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Title Effect of acceleration time history in motorcoach frontal collision on passenger safety under uncertainty of seating posture
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Date Accessioned
Discipline/Department Mechanical Engineering
Degree Level doctor of philosophy (ph.d.)
University/Publisher University of Manitoba
Abstract National authorities constantly work on enhancing the crash safety regulations for motorcoaches in North America, promoting further research on the factors affecting passenger safety in severe collisions. The thesis presents the results of a comprehensive study on the effect of the acceleration load experienced by a coach passenger compartment during a frontal collision on passenger safety. As a large variation in seating posture is found among the coach passengers and owing to its high influence on passenger kinematics during a crash, a special methodology is developed to account for posture uncertainty. The study on the influence of the pulse shape on the occupant’s injury criteria is performed numerically using a validated model of the motorcoach sled test equipped with two belted and two unbelted Anthropomorphic Test Devices. The results indicate that the probability of an injury for unbelted occupants seating in a comfortable posture can be significantly increased compared to the standard posture specified in the regulations, with up to 113% increase in Head Injury Criterion and a 97% increase in Femur Loads. For the parametric pulse shape variations under the uncertainty of seating posture, the dependence of most of the injury criteria values on pulse shape is found to be insignificant on the scale of the values’ deviations due to stochastic posture alternations. Overall, the obtained results emphasize the importance of accounting for posture variations in both regulation testing and numerical parametric studies. It is suggested that a parametric study can be carried out independently from a posture variation analysis, enabling considerable computational time savings while still accounting for the dispersion of the results. For regulation testing, a preparatory numerical posture variation study is recommended before the physical test to identify dangerous seating postures for a given impact scenario and to ensure the worst-case scenario is reproduced. The proposed methodology provides the basis for the development of a contemporary approach to the problems of the occupant protection under real-world conditions relying on probabilistic rather than traditional deterministic design philosophy.
Subjects/Keywords Motorcoach; Frontal Collision; Passenger safety; Posture; Injury criteria; Sled test
Contributors Telichev, Igor (Mechanical Engineering) (supervisor); Luo, Yunhua (Mechanical Engineering) Shalaby, Ahmed (Civil Engineering) Untaroiu, Costin (Biomedical Engineering and Mechanics, Virginia Tech, Wake Forest University) (examiningcommittee)
Country of Publication ca
Record ID handle:1993/32883
Repository manitoba
Date Retrieved
Date Indexed 2019-05-20
Issued Date 2017-01-01 00:00:00
Note [note] May 2018;

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…2 Figure 1-3 – Fatal Events for Motorcoach Passengers by Collision Type ....................................... 3 Figure 2-1 – Sled Test Setup…

…Curve for Retractor ............................................................................. 41 Figure 3-7 – Energy Conservation for Sled Test Simulation.......................................................... 43 Figure 3-8 – Deceleration Pulse…

…59 Figure 3-24 – Sled Acceleration Profile ......................................................................................... 62 Figure 3-25 – Verification of Energy Conservation for Sled Test Simulation................................ 64…

…Parameters Controlling the Pulse Shape .................................................................. 91 Figure 5-3 – Dependence of Head Injury Criterion on pulse shape’s parameters ....................... 93 Figure 5-4 – Modified Sled Test Setup…

…to support the development of safety regulations for motorcoaches in North America. A full-scale frontal crash test was performed for a coach, and 20 sled tests were conducted to determine the influence of seat model, occupant posture and crash pulse…

…real-world conditions. 1.3.2 Thesis Statements The thesis demonstrates the following. 1. Kinematics and, consequently, the injury criteria values for unbelted occupants are highly sensitive to the variations in the sled test parameters namely, the…

…normalized by a magnitude and a total velocity change to a sled test with unbelted passengers, it is demonstrated that injury criteria values, namely Head Injury Criterion and Femur Forces, can vary by up to 30%. 3. Head Injury Criterion and Femur Forces of…

…the values calculated for a reference posture. The dispersion in injury criteria values is consistent across the results from the sled test with different input parameters. 1.3.3 Scope The research in the thesis is limited to the frontal collisions of…

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