Three Methods for evaluating the dynamic response of force transducers against varying force are described in this paper. In all methods, the inertial force of a mass is used as the known dynamic force, and this reference force is applied to a force transducer under test. The inertial force is measured highly accurately as the product of the mass and the acceleration. An aerostatic linear beari...

Investigation of vertical vibrations of a railway turnout is important in designing track components under moving loads of trains. In this paper, the turnout is simulated by a linear finite element model with modal damping. A section of the turnout has a length of 36 sleeper spans surrounding the crossing. Rails and sleepers are modeled with uniform Rayleigh-&#10Timoshenko beam elements. The ra...

We study fluctuations in the drag force experienced by an object moving through a granular medium. The successive formation and collapse of jammed states give a stick-slip nature to the fluctuations which are periodic at small depths but become "stepped" at large depths, a transition that we interpret as a consequence of the long-range nature of the force chains and the finite size of our exper...

Recent work gives a transverse force on an isolated moving vortex which is independent of the normal fluid velocity, but it is widely believed that the asymmetry of phonon scattering by a vortex leads to a transverse force dependent on the relative motion of the normal component and the vortex. We show that a widely accepted derivation of the transverse force is in error, and that a careful eva...

Moving the torso laterally in a walking biped robot can be mechanically more torque-e±cient than not moving the torso according to recent research. Motivated by this observation, a torque-e±cient torso-moving balance control strategy of a walking biped robot subject to a persistent continuous external force is suggested and veri ̄ed in this paper. The torso-moving balance control strategy consis...

the model fluids containing hard ellipses (hes) and gay-berne (gb) particles where their center is moving in one dimension and confined between two parallel walls with different interactions are investigated using monte carlo simulation, nvt ensemble. the dependency of fluid pressure with respect to the wall distances is studied. the oscillatory behaviors are seen in this quantity against wall ...

A method for calculating the fluid flow around moving objects is presented, based on a volumetric representation of the lattice-Boltzmann scheme and surfaces defined by facets. It enables us to move objects of arbitrary shape and orientation independent of the position of the grid nodes. To represent the motion of the object, additional momentum is added to the reflected particles from each fac...

In this lecture we will discuss mathematical aspects of the NavierStokes equations. We will recall some of the important open problems and mention a few recent results. Consider a ball of radius R moving in an incompressible fluid of constant density ρ at constant velocity U . We expect that a force F is needed to keep the ball in motion (to overcome the “resistance of the medium”). The force i...

Here, • m > 0 is the mass. • k > 0 is the spring constant and the spring force −ku(t) is modeled to be proportional to u(t) (i.e. Hooke’s law). The minus sign shows that it is always a restoring force which pulls the mass back towards the equilibrium. • γ ≥ 0 is the damping constant. The damping force may come from the medium (e.g. air, water, or honey), the spring or other sources. It has a mi...

In earlier work, a Hamiltonian describing the classical motion of particle moving in two dimensions under combined influence perpendicular magnetic field and damping force proportio...