ABSTRACT
Speed control humps and dips are the most effective and widely used devices, to control vehicle speeds in urban areas. Their geometry varies from type to type based on the criteria used. This study aims at developing new designs for speed hump and dip using commercially available simulation and optimization software. The numerical simulation for vehicle-hump dynamics was developed using ADAMS software and then is linked to MATLAB software to determine speed hump/dip optimum designs that provide discomfort feeling to the driver if vehicle speed exceeds the specified limit, and tolerable comfort if speed is less than or equal the specified limit. The acceptable range of vibrations and shocks exposure resulted from passing over the humps or dips are based on British BS6841:1987 and ISO2631-5:2004 standards. These standards address human health and comfort level in terms of the acceptable range of whole body vibration exposure. The study shows that, for speed limits lower than 10 km/h and higher than 45 km/h, the optimal humps are more efficient than dips. On the other hand, the study shows that for midrange speed limits between 10 and 45 km/h, the optimal dips were superior over optimal humps.
Nomenclature
a | = | Acceleration (m/s2) |
A | = | Weighting factor between ISO2631-5:2004 (PISed) and BS6841:1987 (PIVDV) standards |
Aik | = | ith peak of the response (spinal acceleration); k = x, y or z |
aw | = | frequency-weighted acceleration (m/s2) |
CD | = | Maximum ideal possible value for Seq as in ISO2631-5:2004 |
CS | = | Critical Speed (m/s) |
CV | = | Maximum ideal possible value for VDV as in BS6841:1987 |
Dkj | = | Vibration dose value for the jth period in k direction |
Fac1 | = | Correction factor used for ideal limits at a critical speed range of [CS to CS+10 km/h] |
Fac2 | = | Correction Factor used for ideal limits at > CS+10 km/h |
h | = | Hump Height or Dip depth (m) |
mk | = | Constant in the k direction (For which standard ISO2631-5:2004) (mx = 0.015, my = 0.035, and mz = 0.032) |
n | = | Total number of vibration exposure periods |
N | = | Average number of speed control devices the driver passes over per day |
PICritical | = | Critical Performance Index |
PISed | = | Health Performance Index |
PIVDV | = | Comfort Performance Index |
Sed | = | daily equivalent static compressive stress (MPA) |
Seq | = | Equivalent static compressive stress (MPa) |
Seq_Limit | = | Ideal Equivalent static compressive stress (MPa) |
T | = | Total period of the day (s) during which road vibration occurs |
td | = | Duration of the vibration exposure per day (s) |
tm | = | Period over which Dk is measured (s) |
v | = | Vehicle Speed (m/s) |
VDV | = | Vibration Dose Value (m/s1.75) |
VDVLimit | = | Ideal Vibration Dose Value (m/s1.75) |
VDVn | = | Vibration Dose Value at n periods |
w | = | Hump/Dip width (m) |
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Emad Khorshid
Emad Khorshid graduated from the University of Wisconsin-Madison in 1998. Since then, he is working as a Faculty Member in the Department of Mechanical Engineering at Kuwait University. His research area is designoptimization, control systems, whole body vibration, and complex system analysis. He published more than 16 journal papers and 22 conference papers.
Habib Awada
Habib Awada, holds a Bachelor's degree in Mechanical Engineering from Kuwait University 2011, MSc. degree in Mechanical Engineering, 2016. Habeib has six years of experience in Elevators, Industry Feild.his research interest includes research interest, Whole body vibration, optimization and mathematical modeling of mechanical systems.
Abdulazim H Falah
Abdulazim H Falah finished his Ph.D. from Case Western Reserve University, Cleveland- Ohio in 2002. Since then, he is working as a Faculty Member in the Department of Mechanical Engineering at Kuwait University. His research area is rotating machinery, gears, and vibration. He published more than 12 journal papers and 8 conference papers.
Ahmed Elkholy
Ahmed Elkholy graduated from the University Of Waterloo, Canada in 1978. He has industrial research and development experience in aerospace engine design in North America with over thirty years of technical consultations. He joined the Mechanical Engineering Department of Kuwait University in 1995. His research interest is in the Solid Mechanics area with an emphasis on Machine Design and Manufacturing. He published a total of 47 refereed journal papers and over 50 conference papers.