support personnnel. Identifying and pursuing opportunities to reduce Habitability costs. Ensuring that Habitability considerations are addressed in analyses, design decisions, trade-offs, and design changes (e.g., Engineering Change Proposals (ECP)). Conducting Habitability analysis activities and supporting human factors analyses (e.g., workload analysis) and other HSI domain analyses to provide evidence to support design decisions and trade-offs and to coordinate shared data. Ensuring that Habitability analyses, results and recommendations are timely, technically competent/complete, and included in design decisions, tradeoffs, and changes. Ensuring that environments experienced by subjects in experiments, simulations, tests, evaluations, and demonstrations are consistent with the customer’s Habitability requirements and meet the U.S. Government and DoD policies for protecton of human subjects. Ensuring that Habitability issues discovered in test, evaluation, demonstration, Operational Test and Evaluation (OT&E), and operations are resolved in a technically competent/complete and timely manner.
G-45 Human Systems Integration
This glossary was written to provide a consistent and uniform definition of terms used in describing an automatic belt tensioner as it applies to an automotive accessory drive system.
Belt Drive (Automotive) Systems Committee
This SAE Recommended Practice establishes minimum performance and test requirements for combination pelvic and upper torso occupant restraint systems provided for off-road self-propelled work machines.
HFTC4, Operator Seating and Ride
This slash document collects general reference material related to gaseous oxygen system flow requirements and sizing calculations. This document will assist oxygen system equipment designers and operators to establish systems and equipment requirements. The document consists of charts, tables, system schematics, system requirements, and sample calculations for system sizing.
A-10 Aircraft Oxygen Equipment Committee
This standard is intended to apply to portable compressed gaseous oxygen equipment. When properly configured, this equipment is used either for the administration of supplemental oxygen, first aid oxygen or smoke protection to one or more occupants of either private or commercial transport aircraft. This standard is applicable to the following types of portable oxygen equipment: a Continuous flow 1 Pre-set 2 Adjustable 3 Automatic b Demand flow 1 Straight-demand 2 Diluter-demand 3 Pressure-demand c Combination continuous flow and demand flow.
A-10 Aircraft Oxygen Equipment Committee
This SAE Recommended Practice describes the test procedures for conducting simulated dynamic lateral rollover restraint system tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
This SAE Recommended Practice provides a standardized test procedure for heavy-duty truck sleeper berth restraints to determine whether they meet the FMCSR 393.76(h) requirements.
Truck Crashworthiness Committee
ITIS Phrase Lists (International Traveler Information Systems)J2540/2_202012 (Current)12/6/2020
This standard provides a table of textual messages meeting the requirements for expressing International Traveler Information Systems (ITIS) phrases commonly used in the ITS industry. The tables provided herein follow the rules of SAE J2540 and therefore allow a local representation in various different languages, media expressions, etc., to allow true international use of these phrases. The phrases are predominantly intended for use in the description of traffic-related events of interest to travelers and other traffic practitioners. Other phrases exist for other specific specialty areas of ITS, and all such phrases follow a set of encoding and decoding rules outlined in SAE J2540 to ensure that the use of these phrases in messages remain interoperable between disparate types of user equipment. Implementers are cautioned to obtain the most recent set of tables by means of the ITS data registry, a process which involves SAE and other standards-setting organizations, and which is intended to maintain and enhance the level of harmonization among ITS standards set by each of the organizations. This standard defines the normative index values to be used to provide phrases needed by ITS practitioners. This standard provides non-normative textual phrases which MAY be used by implementers to ensure intelligible results. This standard follows the formats and rules established in SAE J2540 in the expressions, manipulations, and use of such tables. It should be pointed out that within the rules established by this standard, a variety of final tables are all considered “conformant” with the standard, and may vary as fits the needs of implementers.
V2X Core Technical Committee
This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
This SAE Aerospace Recommended Practice (ARP) provides recommended practices for the cleaning of aircraft oxygen equipment, both metallic and non-metallic articles, such as oxygen lines (tubes, hoses, etc.), components (including regulator and valve parts), cylinders, and ground-based equipment that may be used to support aircraft oxygen systems. This document also specifies work area details, methods for selecting suitable cleaning agents, cleaning methods, and test methods for verifying levels of cleanliness. The cleanliness coding scheme specified in this document provides a method for documenting minimum cleanliness level requirements and for identifying compliance.
A-10 Aircraft Oxygen Equipment Committee
Researchers at MIT and Brigham and Women’s Hospital have designed a new face mask that they believe could stop viral particles as effectively as N95 masks. Unlike N95 masks, the new masks were designed to be easily sterilized and used many times.
This document establishes the minimum training and qualification requirements for ground-based aircraft deicing/anti-icing methods and procedures. All guidelines referred to herein are applicable only in conjunction with the applicable documents. Due to aerodynamic and other concerns, the application of deicing/anti-icing fluids shall be carried out in compliance with engine and aircraft manufacturers’ recommendations. The scope of training should be adjusted according to local demands. There are a wide variety of winter seasons and differences of the involvement between deicing operators, and therefore the level and length of training should be adjusted accordingly. However, the minimum level of training shall be covered in all cases. As a rule of thumb, the amount of time spent in practical training should equal or exceed the amount of time spent in classroom training.
G-12T Training and Quality Programs Committee
Assessment of Collision Markings on Non-Used Vehicle Seat Belt Restraint Systems2020-01-09754/14/2020
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 the seat belt assemblies necessary to produce the distinct physical evidence documented in the real-world samples. The physical evidence observed on the real-world restraint systems were consistent with the markings produced in the laboratory demonstrations. The presence of physical evidence on restraint system hardware and webbing is inadequate to conclude that a seat belt restraint was in use. Careful consideration of restraint system physical evidence combined with restraint system geometry and incorporated technological features can distinguish physical evidence related to seat belt use or non-use during a collision event. These examples will be useful to investigators for the assessment of physical evidence and diagnosis of seat belt use.
Gregg, Richard H.Petroskey, Karla J.
Experimental Investigation of Axial Cutting of AA6061 Extrusions under a Tension Deformation Mode2020-01-02064/14/2020
A plethora of applications in the transportation industry for both vehicular and roadside safety hardware, especially seatbelts, harnesses and restraints, rely on tensile loading to dissipate energy and minimize injury. There are disadvantages to the current state-of-the-art for these tensile energy absorbers, including erratic force-displacement responses and low tensile force efficiencies (TFE). Axial cutting was extensively demonstrated by researchers at the University of Windsor to maintain a stable reaction force, although exclusively under compressive loading. A novel apparatus was investigated in this study which utilized axial cutting under a tensile loading condition to absorb energy. A parametric scope was chosen to include circular AA6061 extrusions in both T4 and T6 temper conditions with an outer diameter of 63.5 mm and wall thickness of 3.18 mm. The experiments were performed quasi-statically utilizing a custom, hydraulically powered long stroke tension/compression testing machine with a maximum capacity of 300kN. Strain-gauge based load cells and non-contact displacement transducers were implemented to measure the cutting force and displacement response of the setup. The results demonstrated highly stable force responses, with cutting force efficiencies typically in the vicinity of 90%. The experimental force-displacement responses exhibited a high degree of repeatability and correlation to the analytical model. Critical performance metrics, including the mean load and total energy absorption, were predicted to within 5 %. Additionally, the complete force-displacement response was predicted utilizing an analytical modeling approach with an average validation metric of approximately 0.92.
Gudisey, AnthonyAltenhof, WilliamMagliaro, John
Evaluation of General Motors Event Data Recorder Performance in Semi-Trailer Rear Underride Collisions2020-01-13284/14/2020
The objective of this study was to analyze the validity of airbag control module data in semi-trailer rear underride collisions. These impacts involve unusual collision dynamics, including long crash pulses and minimal bumper engagement [1]. For this study, publicly available data from 16 semi-trailer underride guard crash tests performed by the Insurance Institute for Highway Safety (IIHS) were used to form conclusions about the accuracy of General Motors airbag control module (ACM) delta-V (ΔV) data in a semi-trailer rear underride scenario. These tests all utilized a 2009 or 2010 Chevrolet Malibu impacting a stationary 48’ or 53’ semi-trailer at a speed of 35 mph. Nine tests were fully overlapped collisions, six were 30% overlapped, and one was 50% overlapped [2]. The IIHS test vehicles were equipped with calibrated 10000 Hz accelerometer units. Event Data Recorder (EDR) data imaged post-accident from the test vehicles were compared to the reference IIHS data. For each test, root mean square error (RMSE), the percent error over time, and the difference between the EDR ΔV and the IIHS ΔV, was quantified, plotted, and related to crash pulse. This analysis revealed a general trend of decreasing EDR ΔV parity with an increasing crash pulse duration, although overall differences remained low for most tests. Eleven tests, all with airbag deployments, converged towards an average of 3.3% error at the end of the crash pulse, which were 150-270 ms. EDR recorded ΔVs were in the range of 29.8-39.9 mph. Five tests, three of which were non-deployments, diverged to higher percentage error averaging 12.7% at an EDR ΔV of 31.8-40.0 mph. All higher error tests were 30% overlapped and had the highest crash pulse durations of 240-300 ms. One fully overlapped test generated highly unusual EDR data due to failure of the rear underride guard mounting bolts and plates.
Famiglietti, NicholasHoang, RyanFatzinger, EdwardLanderville, Jon
Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model2020-01-09794/14/2020
The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact prescribed with an acceleration pulse according to EuroNCAP is considered. Various initial driver sizes in standard seated positions are tested. To extend the study beyond standard testing protocols, out-of-position of driver is also considered, leading to more than 100 simulations of impact scenarios in total. The effect of the innovative head restraint system is assessed from the point of view of driver injury risk.
Vychytil, JanHlucha, JanaKovar, LudekKostikova, MartinaMoravcova, PavlinaBucsuhazy, Katerina
Determination of Seatbelt Use Following a Crash2020-01-06434/14/2020
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 seatbelt usage at the time of the impact. The theory is if the seatbelt is retracted or stowed post-crash, it was not in use at the time of the collision. The validity of this theory was investigated using EDR data from the NHTSA Crash Investigation Sampling System (CISS) as well as EDR files collected during in-house crash investigations. Photographic documentation of the post-crash seatbelt position was compared to EDR reported seatbelt use to determine if post-crash seatbelt position is reliable in determining seatbelt usage at the time of impact. Additionally, EDR seatbelt usage was compared to police reported seatbelt usage. The analysis of the data in this study found that in a third of the cases where the EDR data indicated the occupant was seatbelted, the seatbelt was found in the stowed or retracted position. Therefore, finding a stowed or retracted seatbelt following a crash is not a reliable means of determining seatbelt use by the occupant at the time of the crash. Additionally, a comparison of EDR data to police reported seatbelt usage revealed that 13 to 25 percent of the occupants reported by the police as seatbelted did not have the seatbelt fastened based on EDR data.
Yannaccone, John R.
PTW Passive Safety: Numerical Study of Standard Impact Scenarios with Rider Injury Risk Assessment2020-01-09304/14/2020
Powered two-wheeler (PTW) riders and passengers are among the group of vulnerable road users (VRU). This group uses the road transportation system together with other better-protected users such as passenger cars and truck drivers. The main vulnerability of PTW rider lies in their unequal position during the crash, due to the inability of application of the crashworthiness concept during the PTW vehicle design. This inequality could be somehow mitigated by the design of personal protective equipment (PPE). Mostly the design of the PPE’s is led by the standards which often are obsolete and takes into account only simple drop-tests (ECE 22.05). Those tests did not take into account complicated kinematics of the motorcycle accidents and biomechanics of the human body (the assessment is based only on the linear acceleration of the headform center of gravity). The authors propose a virtual approach for the PTW rider injury risk assessment, which coupled with the pre-impact conditions, could be used for the new PPE protection standards preparation. In this paper, authors want to present a numerical study on the most common PTW impact scenarios, which are described in ISO 13232. The simulations of the accidents were conducted in the VPS numerical environment (PAM-Crash explicit solver). Accidents participants, namely opposite vehicle (OV) modeled by finite element method (FEM) approach, powered two-wheeler (PTW) modeled by multi-body system (MBS) approach, PTW driver represented by hybrid FE-MBS human body model Virthuman and a helmet (modeled by FE approach) were coupled to represent the 7 most common accident scenarios. The helmet is the only PPE enforced by the law, but not in all territories (Afghanistan, Dominica, Guyana, Mexico, Libya, Senegal, USA). Due to the complexity of the OV FE model, there was a necessity of model simplification and revalidation, which also was done in this work. The results of the simulations were examined with special emphasis on realistic representation of real accident kinematics. In each configuration, an injury risk assessment was done on the PTW rider model. The assessment was done based on injury criterion used by the NCAP, UNE 135900 and the LNL criterion. The paper shows that the virtual approach using the Virthuman human body model could be used for the simulation of PTW accidents. The results of this paper could be used for future PPE design.
Bonkowski, TomaszHyncik, LudekLv, Wenle
The Effects of Small Seat Swiveling Angles on Occupant Responses during a Frontal Impact2020-01-05714/14/2020
In highly automated vehicles (HAVs), new seat configurations may be desirable to allow occupants to perform new activities. One of the current HAV concepts is the swiveled seat layout, which might facilitate communication between occupants. The main objective of this study was to investigate the effects of seat swiveling angles on occupant kinematics and injury risk predicted by a Human Body Model (HBM) during a frontal impact. A detailed 50th percentile male HBM (GHBMC M50-O) was subjected to two frontal crash pulses in a sled setup. The model was positioned on a semi-rigid seat and restrained using a pre-inflated airbag and a three-point seatbelt. Simulations included four seat swiveling angles (0, -10, -20, and -30 degrees), three occupant positions (Sedan driver, large VAN driver or Laptop user), two airbag initial locations (nominal or matching the head Y location), and the inclusion of lateral supports on the seat pan. The effects of the seat swiveling angle were similar for all occupant positions. With the airbag in the nominal location, higher seat swiveling angles led to a higher head lateral displacement and a higher risk of head injury, especially for the BrIC criterion. The Sedan driver position had higher BrIC and a larger head lateral excursion than the other two positions. This could be mitigated by aligning the airbag location with the head. Pelvic fractures were also predicted for the configurations with the highest swiveling angles. These fractures were limited by the use of seat pan lateral supports. Overall, the model responses were sensitive to both seating configurations and occupant postures, and the results suggest that swiveled seating may increase the injury risk, especially for the head and pelvis. However, simple countermeasures, such as adapted airbag location or adding lateral seat pan supports, seemed possible to mitigate the risk.
Grébonval, CyrilleTrosseille, XavierPetit, PhilippeWang, XuguangBeillas, Philippe
Load Distribution Optimization of Seatbelt Using Validated Finite Element Approach2019-28-257511/21/2019
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 carried out using TNO-10 R-16 dummy with the given position of D-ring, Buckle and Anchor plate. First correlation was established between the forces at shoulder location, Anchor plate location. Further correlation was established in the pelvis and thorax displacement. Multiple iterations were performed with the different position of anchorages in a given range in the validated model of seatbelt. The results showed significant effect of the Buckle and Anchor position in the force distribution on the dummy.
Satija, AnshulMishra, PriyanshuGaurav, RaviSingh, Virender
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