On the Prediction of Fusion Rate of Ice by Finite Element Analysis

1981 ◽  
Vol 103 (4) ◽  
pp. 727-732 ◽  
Author(s):  
T. R. Hsu ◽  
G. Pizey
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fresh Water ◽  
Close Agreement ◽  
Fusion Rate ◽  
Ambient Conditions ◽  
Element Analysis ◽  
Complicated Geometries ◽  
Multi Phase ◽  
Element Algorithm

A finite element algorithm including phase change is presented for the prediction of the rate of freezing of fresh water under general ambient conditions. This method has shown to be highly versatile in dealing with multi-phase materials of complicated geometries. Experiments were performed to verify the code prediction on the fusion of fresh water and a case with oil inclusion. Close agreement was observed between the predicted and measured values.

scholarly journals Modeling Stray Capacitances of High-Voltage Capacitive Dividers for Conventional Measurement Setups

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1262
Author(s):  
Alessandro Mingotti ◽  
Federica Costa ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli ◽  
Paolo Mazza
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Equivalent Circuit ◽  
High Voltage ◽  
Equivalent Model ◽  
Simulation Environment ◽  
Element Analysis ◽  
Ratio Error ◽  
Complicated Geometries

Stray capacitances (SCs) are a serious issue in high-voltage (HV) applications. Their presence can alter the circuit or the operation of a device, resulting in wrong or even disastrous consequences. To this purpose, in this work, we describe the modeling of SCs in HV capacitive dividers. Such modeling does not rely on finite element analysis or complicated geometries; instead, it starts from an equivalent circuit of a conventional measurement setup described by the standard IEC 61869-11. Once the equivalent model including the SCs is found, closed expressions of the SCs are derived starting from the ratio error definition. Afterwards, they are validated in a simulation environment by implementing various circuit configurations. The results demonstrate the expressions applicability and effectiveness; hence, thanks to their simplicity, they can be implemented by system operators, researchers, and manufacturers avoiding the use of complicated methods and technologies.

scholarly journals Dynamic Analysis of Folded Low Shells by Using Finite Element Analysis

2020 ◽  
pp. 94-103
Author(s):  
Emmanuel E. T. Olodo ◽  
Georges Adjibola A. Ale ◽  
Edmond Codjo Adjovi ◽  
Antoine Vianou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Variational Principle ◽  
Harmonic Analysis ◽  
Forced Vibrations ◽  
Internal Damping ◽  
Element Analysis ◽  
Dynamic Stresses ◽  
Element Algorithm ◽  
Calculation Code

Aims: This work is devoted to the development of a finite element algorithm for solving problem in forced vibrations of folded low shells. Methodology: The differential equations for harmonic analysis are obtained from the Lagrange variational principle. Description of the dynamic behavior is made by the structure discretization into a system of curvilinear iso-parametric finite elements used in modal analysis. The method is implemented by a calculation code on a square-plane folded shell model withnumber of crease edges in both directions k=l=3. Results: Displacement amplitudesare obtained by decomposition into vibration eigenforms. The maximum values of dynamic stresses are determined taking into account the shell's support conditions.The results of the harmonic analysis show thatimprovement in frequency characteristics and reduction of stresses in the folded shell depend on the constructive and internal damping of the structureand the increase in the number of fold edges k and l in both directions for examplebecause this contributes to decrease in the forced vibration amplitudes.

scholarly journals Finite Element Analysis of Springback of High-Strength Metal SCGA1180DUB While U-Channeling, According to Wall Angle and Die Radius

2021 ◽  
Author(s):  
Samet Karabulut ◽  
İsmail Esen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sheet Thickness ◽  
High Strength ◽  
Sheet Forming ◽  
High Yield ◽  
Process Conditions ◽  
Wall Angle ◽  
Element Analysis ◽  
Multi Phase

Abstract Springback is a problem as important as tearing or thinning, while forming high-strength sheets. Springback is an undesirable situation and it is the form difference between the desired form of a part in theory and the form obtained due to mechanical characteristics and process inputs of the material after die forming. It affects operations in shearing, punching or bending dies in subsequent operations in forming die sets. If the part is not within the desired tolerance range, it creates problems during assembly. In order for cost effective production plans for automotive parts to be made, suitable sheet forming simulations are needed. Waste of time and failures during die construction are minimized by defining accurate parameters by finite element analyses and minimizing periods of trial-and-error. In this study, the material SCGA1180DUB in sheet thickness of 0.8 mm from multi-phase steel sheet group was U-channeled, using Autoform sheet forming analysis program, according to appropriate process conditions having wall angles of 7°,10°,12° and die radius values of R3, R5, R8 and the springback values were estimated. The results obtained were compared through the finite element program and suitable wall angle and die radius values for the material SCGA1180DUB for forming advanced high-strength sheets were determined. As the die radii increased at the same wall angles, the amount of spring back increased significantly. In particular, due to high yield and tensile strength of multi-phase high strength sheet, springback values were observed to be high. Negative springbacks were observed in the roof of the part. In the same die radii, under the same process conditions, as wall angles increase, springback values decreased. In the literature, it is interesting that there are few studies regarding forming, springback of high-strength sheets SCGA1180DUB. This study will contribute to the literature. Autoform program was used for Finite Element Analysis.

The influence of lateral spreading on settlements beneath a fill

1994 ◽  
Vol 31 (2) ◽  
pp. 145-150
Author(s):  
C.B. Crawford ◽  
H. Jitno ◽  
P.M. Byrne
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Close Agreement ◽  
Lateral Spreading ◽  
Two Dimensional ◽  
Element Analysis ◽  
Vertical Movements ◽  
One Dimensional ◽  
Dimensional Finite Element ◽  
Earth Embankment

The discrepancy between calculated consolidation settlements and measured settlements under a 3.8 m high section of an earth embankment is investigated in this paper. A conventional one-dimensional analysis underestimated the observed settlement by 40%. A two-dimensional finite-element analysis was carried out to assess the effects of lateral spreading on vertical movements, and the results were in close agreement with the measured values. Key words : case history, consolidation, finite element analysis, settlement.

Laterally Actuated Platinum-Coated Polysilicon NEM Relays

2013 ◽  
Vol 22 (3) ◽  
pp. 768-778 ◽  
Author(s):  
Roozbeh Parsa ◽  
W Lee ◽  
Mohammad Shavezipur ◽  
J Provine ◽  
Roya Maboudian ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Electrical Properties ◽  
Polycrystalline Silicon ◽  
Surface Oxidation ◽  
Experimental Tests ◽  
Ambient Conditions ◽  
Element Analysis ◽  
Drain Bias ◽  
Logic Component

Laterally actuated polycrystalline silicon nanoelectromechanical (NEM) relays with enhanced electrical properties are presented. Due to surface oxidation of polysilicon in room ambient conditions, the relays have a high contact resistance (> 1 GΩ) that requires high drain bias (3-5 V) to break through. The addition of a platinum sidewall coating reduces the on-resistance and the required drain bias to as low as 3 kΩ and 0.1 V, respectively. The platinum coating's stability is demonstrated by two tests: first, a contact-and-hold test where the relay passes current (~1μA) for up to 155 min and, second, a hot cycling test where the relay survives for over 108cycles . The NEMS relays are simulated using finite-element analysis, and the models are verified against experimental tests. Furthermore, the relays are configured and tested as a 2 : 1 multiplexer to show their potential as a digital logic component.

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