Investigation on the braking characteristics of tractor-trailer on jackknifing

• Main Author: Gan, Zhilong
• Other Authors: Lee Yong Tsui
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering::Motor vehicles; DRNTU::Engineering::Mechanical engineering::Motors, engines and turbines
• Online Access: http://hdl.handle.net/10356/53315
• Institution: Nanyang Technological University

This report examines the braking characteristics of a tractor-trailer that leads to the vehicle jackknifing. The investigation on the braking behavior is performed together with the study on the speed and steering characteristics as these three factors are closely related and essential for jackknifing. In particular to study on the braking characteristics of the tractor-trailer, driving conditions that related to vehicle jackknifing such as the road surface and Anti-lock braking system are investigated. The analysis is conducted with the aid of simulation software, TruckSim. The results show that when the wheels remains in rolling motion, the brake input needs to be sufficient enough so as to inhibit the translational motion of the vehicle as well as work against the trailer swing motion or tractor spin-out. On the other hand, when the wheels are in sliding motion, the effective braking force exerted on the wheels is reduced and therefore increases the chance of jackknifing again. It is also shown that the probability of jackknifing increases as the road surface coefficient decreases, and installing ABS on the tractor axles only is identified to be the best choice among the ABS scenarios studied. The investigation aims to proceed further with the use of driving simulator, but was called off due to technical drawbacks. Overall, although it is uncertain whether the simulation results reflect the real vehicle behavior because of some inevitable limitations in the investigation, the report still provides a few recommendations on the jackknifing prevention and it can be served as a guide for future jackknife analysis.