DETC2008-50130 MODELING AND SIMULATION OF A MAGNETORHEOLOGICAL MOUNT

ABSTRACT Magnetorheological (MR) mounts have been developed to replace hydraulic mounts because the MR effect makes the mount controllable and more adaptive. An MR mount, except for the added damping due to magnetic field, operates similarly with a hydraulic mount. Therefore, the geometry of the flow paths (inertia tracks) and the distribution of the magnetic field across these paths affect significantly the mount behavior. In this study, different geometries for the flow paths of an MR mount, designed to operate in flow mode, are considered and their effect on the mount behavior is simulated. The effects of the different geometries considered are quantified through changes in displacement transmissibility of the mount over a 0 to 70 Hz frequency range. The results of the analysis provide useful insights about model parameter values and contribute to the successful design of the flow mode operating MR mount

IMECE2006-13777 A PROBLEM SOLVING APPROACH FOR TEACHING ENGINEERING LABORATORIES

ABSTRACT This paper presents the redevelopment method and process of the laboratory experiments for the Mechanics and Vibration Laboratory, MIME3390, in the Mechanical, Industrial, and Manufacturing Engineering Department at the University of Toledo. The redevelopment objective was to transform the learning process from a subject-based learning to a problem-solving learning. Particular objective was to provide the students with more hands-on experience and to challenge them by requesting the procedure for each laboratory experiment to be designed and carried out by each group of students. This senior level laboratory course consists of experiments in deformable solid mechanics including stress and deflection analysis, fatigue life evaluation, stability and mechanical vibration. Prerequisite courses for this laboratory are Mechanical Design I and Mechanical Vibrations. In line with the program objectives of the department, the following list of objectives has been defined for this course: "Upon successful completion of this course, the students should have: (1) become knowledgeable in the use of standard instrumentation for static and dynamic structural testing, such as strain gages, load frames, impact hammers, and spectrum analyzers; (2) reinforced material studied in previous mechanics and vibrations courses; (3) improved data analysis skills, and (4) further developed laboratory and technical writing skills." Prior to this redevelopment, as part of the subjectbased approach, a classroom lecture preceded each laboratory session. The lecture consisted of the review of the theory pertaining to each experiment to help students refresh their knowledge on the subject. Additionally the description and procedure of the laboratory experiment was covered during this lecture. Prior to each class, the lecture notes, along with the laboratory procedures, were posted on the course website. The step-by-step instructions for each experiment were provided to assist the students in setting up and conducting each experiment. Throughout the semester, eleven experiments were performed. The students wrote individual reports on the experiments consisting of a summary of the acquired data, data analysis, and observations. However, due to the number of students and limited number of lab sessions it was difficult to provide the students with the real hands-on experience with the instrumentation and lab setup. As a result, during the lab the student mostly collected data according to the lab procedure and compiled a report that sometimes was inspired by samples of reports written by former students

IMECE2004-61726 MR FLUID BEHAVIOR UNDER CONSTANT SHEAR RATES AND HIGH MAGNETIC FIELDS OVER LONG TIME PERIODS

ABSTRACT MR fluids are smart materials that reversibly change their rheological properties in the presence of a magnetic field. Their capability to support a high range of shear stresses makes them an ideal component of many mechanical devices. However, to be suitable for applications requiring a large number of cycles, e.g. a clutch, the long term behavior of these fluids needs to be thoroughly investigated and well understood. The paper presents a new MR cell design along with a study of the shear rate, shear strain, magnetic field and time influences on the properties and behavior of a MR fluid tested for long periods of time. The MR cell is required to adapt a commercially available rheometer to measure the rheological properties of the fluid. Overall characteristics of the designed MR cell output capability are provided. Constant shear rate tests, two hours in duration, have been performed at shear rates between 0.1 and 200 1/s under magnetic field intensities up to 0.4 T. The rheological measurements indicated that the time, the shear strain and the shear rate influence the fluid's shear stress magnitude