Transformation Mechanism of Dual-mode Penetrators Achieved by Changing of Single-point Detonation

2016 ◽  
Vol 67 (1) ◽  
pp. 26 ◽  
Author(s):  
Weibing Li ◽  
Huan Zhou ◽  
Wenbin Li ◽  
Xiaoming Wang ◽  
Jianjun Zhu
Keyword(s):  
Structural Parameters ◽  
Single Point ◽  
Simulation Software ◽  
Transformation Mechanism ◽  
Dual Mode ◽  
X Ray Imaging ◽  
Element Simulation ◽  
Optimizing Design ◽  
Liner Surface ◽  
Projectile Charge

<p>A shaped charge was produced with a wave shaper that can transform dual-mode penetrators by changing the single-point detonation location. Specifically, the theory of denotation wave formation was applied to analyze changes in the liner surface pressure in different initiation situations. An analytical model was established of the projectile explosively formed by denotation at the top of the liner and jetting projectile charge formed by denotation at the center of charge. LS-DYNA finite element simulation software was used to study the effects of the liner configuration parameters on the formation of dual-mode penetrators, and orthogonal optimizing design and simulation calculation was conducted to obtain suitable structural parameters of a uniform-thickness eccentric hemisphere liner. X-ray imaging and penetration experiments were then conducted. The penetration depth of the explosively formed projectile in a steel target was 0.64<em>D</em><sub>k</sub>（the charge diameter）,while that of the jetting projectile charge was 2.42<em>D</em><sub>k</sub> when the burst height was approximately 13<em>D</em><sub>k</sub>.</p>

scholarly journals Investigation on Design Theory and Performance Analysis of Vacuum Capacitive Micromachined Ultrasonic Transducer

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1127
Author(s):  
Xiao Huang ◽  
Hongliang Wang ◽  
Lijun Yu
Keyword(s):  
Influencing Factors ◽  
Design Theory ◽  
Structural Parameters ◽  
Cell Structure ◽  
Ultrasonic Transducer ◽  
Simulation Software ◽  
Performance Parameters ◽  
Element Simulation ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
And Performance

The capacitive micromachined ultrasonic transducer (CMUT), as a new acoustic-electric conversion element, has a promising application prospect. In this paper, the structure of the vacuum capacitive micromachined ultrasonic transducer is presented, and its performance-influencing factors are investigated. Firstly, the influencing factors of the performance parameters of the vacuum CMUT are analyzed theoretically based on the circular plate model and flat plate capacitance model, and the design principles of the structural parameters of the CMUT cell are proposed. Then, the finite element simulation software COMSOL Multiphysics is used to construct CMUT cell models with different membrane materials, membrane shapes, membrane radius thicknesses, and cavity heights for simulation verification. The results show that both the membrane parameters and the cavity heights affect the performance parameters of the Vacuum CMUT. In order to improve the efficiency of the CMUT, materials with low bending stiffness should be selected, and the filling factor of the membrane should be increased. In order to achieve high-transmission sound pressure, a smaller radius thickness and a larger cavity height should be selected. To achieve high reception sensitivity, a larger membrane radius thickness and a smaller cavity height should be selected. In order to obtain high fractional bandwidth, a larger membrane radius thickness should be selected. The results of this paper provide a basis for the design of Vacuum CMUT cell structure.

Influence of Ultrasonic Vibration on Metal Plastic Forming

2013 ◽  
Vol 470 ◽  
pp. 162-169 ◽  
Author(s):  
Xing Jia Hu ◽  
Xin He Li ◽  
Qing Yuan Qin
Keyword(s):  
Ultrasonic Vibration ◽  
Single Point ◽  
Volume Effect ◽  
Simulation Software ◽  
Stress Strain ◽  
Processing Application ◽  
Experiment Platform ◽  
Element Simulation ◽  
Plastic Forming ◽  
The Impact

Establish the ultrasonic single-point extrusion experiment platform to carry out the experiment of conventional extrusion and ultrasonic extrusion for different materials. Compared with experimental results, explore volume effect of ultrasonic vibration plastic forming and analyze the impact of different amplitude of ultrasonic resonance on material's plastic deformation volume. It can be found that ultrasonic vibration has an influence on stress-strain of material to a certain extent. Take advantage of the MSC.Marc finite element simulation software to continually modify the stress-strain curves of the material, finally the simulation result coincides with experimental conclusion. The results show that ultrasonic vibration has a significant impact on metal forming, improving the flowing property of metallic material processing, and softening materials, which further proves that ultrasonic vibration has great effects and provides the theoretical basis for it in material of plastic processing application.

scholarly journals Performance evaluation of GPS / BDS combined single-point positioning based on RTKLIB

2020 ◽  
Vol 165 ◽  
pp. 03009
Author(s):  
Li Yan-yi ◽  
Huang Jin ◽  
Tang Ming-xiu
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Single Point ◽  
Least Square Method ◽  
Least Square ◽  
Filter Method ◽  
Single System ◽  
Positioning Error ◽  
Dual Mode ◽  
Kalman Filter Method

In order to evaluate the performance of GPS / BDS, RTKLIB, an open-source software of GNSS, is used in this paper. In this paper, the least square method, the weighted least square method and the extended Kalman filter method are respectively applied to BDS / GPS single system for data solution. Then, the BDS system and GPS system are used for fusion positioning and the positioning results of the two systems are compared with that of the single system. Through the comparison of experiments, on the premise of using the extended Kalman filter method for positioning, when the GPS signal is not good, BDS data is introduced for dual-mode positioning, the positioning error in e direction is reduced by 36.97%, the positioning error in U direction is reduced by 22.95%, and the spatial positioning error is reduced by 16.01%, which further reflects the advantages of dual-mode positioning in improving a system robustness and reducing the error.

Research on Surface Roughness of Supersonic Vibration Auxiliary Side Milling for Titanium Alloy

2021 ◽  
Author(s):  
XueTao Wei ◽  
caixue yue ◽  
DeSheng Hu ◽  
XianLi Liu ◽  
YunPeng Ding ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Prediction Model ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Simulation Software ◽  
Surface Roughness Prediction ◽  
Contour Shape ◽  
Element Simulation ◽  
Roughness Prediction

Abstract The processed surface contour shape is extracted with the finite element simulation software, and the difference value of contour shape change is used as the parameters of balancing surface roughness to construct the infinitesimal element cutting finite element model of supersonic vibration milling in cutting stability domain. The surface roughness trial scheme is designed in the central composite test design method to analyze the surface roughness test result in the response surface methodology. The surface roughness prediction model is established and optimized. Finally, the finite element simulation model and surface roughness prediction model are verified and analyzed through experiment. The research results show that, compared with the experiment results, the maximum error of finite element simulation model and surface roughness prediction model is 30.9% and12.3%, respectively. So, the model in this paper is accurate and will provide the theoretical basis for optimization study of auxiliary milling process of supersonic vibration.

Wear of Coated Cutting Tool Based on AdvantEdge

2014 ◽  
Vol 551 ◽  
pp. 221-227
Author(s):  
Zhi Qiang Zhang ◽  
Tie Qiang Gang ◽  
Yi Kai Yi
Keyword(s):  
Wear Rate ◽  
Coating Thickness ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Simulation Software ◽  
Machining Process ◽  
Sliding Velocity ◽  
Coating Materials ◽  
Element Simulation ◽  
Coated Tool

In this paper, based on finite element simulation software AdvantEdge, the effects of different coating materials and thickness on the wear of cutting tools during the machining process have been studied. For the tools with coating materials of TiAlN, Al2O3, TiN, TiC, we can calculate the wear rate according to the Usui mathematical model of tool wear, and then consider thickness factor of TiC coating. Because of the lowest thermal conductivity, the workpiece cut by TiC coated tool will soften first and more over cutting time, it result in the lowest wear rate. And with the increase of coating thickness, the effect of "thermal barrier" is more obvious for the relatively thicker coating tool, but the relative sliding velocity between the chip and tool is increasing meanwhile, so a suitable coating thickness is necessary.

The Study on Airborne Equipments Life Prediction Based on the Finite Element Simulation under Comprehensive Stress

2013 ◽  
Vol 365-366 ◽  
pp. 224-228
Author(s):  
Tian Ma ◽  
Chuan Ri Li ◽  
Shuang Long Rong
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Life Prediction ◽  
Single Point ◽  
Simulation Method ◽  
Distribution Fitting ◽  
Kinetic Experiment ◽  
Element Simulation ◽  
Vibration Stress ◽  
Equipment Lifetime

To predict an airborne equipment lifetime with finite element simulation method, use ANSYS and Flothem, respectively, to analysis vibration stress and temperature stress, corrected by kinetic experiment; then import the results into the failure prediction software-CALCE PWA, set the intensity and duration of stress according to its mission profile, finally get the component failure life prediction results under comprehensive temperature and vibration stress; extract the Monte-Carlo simulation data, use the single point of failure distribution fitting, fault clustering and multipoint distribution fusion method to get the board and the whole machines lifetime and reliability prediction. The design refinement suggestion of the airborne equipment is given at the end of the conclusion.

scholarly journals Movable Die and Loading Path Design in Tube Hydroforming of Irregular Bellows

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1518
Author(s):  
Yeong-Maw Hwang ◽  
Yau-Jiun Tsai
Keyword(s):  
Tube Hydroforming ◽  
Simulation Software ◽  
Die Design ◽  
Loading Path ◽  
Feeding Types ◽  
Element Simulation ◽  
Hydroforming Process ◽  
Formed Product ◽  
Loading Path Design ◽  
Deform 3D

Manufacturing of irregular bellows with small corner radii and sharp angles is a challenge in tube hydroforming processes. Design of movable dies with an appropriate loading path is an alternative solution to obtain products with required geometrical and dimensional specifications. In this paper, a tube hydroforming process using a novel movable die design is developed to decrease the internal pressure and the maximal thinning ratio in the formed product. Two kinds of feeding types are proposed to make the maximal thinning ratio in the formed bellows as small as possible. A finite element simulation software “DEFORM 3D” is used to analyze the plastic deformation of the tube within the die cavity using the proposed movable die design. Forming windows for sound products using different feeding types are also investigated. Finally, tube hydroforming experiments of irregular bellows are conducted and experimental thickness distributions of the products are compared with the simulation results to validate the analytical modeling with the proposed movable die concept.

scholarly journals Dual-Mode On-to-Off Modulation of Plasmon-Induced Transparency and Coupling Effect in Patterned Graphene-Based Terahertz Metasurface

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Zhimin Liu ◽  
Enduo Gao ◽  
Zhenbin Zhang ◽  
Hongjian Li ◽  
Hui Xu ◽  
...  
Keyword(s):  
Slow Light ◽  
Coupling Effect ◽  
Structural Parameters ◽  
Fdtd Simulation ◽  
Destructive Interference ◽  
Dual Mode ◽  
Coupled Mode ◽  
Induced Transparency ◽  
Difference Time ◽  
Plasmon Induced Transparency

AbstractThe plasmon-induced transparency (PIT), which is destructive interference between the superradiation mode and the subradiation mode, is studied in patterned graphene-based terahertz metasurface composed of graphene ribbons and graphene strips. As the results of finite-difference time-domain (FDTD) simulation and coupled-mode theory (CMT) fitting, the PIT can be dynamically modulated by the dual-mode. The left (right) transmission dip is mainly tailored by the gate voltage applied to graphene ribbons (stripes), respectively, meaning a dual-mode on-to-off modulator is realized. Surprisingly, an absorbance of 50% and slow-light property of 0.7 ps are also achieved, demonstrating the proposed PIT metasurface has important applications in absorption and slow-light. In addition, coupling effects between the graphene ribbons and the graphene strips in PIT metasurface with different structural parameters also are studied in detail. Thus, the proposed structure provides a new basis for the dual-mode on-to-off multi-function modulators.

scholarly journals Simulation, Design, and Test of a Dual-Differential D-Dot Overvoltage Sensor Based on the Field-Circuit Coupling Method

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3413 ◽  
Author(s):  
Pengcheng Zhao ◽  
Jingang Wang ◽  
Qian Wang ◽  
Qianbo Xiao ◽  
Ruiqiang Zhang ◽  
...  
Keyword(s):  
Steady State ◽  
Power Transmission ◽  
Circuit Simulation ◽  
Structural Parameters ◽  
Equivalent Circuit Model ◽  
Simulation Software ◽  
Power Grids ◽  
Coupling Method ◽  
Transient Performance ◽  
Simulation Design

Accurate measurement of overvoltage in power grids is of great significance to study the characteristics of overvoltage and design of insulation coordination. Based on the research of D-dot voltage sensor, we designed a Dual-Differential D-dot overvoltage sensor. In order to quantify the structural parameters of the sensor, improve the performance and measurement accuracy of the sensor. The Field-Circuit Coupling method was proposed to be used in the parameter design of D-dot overvoltage sensor. The joint simulation of space electromagnetic field model and equivalent circuit model of the Dual-Differential D-dot overvoltage sensor was established with the finite element simulation software Ansoft Maxwell and circuit simulation software Simplorer. Finally, the actual sensor was manufactured. A test platform was built to verify the steady-state and transient performance of the sensor. The results show that the Dual-Differential D-dot sensor has excellent steady-state and transient performance, the error of phase and amplitude are small, and the sensor can achieve the non-contact measurement of power transmission line. Simultaneously, the rationality of the Field-Circuit Coupling method was further verified.

Finite Element Analysis of Thermal-Mechanical Stress Induced Failure in Interconnects

1998 ◽  
Vol 539 ◽  
Author(s):  
X. Yu ◽  
K. Weide
Keyword(s):  
Finite Element ◽  
Mechanical Stress ◽  
Simulation Software ◽  
In Situ Observation ◽  
Stress Tests ◽  
Flux Divergence ◽  
Element Analysis ◽  
Element Simulation ◽  
Thermal Oxide ◽  
Failure Location

AbstractIn this work a study of the nature as well as an evalution of the thermal-mechanical stress in aluminum interconnects was carried out. A theoretical model discribes the atom flux which can be induced by the relaxation of the stress. Based on this theory an algorithm has been developed and integrated into the finite element simulation software. This algorithm allows the calculation of the mass flux divergence and prediction of the failure location before the damage occurs. For the verification of this algorithm an aluminum pad structure sputtered on thermal oxide layer was used. The failure location was correlated with in situ observation during the long term stress tests. Experimental results confirm that the observed structure degradations correspond with the simulations very well.

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