Solid State Phenomena Vol. 177

Abstract: The paper addresses analytical, numerical and experimental aspects of the design of magnetorheological (MR) fluid valve. Magnetic flux in valve’s cross-section is analysed with the help of finite element method (FEM) software. Based on the magnetic field intensity distribution within valve’s MR fluid annular gap, simulation model of the shock absorber equipped with newly designed MR valves is developed. Prototypes of MR valve are built and embedded in the stationary barrier of the rotary shock absorber, instead of standard, passive check valves. Simulation and preliminary experimental results comprising resistance force values as a function of angular displacement and angular velocity are presented.

Abstract: Recent advances in the research of magnetorheological (MR) fluid based devices have indicated the opportunities for squeeze mode devices using the smart fluids. The mode seems suitable for small amplitude and high force applications. Therefore, it is of a research and engineering interest to explore the model of a controlled squeeze mode MR mount (damper). As such, in the paper the authors highlight the model of a squeeze mode hydraulic mount, then present the simulation results in the form of dynamic stiffness and damping vs. frequency plots, respectively.

Abstract: This paper discusses a visual method of measuring the geometric parameters of ropes and evaluating their wear based on measurements of a three-dimensional rope model. The 3D model is created using the method of laser triangulation. Selection of appropriate geometry of camera and laser lighting arrangement allows collection of the height profile of the observed rope surface in the selected cross-section and, subsequently, building of a 3D model. The resulting model is a representation of the actual dimensions of the rope and allows determination of the parameters describing its basic geometric dimensions and condition of rope surface. Determination of those values and parameters allows estimation of the degree of rope wear. The article discusses issues related to resolution of the vision system, resolution of laser beam analysis, and resolution relating to the measurement of the height profile on the surface of the rope. Based on the model constructed in such a way, measurements are presented in order to assess the dimensional parameters and surface defects in sample rope structures. Based on tests and analyses of the three-dimensional model, a range of inspection tasks using 3D vision systems is indicated.

Abstract: In the paper the galloping phenomenon is modelled by self-excited waves travelling along the cable. The critical conditions of air flow and corresponding changes in the lift coefficient are presented. The motion of the cable was described in relation to equilibrium configuration. Since the wavelengths are small with reference to considered distances and additionally the tension and curvature of equilibrium line of the cable are slowly varying functions of the arc co-ordinate, the problems concerning the travelling waves can be solved using the Wentzel-Kramers-Brillouin (WKB) method. Using this method the equations describing wave numbers and amplitudes of waves were derived. The results of the calculations of amplitudes are presented in the form of plots.

Abstract: In the paper a sandwich plate, of rectangular form, with magnetorheological (MR) fluid core is investigated. The plate consists of two outer layers made of aluminium and an MR fluid layer in between. The plate edges are clamped. It was assumed that the aluminium layers are pure elastic. The energy is dissipated only in the MR fluid layer. Additional assumptions concerning displacements, deformations and stresses are introduced in the calculations. The average power dissipated per unit area of the plate for selected modes of vibrations was determined. A simple method of energy assessment was presented. The results of the calculations can be useful in a semiactive control of continuous systems.

Abstract: A review of the studies carried out on this subject so far was made, and the available mathematical models applicable at Phase I of the diecasing process were presented. Own model testing of the examined process phase was described. The tests were conducted on a laboratory station designed and constructed to serve this purpose. Basing on the obtained results, the fundamental Garber's model was modified and extended further to include the coefficient of liquid metal viscosity.

Abstract: The article deals with the accumulated defect impact on magnetic field distribution around a magnetized rope. A study of such effects was made on a cylinder-shaped model of steel wire rope with a diameter of 40 mm, in which individual wires with a diameter of 1 mm are parallel to the cylinder axis. Defects are wire breaks with the face distance of 1 mm. An analysis was made of the accumulated defect responses in a rope in one radial direction at various distances from the rope axis, then in two different radial directions, and surface defects in the direction of the rope.

Abstract: We present information about construction tasks of tracked vehicle model in MSC.ADAMS computer program. Kinematic and dynamic relationships inside entire suspension system are described here. Elements of the vehicle are grouped in few subsystems, like suspension, wheels or tracks. The significant accent is put on the tracks with its force connections. Those connections are between all track links as also between wheels, links and ground surface. Also significant accent are put on damping value estimation. It is estimated based on tolerance area of characteristics of real damper element, which is applied in this type of vehicles. In next part of the article, process of appropriate damping characteristics selection is described. This process is applied for high fidelity model building.