Forced Response of PZT Glide Heads1

2000 ◽  
Vol 122 (4) ◽  
pp. 780-786 ◽  
Author(s):  
Jin-Hui Ou-Yang ◽  
Alex Y. Tsay ◽  
I. Y. Shen ◽  
C.-P. Roger Ku ◽  
David Kuo
Keyword(s):  
Finite Element ◽  
Impact Force ◽  
Laser Doppler Vibrometer ◽  
Forced Response ◽  
Finite Element Analyses ◽  
Pass Filter ◽  
Electric Circuits ◽  
Resonance Frequencies ◽  
Before And After ◽  
The Impact

This paper studies forced response of PZT glide heads through calibrated experiments and finite element analyses. The PZT glide heads consist of an Al2O3TiC slider and a PZT transducer. In the first part of the research, the PZT transducer serves as an actuator exciting the glide heads from 100 kHz to 1.3 MHz. A laser Doppler vibrometer (LDV) and an impedance analyzer are used to measure frequency response functions (FRF) and PZT impedance. In addition, the response of the PZT glide heads is simulated through finite element analyses (FEA). The FEA predict the resonance frequencies with less than 5 percent difference. For the first two slider modes, the FEA also predict resonance amplitudes with good accuracy. In the second part of the research, the PZT transducer serves as a sensor, and the glide head is subjected to an impact force. To produce short impacts experimentally, miniature balls are dropped to the glide heads. The impact force is estimated through the impact duration and the momentum change before and after the impact. Then the impact force and the PZT output voltage are processed to produce FRF. Since the PZT sensor and its circuit form a high-pass filter, the FEA need to consider the slider, the PZT transducer, and the electric circuits simultaneously to produce meaningful results. The FEA predictions agree with the experimental measurements for the first two slider modes as well. [S0742-4787(00)01004-3]

Revealing Mechanical Strength of Nanopores Using Atomic Finite Element Techniques

2018 ◽  
Vol 934 ◽  
pp. 24-29
Author(s):  
Prapasiri Pongprayoon ◽  
Attaphon Chaimanatsakun
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Fluid Flow ◽  
Mechanical Strength ◽  
Impact Force ◽  
Pore Surface ◽  
Vertical Rectangle ◽  
The Impact ◽  
Graphene Nanopore

Graphene nanopore has been widely employed in nanofilter or nanopore devices due to its outstanding properties. The understanding of its mechanical properties at nanoscale is crucial for device improvement. In this work, the mechanical properties of graphene nanopore is thus investigated using atomistic finite element method (AFEM). Four graphene models with different pore shapes (circular (CR), horizontal rectangle (RH), and vertical rectangle (RV)) in sub-nm size which could be successfully fabricated experimentally have been studied here. The force normal to a pore surface is applied to mimic the impact force due to a fluid flow. Increasing pore size results in the reduction in its strength. Comparing among different pore shapes with comparable sizes, the order of pore strength is CR>RH>RV>SQ. In addition, we observe that the direction of pore alignment and geometries of pore edge also play a key role in mechanical strength of nanopores.

scholarly journals Study on the Impact Resistance of Metal Flexible Net to Rock fall

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Gaosheng Wang ◽  
Yunhou Sun ◽  
Ao Zhang ◽  
Lei Zheng ◽  
Yuzheng Lv ◽  
...  
Keyword(s):  
Finite Element ◽  
Impact Force ◽  
Impact Resistance ◽  
Time History ◽  
Rock Fall ◽  
Fe Model ◽  
Element Analysis ◽  
Inclination Angles ◽  
Fall Protection ◽  
The Impact

Based on experiments and finite element analysis, the impact resistance of metal flexible net was studied, which can provide reference for the application of metal flexible net in rock fall protection. The oblique (30 degrees) impact experiment of metal flexible net was carried out, the corresponding finite element (FE) to the experiment was established, and the FE model was verified by simulation results to the experimental tests from three aspects: the deformation characteristics of metal flexible net, the time history curves of impact force on supporting ropes, and the maximum instantaneous impact force on supporting ropes. The FE models of metal flexible nets with inclination angles of 0, 15, 30, 45, 60, and 75 degrees were established, and the impact resistance of metal flexible nets with different inclination angles was analyzed. The research shows that the metal flexible net with proper inclination can bounce the impact rock fall out of the safe area and prevent rock fall falling on the metal flexible net, thus realizing the self-cleaning function. When the inclination angle of the metal flexible net is 15, 30, and 45 degrees, respectively, the bounce effect after impact is better, the remaining height is improved, the protection width is improved obviously, and the impact force is reduced. Herein, the impact force of rock fall decreases most obviously at 45 degrees inclination, and the protective performance is relatively good.

Vibration Analysis of Different Micro-Beams with Laser Ablation

2013 ◽  
Vol 462-463 ◽  
pp. 428-431
Author(s):  
Liang Cai Xiong ◽  
Quan Sheng Zhou ◽  
Peng Chen
Keyword(s):  
Laser Ablation ◽  
Dynamic Response ◽  
Vibration Analysis ◽  
Laser Excitation ◽  
Impact Force ◽  
Laser Doppler Vibrometer ◽  
Impact Response ◽  
Vibration Velocity ◽  
Laser Shock ◽  
The Impact

The dynamic response of different micro-beams after laser excitation experiments have been investigated in this paper. The impact force that induces the vibration of micro-beams is the interaction of focused pulse laser and tested beams. The impact response of micro-beams after being excited is measured by Laser Doppler Vibrometer. Different beams such as cantilever beam, L-shaped beam are employed in our experiments. Comparisons of the vibration velocity and its frequencies of different beams have also been performed. Experimental results show that the mechanical effects of laser shock do really exist and can be utilized.

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 Impact of Seawater Corrosion on Friction Force of Cylindrical Deputy Campaign Latch

2012 ◽  
Vol 531 ◽  
pp. 597-600
Author(s):  
Cheng Zhao ◽  
Kun Luo
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Friction Force ◽  
Similarity Theory ◽  
Research Subject ◽  
Seawater Corrosion ◽  
Load Calculation ◽  
Before And After ◽  
The Impact

According to the stress state and importance of cylindrical deputy campaign latch, NO. 2 cylindrical deputy campaign latch was selected as research subject. The work including design , processing, finite element load calculation, friction force before and after corrosion of similarity samples were carried out according to similarity theory. Friction force calculations of cylindrical deputy campaign latch before and after corrosion were 1206N and 1222N respectively. Compared with the friction force before corrosion, the friction force of cylindrical deputy campaign latch was increased by 19.1% because of seawater corrosion.

Comprehensive Dynamic Model of a Viscously Damped RF-MEMS Switch Including Squeeze Film and Impact Force Effects

2013 ◽  
Vol 389 ◽  
pp. 660-667 ◽  
Author(s):  
Ameen H. El-Sinawi ◽  
Omar A. Awad ◽  
Abdulaziz H. El-Sinawi
Keyword(s):  
Rf Mems ◽  
Impact Force ◽  
Squeeze Film ◽  
Rf Mems Switch ◽  
New Approach ◽  
Mems Switch ◽  
Switch Structure ◽  
Proposed Model ◽  
Resonance Frequencies ◽  
The Impact

This work presents a new approach to modeling the dynamic behavior of a viscously damped RF-MEMS switch. The model takes into account the effect of squeeze film on resonance frequencies of the switch structure. It also presents a new approach to modeling the impact force as well as its effect on transient pull-in, and release dynamics of the perforated switch membrane. Simulation results of the proposed model are validated against experimental results of the same exact switch, and the comparison was impressive. Model results show that the model is able to capture the experimental behavior of the switch with less than 2% error.

The Impact of Seawater Corrosion on Friction Torque of Bearing Deputy Campaign

2011 ◽  
Vol 121-126 ◽  
pp. 2965-2968
Author(s):  
Cheng Zhao ◽  
Kun Luo ◽  
Chang Yin Gao
Keyword(s):  
Finite Element ◽  
Corrosion Resistance ◽  
Stress State ◽  
Similarity Theory ◽  
Friction Torque ◽  
Seawater Corrosion ◽  
Load Calculation ◽  
Before And After ◽  
The Impact

According to the stress state and corrosion resistance of bearing deputy campaigns,NO.5 bearing deputy campaign was selected as research subject.The work including design, processing, finite element load calculation, friction torque before and after corrosion of bearing deputy campaign samples were carried out according to similarity theory. Friction torque calculations of bearing deputy campaign before and after corrosion were 2.9×106N•mm and 3.2×106N•mm respectively. Compared with the friction torque before corrosion,the friction torque of bearing deputy campaign was increased by 10.4% because of seawater corrosion.

Analyze the Impact of the Thin-Walled Hollow Pier by Construction of Reservoir

2013 ◽  
Vol 438-439 ◽  
pp. 1262-1264
Author(s):  
Ke Dong Tang ◽  
Feng Gui Jin
Keyword(s):  
Finite Element ◽  
Realistic Model ◽  
Finite Element Software ◽  
Before And After ◽  
Reservoir Construction ◽  
Thin Walled ◽  
The Impact

The river dam intends to build at 280m downstream of a built bridge. This paper, using ANSYS finite element software, establishes a rational and realistic model to analyze the influence of the reservoir construction on the thin-walled hollow pier of built bridge. The variation of the stress of the bridge thin-walled hollow pier before and after impounding of the reservoir is given out, which can be as a guidance for future reinforcing the thin-walled hollow pier.

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