%0 Journal Article %A Miralles Pérez, Antono %T Analysis of dry friction by friction test bench %D 2015 %U http://hdl.handle.net/10317/4404 %X A test of a device equivalent to a Girling duo-servo brake mechanism has been made. The main result is the characterization of a series of frequency associated to the system. The frequency in the spectrum that matches with the belt’s turn frequency is the clearest relation response excitation. The excitation source is related to two small notches on the surface of the belt. A frequency bandwidth with a main frequency, which has no relation to the natural frequencies of the system, is present in each spectrum and is related to non-linear friction phenomenon. Several probes have been studied to find the best solution, which is obtained with the laser distance sensor. Even using this sensor, the block’s displacement in the workbench is greater than the probe’s measure threshold in some assemblies. Several belts have been tested and the belt with smoother notches has been selected. Another source of instability comes from the necessary velocities used in the test. These force the electric motor to run at very low velocity that produces instabilities that has been considered in the analysis results. Amid the recommendations, it would be suitable get a belt without notches and another driver. In the present work the following tests has been developed with three springs set. With a set of 0.14 N/mm stiffness springs, tests have been completed at 20, 15 and 10 rpm. With a set of 0.34 N/mm stiffness springs, tests have been completed at 20, 15, 10 and 5 rpm. With a set of 0.14 and 0.34 N/mm, a test has been completed at 5 rpm. For measures related to the set of 0.14 N/mm stiffness springs, the lower angular velocity is, the more chaotic the system’s behaviour is. For measures related to the set of 0.34 N/mm stiffness springs, the higher angular velocity is, the more chaotic the system’s behaviour is. For the measure related to the set of hybrid springs, the phase’s plane space shows an area which has not relation to stick phenomenon owing to a negative slope, instead of the positive slope associated to the stick. A comparison of the results at 10 rpm for both kinds of springs sets, 0.14 and 0.34 N/mm, shows the stiffer springs are, the more chaotic behaviour is. %K Ingeniería Mecánica %K Electric engine %K Friction %K Girling %~ GOEDOC, SUB GOETTINGEN