Скачать или смотреть E0075 Roll Center 7 Lateral Load Transfer Distribution & Total Lateral Load Transfer - EulSeoggy Ko

There are six lateral load transfer elements that lateral acceleration generates. As explained in the previous videos, there are two types of vehicle mass, and both the sprung mass and the unsprung mass contribute to the lateral load transfer. If we introduce the concept of the roll center, the force generated by the lateral acceleration at the center of gravity of the sprung mass is divided into the force transmitted to the spring and anti-roll bar in the form of a moment, and the force that acts laterally to the roll center and is transmitted to the suspension link. The moment transmitted to the spring and anti-roll bar can be divided again into the front suspension moment generated by the sprung mass wrt. the roll center and the rear suspension moment generated by the sprung mass with respect to the roll center. Similarly, the force transmitted to the suspension link can be divided into the lateral force acting on the front suspension roll center by the front sprung mass and the lateral force acting on the rear suspension roll center by the rear sprung mass. Since the unsprung mass is not related to the roll center, no moment is generated about the roll center. The force generated by the unsprung mass can be divided into the lateral force acting on the unsprung center of gravity of the front suspension and the lateral force acting on the unsprung center of gravity of the rear suspension. The lateral load transfer for the lateral forces 3 and 4 of the sprung mass can be obtained by calculating the sprung weight supported by the front and rear suspensions, and then using the corresponding roll center height and the corresponding wheel track. The lateral load transfer for the lateral forces 5 and 6 of the unsprung mass can be easily obtained using the corresponding center of gravity height and the corresponding wheel track. The load transfer due to the lateral force generated by the sprung mass and the unsprung mass can be calculated independently from the front and rear suspensions. On the other hand, the lateral load transfer caused by the moment generated by the sprung mass on the front and rear suspensions is directly related to the suspension roll stiffness. The sprung mass is connected to both the front and rear suspensions, and rotates at the same roll angle along the longitudinal direction of the vehicle when lateral acceleration occurs. Accordingly, the magnitude of load transfer differs between the front and rear wheels depending on the ratio of the rear suspension roll stiffness to the front suspension roll stiffness. This phenomenon is called the load transfer distribution in the roll motion. In the lateral load transfer, the load transfer distribution between the front and rear axles is related only to the moment generated by the sprung mass. This fact is very important in the lateral load transfer. In order to derive the formula simply, the following five assumptions are made. First, the sprung mass is assumed to be rigid. Therefore, no torsion of the sprung body is assumed. Second, the roll angle of the sprung body is assumed to be small. Therefore, the cosine of the roll angle pi is one, and the sine of the roll angle pi can be used as the roll angle pi in radians. Third, the roll axis tilt angle alpha is assumed to be small. Therefore, the cosine alpha of the roll axis tilt angle alpha become 1. Forth, The longitudinal axis passing through the roll axis and the center of gravity is assumed to be in the same vertical plane that runs through the center of the vehicle. Finally, the tire deformation is ignored. However, here, if the suspension stiffness is too large compared to the tire stiffness, the suspension displacement becomes relatively small and the tire deformation becomes relatively large, so the tire deformation should not be ignored. In this case, the tire deformation should be considered. how do we calculate the lateral load transfer and weight distribution? Find the roll centers of the front and rear suspension. Calculate the roll moment of the sprung mass in terms of the roll angle at the front and rear suspensions. Find the roll angle using the overall roll couple curve or roll stiffness curve. Calculate the roll load transfer at the front and rear suspensions using the roll couple curve or roll stiffness curve. Calculate the front and rear lateral force acting on the roll center from the sprung mass. Calculate the sprung mass load transfer at the front and rear suspensions using the roll center height. Calculate the unsprung mass load transfer at the front and rear suspensions using the front and rear unsprung mass heights. Add together the roll stiffness moments due to the sprung mass at the front and rear suspensions, the load transfer through the suspension links, and the load transfer due to the unsprung masses.