As an important member of smart materials, magnetorheological elastomers (MREs) exhibit characteristics that their modulus can be controlled by an external magnetic field. Based on these experimental results, a viscoelastic solid model with four parameters was proposed to predict the performance of MRE. A building model, three stories high, was constructed using MATLAB SIMULINK to evaluate the ...

This paper examines efficient methods for the calculation of open circuit voltage distortion in salient pole synchronous generators with damper windings. It then proceeds to examine the role of damper bars in the level of distortion. The simplified finite element method employed is inclusive of eddy current effects, dynamic field current and full interaction of all MMF sources. It allows accura...

This article proposes a design method for producing H control performance for structural systems using the Tagagi-Sugeno (T-S) fuzzy model. A structural system with a tuned mass damper is modeled using a T-S type fuzzy model. Using the parallel distributed compensation (PDC) scheme, we design a nonlinear fuzzy controller for the tuned mass damper system. A sufficient stability condition for the...

Phase windings of switched reluctance machines are modeled by a nonlinear inductance and a resistance that can be estimated from standstill test data. During online operation, the model structures and parameters of SRM’s may differ from the standstill ones because of saturation and losses, especially at high current. To model this effect, a damper winding is added into the model structure. This...

Free cooling techniques can be used to substantially reduce energy costs. During cold weather, the outside ambient temperature can help in saving energy in refrigeration systems. The low temperature of the cooling ambient air supply enables free cooling technique to store fresh fruits and vegetables. This energy-efficiency measure can save enough compressor electric power to pay for modulating ...

A multi-zone air-handling unit was popular several decades ago due to the convenience of small sized modular units, which were inexpensive to install and easily maintained in a mechanical room. The cost and convenience proved to be of little benefit as the units perform poorly from an energy usage perspective. A “three-deck” multi-zone unit is a hybrid of its kind, and it can be very efficient ...

Dampers can reduce structural response under dynamic loads. Since dampers are costly, the design of structures equipped with dampers should make their application economically justifiable. Among the effective cost reduction factors is optimal damper placement. Hence, this study intended to find the optimal viscous damper placement using efficient optimization methods. Taking into account the no...

In this work we study the problem of rope sway dynamics control for elevator systems. We choose to actuate the system with a semi-active damper mounted on the top of the elevator car. We propose nonlinear controllers based on Lyapunov theory, to actuate the semi-active damper and stabilize the rope sway dynamics. We study the stability of the proposed controllers, and test their performances on...

A comprehensive method of theoretical analysis for finite Squeeze Film Damper using finite element method is presented. The modified Reynolds equation in the film is solved using the finite element discretization. A Galerkin variational method is applied for solving modified Reynolds equation to determine the pressures as well as load carrying capacities. The pressure distribution and load carr...