Comparative modal analysis for a twisted beam axle for a hybrid vehicle

In this article it is presented a comparative analysis of natural mode frequencies for a non-powered rear axle used to fit mass production vehicle and for a similar rear axle derived from the first one to be used to fit a hybrid powered vehicle. The CAD model of the axle and the computed natural mode frequencies were realised using CATIA V5. For calculation, finit element method was used.

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

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.

Hybrid quenching method of hot stamping for automotive tubular beams

Recently, tubular-type coupled torsion beam axle, which is a component of the automotive rear suspension systems, has been developed by using ultra-high strength steel. It is manufactured by hot stamping process to enhance the strength and reduce springback. The hot stamping process is classified as a direct method and an indirect method according to forming sequence and quenching method, so-called die quenching or water quenching. Each of these methods has limitations in the aspect of dimensional accuracy and strength. Hybrid quenching is a new quenching method which sprays water to the tube directly in addition to die quenching. In this study, direct hot stamping with hybrid quenching was applied to produce an automotive tubular coupled torsion beam axle of ultra-high strength steel. This study proposes a simulation method of hybrid quenching for tubular beam and the hybrid quenching method was evaluated experimentally. Finally, the proposed hybrid quenching method has been found very effective in reducing the cooling time and thermal deformation.