Keywords and Phrases
Dumping Height; Dump Truck; HISLO; Impact Force; RMS Acceleration; Vibrations
"The deployment of large capacity shovels and dump trucks, for achieving economic bulk production capacities, has resulted in high impact shovel loading operations (HISLO). These large shovels generate high impact forces when loading dump trucks with over 100-ton passes under gravity. The impact forces also generate high frequency shock waves, which cause severe truck vibrations, and thus, expose dump truck operators to high levels of whole body vibrations (WBV). The dynamic impact force generates these vibrations, and thus, there is a need to develop efficient technologies to eliminate or reduce its impact. Existing literature and industry practice show that this problem significantly impacts the health and safety of operators. There exists no fundamental work to address this problem. Thus, the primary objective of this research study is to provide scientific solutions to this problem.
This research study develops a rigorous mathematical model to capture the dynamic impact force using all dependent underlying variables. A 3D virtual simulation model for a shovel dumping operation has also been developed using discrete element modeling (DEM) techniques in PFC3D. This model captures material dumping from a P&H 4100XPC shovel (100 tons per pass) into a CAT 793D truck. The results from the mathematical and simulation models showed good agreement. Analysis of the simulation results showed that a percent reduction of 4.88, 7.42, 11.45, 12.01, 15.08 and 17.34 % can be achieved by reducing the dumping height from 7.33 m to 6.33, 6.00, 5.50, 5.33, 5.00 and 4.9 m, respectively. The effect of the impulse force reductions on WBV exposures was examined using the model by Aouad and Frimpong (2013) in MSC ADAMS. Analysis of the results showed that for dumping height reductions to 7.33, 6.33, 6.00, 5.50, 5.33, 5.00 and 4.9 m, the RMS acceleration value of 3.56 m/s2 from Aouad and Frimpong (2013) can be reduced by 10.42, 15.51, 15.53, 15.73, 17.22, 18.85 and 19.61 %, respectively. This is equivalent to a reduction of 3.56 m/s2 to 2.86 m/s2 at a dumping height of 4.90 m.
This research is a pioneering effort to address the problems associated with the operator exposures to severe WBV levels. It advances the heavy mining machinery vibrations frontier and contributes significantly to its body of knowledge. The mathematical and simulation models can be used to analyze any HISLO operation to reduce or possibly eliminate WBV exposures. This study ensures workplace safety and operator health under HISLO conditions in surface mining operations"--Abstract, page iii.
M.S. in Mining Engineering
Missouri University of Science and Technology
xiv, 97 pages
© 2016 Danish Ali, All rights reserved.
Thesis - Open Access
Dump trucks -- Vibration -- Measurement
Mining machinery -- Vibration -- Measurement
-- Vibration -- Prevention
Electronic OCLC #
Ali, Danish, "Mechanics of impulse force reduction for mitigating dump truck vibrations under HISLO conditions" (2016). Masters Theses. 7494.