机械专业毕业论文中英文翻译--在全接触条件下，盘式制动器摩擦激发瞬态热弹性不稳定的研究(编辑修改稿)

机械专业毕业论文中英文翻译--在全接触条件下，盘式制动器摩擦激发瞬态热弹性不稳定的研究(编辑修改稿)内容摘要：

conditions under which a spatially sinusoidal perturbation in the temperature and stress fields can grow exponentially with respect to the time in a similar manner to that adopted by Lee and Barber. It is evidenced in their work [7] that it is sufficient to handle only the antisymmetric problem. The perturbations that are symmetric with respect to the midplane of the disc can grow at a velocity well above the sliding velocity V thus being made uninteresting. Let us introduce a coordinate system （ x1。 y1） fixed to one of the pads (see Fig. 1) the points of contact surface between the pad and disc having y1 = 0. Furthermore, let a coordinate system （ x2。 y2） be fixed to the disc with y2=0 for the points of the midplane. We suppose the perturbation to have a relative velocity ci with respect to the layer i, and the coordinate system （ x。 y） to move together with the perturbated field. Then we can write V = c1 c2。 c2 = c3。 x = x1 c1t = x2 c2t, x2 = x3。 y = y2 =y3 =y1 + a2 + a3. We will search the perturbation of the uniform temperature field in the form and the perturbation of the contact pressure in the form where t is the time, b denotes a growth rate, subscript I refers to a layer in the model, and j =1189。 is the imaginary unit. The parameter m=m（ n） =2pin/cir =2pi/L, where n is the number of hot spots on the circumference of the disc cir and L is wavelength of perturbations. The symbols T0m and p0m in the above formulae denote the amplitudes of initial nonuniformities (. fluctuations). Both perturbations (2) and (3) will be searched as plex functions their real part describing the actual perturbation of temperature or pressure field. Obviously, if the growth rate b0, the initial fluctuations are damped. On the other hand, instability develops if B〉 0. . Temperature field perturbation Heat flux in the direction of the xaxis is zero when the ribbed portion of the disc is considered. Next, let us denote ki = Ki/Qicpi coefficient of the layer i temperature diffusion. Parameters Ki, Qi, cpi are, respectively, the thermal conductivity, density and specific heat of the material for i =1,2. They have been recalculated to the entire volume of the layer (i = 3) when the ribbed portion of the disc is considered. The perturbation of the temperature field is the solution of the equations With and it will meet the following conditions: 1， The layers 1 and 2。