【作者】 周坤；

【导师】 肖林京；

【作者基本信息】 山东科技大学 ， 机械设计及理论， 2018， 硕士

【摘要】 制动性能严重影响着电机车的运输效率,从而影响着煤矿开采的效率。盘式制动器因其结构简单、散热性能优良、制动效率高的特点而被逐渐应用到矿用电机车上,但其制动过程中会产生大量,伴随着会产生磨损、裂纹等一系列问题,同时在矿井条件下要求其最高温度不能高于150°C,所以对盘式制动器进行摩擦热力耦合分析,研究其温度场以及应力场的变化规律,并对其疲劳寿命做出较好的预测具有非常重要的意义。本文针对目前研究所存在的问题,对以下几个方面进行了研究。对盘式制动器的摩擦热力学研究。确定了电机车盘式制动器工况载荷、摩擦副的摩擦机理及接触状态、摩擦力的组成、热传递方式。分析了制动过程中热机耦合的机理及相互耦合过程。基于热传导及热力耦合理论方程,确定了求解的初始及边界条件,并提出了有限元求解方法,为后续的试验测试和仿真分析奠定了理论基础。利用摩擦磨损实验机完成了摩擦副性能参数的测试和分析评价。以制动压力和制动速度为测试变量,摩擦系数为测试目标,研究了不同制动压力和制动速度下摩擦系数的变化规律及其变化机理。结合有限元求解理论方法和试验测试结果完成了盘式制动器热机耦合的模拟分析。基于动态变化下的摩擦系数和对流换热系数,采用有限元软件ABAQUS求解热机耦合下的温度场和应力场,揭示了温度场和应力场的分布规律并与非耦合下的温度场和应力场进行了对比。结果表明:制动盘的温度场和应力场都表现出先上升后下降的变化规律,并且与非耦合下的温度场和应力场存在一定的偏差,摩擦副应力主要表现为热应力且应力场分布变化规律和温度场的变化十分的相似。分析说明了温度场和应力场的相互耦合性。根据模拟仿真结果对电机车制动盘使用寿命进行了预测。得到了制动盘在制动过程中应力的分布情况,确定了制动盘热疲劳寿命的预测模型以及制动盘易发生热疲劳损坏的部位,采用了 Manson-Coffin公式对制动盘的使用寿命进行了预测,分析得出了制动盘失效的循环次数。验证了盘式制动器在矿用电机车中较好应用性。更多还原

【Abstract】 Braking performance affects the efficiency of mining electric locomotives transportation seriously,as well as the efficiency of coal minings.Disc brakes have the characterastics of simple structure,excellent heat dissipation and high braking efficiency,and can be applied to the mining electric locomotives.However,during the braking process,a great amount heat will be generated and a series of problems such as wear and crack will occur and its highest temperature is below 150℃.So it is very important to study the variation law of temperature field and stress field and make a good prediction of the fatigue life of disc brakes.In view of the existing problems,this disseration studies the following aspects.The friction thermodynamics of disc brakes was studied.The composition,working condition load,friction mechanism and contact state of electric locomotives disc brake were determined.The coupling mechanism and the coupling process of the engine were analyzed.Based on the heat conduction and coupling theory equation,the initial and boundary conditions of the solution were determined and the method of solving finite element solution was put forward.It laid a theoretical foundation for subsequent test and simulation analysis.Based on the friction test bed,the friction performance parameters were tested and analyzed.Taking the brake pressure and braking speed as the test variables and the friction coefficient as the test target.,the influence of different brake pressure and braking speed on the friction performance of brake discs were studied and the variation law and the mechanism of its effect were analyzed.Combined with the finite element method and experimental test results,the thermal-mechanical coupling numerical analysis of disc brakes was completed.Based on the dynamic change of the friction coefficient and convective heat transfer coefficient,the finite element analysis software ABAQUS was used to solve the temperature field and stress field of the brake disc.The results show that the temperature field and stress field of brake discs show the change of first rises and then decreases and there is a certain deviation compared with the non-coupled.The stress of friction pairs is mainly thermal stress,and the variation law of stress field is very similar to that of temperature field,so the interaction between the temperature field and the stress field is explained.According to the simulation results the fatigue life of brake discs of mining electric locomotives was predicted.The stress distribution of brake discs in the braking process was obtained and the prediction model of the thermal fatigue life of the brake disc and the location of the thermal fatigue damage were determined.The life of the brake disc was predicted based on the Manson-Coffin formula.Finally,the cycle times of the failure of the brake disc was obtained.It verified the good application of disc brakes in mining electric locomotives.更多还原