| 1. | Coulomb friction model with high accuracy is proposed so that more accurate equations of motion can be established for the transient response of the single - disk rotor which drops onto the back - up bearing as soon as amb shuts down 摘要就磁轴承发生故障时转子坠入备用轴承所?生的非线性瞬态响应,提出了摩擦力的计算模型,从理论上建立了更为精确的运动微分方程。 |
| 2. | A coulomb friction model with high accuracy is proposed so that more accurate equations of motion can be established for the transient response of the single - disk rotor which drops onto the back - up bearing as soon as amb shuts down 摘要就磁轴承发生故障时转子坠入备用轴承所?生的非线性瞬态响应,提出了摩擦力的计算模型,从理论上建立了更为精确的运动微分方程。 |
| 3. | By considering the contact between the teeth and utilizing the face to face contact model with contact element and coulomb friction model , the author have developed a computing method for plastic load of tooth - locked quick actuating pressure vessel based on finite element stress analysis and stress categorization 摘要通过接触单元来数值模拟啮合齿的接触过程,建立了基于整体有限元分析的齿啮式快开压力容器塑性载荷计算方法。 |
| 4. | Fist of all , on the basis of the research of agone boffins , this author investigates the interaction mechanism of bolts and rock , and introduces the elastic ? lastic analytical resolution which is consist of the liner structure , the equivalent reinforced wall rock and the original wall rock in the simple loading from the equivalent well - proportioned view ; this solution is very important meaning for the engineering design . on the basis of coulomb friction model , the author introduces the finite element equation of the contact problem in order to provide the academic foundation for the application of msc . marc . finally , combining the engineering practice of the non - linear analysis of shield tunnel through yellow river of the south - north water transfer and using the model of friction , the author researched the evolution law of stress and displacement field in the structure of grouted rock bolts , and analyzed the effect to the stress and deformation of surrounding rock mass due to anchor supports 首先,在前人研究成果的基础上,对锚杆与围岩的相互作用机理进行研究,利用全长锚固锚杆的中性点理论,从等效均化的角度来考虑锚杆对围岩的加固作用,并推导了在简单荷载作用下,含有衬砌、等效加固后的围岩、原始围岩三者的弹塑性解析解,对工程设计有着重要的参考意义;在数值模拟方面,以考虑锚固围岩满足规则化库仑摩擦模型为基础,利用虚功原理推导了接触问题的有限元方程的计算格式,为开发运用大型商用有限元软件msc . marc提供了理论根据,也形成了本文的理论基础:最后,论文以南水北调东线穿黄隧洞稳定性分析项目为工程实例,利用本文所述的接触问题的摩擦模型理论,对锚杆支护结构的应力场、位移场的变化规律进行了研究,分析了加锚支护对隧洞围岩应力、变形的影响。 |
| 5. | The main research results are as follows : the friction contact between teeth in the tooth - locked quick closure device is studied , and the simulation is made to the contact conduct between the teeth utilizing the face to face contact model with contact element and coulomb friction model , the whole finite element model of tooth - locked quick closure device is created 本文主要有以下成果: ( 1 )对齿啮式快开装置中啮合齿间存在的摩擦接触现象进行了研究,利用接触单元法采用面-面接触模型和库仑摩擦模型对齿间的接触行为进行数值模拟,建立了齿啮式快开装置的整体有限元模型。 |
| 6. | Presents a simple method of compensating friction against the character of the nonlinear model of a brushless dc motor system which transfers the original system model to a simple linear model using the method of input - output linearization , and estimates the coulomb friction in the system in real - time using a nonlinear friction estimator , and then compensate the friction in the system using a friction feedforward , and concludes from simulation results that this method can effectively eliminate the influence of friction in brushless dc motor systems 针对无刷直流电动机系统的非线性数学模型特点,提出了一种简单的摩擦补偿方法.该方法首先利用输入输出线性化方法将原系统模型转化为一种简单的线性模型,然后给出一种非线性摩擦估计器实时估计系统中的库仑摩擦值,最后利用摩擦前馈补偿方法对其进行补偿.仿真结果表明该方法可以有效地抑制无刷直流电动机系统中的摩擦影响 |
| 7. | When impact applies on a discrete system in which one of constraints is a constant with coulomb friction , the phenomenon of slip - stick at the point can cause the change of friction and the integration for frictional force during infinitesimal impulsive interval becomes impossible according to traditional impulsive dynamics of discrete systems . by introducing a new dimensional time parameter , first - order momentum - impulse differential equations are obtained and the discussion over infinitesimal impulsive interval is transformed into a piece - wise study on the finite region of impulse 在引入新的无量纲的时间参数后,通过建立相应的动量-冲量的一阶微分方程,在趋近于零的冲击区间的讨论变为在有限区间中来分段研究含滑动-黏滞的冲击过程,得到了受到多点打击的离散系统考虑库仑摩擦时的动力学的求解方法,即根据冲击前的初始状态无需回到繁琐的微分方程的求解便可以得到冲击后系统的动力学响应。 |
| 8. | Against two kinds of nonlinear friction observers , the analytic expression of zero ve - locity interval t based on the nonlinear model of brushless dc motor system is deduced in this paper . simulation results indicate that the system performance at low velocity can be im - proved effectively using the friction observer based on coulomb friction model 针对两种不同的非线性摩擦观测器,推导了基于无刷直流电动机非线性模型的零速度时间间隔脶解析表达式,通过仿真证实,利用基于库仑摩擦模型的摩擦观测器可以有效地改善系统的低速控制性能。 |
| 9. | In the end , the stability is discussed under the coulomb friction model , getting the normal force compensation method and the additive vibration control method , which are to stabilize the friction drive system to realize the controllability and stability , which is simple to realize in the micro manipulator 并通过对coulomb摩擦模型的稳定性讨论,得出正压力补偿控制法,即以稳定摩擦力驱动摩擦振子实现微操作手运动的可控性及稳定性的方法分析。通过数值方法验证正压力补偿控制法的适用性,为微操作器的运动控制提出可行方法。 |
| 10. | Basing on the coulomb friction model , a model reference adaptive control system is designed first according to lyarpnov stable theory . considering the real situation at low speed region , the stribeck model controller is put into use also . the both regulators are studied through simulation 针对非线性摩擦对系统低速性能的影响,根据自适应控制理论,采用李雅普诺夫稳定理论,首先设计了基于库仑摩擦的模型参考模型自适应控制系统,考虑到转台伺服系统低速时工作在stribeck区的真实情况,理论上综合出利用非线性stribeck摩擦模型的自适应控制器,并进行了仿真研究。 |