Fatigue Bench Test for Internal Parts of Shock Absorbers in Commercial Vehicles 2013-36-0471
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.
Development: For the development of shock absorbers in commercial vehicles, it is important to evaluate their lifetime, which means, the point when their characteristics affect functionality. It is important to remark that lifetime of a shock-absorber is not usually reached when a simple break occurs, but due to losing of a significant value of the damping forces caused by wear of the internal parts of the component.
Usual testing procedure: In general fatigue evaluation of internal components of shock absorbers is done by means of durability test using commercial vehicles under real conditions (load and representative tracks for the application), running during a period which permits evaluation of losing dumping forces of the shock absorbers. This requires high costs and a long time for the test.
Bench test criteria were established in order to accelerate tests, they run under extreme conditions. This requires control of temperature, course and acceleration.
Advantage over usual testing procedure: Cost and time reduction.