Due to the complex nonlinearity of magnetorheological (MR) behavior, the modeling of MR dampers is a challenge. A simple and effective model of MR damper remains a work in progress. A novel model of MR damper is proposed with force-velocity hysteresis division method in this study. A typical hysteresis loop of MR damper can be simply divided into two novel curves with the division idea. One is ...

The fluid distribution as a function of height in transition zones is often very complex. This may be due to movement of water-oil contact, tilting of the reservoir at some point in time, leak of fluid out of the reservoir zone or complex inflow during secondary migration. The resultant fluid distribution seen in saturation logs may be difficult to model. In this paper we address the changes in...

Motion Control of Smart Material Based Actuators: Modeling, Controller Design and Experimental Evaluation Sining Liu, Ph.D. Concordia University, 2013 Smart material based actuators, such as piezoelectric, magnetostrictive, and shape memory alloy actuators, are known to exhibit hysteresis e ects. When the smart actuators are preceded with plants, such non-smooth nonlinearities usually lead to p...

Piezoelectric actuator (PEA) is an ideal microscale and nanoscale actuator because of its ultra-precision positioning resolution. However, the inherent hysteretic nonlinearity significantly degrades the PEA’s accuracy. The measured hysteresis of PEA exhibits strong rate-dependence and saturation phenomena, increasing the difficulty in the hysteresis modeling and identification. In this paper, a...

Two distinct regimes are considered when it comes to friction: gross-sliding regime and presliding regime [1]. Friction in the gross-sliding regime contains familiar and classic concepts of static friction, Coulomb friction, and Stribeck curve. It is more intriguing, on the other hand, that friction in the pre-sliding regime behaves like a non-linear spring with hysteresis, significantly impact...

Two distinct regimes are considered when it comes to friction: gross-sliding regime and presliding regime [1]. Friction in the gross-sliding regime contains familiar and classic concepts of static friction, Coulomb friction, and Stribeck curve. It is more intriguing, on the other hand, that friction in the pre-sliding regime behaves like a non-linear spring with hysteresis, significantly impact...

In this study we tested the hypothesis that during steady contractions of human wrist extensors or flexors, the torque-angle relationship during movements imposed about the wrist is predicted by the classical isometric muscle length-tension curve, with ascending, descending and ascending limbs. Angle-torque relationships were measured during steady muscle activation (10% of maximal voluntary co...