Abstract. The vehicle cornering behavior is an important performance in handling stability especially for the intercity bus. Accordingly, one of the significant parameters concerns the weight distribution which is affected by the center of gravity (CG). In this paper, the effect of weight distribution while varying the turning radius is compared and it should be expressed, and interpreted by understeer gradient which is influenced by the location of CG. The characteristic of intercity bus was modeled and evaluated using the multi-body dynamic analysis software. The analysis has been conducted under steady state cornering based on a total of three configurations, with front/rear axle weight in percent, as 40/60, 45/55, and 50/50.The results stated that the magnitude of weight distribution on front axle of bus in a range of 40% to 50% caused the incremental value of understeer gradient and it was also increased as three times in each turning radius since the difference lateral slip angles between front and rear are expanded.

The Low Floor electric bus, which had been promoted by the Government of Thailand, boost design technologies and research in the automotive industry. In order to fulfill the safety requirements regulated by the Department of Land Transport of Thailand, it must undergo both static and dynamic analysis. The vehicle dynamic cornering behavior plays an important role to demonstrate handling stability especially for active safety. In this paper, we study effect of the parameters of weight distribution and the road friction coefficient, which were indicated in terms of understeer gradient. The analysis had been conducted by ADAM CARS based on the vehicle's multi-body model. The analysis was applied under steady state cornering conditions based on three front to rear weight distribution configurations in percent of 50/50, 45/55 and 40/60, and a lateral tire road friction coefficient of 0.5, 0.7 and 0.9. The results show that the greater the friction coefficient between road and tire, the better handling behavior. The trends are in the same fashion when the three weight distributions are varied and the 40/60 configuration has the smallest understeer gradient. But in the real design we should consider other behavior like ride performance and static analysis, so that the configuration of 45/55 is chosen in our real design. Keywords: Center of Gravity, Cornering Dynamic, LowFloor Electric Bus, Understeer gradient, Bus handling. NotationIn this paper, the following notation is used throughout: