Method for the quasi-static analysis of beam axle suspension systems used for road vehicles

Abstract

This paper addresses an analytical method for determining the static equilibrium position of beam axle suspension systems used of motor vehicles. This method is applicable to most types of suspension systems and is based on the definition of the spatial positioning of the guiding mechanism as a result of the forces and torques acting in the suspension system. The static model is defined in analytical form, in terms of virtual work, considering the system of applied forces and reactions in the elastic suspension elements (springs, bumpers, anti-roll bar and bushings), whose deformations are determined by the spatial positioning of the guiding mechanism. The proposed method is based on an iterative algorithm by which, for a given set of contact forces on wheels, the equilibrium position is identified by scanning the entire vertical motion domain of the wheels and selecting the configuration that ensures minimal static function. The results obtained by the algorithmization of the method and computer programming allow an accurate assessment of the static behaviour of a beam axle suspension system (in terms of equilibrium configuration and reaction forces) in various regimes, without the need for costly experimental testing.

A Method for Finding the Static Equilibrium of the Non-Steered Wheel Suspension Systems Used in Passenger Cars

“…This paper actually continues a previous study [23], which dealt with a method for the quasi-static analysis of beam axle suspension, a dependent suspension design in which the set of two wheels is connected laterally by a single beam. Unlike this, the current work is about independent wheel suspension systems, where each wheel has its own suspension mechanism relative to the chassis.…”

“…Then, the magnitudes of the forces and torques in the elastic elements of the suspension are computed, depending on the previously calculated deformations and the corresponding stiffness characteristics. The proposed method gives the definition of the characteristics of the elastic elements, which in the real case are more or less nonlinear, either by stiffness coefficients or by characteristics linearized in steps [23]. In this regard, Figure 7 shows the stepwise linearization in three steps, which is usually sufficient to obtain a good accuracy, with the elastic force corresponding to such a case being expressed as follows: (42) where F i = k i • d i , i = I, II, III.…”

“…Determining the coordinates of the center of the wheel carrier (23) and the coordinates of the guidance points (20) in the neutral (initial) position of the mechanism; c.…”

Multi-Criteria Optimization of an Innovative Suspension System for Race Cars

“…While passing over irregularities on the rolling surface, the car wheel was subjected to vertical displacement. The suspension system (which includes the wheel guiding mechanism, and the elastic and damping elements) has the role of minimizing the impact that the rolling surface irregularities has on the chassis, reducing the forces, damping the vibration, isolating the interior (cabin/cockpit) from noise and shocks, and thus improving the ride and handling of the vehicle [1][2][3][4][5][6][7][8]. Optimal suspension design, including the development of innovative solutions such as those shown in [9,10], has been a permanent concern and challenge.…”