Vehicular Deceleration and Its Relationship to Friction

Reed, Walter S.; Keskin, Ahmet

doi:10.4271/890736

Cited by 23 publications

(6 citation statements)

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“…For instance in previous papers [1], [5], [6][7][8], [9,10,15], a whole range of values is presented, sometimes expressed as a function of speed, some other as a function of weather conditions, tire tread height or road surface. Usually they are the product of direct friction measurements (for instance by the drag-tire method) and most of the times concern friction coefficient with locked wheels (slip = 100%); nevertheless a comparison between locked wheel f and peak values can be found [1].…”

Section: Prediction Of Friction Properties (F )mentioning

confidence: 99%

Evaluation of emergency braking deceleration for accident reconstruction

Vangi

Virga

2007

Vehicle System Dynamics

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Section: Prediction Of Friction Properties (F )mentioning

confidence: 99%

Evaluation of emergency braking deceleration for accident reconstruction

Vangi

Virga

2007

Vehicle System Dynamics

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“…In addition, restrictions are made so that parts of the system move as a whole, in a direction tangential to the plane of the contact, resulting in stresses that are due to the friction between the parts and the stresses that are defined by static and dynamic coefficients of friction of 0.3 and 0.2, respectively [17]. However, the coefficients of static and dynamic friction between the vehicle and the concrete are both 0.85 [18]. e nodal elements (Foam-LBB) are linked so that they behave as a single body.…”

Section: Boundary Conditionsmentioning

confidence: 99%

Numerical Low-Back Booster Analysis in a 6-Year-Old Infant during a Dolly Rollover Test

Cruz-Jaramillo

Miguel

Martínez-Sáez

et al. 2020

Journal of Advanced Transportation

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This paper analyzes the possible head and chest injuries, produced in a Hybrid III dummy model of a six-year-old child during a rollover test, while the child uses a passive safety system low-back booster (LBB). Vehicle seats and passive safety systems were modeled with a CAD (Computer Aided Design) software; later, all elements were analyzed using the finite element method (FEM) with LS-DYNA® software. The border conditions were established for each study, in accordance with the regulations of Federal Motor Vehicle Safety Standards (FMVSS), and following the FMVSS 213 standard for the mounting and fastening of the infant, the FMVSS 208 for the dolly methodology test with the vehicle rollover was performed, implementing such analysis under the same conditions for a vehicle Toyota Yaris 2010. The numerical simulations were performed during an interval of 1 second, obtaining data values for periods of 2 milliseconds. This paper examines the efficiency of the system; three case studies were carried out: Study I: vehicle seat belt (VSB); Study II: the LBB system was secured by the seat belt; Study III: the LBB system with ISOFIX anchorage. The values of decelerations for the head and thorax of the infant were obtained, as well as neck flexion and thoracic deflection. The main factor to reduce injuries during a rollover accident is the correct anchorage of the LBB, and this is achieved with the ISOFIX system, since it prevents the independent movement of the LBB, unlike when it is fastened with the seat belt of the vehicle. The results show low levels of head and chest injury when ISOFIX is used because of reduced thoracic deflection during infant retention.

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“…Pero, a medida que la llanta bloqueada sigue su deslizamiento sobre la superficie asfáltica, la huella se convierte en una marca totalmente oscura, con algunos surcos o espacios sin marcas de neumático, los cuales dependen del tipo de labrado de la banda de rodadura de la llanta. Esta marca es producida por los efectos físico-químicos de la adherencia de material de la llanta al asfalto, la cual, a su vez, es provocada por la temperatura que resulta del frenado sobre la capa asfáltica (Reed, 1989). En algunos casos, es posible observar la huella de frenado durante la maniobra de emergencia o bloqueo total de llantas realizada por un vehículo con Fuente: elaboración propia a partir de 150 datos obtenidos de la prueba de frenado de emergencia número 1 del experimento 8. sistema de frenos ABS, huellas que son totalmente oscuras con marcación de segmentos cortos, que el investigador debe medir desde el inicio hasta el final de la marcación total (sin segmentar las medidas).…”

Section: Procedimientos Para El Análisis De Los Datosunclassified