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We present a sensor concept for measuring rotation angle based on magnetostrictive materials and fiber Bragg grating strain sensors. The fiber optic strain sensors are used to measure strain in developed in the magnetostrictive rods due to the rotating permanent magnets. The measured strain is related to the angle of rotation. Numerical modeling was performed to investigate the response of magnetostrictive rods due to different angular orientation of magnets. A prototype based on a pendulum was designed to measure the angle with respect to the direction of gravity. Experimental evaluation of its performance revealed a large amount of hysteresis present in the strain data. Finally, we provide some suggestions for further improvement of the design to improve performance and reduce the amount of hysteresis. [Display omitted] • Typical fiber-optic rotation sensors utilize mechanical contact between the sensing element and the motion input terminal. • Magnetostrictive materials allow sensor design without direct mechanical contact with motion input terminal. • Magnetostrictive materials introduce hysteresis in sensor performance. [ABSTRACT FROM AUTHOR]

Hydraulic engine mounts are generally applied to the aerospace and automotive applications for the purpose of cabin noise and vibration reduction. By careful selection of mount design parameters, at a certain frequency called the notch frequency, the dynamic stiffness will be smaller than the static stiffness. Following the notch frequency there will be a frequency, called the peak frequency, where the dynamic stiffness is much higher than the static stiffness. Increase in the dynamic stiffness above the static stiffness is not desirable because of the increase in transmitted force to the airframe or the chassis. Here in this paper, a new hydraulic engine mount design is proposed that uses two working fluids. This new design has two notch frequencies and two peak frequencies. Under special conditions, the peak frequency can be eliminated. As a result, one can obtain a hydraulic engine mount design with only one notch frequency but no peak frequency, by using a controllable fluid or a high viscosity fluid as one of the working fluids. The new hydraulic engine mount design, its mathematical model, and some discussions on the simulation results are presented. [ABSTRACT FROM PUBLISHER]

Abstract: Hard disk drives (HDD) are increasingly being used in mobile applications and consumer electronic devices in potentially harsh dynamic environments. In mission-critical applications such as in computers on board trains and military vehicles, the vibration experienced by the operating HDD can be very severe. An effective suspension system is necessary to isolate the HDD from the strong vibration transmitted from the ground, vehicle engine, etc. This paper gives details on how to design, test and evaluate vibration isolation systems for operating HDD subjected to very severe random vibrations based on military specifications MIL-STD-810E. One design is presented and evaluated based on well-defined criteria. Design principles on how to achieve the required degree of vibration isolation is described. A computer simulation model of an example design is formulated and correlated with experiments. It is shown that a low-cost, vibration isolation system can indeed be made that will allow an HDD to operate well when subjected to strong input vibration. [Copyright &y& Elsevier]

In this paper, first a new design for a disk-type magneto-rheological (MR) brake for automotive applications is proposed and then, a finite element analysis is performed to analyze the resulting magnetic field intensity distribution within the MR brake configuration. This finite element model of the brake is then utilized in a optimization process which incorporates Genetic Algorithm (GA) to obtain optimal design parameters. The optimization process goal is to increase the braking torque capacity of the brake while keeping the weight of the brake as low as possible. Although, the braking torque of the present design is larger compared to the previous designs, the braking toque capacity of the present design is still smaller than the required braking torque for automobiles. [ABSTRACT FROM AUTHOR]

The drop test analysis by using finite element method (FEM) needs effective techniques to achieve solutions within reasonable computational time. Therefore a global-local (GL) model is suggested in this work to reduce the computation time of the whole solution process with a reasonable accuracy. The proposed GL method is used to analyze a large-scale finite element TV model with complex and detailed components. The possibility of partial breaking of TV undergoing impact-contact condition is discussed. It also shows that the impact problem of TV finite element model with complex and a large number of detailed components in impact problem can be solved with an existing software within reasonable computational time. The Hertz''s theory is also used in this work to reduce the impact force of the original model by changing certain properties. The results obtained through different parameters are presented and discussed. [Copyright &y& Elsevier]