| The function of brake system is important for the safety of fly, and the temperature field of the brake is one of the important parameters to describe the performance of brake system. Therefore, the research of the formation and distribution of the temperature field during braking is very important to the employment and the safety of brake system, and it is helpful to the design of brake system and the selection of friction materials as well.Based on theories of heat transfer and tribology, the caculatemethods of convection, rediation and heat source were confirmed, and three-dimension heat conduction model of the brake has been developed. The temperature field in the brake during the process of braking was simulated. As a result, temperature distributions under three typical circumstances, i.e. normal landing, overload landing and abeyant takeoff, were calculated. Compared with the experimental results, the computational error is small and acceptable, especially the results under normal landing, which proves reliability of the model and the research methods.The model developed has been applied to another brake system. By using two different friction materials, the influence of the material on the distribution of temperature field has been Compared. It is found that, using Cu-based friction material can decrease the temperature of friction area; and as the temperature of the framework discs increases, the temperature of the whole brake is more uniform. What’s more, since the temperature gradients in friction area decreases, it reduces the danger of cracking of friction area by uneven thermal expansion.At the end of the desertation, how the thermal properties of friction materials influences the temperature in the brake has been discussed. Calculation drawn in the analysis include:①by increasing the conductivity of the friction material, the potential trouble of tyre explosion can be eliminated, and the danger of the friction aera cracking by uneven thermal expansion can be decreased;②the highest temperature of the whole brake can be decreased by increasing the conductivity or the thermal capability of the friction material, however, change of the thermal capability will be more effective;③increasing the conductivity of the friction material will greatly decrease the axial temperature gradients of the stators, whilst increasing the thermal capability will increase the axial temperature gradients; It also discussed the influence of changing landing state and brake time on the temperature distribution. |
