The yaw brake systems are used in wind turbines to control the plan rotating wind turbine blade to be perpendicular to the wind. These devices are very important because they are closely related to the overall efficiency of wind turbines. One set of yaw brakes is normally composed of pad and caliper parts. In this study, tangential forces between the pad and the disk due to the friction have been applied to analyze induced stress level of the sind turbine brake system. Stress distribution and the structural deformation of the caliper are predicated by linear and nonlinear finite element analyses. It is importantly shown from this numerical simulation that there are critically concentrated high stress regions for the typical yaw brake system due to rotational operation of the disk. Also, the results for simplified linear and full nonlinear structural analyses are compared and investigated each other in order to show the effect of different structural analysis methods.