scholarly journals Investigation of the motion characteristics for a long flexible rotating pipe in flow by IDVM–FEM method

AIP Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 115304
Author(s):  
Wei Chen ◽  
Chang-kyu Rheem ◽  
Shuangxi Xu ◽  
Xiaobin Li
Keyword(s):  
Fem Method ◽  
Motion Characteristics

scholarly journals Influence of motion characteristics of dual stealth aircraft on monopulse radar performance

2020 ◽  
Vol 1676 ◽  
pp. 012222
Author(s):  
Lei Bao ◽  
Chun-yang Wang ◽  
Tao-dong ◽  
Juan Bai ◽  
Sheng-Jun Wei ◽  
...  
Keyword(s):  
Motion Characteristics

scholarly journals Research on Measurement Method of Parachute Scanning Platform Based on MEMS Device

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 402
Author(s):  
Ning Liu ◽  
Tianqi Tian ◽  
Zhong Su ◽  
Wenhao Qi
Keyword(s):  
Physical Simulation ◽  
Inertial Sensors ◽  
Rotational Velocity ◽  
Attitude Measurement ◽  
Matlab Simulation ◽  
Scanning Angle ◽  
Reduce Development Time ◽  
Motion Parameters ◽  
Motion Characteristics ◽  
Scanning Motion

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

scholarly journals Influence of CFRC Insulating Plates on Spark Plasma Sintering Process

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 393
Author(s):  
Alexander M. Laptev ◽  
Jürgen Hennicke ◽  
Robert Ihl
Keyword(s):  
Temperature Distribution ◽  
Spark Plasma Sintering ◽  
Energy Demand ◽  
Composite Powders ◽  
Fem Method ◽  
Plasma Sintering ◽  
Axial Temperature ◽  
Spark Plasma ◽  
Power And Energy ◽  
The Impact

Spark Plasma Sintering (SPS) is a technology used for fast consolidation of metallic, ceramic, and composite powders. The upscaling of this technology requires a reduction in energy consumption and homogenization of temperature in compacts. The application of Carbon Fiber-Reinforced Carbon (CFRC) insulating plates between the sintering setup and the electrodes is frequently considered as a measure to attain these goals. However, the efficiency of such a practice remains largely unexplored so far. In the present paper, the impact of CFRC plates on required power, total sintering energy, and temperature distribution was investigated by experiments and by Finite Element Modeling (FEM). The study was performed at a temperature of 1000 °C with a graphite dummy mimicking an SPS setup. A rather moderate influence of CFRC plates on power and energy demand was found. Furthermore, the cooling stage becomes considerably longer. However, the application of CFRC plates leads to a significant reduction in the axial temperature gradient. The comparative analysis of experimental and modeling results showed the good capability of the FEM method for prediction of temperature distribution and required electric current. However, a discrepancy between measured and calculated voltage and power was found. This issue must be further investigated, considering the influence of AC harmonics in the DC field.

A reciprocating permanent magnetic actuator for driving magnetic micro robots in fluids

2021 ◽  
pp. 095440622110145
Author(s):  
Chuan Qu ◽  
Yong-Chen Pei ◽  
Qing-Yuan Xin ◽  
Zhen-Xing Li ◽  
Long Xu
Keyword(s):  
Permanent Magnet ◽  
Analytical Calculation ◽  
Magnetic Actuator ◽  
Cross Sectional ◽  
Permanent Magnetic Actuator ◽  
Element Simulation ◽  
Micro Robot ◽  
Analytical Formulas ◽  
Motion Performance ◽  
Motion Characteristics

Magnetic-based driving applications are receiving increasing attention. This study proposed a novel reciprocating permanent magnetic actuator (PMA) to manipulate magnetic micro robots to impact and clear blockages inside fluid pipes in a linear path. The PMA consisted of a cylindrical permanent magnet and a crank slider structure. A straight pipe with a circular cross-sectional area was located in front of the actuator to study the driving performance of PMA. A micro permanent magnet with a cylinder shape was employed as a working robot for manipulation inside the pipe. Firstly, analytical formulas were derived to obtain the magnetic driving force acting on the micro robot and determine the most suitable magnet configuration. The finite element simulation verified the analytical calculation. The developed reciprocating PMA prototype was then introduced, and the PMA and micro robot’s motion performance was analysed. Lastly, preliminary experiments were carried out for evaluating the micro robot’s motion characteristics. Performance tests for different excitation frequencies, flow rates, viscosities, and axial distances, indicating that PMA could manipulate the magnetic micro robot inside the pipe. The results confirmed that the developed PMA could effectively drive the micro robot with the advantage of consecutive magnetic driving. Especially, the micro robot featured good flexibility, rapid response, and a simple structure, suggesting that this micro robot may play an important role in industrial and medical applications, such as blockage elimination and thrombus clearance.

scholarly journals Out-of-plane local mechanism analysis with finite element method

2021 ◽  
Vol 8 (1) ◽  
pp. 130-136
Author(s):  
Roberto Spagnuolo
Keyword(s):  
Finite Element ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Mechanism Analysis ◽  
Fem Method ◽  
Local Mechanism ◽  
Out Of Plane ◽  
Smeared Crack ◽  
The Stability ◽  
No Tension Material

Abstract The stability check of masonry structures is a debated problem in Italy that poses serious problems for its extensive use. Indeed, the danger of out of plane collapse of masonry walls, which is one of the more challenging to evaluate, is traditionally addressed not using finite element models (FEM). The power of FEM is not properly used and some simplified method are preferred. In this paper the use of the thrust surface is suggested. This concept allows to to evaluate the eccentricity of the membrane stresses using the FEM method. For this purpose a sophisticated, layered, finite element with a no-tension material is used. To model a no-tension material we used the smeared crack method as it is not mesh-dependent and it is well known since the early ’80 in an ASCE Report [1]. The described element has been implemented by the author in the program Nòlian by Softing.

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