Search results for "Bearing"

MULTIBODY NUMERICAL SIMULATION OF AN INTERNAL COMBUSTION ENGINE WITH APPRAISAL OF THE WEAR DAMAGE

2009

An internal combustion engine at four times (Otto cycle) and three cylinders is simulated by multibody software MSC Visual Nastran. The bearings are simulated by means of the library of constraint of the software, putting a particular attention to bench bearings and to the lubrication conditions. The loads on the bench bearings and in both the feet and head of the connecting rods, are evaluated by dynamical simulation, so that the inertia loads can be take in account, considering the condition of the maximum couple furnished by the engine. By making the necessary hypothesis, the evaluation of the wear damage is executed by Bayer theory on zero wear, obtaining that a good expectation of life…

DYNAMIC BEHAVIOUR COMPARISON OF ROTATING SHAFT SUSPENDED BY TWO RADIAL ACTIVE MAGNETIC BEARINGS.

2012

EXPERIMENTAL INVESTIGATIONS OF MINIMUM POWER CONSUMPTION OPTIMAL CONTROL FOR VARIABLE SPEED AMB ROTOR

2010

The purpose of this paper is to present a method for development of the optimal speed-dependent control matrix for a rotor supported on active magnetic bearings (AMBs) with the provision of minimum control power consumption over the operating speed range. The speed dependency of the optimal control matrix is the result of the dynamics of rotating machines. Most of published works on optimal control use a stationary optimal control matrix derived for the non-rotating system and thus neglecting the effect of gyroscopic phenomena. This paper employs the minimum energy consumption condition to derive the speed varying optimal control for rotating AMB rotor system. In the presented approach the …

Failure mechanisms of flax/epoxy laminates with open hole: a failure map

2017

Aim of this paper is the investigation of the pin/hole contact stress and failure mechanisms of flax/epoxy composite laminates underwent to tensile bearing tests. In particular, the maximum loads and failure modes are evaluated at varying joint geometry. In order to optimize the use of composite materials in structural applications, an experimental failure map, identifying main failure modes of mechanically fastened joints, is obtained by evaluating failure modes (i.e., net tension, shear out, cleavage and bearing) as a function of the pin diameter and the position of the hole from the free edge of the laminate. Main goal of this paper is give a simple experimental methodology to support th…

Granular packings and fault zones

2000

The failure of a two-dimensional packing of elastic grains is analyzed using a numerical model. The packing fails through formation of shear bands or faults. During failure there is a separation of the system into two grain-packing states. In a shear band, local ``rotating bearings'' are spontaneously formed. The bearing state is favored in a shear band because it has a low stiffness against shearing. The ``seismic activity'' distribution in the packing has the same characteristics as that of the earthquake distribution in tectonic faults. The directions of the principal stresses in a bearing are reminiscent of those found at the San Andreas Fault.

A Review on Approaches for Condition Based Maintenance in Applications with Induction Machines located Offshore

2012

Published version of an article in the journal: Modeling, Identification and Control. Also available from the publisher at: http://dx.doi.org/10.4173/mic.2012.2.4 Open access This paper presents a review of different approaches for Condition Based Maintenance (CBM) of induction machines and drive trains in offshore applications. The paper contains an overview of common failure modes, monitoring techniques, approaches for diagnostics, and an overview of typical maintenance actions. Although many papers have been written in this area before, this paper puts an emphasis on recent developments and limits the scope to induction machines and drive trains applied in applications located offshore.

Synthesis and Biological Evaluation of Organometallic Complexes Bearing Bis‐1,8‐naphthalimide Ligands

2018

Organometallic N-heterocyclic carbene (NHC) complexes with intercalating bis-naphthalimide ligands were prepared and evaluated biologically. Cytotoxic effects against tumor cells or bacteria were strongly ligand dependent with minor influence of the metal (Ag, Ru, Rh, Au) centers. Complex 8b with a rhodium(I) NHC moiety was studied in more detail for its DNA interacting properties in comparison to the metal free ligand. These studies showed a good DNA binding pattern with some preference for the telomeric quadruplex structure hTelo. Complex 8b was also shown to trigger additional coordinative binding to the DNA and therefore represents an useful tool compound with a mixed intercalative/coor…

Computing the Arrangement of Circles on a Sphere, with Applications in Structural Biology

2009

International audience; Balls and spheres are the simplest modeling primitives after affine ones, which accounts for their ubiquitousness in Computer Science and Applied Mathematics. Amongst the many applications, we may cite their prevalence when it comes to modeling our ambient 3D space, or to handle molecular shapes using Van der Waals models. If most of the applications developed so far are based upon simple geometric tests between balls, in particular the intersection test, a number of applications would obviously benefit from finer pieces of information. Consider a sphere $S_0$ and a list of circles on it, each such circle stemming from the intersection between $S_0$ and another spher…

Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 1-Review of Design Methods

2012

AbstractWhen selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating soils that are not suitable for road or railways construction.Advances in lime stabilization technique allowed the successful use of this technique also for improving the bearing capacity of the subgrade, with noticeable savings on both aggregate and disposal charges.In this paper a review of internationally adopted design methods for soil-lime mixture is presented, in order to compare testing methods and requirements of the adopted criteria, as discussed in Part 2.

The Mean-Field Limit for Solid Particles in a Navier-Stokes Flow

2008

We propose a mathematical derivation of Brinkman's force for a cloud of particles immersed in an incompressible viscous fluid. Specifically, we consider the Stokes or steady Navier-Stokes equations in a bounded domain Omega subset of R-3 for the velocity field u of an incompressible fluid with kinematic viscosity v and density 1. Brinkman's force consists of a source term 6 pi rvj where j is the current density of the particles, and of a friction term 6 pi vpu where rho is the number density of particles. These additional terms in the motion equation for the fluid are obtained from the Stokes or steady Navier-Stokes equations set in Omega minus the disjoint union of N balls of radius epsilo…