| Abstract: |
This work described in this thesis is concerned with theoretical study of numerical modeling of frictional behavior that is presented, particularly stability of mechanical sliding system.The identified principal parameters affecting in the response of the pin-on-disk system namely stiffnesses, rotational velocity and normal force, provide an intuitive insight into the mechanism of stable system and guidance in the way of avoiding instability in the design of sliding system.Although the analyzed model is relatively simple, the observations and the method used in this work can be applied to analyze of more complex systems, possibly discretized by Direct Integration Method. However, as happened even this simple model, the twice-coupling vibration at three degrees of freedom, can in general, take the form of a variety of different response occurring in sliding system. It is of importance to note that the response analysis of system is extremely sensitive to period taken.A Math CAD programme can be used to the analysis of the current work with Direct Integration Method to show the value of affect parameters in the response of the pin-on-disk system.5.2 ConclusionsThe constant set-up parameters are used to be reference parameters to figure out the factors, which may affect the response of the dynamic system in both normal, tangential and torsional directions. However, changing thevalues of the applied load and the rotational velocities. A range of ± 20 % is applied to the set-up stiffness to test the response. The results show that:1) Increasing the normal stiffness value (K1) by 10 % of the set-up normal stiffness value, decreasing the normal amplitude value (Y) by 8.78 %, and torsional amplitude by 2.7 % and visa-versa. While tangential amplitude (X) remains constant2) Increasing the tangential stiffness value (K2) by 10 % of the set-uptangential stiffness value, decreasing tangential amplitude (X) by 2.6 % and torsional amplitude by 2.6 % and visa-versa. While the normal amplitude value (Y) remains constant4) Increasing he torsional stiffness value (K3) by 10 % of the set-up torsional stiffness value, decreasing the normal amplitude value (Y) by 3.9 %, and torsional amplitude by 10.55 % and visa-versa. While tangential amplitude (X) remains constant5) Normal force increasing lead to increasing of the maximum amplitudevalue. As the normal force increases, the normal amplitude value (Y) increases by 20 0/0, tangential amplitude (X) increases by 8 % and torsional amplitude increases by 29.6 0/0.From the previous results, we found that the increasing of the normal force has affected both of normal and torsional directions. While, this affecting decreases on tangential direction.Also, we found that increasing the normal stiffness has affecting both of normal and torsional amplitude. While, not affected on tangential amplitude. Increasing of the tangential stiffness is affected on tangential and torsional amplitude. While, not affected on normal amplitude. Increasing of the torsional stiffness is affected on normal and torsional amplitude. While, not affected on tangential amplitude.
|
|
|