High performance force sensors often encounter the problem of vibrations during the process of calibration and measurement. To address this problem, this paper presents a novel passive eddy current damper (ECD) for vibration suppression. The conceived ECD utilizes eight tubular permanent magnets, arranged in Halbach array, and a conductive copper rod to generate damping. The ECD does not requir...

A generalised method for the identification of the parameters which describe the dynamic properties of media between coupled substructures using measured FRFs is presented in this paper. The effort is mainly focused on the development of this generalised method and the improvement of its constituent algorithms. The method presented here is more general and more practical in some aspects when co...

Vertebrates and arthropods are both capable of load compensation during aimed limb movements, such as reaching and grooming. We measured the kinematics and activity of individual motoneurons in loaded and unloaded leg movements in an insect. To evaluate the role of active and passive musculoskeletal properties in aiming and load compensation, we used a neuromechanical model of the femur-tibia j...

Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeez...

Negative stiffness is understood as the occurrence of a force in the same direction as the imposed deformation. Structures and composites with negative stiffness elements enable a large amplification in damping. It is shown in this work, using an experimental approach, that when a flexible flat-ends column is aligned in a post-buckled condition, a negative structural stiffness and large hystere...

The objective of this paper is to mitigate the wave-induced vibration of offshore platform with magneto-rheological (MR) damper. The model of the platform coupled with MR damper is established where the external wave force is approximated with a white noise via a designed filter. Based on Linear Quadratic Gaussian (LQG) method, the optimal control force is determined when taking the measurement...

A thickness gradient interpenetrating polymer network (IPN) was easily created that takes advantage of the relatively poor compatibility and curing rates discrepancy between epoxy (EP) and polyurethane (PU). Ultraviolet absorption spectrum (UV-Vis), thermogravimetric (TG), Differential scanning calorimetry (DSC), Dynamic thermomechanical analysis (DMA), Atomic force microscope (AFM) and water c...

The objective of this paper is to study the performance of a sixth order polynomial approach to model hysteresis behaviour of a magnetorheological (MR) damper under harmonic excitations. The polynomial model is developed based on curve fitting from the experimental results and consists of a pair subsystem namely positive and negative acceleration which correspond to the upper and lower curves. ...

The resonant frequency and sensitivity of an atomic force microscope (AFM) cantilever with assembled cantilever probe (ACP) have been analyzed and a closed-form expression for the sensitivity of vibration modes has been obtained. The proposed ACP comprises an inclined cantilever and extension, and a tip located at the free end of the extension, which makes the AFM capable of topography at sidew...