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Due to the growing necessity to reduce time for new products development, or even to evaluate the reliability of them, a rationalization tendency of the tests has been observed in the field through more and more representative bench tests in a shorter time and with smaller costs. In the automotive industry, the amount of simulated parameters is always increasing; therefore it is necessary to collect a great number of sign measurements in suspension systems (accelerations, temperatures, strokes and deformations), using prototype vehicles. In the present paper we will present the measurements made in a representative track, where it was possible to analyze the measured signs. In a second step they were compiled and compacted, and finally applied in a one-axial bench test. This procedure permits to get a correlation between field and laboratory results.

This paper shows a performance analysis of a tractor-semitrailer during the braking process, on a dry road surface, under any operating condition. In order to carry out this analysis, mathematical modelling with the “static equilibrium” or “centre of gravity range” technique application was used. The results obtained were corroborated by experimental data and were very satisfactory. The related computer program was developed in association with Mercedes-Benz of Brazil. At present, this mathematical modelling and the related computer program are being used by Mercedes-Benz of Brazil for definition of the brake system of their heavy vehicles.

This paper shows a study of the influence of the brake force distribution on the directional stability of a tractor-semitrailer during the braking process in a rectilinial trajectory, for different operating conditions (empty and with full load). A computer program was developed in association with Mercedes-Benz of Brazil it will be used.

The purpose of this paper is to show a multiaxial bench test for static and dynamic testing of leaf springs for suspension of commercial vehicles. The bench test simulates the critical operating conditions (track, ramp, speed bump on track, curves and braking), with stroke control for strength and deformation analysis. One of the main advantages in bench test is to reduce the time of the test, its repeatability, its cost saving and monitoring its performance through inspections and graphic records. The aim of the test is to evaluate the behavior in durability of the components, to analyze the possible failure mode and to be able to approve or reject the component based on the test's results. Criteria were set to accelerate the test by comparing signals measured on the field and bench test with deflection by stress curves. These criteria were maintained under extreme conditions for longer than the observed in previous and real applications.

The aim of this paper is introduce an original and innovative technique called performance charts to obtain the performance of heavy vehicles during braking process. Several performance charts are shown for an example heavy vehicle and are discussed the results obtained, that include values of stopping distance, maximum and average deceleration, efficiency and others obtained during the braking process of the example vehicle. As well is shown the importance of the application of this technique on the braking system definition process of heavy vehicles, on the orientation of the users of these vehicles or fleet-owner and on the verification of legal requirements established by regulations of braking performance of these vehicles.

This paper shows the performance, the braking distribution and the compatibility of heavy vehicles during braking process. including some ECE-R13 [1] requirements to brake systems of these vehicles. Also, it will be shown satisfactory results reached on comparisons between theoretical and experimental values of braking performance of the example vehicle. For the achievement of this work, a mathematical model and a computer program developed for the commercial vehicles braking process study were used, that permits the obtainment of performance and of braking and vertical forces distribution charts to the example tractor-semi-trailer during braking process.