Textile technology and resin transfer molding (RTM) process have been combined to manufacture composites coil springs. Preforms for coil springs were made by braiding process, in which axial yarns are located in the central region and braiding yarns covered them circumferentially. The geometric and process parameters that are related with the fiber orientation and fiber volume fraction of the b...

in this paper, the nonlinear conjugate map based on the conjugate hasofer-lind and rackwitz- fiessler (chl-rf) method is applied to evaluate the reliability index using first order reliability method of the embedded noanocompsite beam, which is made from polymer reinforced with carbon nanotubs (cnts). the structure is simulated with timoshenko beam model. the mori-tanaka model is applied for ca...

In the present study, numerical simulations of the ow in a three-dimensional axisymmet-ric poppet valve are conducted using a vortex method. The uids are assumed inviscid and incompressible. The vibration of the poppet, supported by a spring and a dash pot, occurs in the axial direction in some range of parameters. The numerical simulations are carried out by varying systematically the paramete...

We report on the characterization of nanometer-scale torsional devices based on individual single-walled carbon nanotubes as the spring elements. The axial shear moduli of the nanotubes are obtained through modeling of device reaction to various amounts of applied electrostatic force and are compared to theoretical values.

Presented here is a novel technique for the in situ calibration and measurement of friction with the atomic force microscope that can be applied simultaneously with the normal force measurement. The method exploits the fact that the cantilever sits at an angle of about 10° to the horizontal, which causes the tip or probe to slide horizontally over the substrate as a normal force run is performe...

The critical current density in NbJSn conductors is described with an improved scaling formula for the temperature, magnetic field and strain dependence. In an earlier study it is concluded that the largest uncertainties in this description arise from the temperature dependence that is described with various slightly different empirical relations. For the optimization of the numerical codes, us...

In this paper the line-spring model developed by Rice and Levy is used to obtain an approximate solution for a cylindrical shell containing a part-through surface crack. It is assumed that the shell contains a circumferential or axial semi-elliptic internal or external surface crack and is subjected to a uniform membrane loading or a uniform bending moment away from the crack region. To formula...

Impact forces and shock deceleration during jumping and running have been associated with various knee injury etiologies. This study investigates the influence of jump height and knee contact angle on peak ground reaction force and segment axial accelerations. Ground reaction force, segment axial acceleration, and knee angles were measured for 6 male subjects during vertical jumping. A simple s...