IMPACT SIMULATION OF KICKING USING FLUID AND STRUCTURE INTERACTION ANALYSIS

INTRODUCTION Multi-Body System Analysis (Mechanical System Simulation), Finite Element Analysis(FEA), and Computational Fluid Dynamics Analysis are typical methods of computational human motion analysis. The purpose of this study is to create a impact model using fluid-strueture interaction technique in FEA, and analyze the impact process of kicking in football. METHODS Six university football players were chosen as the subjects. The experiment of ball-kicking was photographed using the high-speed camera (FASTCAM-ultima), which earl take 4,500 frames per second with 256 X 256 pixels, which was recorded on a VTR. Nine markers for digitizing were attached to the kicking leg of the subjects. The coordinate values were input in the computer by a video-position-analyzer. The ball model of this study is created using Euterian technology. The inside of the ball is defined by a air model which is called Gammer Law. The foot model of that is used Lagrangian technology. This study used explicit time integration codes (MSC/DYTRAN) of FEA. In this type of analysis, fluid forees from the Eulerian mesh load the foot model as the material in the Eulerian mesh flows around the foot. At the same time, the resulting deformation of the foot model influences subsequent fluid forces from the Eulerian mesh. RESULTS An example of a contour plot of pressure on the deformed shape is shown in Figure 1. The stress wave is propagated from the contact surface to the tibia, talus, and toe of the foot. At half impact, high intensity compressive stress is observed in the instep and a high intensity tensile stress is observed in the tibia. The first half of the horizontal velocity of the simulation data is similar to that of the experiment data, but the second half is not very similar to the experiment data. The contact time of the ball and foot of experiment data was 9 msec., that of all solid model was 5 msec., and that of fluid-structure interaction model was 8 msec.. CONCLUSION It is considered that the fluid-structure interaction model of this study will give better approximation to experiment data than the all solid model in kicking simulation using FEA. ....

Development of High-Speed Fluorescent X-Ray Micro-Computed Tomography

A high-speed fluorescent x-ray CT (FXCT) system using monochromatic synchrotron x rays was developed to detect very low concentration of medium-Z elements for biomedical use. The system is equipped two types of high purity germanium detectors, and fast electronics and software. Preliminary images of a 10mm diameter plastic phantom containing channels field with iodine solutions of different concentrations showed a minimum detection level of 0.002 mg I/ml at an in-plane spatial resolution of 100µm. Furthermore, the acquisition time was reduced about 1/2 comparing to previous system. The results indicate that FXCT is a highly sensitive imaging modality capable of detecting very low concentration of iodine, and that the method has potential in biomedical applications

Plasma analysis of Inductively Coupled Impulse Sputtering of Cu, Ti and Ni

Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The IEDFs were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5 %. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time- dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse

Z boson production in Pb+Pb collisions at √Snn = 5.02 TeV measured by the ATLAS experiment

The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at √S = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3σ above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. nn -

Measurement of J/ψ production in association with a W ± boson with pp data at 8 TeV

A measurement of the production of a prompt J/ψ meson in association with a W± boson with W± → μν and J/ψ → μ+μ− is presented for J/ψ transverse momenta in the range 8.5–150 GeV and rapidity |yJ/ψ| < 2.1 using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of s = 8 TeV and correspond to an integrated luminosity of 20.3 fb−1. The ratio of the prompt J/ψ plus W± cross-section to the inclusive W± cross-section is presented as a differential measurement as a function of J/ψ transverse momenta and compared with theoretical predictions using different double-parton-scattering cross-sections. [Figure not available: see fulltext.]

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range |η|<2.4. A significant nonzero elliptic anisotropy coefficient v_{2} is observed for muons from charm decays, while the v_{2} value for muons from bottom decays is consistent with zero within uncertainties