关键词: 扭力梁；刚柔耦合多体动力学；K&C；CAE；交替轮跳

Abstract: Torsion-beam semi-independent suspension represents one of the mainstream applications for passenger-car rear suspensions. The torsion-beam body bears combined bending-and torsion loads during vehicle operation under severe service conditions, and directly determines chassis performance and driving safety. Taking the torsion-beam rear suspension of a certain vehicle as the research object, this paper establishes a rigid-flexible coupled multi-body dynamics model to complete the K&C dynamic performance analysis of the suspension. Working-condition loads are extracted based on the multi-body dynamics model to carry out structural strength and modal computer-aided engineering (CAE) simulation evaluation for the torsion beam. With the equivalent beam model and Morphing shape-optimization method, this paper investigates the influence laws of torsion-beam design parameters on suspension K&C characteristics and structural strength. The results show that for the K&C roll-steer performance, increasing the opening angle of the torsion beam, changing the opening direction from forward to downward, moving forward the mounting position of components, optimizing the bending form of members and extending the length of the middle V-shaped section can effectively improve the roll-steer effect. Under the alternate wheel-hop strength condition of ±30 mm, increasing the contour dimension of the end-section relieves stress concentration, and structural performance exhibits high sensitivity to the wall-thickness parameter of the torsion beam under all strength conditions.

Key words: torsion beam; rigid-flexible coupled multi-body dynamics; K&C; CAE; alternate wheelhop