主讲人：Ramin Sedaghati（加拿大康考迪亚大学教授）
题 目：基于磁流变混合旋转阻尼器的扭转振动的半主动与半主动控制
Title: Semi-Active Control of Torsional Vibrations using a MR based-Hybrid Rotary Damper
时 间: 2015年10月9号 星期五上午8.30～11.30
地点：机械与汽车工程学院2楼会议室
欢迎广大师生参加！
机械与汽车工程学院
2015.10.08
报告概要:
在绝大部分具有旋转构件的机械系统的工作中，譬如：汽车中的曲轴、飞机发动机中的涡轮转子轴等，都承受着扭转振动。若对过量的扭转振动不能加以有效控制的话，必将造成对系统性能的严重限制、过度噪声及压力，甚至会引起过早的疲劳失效。离心摆式阻尼器（CPVA）作为一种有效的被动扭转阻尼器，已经被广泛应用于旋转和往复机械系统中对扭转振动进行抑制。尽管CPVA在稳态条件下是一种简单、可靠的扭转振动阻尼器，但对非稳态环境或不可预知的环境，其表现不佳。基于磁流变混合的旋转式阻尼器是一种非常有前景的能量吸收装置，具有固有故障保险功能、低功耗及良好的对外部环境的适应性，可以被用来进行扭转振动的半主动控制。
在本次讲座中，首先从传统的CPVA及基于磁流变混合的旋转式阻尼器的控制方程组的推导开始。在体积与惯性约束下，采用优化设计策略以最大化旋转磁共振阻尼器的动态范围，并对其进行测试，以评估其在不同应用场合磁场下的阻尼性能。然后介绍了一种结合了两种阻尼器优点的新的混合式磁共振旋转式阻尼器。最后，对本次讲座中所提出的三种类型的阻尼器进行性能对比与研究。
Machinery systems with rotating components such as crankshafts in automobile and turbine rotor shaft in aircraft engines experience torsional vibrations. Excessive torsional vibrations if not controlled properly may cause severe system performance limitation, excesses noise and stress and even early fatigue failure. Centrifugal Pendulum Vibration Absorber (CPVA) is an effective passive torsional vibration absorber (TVA) that has been widely used in rotating and reciprocating machines to suppress torsional vibrations. While CPVAs are simple and reliable torsional vibration absorbers that are expected to be efficient under steady-state conditions, they have shown performance limitations for unsteady and unpredictable environmental conditions. MR based-torsional vibration absorbers are promising energy absorption devices for semi-active control of torsional vibrations due to their inherent fail-safe feature, low power requirement and their adaptability to varying external exactions. In this research seminar, first the governing equations of conventional CPVA and rotary MR damper will be derived. An optimum design strategy has been formulated to maximize the dynamic range of a rotary MR damper under volume and inertial constraints. The rotary MR damper with optimal design geometry has been fabricated and then tested to evaluate its damping performance under varying applied magnetic field. A new hybrid rotary MR damper combing CPVA and rotary MR damper has been proposed in which CPVA has been connected to the housing of the rotary MR damper. A closed-loop feedback control system using semi-active skyhook control algorithm has been used to control the damping torque in the proposed hybrid rotary MR damper. Finally, the performance of CPVA, rotary MR damper and hybrid rotary MR damper to attenuate vibration has been studied and compared.
主讲人介绍：
Prof. Ramin Sedaghati, Ph.D., P.Eng., Fellow ASME, Fellow CSME Professor
Sedaghati教授一直致力于被动、半主动及主动的结构振动控制研究，并具有丰富的业界工作经验。其是美国航空航天学会资深会员，同时，其还是美国工程师协会及加拿大工程师协会的院士。并同时担任国际期刊《智能材料系统与结构》的副主编。其并多次获得了加拿大康考迪亚大学优秀教学奖，在康考迪亚大学工程与教学领域备受学生推崇。Sedaghati教授目前已经发表了多篇论文与著作，对涉及被动、半主动及主动的结构振动控制等相关的领域展开了深入的学术研究。
