Magnetorheological (MR) fluid shows different performances under different temperature, which causes so many problems like the reduction of rheological properties of MR fluid under a high temperature condition, the uncontrollability of shear stress, and even failure of transmission; on that basis, the influence of temperature on the performance of MR fluid and the cause of the rise in temperature of MR transmission device are analyzed in this paper; the shearing transmission performance of the MR transmission device under the effect of an external magnetic field and the influence of temperature on the shearing stress and transmission performance are analyzed. The study results indicate that temperature highly influences the viscosity of MR fluid, and the viscosity influences the shear stress of the MR fluid. The viscosity of MR fluid gradually declines when temperature rises from 100°C. Once the temperature exceeds 100°C, the viscosity would increase and the temperature stability would decline. Temperature obviously influences the characteristics of MR transmission, and particularly, highly influences the characteristics of MR transmission once being higher than 100°C. The chaining of the material in the magnetic field is influenced, which causes the reduction of the rheological properties, the uncontrollability of the shear stress, and even the failure of transmission.

Digital holographic microscopy is presented in this study, which can measure the magnetorheological (MR) fluid in different volume fractions of particles and different magnetic field strengths. Based on the chain structure of magnetic particle under applied magnetic field, the relationships between shear yield stress, magnetic field, size, and volume fraction of MR fluid in two parallel discs are established. In this experiment, we choose three MR fluid samples to check the rheological properties of MR fluid and to obtain the material parameters with the test equipment of MR fluid; the conclusion is effective.

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Modal sensors are sensitive to the structure's response at one or more modes and insensitive to the response due to other modes. Design techniques are well established for distributed sensors for beam structures, but plate structures are more difficult unless the sensor thickness or effectiveness is altered. This study considers the design of distributed modal sensors for plate structures. The sensors are assumed to be of constant thickness and the modes of the plate are assumed to be known functions. The boundary is assumed to be smooth and parameterized using a finite number of points and spline interpolation. The approach is demonstrated on a simply supported uniform rectangular plate and the modes are obtained from the analytical solution. The effect of the number of modes of interest, the form of the objective function, and the number of boundary points is highlighted.

SUMMARYIn this paper, an explicit time integration method with three parameters is proposed for structural dynamics using periodic septuple B‐spline interpolation polynomial functions. In this way, by use of septuple B‐splines, the authors have proceeded to solve the DE of motion governing a single DOF system, and later, the presented method has been generalized for a multiple DOF system. In the proposed method, a direct recursive formula for response of the system was formulated on the basis of septuple B‐spline interpolation approximation. In terms of the specific requirements of this proposed method, two initialization approaches are given for initial calculation. One is called direct initialization, and the other is indirect initialization. The stability analysis of the proposed method illustrates that, by use of adjustable parameters, a high‐frequency response can be damped out without inducing excessive algorithmic damping in important low frequency modes. The computational accuracy and efficiency of the proposed method is demonstrated with three numerical examples, and the results from the proposed method are compared with those from some of the existent numerical methods, such as the Newmark and Wilson‐ θ methods. The compared results show that the proposed method has high accuracy with low time consumption. Copyright © 2013 John Wiley & Sons, Ltd.