finite element Definition and 115 Threads

..though I figure it's sort of an analysis type problem. ∫wvdx=0 (int from 0 to 1) for all v in V. w is continuous on [0,1]. What it means to be in V: v in V satisfies being continuous on [0,1], v(0)=v(1)=0, and derivatives of v are piecewise continuous . Problem is: Show that w(x)=0 for x in...

Homework Statement I have the following practice problem which is presented as follows: What is the size of the global stiffness matrix K (i.e., Kuu) for the 2-D problem? http://imgur.com/KZec3 (Unsolved) http://imgur.com/piv1J (Solved) Homework Equations The Attempt at a...

Homework Statement The problem picture is attached(file 1),its a beam subjected to horizonatal ditributed load 2. Relevant examples the MATLAB solution for rectangular shape with vertical load on the upper right corner is like follow, i try to modify it according to the new picture...

Hi, Recently started with FEA - loving it, at least the modelling / load application part. Interpreting the results is tricky - particularly around where loads are applied. Got a project (no pics sorry) which has a drilled hole in a plate, and have applied the load as a a pressure...

As I know, the method to solve neutron problem is divided into two steps now, neutron transport calculation for fuel assemblies and neutron diffusion calculation for whole reactor core, both using specified code such as CASMO and SIMULATE from STUSVIK. I want to know whether the commercial...

Hi All, I'd like to what kind of steps need to be taken to accurately estimate the yield lines of RC structures. My intention is, to know what type of loading is acting on beams transferred from slabs. I know how to formulate thin/thick plates and shells. The results converges with commercial...

Folks, I have the book An Introduction to the Finite Element Method by J.N Reddy. The following website provides http://highered.mcgraw-hill.com/sites/0072466855/student_view0/executables.html access to the Fortran Executable but I am not sure how to work them. I am just beginning to...

Folks, Is there anyone out there familiar with 'An introduction to the Finite Element Method' by J.N. Reddy? I am struggling to decipher what is happening on page 129 as shown in the attachment. If some-one is willing to help I will reply with a more specific query on that page. Thanks

Hello, I know the value of a field variable in a 3d mapped finite element mesh. Can anyone suggest an effective method/methods to find its gradient throughout the mesh.

Hi, I'm facing a real-life problem and I don't what specific mathematics topic it's related to. Homework Statement I know the value of the components of a vector field in three points of space and I have to find the flux of this vector field through the surface defined by those...

Hi all. I would like to do a finite element simulation of a coil in a time-varying magnetic field, to see how much current is induced in the coil, and also to see how the coil itself affects its surroundings. Now my question is, how do I model a coil with several thousand turns in a practical...

Structural Analysis-Writing Finite Element Code, Dear all, I have written a code ( in fact it is a software) for 3D finite element structural analysis. While developing the code I found that assembling global stiffness matrix is quite complicated. The complication is even more when we...

Dear all, I have written a code for dynamic analysis of a mechanical structure. My primary purpose is to find natural frequencies of the structure. When I test my code for a cantilever bar whose natural frequencies are known analytically, I found a big difference between the the first...

Dear all, I have written a code for structural analysis using the finite element method. For some reason, I directly started with 3D elements ( hexahedron). I used to believe that the code was fine but recently i realized that the results ( deformation, natural frequency,..) strongly depend...

Hi all, A fixed-free bar has a single natural frequency. When we discretize such a bar in the finite element method, then the natural frequencies are the eigenvalues and an nχn matrix where n is the number of the degree of freedom which is usually large. Thus we obtain up to n natural...

Hi all, I need to do a dynamic structural analysis using finite element method and I have a question about the mass matrix. Question: I have the force per nodes and I need to calculate the displacement of each node at a given time. For this purpose, it seems that I need to distribute the...

So I just started learning to use the finite element package abaqus for modelling beam tip deflection under different loading conditions. I think I understand the theory behind it but was wondering if some one could answer a few questions about it to further my understanding. Firstly, how do...

Hello, I have been following this forum for some time now, but this is the first time I participate. I would appreciate if you could give me a hand in understanding the results of a finite element analysis of an automotive component we have designed. The analysis results indicate that the...

Hi Could anyone point me in the right direction? I'm employed at a small firm, only three employees at the time being. Our competencies spans from architecture to programming. We're in need of somebody who can help us create a finite element solution which we can implement in the cad...

Hello, I am trying to solve the shallow water equations using finite element method. Can anyone explain me how to treat nonlinear term in the Galerkin equation? so for example in the equation for the velocity we will have the term u\nabla v where u and v are the velocity components. For...

I am solving the heat equation in a non comercial C++ finite elements code with explicit euler stepping, and adaptive meshes (coarse in the boundaries and finer in the center). I am aware the CFL condition for the heat equation depends on dt/h**2 for the 1D, 2D, 3D case. When I solve the...

Hello all: For modeling flow (or whatever) in a non-rectangular geometry, can anyone comment on whether the finite element method would be better or worse or the same as the integrated finite difference method? I'm reading some papers by competing groups (so I can decide which code to...

Homework Statement Two ends of a bar of length L are held at temperatures To and TL at positions x=o and x=L, respectively. Thermal conductivity k(x)= Ko/(1+ x/L) , ko is a constant. cross section of the bar is uniform and longs sides are thermally insulated, there's no source of heat...

I'm looking for information regarding the use of the finite element method (FEM) for crash test analysis and crumple zones? Basically I'm wondering what part of FEM do I use to make crash test analysis possible. I'm also looking for books on the subject or software libraries that can be used for...

I am trying to do a finite element analysis ofcold extrusion process of a tube wherein the steel tube is reduced from a larger outer diamter to a smaller one by extrusion process.The tube is held stationary and the die is pushed into the tube for a particular length and then retrieved.I am...

To the EE Forum, I am a new guy on this Physics Forum and this is my first post. I have downloaded a free software code, Finite Element Method Magnetics (FEMM) solver (see http://www.femm.info/wiki/Download) but it doesn’t work because FEMM is limited to solving low frequency electromagnetic...

Hi guys I wish to self-study the Finite Element Method. I am mostly interested in learning how to understand and implement the method rather than to investigate if a solution exists, i.e. I wish to follow the "engineering-approach" rather than the "mathematician-approach". Do you have any...

Homework Statement I have a designed a Finite Element code for a Poisson problem using Bilinear Element. - \DeltaU= 2\pi^{2}Sin(\pi X)Sin(\pi Y) U = 0 The exact solution is given by : UEX = Sin(\pi X)Sin(\pi Y). 2. The attempt at a solution On convergence analysis:Theoretically, if...

Homework Statement The MATLAB program below uses the finite element method to solve a Dirichlet problem for Poisson's equation. -a1u''(x) = 0, xl < x < xh u(xl) = 0, u(xh) = 1 Modify the problem to solve -u''(x) + u(x) = 1, xl < x < xh...

I am doing BE in mechanical engineering. I'm looking for a comprehensive book on finite element methods preferably with a lot of solved numericals . Suggestions, please?

Homework Statement Hi guys Is there a difference between finite element methods and finite volume methods? Or do they both rely on each other? Niles.

i am a 3rd year civil engineering student, currently taking a course in which i need to use finite element software for assignments. the course is 100% theory, and i need to learn how to use the software on my own, i am looking for FREE software with FE capabilities, and preferably one that...

do suggest a good book for finite element method?some books have left me confused over the various methods

Hello all, I am trying to create a simple finite element program in C++ and have been able to build and assemble the GLOBAL stiffness matrix as well as the load vector. I want to apply the boundary conditions using the elimination approach, can anyone tell me how to do this? I am sorry for...

Hi everyone, I'm currently working on coding a finite element heat problem in Matlab that is as follows: I have a cross section of a beam made of an isotropic material (concrete) that is placed in a furnace, and the outside temperature is raised at a constant rate. I am interested in...

Hi everyone, As part of a project, I am required to numerically compute the expression b_{i}^{e} &=& \frac{E_{0}^{i}k_0^2(\epsilon_r-1/\mu_r)}{2\Delta^e}\left[\iint\limits_{\Omega^e}(a_i^e + b_i^e x + c_i^e y)e^{-jk_0 x} dx dy\right] \nonumber\\&&- \frac{jk_0 E_0^i r'}{2\Delta^e...

I am trying to run a finite element analysis for a collision impact. The program I am using is MD Patran/Nastran. My model consists of moving object colliding with a stationary object. I have created the mesh, applied the appropriate material, applied the boundary conditions (fixed for the...

I am on a research project where I am finding the heat capacitance and thermal conductance of a material and would like to simulate it on a larger scale as material for heated flooring. Is there a program where I can do a looping heating pipe at a set temperature and show the conductance of the...

Hi there I'm having a trouble with the following proof.I have the exam soon and he has asked this question every year so I have no doubt that he will ask it again.I have no idea how to do it?If you can help me I would be greatly appreciative. Question: Consider the 2-point boundary value...

Hi there I'm having a trouble with the following proof.I have the exam soon and he has asked this question every year so I have no doubt that he will ask it again.I have no idea how to do it?If you can help me I would be greatly appreciative. Question: Consider the 2-point boundary value...

Homework Statement this is part of a theorem for the error estimate for the model problem for finite element method. i have to prove the following inequality: \left|u'(x)-\tilde{u}'_h(x)\right|\leq max_{0\leq(y)\leq1}\left|u''(y)\right| Homework Equations \tilde{u_h} is the...

Hello, I was just reading about implicit vs explicit finite element solvers and have a question about the difference between them. I understand that the implicit solver has a linear approximation step that is used to force equilibrium. My question is does that make the explicit solver...

I am trying to make a program that solves elasticity problems with finite element method and I don't understand how to bring in boundary conditions. Constant displacement boundary conditions seem simple: replace variables that represent the displacements at surface nodes with the prescribed...

To the moderator: Please shift this to the appropriate forum if this isn't the place for it. EDIT -- It seems this (https://www.physicsforums.com/forumdisplay.php?f=189) is the right place for it? Sorry I overlooked this forum. ----- Hi everyone, I am solving some 2D boundary value problems in...

Hello I have an assignemt to analysis a landing gear for the cyclone earoplane, an initial design being supplied, I have being askedto check for the suitability of the part, the conditions are: Aircraft mass with fuel: 43000 lbs Landing speed: 65 Knots Maximum deceleration: 3g Each part...

Hi, Does anyone know where I can get any programming for finite element in 3d object not calculation but for the display such as cad (e.g. meshing display)? Also what software that can do above operation? I mean, not ansys, nastran, algor, etc., but other that I can make it by myself by my...

Find the Finite element solution for a equation: (∂^2 u)/〖∂x〗^(2 ) +(∂^2 u)/〖∂y〗^2 +λu-c=0 using linear triangular finite elememts. In the above equation u is scalar,λ is a constant and is a body force term(constant). The boundary conditons are in terms of prescribed values of the function...

Homework Statement Hi, I've got a civ engineering problem relating to conductive heat flow using finite element analysis. I'm investigating the dissipation of heat from square and circular pile foundations. I'm applying a thermal load to the centre of the concrete pile which induces heat...

I'm looking at project investigating thermal dissiplation around circular and square concrete piles, resting in a homogeneous material (soil) using two-dimensional finite element analysis. I'm applying a transient thermal loading cycle to the centre of the concrete pile over a 7-day test...

i need a full explanation on finite element method or better still a material i can read to help me understand better