In recent years, many types of variable stiffness devices are developed. These devices have an ability to change the stiffness of a mechanical system. They can also store energy thanks to elastic elements, and convert it to kinetic energy. By installing these devices in the mechanical system, it is expected that an actuator’s energy which is required to achieve a periodic motion will be reduced...

This paper presents a vibration suppression approach for precision positioning mechanisms including harmonic drive gearings (HDGs), using a variable notch filter to suppress mechanical vibrations due to angular transmission errors (ATEs) in HDGs. Mechanisms with HDGs excite resonant vibrations, especially in the condition that the frequency of synchronous components of ATE correspond to the cri...

This paper is concerned with the development of a control system for tracking of a desired temperaturetime profile for accelerated cooling processes in hot rolling of steel. Control of temperature during cooling is essential for achieving desired mechanical and metallurgical properties of steel. The cooling process is represented by the heat equation in Lagrangian coordinates which is approxima...

In this paper, the effects of carbon nanotube (CNT) orientation and aggregation on the static behavior of functionally graded nanocomposite cylinders reinforced by CNTs are investigated based on a mesh-free method. The used nanocomposites are made of the straight CNTs that are embedded in an isotropic polymer as matrix. The straight CNTs are oriented, randomly or aligned or local aggregated int...

in this paper, a robust pid control scheme is proposed for micro-electro-mechanical-systems(mems) optical switches. the proposed approach is designed in a way which solves twochallenging and important problems. the first one is successful reference tracking and the second ismitigating the system nonlinearities. the overall system composed of nonlinear mems dynamicsand the pid controller is prov...

We study the shapes and biochemical characteristics of human red blood cells using a unified biochemical and continuum mechanical model. In particular, we model the crenated, echinocytic shapes and show how they may shift due to changes in the pH and various amphipaths affecting the osmotic pressure by also utilizing pressure as an independent variable. In contrast to earlier works which advoca...

The oil and gas industry has a growing demand for electrically driven trains operated at variable speeds. Variable frequency electrical drives enable increased operational flexibility and energy efficiency. This is of great importance in applications requiring high power, such as gas compression. Load commutated inverters (LCIs) are one of the most widespread technologies for driving large gas ...