Moving Path Analysis of a Cannonball Colliding onto Water

2011 ◽  
Vol 120 ◽  
pp. 414-417
Author(s):  
Joon Sik Youn ◽  
Young Hun Jung ◽  
Han Seok Bang ◽  
Hae Suk Lee ◽  
Yeon Sik Cho ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Path Analysis ◽  
Normal Force ◽  
Initial Conditions ◽  
Moving Path ◽  
Element Method

When a cannonball collides onto water, it can ricochet several times because normal force is generated larger than the weight. In order to determine the moving path, an analysis is done to calculate the position and velocity of the cannonball and the force acting on the cannonball using a finite element method. It is shown that the cannonball motion depends on the initial conditions such as cannonball shape, firing velocity, and firing angle.

Computer simulation of optical radiation scattering by aerosol media

2020 ◽  
Vol 86 (8) ◽  
pp. 43-48
Author(s):  
V. V. Semenov
Keyword(s):  
Finite Element Method ◽  
Computer Simulation ◽  
Finite Element ◽  
Optical Radiation ◽  
Light Transmission ◽  
Initial Conditions ◽  
Practical Significance ◽  
The Finite Element Method ◽  
Dispersed Medium ◽  
Element Method

Development of the technologies simulating optical processes in an arbitrary dispersed medium is one of the important directions in the field of optical instrumentation and can provide computer simulation of the processes instead of using expensive equipment in physical experiments. The goal of the study is simulation of scattering of optical radiation by aerosol media using the finite element method to show a practical significance of the results of virtual experiments. We used the following initial conditions of the model: radius of a spherical particle of distilled water is 1 μm, wavelength of the incident optical radiation is 0.6328 μm, air is a medium surrounding the particle. An algorithm for implementation of the model by the finite element method is proposed. A subprogram has been developed which automates a virtual experiment for a group of particles to form their random arrangement in the model and possibility of changing their geometric shape and size within predetermined intervals. Model dependences of the radiation intensity on the scattering angle for single particle and groups of particles are presented. Simulation of the light transmission through a dispersed medium provides development of a given photosensor design and determination of the minimum number of photodetectors when measuring the parameters of the medium under study via analysis of the indicatrix of scattering by a group of particles.

Effect of geosynthetics on the hydraulic performance of leak-detection systems

2005 ◽  
Vol 42 (5) ◽  
pp. 1359-1376 ◽  
Author(s):  
R Kerry Rowe ◽  
T Iryo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Conditions ◽  
Leak Detection ◽  
Hydraulic Performance ◽  
Degree Of Saturation ◽  
Geosynthetic Clay Liners ◽  
Composite Liner ◽  
Leachate Collection ◽  
Element Method

The hydraulic performance of a leak-detection – secondary leachate collection system below a composite liner consisting of a geomembrane (GM) over a geosynthetic clay liner (GCL) is studied using the finite element method. The effect of the initial conditions in the underlying foundation layer (e.g., compacted site soils), distance from the leakage point to the drainage point, properties of the GCL, hydration history of the GCL, and the presence–absence of a foundation layer are examined. The interaction between the GM–GCL interface, GCL foundation layer interface, and the underlying geocomposite is investigated. The time for leakage to be detected is shown to be highly dependent on the material below the composite liner, the initial degree of saturation of the material, and the distance between the hole wrinkle and the drainage point in the system. Under some circumstances this could result in leakage not being detected for a considerable period of time. Predicted leakage is shown to be similar in magnitude to that reported in field monitoring. A comparison of an analytical solution for steady state conditions with the numerical solution shows excellent agreement.Key words: geomembranes, geosynthetic clay liners, leakage, leachate collection, finite element method.

Convergence of a homotopy finite element method for computing steady states of Burgers’ equation

2019 ◽  
Vol 53 (5) ◽  
pp. 1629-1644 ◽  
Author(s):  
Wenrui Hao ◽  
Yong Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steady State ◽  
Burgers Equation ◽  
Initial Conditions ◽  
Steady State Solution ◽  
State Problem ◽  
Steady State Problem ◽  
Steady State Solutions ◽  
Element Method

In this paper, the convergence of a homotopy method (1.1) for solving the steady state problem of Burgers’ equation is considered. When ν is fixed, we prove that the solution of (1.1) converges to the unique steady state solution as ε → 0, which is independent of the initial conditions. Numerical examples are presented to confirm this conclusion by using the continuous finite element method. In contrast, when ν = ε →, numerically we show that steady state solutions obtained by (1.1) indeed depend on initial conditions.

Modal reduction-based finite element method for nonlinear FG piezoelectric energy harvesters

2021 ◽  
pp. 107754632110481
Author(s):  
Parisa Fatehi ◽  
Mojtaba Mahzoon ◽  
Mehrdad Farid ◽  
Hassan Parandvar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Conditions ◽  
Geometrical Nonlinearity ◽  
Polymer Materials ◽  
Computational Time ◽  
Accurate Estimation ◽  
Piezoelectric Energy ◽  
Modal Reduction ◽  
Element Method

In this study, harvesting energy from a nonlinear functionally graded (FG) piezoelectric cantilever beam under harmonic excitation is investigated. The material properties of the piezoelectric are assumed to be a combination of piezo-ceramic and piezo-polymer materials for high performance and flexibility. The neutral axis is obtained in order to eliminate bending–stretching coupling. The geometrical nonlinearity and electromechanical coupling are incorporated in the coupled nonlinear equations that are derived using the generalized Hamilton’s principle and solved using the combination of modal reduction and finite element methods. The shooting method is employed to obtain steady-state periodic response of an FG nonlinear harvester with appropriate initial conditions. Also it is shown that at least two-mode approximation is required for accurate estimation of nonlinear response and harvested power. Using the method of nonlinear modal reduction, the unstable branches for frequency domain solution are estimated and the computational time is reduced considerably compared to full finite element method. A case study is also accomplished in detail to analyze the effects of base amplitude values and material distribution on harvested power and bandwidth.

scholarly journals Methods for Determining the Thermal Transfer in Phase-Changing Materials (PCMs)

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 467
Author(s):  
Vasile Bendic ◽  
Dan Dobrotă ◽  
Ionel Simion ◽  
Emilia Bălan ◽  
Nicoleta-Elisabeta Pascu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Research ◽  
Initial Conditions ◽  
Complex Coacervation ◽  
The Finite Element Method ◽  
Hot Plate ◽  
Plate Interface ◽  
Thermal Transfer ◽  
Element Method

A very important issue that needs to be solved as simply and correctly as possible is how to establish the thermal performance of phase-changing materials (PCM). The undertaken researches have analyzed the values of the thermal performances of the PCM taking into account the method of finite elements and the experimental research, respectively, based on a modern measurement system that was designed and implemented. Butyl stearate which has been encapsulated through complex coacervation in polymethyl methacrylate has been used as a PCM. Samples were made containing 10%, 20%, 30% and 40% PCM, respectively, within their structure. The research has established that at both the hot plate and the cold plate interface, the evolution of the temperature over time, established by both the finite element method (FEM) and experimental research, are quite close, and the best results have been obtained for the P30 sample. A very important thing observed during the finite element method (FEM) is that the simulated thermal flow variation extends between 2700-3110W/m2 being small enough not to influence the temperature measurement at the interface of hot or cold plates. Thus, the use of the FEM or the experimental research method can be applied with good results, provided that the correct initial conditions are used in the finite element method and that the experimental research is performed using the best possible apparatus.

Analysis of Creep in a Si-SiC C-Ring by Finite Element Method

1992 ◽  
Vol 114 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Tze-jer Chuang ◽  
Zheng-Dong Wang ◽  
Dongdi Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Constitutive Equations ◽  
Initial Conditions ◽  
Damage Zone ◽  
Time History ◽  
Principal Stresses ◽  
Creep Tests ◽  
Time Step ◽  
Element Method

The long-term creep deformation of a siliconized silicon carbide ceramic C-ring subjected to a compression load at 1300°C in air is studied by the finite element method. Based on asymmetric creep responses observed under uniaxial creep tests, multidirectional constitutive equations in power-law form are derived using the parameters of effective stress/strain. The elastic solutions are first solved and used as a guide to reach the final mesh design and as initial conditions. Solving the initial value problem in which equilibrium and constitutive equations are satisfied at all times, this model gives time-history of stresses and displacements. Fair agreements were obtained in load-point displacement rate, damage zone, neutral axis locations, stress relaxation and redistribution when compared with simple curved beam theory and experimental data. As common with other nonlinear problems, the convergence of the finite element solutions strongly depends on the time step as well as the finess of the element size, particularly at the regions where principal stresses are close to the threshold stress for creep damage.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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