Browse Topic: Accident types
ABSTRACT As a continuation of previous collaborative efforts between several US Army organizations and industry leaders which led to the procurement of a National Stock Number (NSN) for a near commercial-off-the-shelf winter tire/wheel assembly for the High Mobility Multipurpose Wheeled Vehicle (HMMWV), this study investigates a low-cost, postproduction modification known as ‘siping’ which may incrementally improve standard tires deployed on the Joint Light Tactical Vehicle (JLTV) in cold regions. Data from engineering tests will quantify performance differences as well as driver feedback from the 11th Airborne Division Soldiers in Alaska show moderate improvement from cutting razor-thin grooves known as ‘sipes’ on conventional winter tire sets. However, Army winter performance specifications developed in 2021 from HMMWV testing quantify greater available improvement to traction available, necessitating further development for winter traction in the JLTV family of tire sets as well as
ABSTRACT TARDEC researched head impact protective, energy attenuating materials for use in U.S. Army Ground System Vehicle (GSV) applications. The purpose of the project is to reduce potential head impact related mounted crew injuries and deaths which may occur during underbody blast, crash and rollover events. Commercial-off-the-shelf materials were evaluated for their energy attenuating performance. Exposed surface materials in combination with core material were also researched and evaluated. Baseline vehicle testing was conducted to understand the current head impact criterion. The results of this effort identified solutions which may potentially meet the needs of the Army to reduce head impact related injuries which may occur during crash, rollover and blast events. TARDEC used the knowledge gained from this project to create performance specification requirements for interior head impact protective components and materials for use in U.S. Army vehicles
ABSTRACT The need for up-armored vehicles has increased over the years. This has put a greater emphasis on suspensions that can provide improved ride and handling capabilities while facing the additional weight. One of the challenges with these vehicles traditionally has been increased likelihood of rollover. Increased rollover is due to high center of gravity, kinematics of the overloaded suspension, and the low damping that is needed to satisfy 6-Watt ride speed performance criteria. The Lord magneto-rheological (MR) suspension system addresses these issues by improving the ride quality and handling characteristics thereby increasing safety and mission effectiveness. During handling maneuvers, algorithms inside the controller unit apply corrective forces to minimize peak roll angle and peak roll rate. The benefit of this has been tested on a vehicle comparing the stock passive dampers to the MR dampers over NATO Lane change events. Furthermore, the controller has the capability to
ABSTRACT Teleoperated ground vehicles are an integral part of the U.S. Army and Marine Corps long range vision and a key transition technology for fully autonomous vehicles. However, the combination of marginally-stable vehicle dynamics and limited perception are a key challenge facing teleoperation of such platforms at higher speeds. New technologies for enhancing operator perception and automatically detecting and mitigating rollover risk are needed to realize sufficient safety and performance in these applications. This paper presents three rollover mitigation concepts for high speed teleoperation of heavy tactical vehicles, including model-predictive warning, negative obstacle avoidance, and reactive brake controls. A modeling and simulation approach was used to evaluate these concepts within the Autonomous Navigation Virtual Environment Laboratory (ANVEL). Vehicle models for both the M1078 cargo truck and RG-31 MRAP were used throughout concept evaluation over terrain ranging from
Rear-end vehicle collisions may lead to whiplash-associated disorders (WADs), comprising a variety of neck and head pain responses. Specifically, increased axial head rotation has been associated with the risk of injuries during rear impacts, while specific tissues, including the capsular ligaments, have been implicated in pain response. Given the limited experimental data for out-of-position rear impact scenarios, computational human body models (HBMs) can inform the potential for tissue-level injury. Previous studies have considered external boundary conditions to reposition the head axially but were limited in reproducing a biofidelic movement. The objectives of this study were to implement a novel head repositioning method to achieve targeted axial rotations and evaluate the tissue-level response for a rear impact condition. The repositioning method used reference geometries to rotate the head to three target positions, showing good correspondence to reported interverbal rotations
With the current trend of including the evaluation of the risk of brain injuries in vehicle crashes due to rotational kinematics of the head, two injury criteria have been introduced since 2013 – BrIC and DAMAGE. BrIC was developed by NHTSA in 2013 and was suggested for inclusion in the US NCAP for frontal and side crashes. DAMAGE has been developed by UVa under the sponsorship of JAMA and JARI and has been accepted tentatively by the EuroNCAP. Although BrIC in US crash testing is known and reported, DAMAGE in tests of the US fleet is relatively unknown. The current paper will report on DAMAGE in NCAP-like tests and potential future frontal crash tests involving substantial rotation about the three axes of occupant heads. Distribution of DAMAGE of three-point belted occupants without airbags will also be discussed. Prediction of brain injury risks from the tests have been compared to the risks in the real world. Although DAMAGE correlates well with MPS in the human brain model across
This study was conducted to assess the occupant restraint use and injury risks by seating position. The results were used to discuss the merit of selected warning systems. The 1989-2015 NASS-CDS and 2017-2021 CISS data were analyzed for light vehicles in all, frontal and rear tow-away crashes. The differences in serious injury risk (MAIS 3+F) were determined for front and rear seating positions, including the right, middle and left second-row seats. Occupancy and restraint use were determined by model year groups. Occupancy relative to the driver was 27% in the right-front (RF) and 17% in the second row in all crashes. About 39% of second-row passengers were in the left seat, 15% in the center seat and 47% in the right seat. Restraint use was lower in the second row compared to front seats. It was 43% in the right-front and 32% in the second-row seats in all crashes involving serious injury. Restraint use increased with model year groups. It was 63% in the ‘61-‘89 MY vehicles and 90
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