The harmony search algorithm is applied to the optimum designs of functionally graded (FG)-carbon nanotubes (CNTs)-reinforced pipes conveying fluid which are subjected to a moving load. The structure is modeled by the Reddy cylindrical shell theory, and the motion equations are derived by Hamilton's principle. The dynamic displacement of the system is derived based on the differential quadratur...

We study a mathematical model of hinged flexible beam with piezoelectric actuators and electromagnetic shaker in this paper. The is modelled as mass spring system attached to the beam. To analyze free vibrations mechanical system, we consider corresponding spectral problem for fourth-order differential operator interface conditions that characterize dynamics. characteristic equation studied ana...

This study aims to design vibration isolators, using two types of coil springs with different hysteresis, and evaluate the isolation performance each design. Vibration is achieved through nonlinear spring characteristics isolators an origami-inspired foldable structure attached spring, which have quasi-zero stiffness. However, exhibited load-displacement curves between expansion contraction pro...

In this study, an impact behavior of spherical striker on a double-walled carbon nanotube (DWCNT) is presented based on a three degree of freedom spring-mass model and the finite element (FE) simulations. The semi-analytical solution of the transverse impact of a striker on a DWCNT is investigated by using the elasticity nonlocal theory of Euler-Bernoulli (EBT) and Timoshenko (TBT) nanobeams. T...

In running, the spring-like axial behavior of stance limbs is a well-known and remarkably general feature. Here we consider how the rotational behavior of limbs affects running stability. It is commonly observed that running animals retract their limbs just prior to ground contact, moving each foot rearward towards the ground. In this study, we employ a conservative spring-mass model to test th...

A simple and accurate experimental method is described for determining the effective cantilever spring constant and the detector sensitivity of atomic force microscopy cantilevers on which a colloidal particle is attached. By attaching large (approximately 85 microm diameter) latex particles at various positions along the V-shaped cantilevers, we demonstrate how the normal and lateral spring co...

This article studies the dynamics and control of a novel underactuated system, wherein a plate suspended by cables and with a freely moving mass on top, whose other ends are attached to three quadrotors, is sought to be horizontally stabilized at a certain height, with the ball positioned at the center of mass of the plate. The freely moving mass introduces a 2-degree of underactuation into the...