Dynamic Response Measurement of 1-Inch HDD Head Arm Assembly

2010 ◽  
Vol 36 ◽  
pp. 52-56
Author(s):  
Bin Gu ◽  
Dong Wei Shu ◽  
Yusaku Fujii ◽  
Bao Jun Shi
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Frequency Shift ◽  
Impact Load ◽  
Inertial Force ◽  
Time History ◽  
Doppler Frequency ◽  
Doppler Frequency Shift ◽  
Bending Test ◽  
Element Analysis

In this paper, dynamic response of 1-inch hard disk drive (HDD) head arm assembly (HAA) against an impact load is obtained by means of a 3D non-linear finite element model in ANSYS/LS-DYNA and experiments using Optical method. A mass is modeled as a rigid body and is made to collide with the arm. The velocity, displacement, acceleration and the inertial force of the mass are obtained from the time- history of finite element analysis (FEA). In the experiment, a mass that is levitated with an aerostatic linear bearing, and hence encounters negligible friction, is made to collide with the HAA and the dynamic bending test for the arm is realized. During the collision the Doppler frequency shift of the laser beam reflecting from the mass is accurately measured using an optical interferometer. The velocity, the position, the acceleration and the inertial force of the mass are calculated from the measured time-varying Doppler frequency shift. A good correlation between the experimental data and FEA results is observed.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

The Dynamic Response Analysis on the Surrounding Ground of Underground Structure

2012 ◽  
Vol 204-208 ◽  
pp. 1301-1306
Author(s):  
Guo Dong Zhang ◽  
Jian Long Zhang ◽  
Jian Long Cao ◽  
Wen Luo
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Underground Structure ◽  
Time History ◽  
Limited Range ◽  
Seismic Effect ◽  
Response Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
History Of

Based on the theory of soil-structure interaction, the underground structure and surrounding soil as a system, and the finite element analysis model is established, and finite element dynamic analysis method is implemented, the three seismic acceleration time history of the different spectrum characteristics is inputted, the seismic effect on the surrounding ground of underground structure is analyzed. The results show that the effect on dynamic response is the limited range and not significant, when seismic design of structures on the surrounding sites is implemented, additional dynamic response on surrounding sites does not need to consider.

Rotational Doppler Frequency Shift from Time‐Evolving High‐Order Pancharatnam–Berry Phase: A Metasurface Approach

2021 ◽  
pp. 2000576
Author(s):  
Fuyong Yue ◽  
A. Aadhi ◽  
Riccardo Piccoli ◽  
Vincenzo Aglieri ◽  
Roberto Macaluso ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Berry Phase ◽  
Doppler Frequency ◽  
Doppler Frequency Shift ◽  
High Order

scholarly journals Broadband Laser Doppler Frequency Shift Emulator for Satellite Laser Communication

2019 ◽  
Vol 11 (6) ◽  
pp. 1-12
Author(s):  
Jinye Li ◽  
Yuan Yao ◽  
Guozhang Wu ◽  
Jiaqing Hou ◽  
Wenqi Yu ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Doppler Frequency ◽  
Doppler Frequency Shift ◽  
Laser Doppler ◽  
Laser Communication ◽  
Satellite Laser Communication ◽  
Broadband Laser

Dynamic Loading Approach for Structural Evaluation of Ultra Large Container Carriers

2005 ◽  
Author(s):  
Bill Shi ◽  
Donald Liu ◽  
Christopher Wiernicki
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Loading ◽  
Impact Load ◽  
Failure Mechanisms ◽  
Direct Calculation ◽  
Element Analysis ◽  
Design Philosophy ◽  
Non Linear ◽  
Large Container

The emerging global economic needs are driving the designs for the next generation of ocean going vessels. Current ultra-large container carrier (10,000 TEU plus) designs are considerably larger and more complex than any currently in service. Proper and rational classification assessment requires that first principles based direct calculation methods be used to augment the standard classification review. The design philosophy behind the ABS Dynamic Loading Approach enables comprehensive identification of potential failure mechanisms. The scope of the necessary engineering assessment encompass full-ship finite element analysis under non-linear sea loads, spectral fatigue analysis, finite element lashing analysis, free and forced vibration analysis, and transient and impact load analysis. This paper describes key aspects of the DLA design philosophy such as non-linear sea loads, load combinations, various applications derived from full-ship finite element analysis. Several examples are given to highlight some critical failure mechanisms to be considered for ultra-large container carriers.

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