Dynamics of Gas-Lubricated Slider Bearings in Magnetic Recording Disk Files—Part I: Experimental Observation

1986 ◽  
Vol 108 (4) ◽  
pp. 584-588 ◽  
Author(s):  
D. K. Miu ◽  
D. B. Bogy
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Experimental Observation ◽  
Magnetic Recording ◽  
Laser Doppler ◽  
Rotating Disks ◽  
Interferometric Technique ◽  
Slider Bearings

This two part paper presents the experimental observation and numerical simulation of the dynamic response of self-acting gas-lubricated slider bearings used to maintain the sub-micron spacings between the Read/Write transducers and the rotating disks in magnetic recording disk files. In this Part I, a novel laser Doppler interferometric technique is used to measure the transient motions of the R/W head as it encounters an artificially introduced crater-like surface imperfection and a sputtered rectangular step.

Dynamics of Gas-Lubricated Slider Bearings in Magnetic Recording Disk Files—Part II: Numerical Simulation

1986 ◽  
Vol 108 (4) ◽  
pp. 589-593 ◽  
Author(s):  
D. K. Miu ◽  
D. B. Bogy
Keyword(s):  
Numerical Simulation ◽  
Magnetic Recording ◽  
Dynamic Performance ◽  
Equations Of Motion ◽  
Disk Surface ◽  
Surface Velocity ◽  
Rotating Disks ◽  
Step Size ◽  
Slider Bearings ◽  
Lubrication Equation

This two part paper presents the experimental observation and numerical simulation of the dynamic response of self-acting gas-lubricated slider bearings used to maintain the sub-micron spacings between the Read/Write transducers and the rotating disks in magnetic recording disk files. In this Part II, a factored implicit finite difference scheme is used to integrate the Reynolds lubrication equation, which describes the isothermal compressible fluid flow within the bearing region, and a fourth order Runge-Kutta method is used to solve the equations of motion, which describe the slider dynamics. Using this numerical model, the theoretical slider response due to a rectangular step in the disk surface is obtained. Excellent correlation is observed between theory and experiment. Results are presented to illustrate the effects of step size, step location, and surface velocity on the dynamic performance of slider bearings.

Impact Simulation of a Crashworthy Composite Fuselage Section with Energy-Absorbing Floor

2014 ◽  
Vol 529 ◽  
pp. 102-107
Author(s):  
Hai Bo Luo ◽  
Ying Yan ◽  
Xiang Ji Meng ◽  
Tao Tao Zhang ◽  
Zu Dian Liang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Dynamic Response ◽  
Relative Error ◽  
High Strength ◽  
Computer Code ◽  
Impact Simulation ◽  
Average Acceleration ◽  
Simulation Results ◽  
Energy Absorbing

A 7.8m/s vertical drop simulate of a full composite fuselage section was conducted with energy-absorbing floor to evaluate the crashworthiness features of the fuselage section and to predict its dynamic response to dummies in future. The 1.52m diameter fuselage section consists of a high strength upper fuselage frame, one stiff structural floor and an energy-absorbing subfloor constructed of Rohacell foam blocks. The experimental data from literature [6] were analyzed and correlated with predictions from an impact simulation developed using the nonlinear explicit transient dynamic computer code MSC.Dytran. The simulated average acceleration did not exceed 13g, by contrast with experimental results, whose relative error is less than 11%. The numerical simulation results agree with experiments well.

Dynamic Test of Bird Strike on a Flat Plate Made from LY-12 Aluminium

2013 ◽  
Vol 765-767 ◽  
pp. 3158-3161
Author(s):  
Jun Liu ◽  
Zheng Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Dynamic Test ◽  
Time History ◽  
Aircraft Design ◽  
Bird Strike ◽  
Test Results ◽  
Valuable Data ◽  
Good Agreement ◽  
Peak Value

Tests of bird strike have been carried out on plate made from LY-12 Aluminium. The test was down with the projectile impacting the target perpendicularly at velocity of 40m/s, 80m/s, 120m/s respectively. The displacement-time history curves and strain-time history curves of on LY-12 Aluminium plate were measured. The good agreement of the results between two specimens in one group indicated that the results tested in the presnet paper are reliable. The dynamic response of the plate and damage modes of the bird influenced by striking velocity were analyzed. The peak value of the displacement linear enlarged with the increasing of the striking velocity. The test results in the present paper provided valuable data for aircraft design impacted by bird, and also provided abundant test datas for the numerical simulation model applied in bird striking.

Dynamic Response of a Spar-Type Floating Wind Turbine at Power Generation

2014 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Soichiro Kiyoki ◽  
Iku Sato ◽  
Shigesuke Ishida
Keyword(s):  
Numerical Simulation ◽  
Power Generation ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Prestressed Concrete ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Foundation ◽  
Mooring Dynamics ◽  
Nagasaki Prefecture

In this paper, dynamic response of a Floating Offshore Wind Turbine (FOWT) with spar-type floating foundation at power generation is presented. The FOWT mounts a 100kW wind turbine of down-wind type, with the rotor’s diameter of 22m and a hub-height of 23.3m. The floating foundation consists of PC-steel hybrid spar. The upper part is made of steel whereas the lower part made of prestressed concrete segments. The FOWT was installed at the site about 1km offshore from Kabashima Island, Goto city, Nagasaki prefecture on June 11th, 2012. Since then, the field measurement had been made until its removal in June 2013. In this paper, the dynamic behavior during the power generation is presented, where the comparison with the numerical simulation by aero-hydro-servo-mooring dynamics coupled program is made.

Experimental observation and numerical simulation of transient “stress fangs” within flowing molten polyethylene

2001 ◽  
Vol 45 (6) ◽  
pp. 1261-1277 ◽  
Author(s):  
K. Lee ◽  
M. R. Mackley ◽  
T. C. B. McLeish ◽  
T. M. Nicholson ◽  
O. G. Harlen
Keyword(s):  
Numerical Simulation ◽  
Experimental Observation ◽  
Transient Stress

Numerical Simulation on Failure Process of Internally Pressured Cylindrical Shell Subjected to Wedge Impact

2006 ◽  
Vol 324-325 ◽  
pp. 523-526 ◽  
Author(s):  
Gang Chen ◽  
Qing Ping Zhang ◽  
Zhong Fu Chen ◽  
Si Zhong Li ◽  
Yu Ze Chen
Keyword(s):  
Numerical Simulation ◽  
Cylindrical Shell ◽  
Experimental Observation ◽  
Impact Loading ◽  
Cylindrical Shells ◽  
Failure Process ◽  
Dynamic Failure ◽  
Local Impact ◽  
Wedge Impact ◽  
Numeral Simulation

Cylindrical shell is a kind of common used structure in engineering. Interest in the response of cylindrical shells to local impact loading has increased over the last few years. A structure always endures working load more or less. For a cylindrical shell, the working load commonly is internally pressure. In this paper, a numeral simulation of wedge block impact internally Pressured cylindrical shell was carried out. The dynamic failure process of the structure was obtained. The consistency between experimental observation and numerical simulation is satisfactory.

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