CAJ | 학술논문

提出考虑摩擦层闸片厚度的影响，建立二维轴对称摩擦制动器热弹性失稳的数学模型。基于扰动分析法，推导摩擦副的温度场扰动以及不同热点分布模式下的热特征平衡方程。研究临界速度和扰动增长系数的变化规律。计算摩擦面瞬态名义温度随制动时间的变化关系。分析和比较不同摩擦副厚度比、热导率、弹性模量、比热容以及热膨胀系数对系统稳定性的影响。结果表明，当热点呈反对称分布时，系统发生热弹性失稳时所需的最低临界速度远低于对称分布模式，临界速度随扰动频率的增加呈先减小后增加的变化趋势。不同扰动频率对应的扰动增长系数随滑动速度近似呈线性增加，最低临界扰动频率对应的扰动增长系数最大。当扰动频率低于临界扰动值时，温度随扰动频率的增加而增加，反之，则降低。增加摩擦副的厚度、摩擦层闸片的热导率和比热容以及减小滑动层制动盘的热导率和热膨胀系数和摩擦层闸片的弹性模量均可以提高滑动摩擦系统的稳定性。
제출고필마찰층갑편후도적영향，건립이유축대칭마찰제동기열탄성실은적수학모형。기우우동분석법，추도마찰부적온도장우동이급불동열점분포모식하적열특정평형방정。연구림계속도화우동증장계수적변화규률。계산마찰면순태명의온도수제동시간적변화관계。분석화비교불동마찰부후도비、열도솔、탄성모량、비열용이급열팽창계수대계통은정성적영향。결과표명，당열점정반대칭분포시，계통발생열탄성실은시소수적최저림계속도원저우대칭분포모식，림계속도수우동빈솔적증가정선감소후증가적변화추세。불동우동빈솔대응적우동증장계수수활동속도근사정선성증가，최저림계우동빈솔대응적우동증장계수최대。당우동빈솔저우림계우동치시，온도수우동빈솔적증가이증가，반지，칙강저。증가마찰부적후도、마찰층갑편적열도솔화비열용이급감소활동층제동반적열도솔화열팽창계수화마찰층갑편적탄성모량균가이제고활동마찰계통적은정성。
A mathematical model on thermoelastic instability(TEI) of two dimensional axisymmetric friction brake is proposed by considering the impact of friction layer’s thickness. Based on the perturbation method, temperature perturbation of the brake pair and the characteristic balance equation under different types of distribution of hot spots are respectively derived. The change rules of the critical speed and growth rate of perturbation are studied. Transient normal temperature of the frictional surface changing with time is calculated. The effects of brake pair’s different thickness ratio, thermal conductivity, elastic modulus, specific heat and thermal expansion coefficient on critical speed are analyzed and compared. The results show that the critical speed of the model whose hot spots are antisymmetrically distributed is much lower than that of symmetric mode and it will decrease firstly and then grow again with the increase of wave number. The growth rates of perturbation of different wave numbers have a approximate linear relationship with the sliding velocity. Meanwhile, the perturbation which has the lowest critical speed has the largest growth rate. For perturbations with wave number smaller than critical value, the temperature will increase,vice versa perturbations with wave number greater than critical value, the temperature will decrease. The stability of the braking system can be enhanced by increasing the thickness of the brake pair, thermal conductivity, specific heat of the friction layer and decreasing the thermal conductivity, thermal expansion coefficient of the sliding layer and the elastic modulus of the friction layer.