A methodology for a thermal-displacement simulation applied on clutches by finite element analysis

摘要

Clutches are mechanisms used for coupling between shafts in order to transmit torque from one to the other. This coupling is made mechanically by friction between the parts with a high friction intermediate material. In this process, the slippage between the parts becomes a source of heat that makes the system temperature to raise up to high values. Under high temperature, the capacity of torque transmission of the clutch can be reduced by the variation of the effective contact diameter, once the contact region of friction change as the temperature is rising. This is caused by the thermal-displacement effect induced by the friction. The torque capacity also can be affected by the friction coefficient that varies with the temperature. Therefore, in order to design an optimized system, it is necessary an analysis of the parts and materials under the influence of temperature changing. This work proposes a simulation methodology for the evaluation of tensions and deformations influenced by the friction heat generation through a test of 15 uniform load cycles of energy by 30 kJ converted into thermal energy. The mechanical coupling dynamic is modeled in the Matlab software and the results are fed into the Abaqus, a Finite Element software, where the thermal dynamic is calculated to result the stresses and strains. The proposed methodology was applied in a generic magnetic clutch where the thermal distribution of the clutch is observed according to the load cycles. At the end of these steps it will be possible to improve the design of clutches aiming the optimization of the system.