# Pde and fem simple example

1. Jul 31, 2006

### chandran

i want to understand finite element method by solving the simple differential equation of falling mass

d2y/dx2=force/mass

eventhough this equation contains derivative of only one variable i want to understand fem using this

Or some one can give a somemore difficult pde and solve using fem

with this DE how can i understand boundary condition and initial condition. i

2. Sep 19, 2006

### Staff: Mentor

FEM is used in various boundary value problems (BVP), and BVP-IVP (initial value problems), both static and dynamic.

The falling mass is a simple one dimensional problem and would be rather poor for understanding FEM.

FEM is used to calculate stresses and strain in various mechanical (static and dynamic) problems, fluid mechanics, computational fluid dynamics, heat transfer problems, and combinations thereof.

3. Sep 23, 2006

### pravinsingh

i want some relevant problem in nodal analysis

4. Sep 23, 2006

### Staff: Mentor

Well, first of all, the convention is to right acceleration as d2y/dt2 = F/m = g. Of course this can be solved analytically, although one could do it numerically.

Say, Please. Let me see what I can do.

Basically, FEM involves the numerical solution to differential equations (ordinary or partial), and these are generally those equations which are applied to 2D (areas) or 3D (volumes) elements. The boundaries of 2D areas are lines (1D), and the boundaries of volumes are areas (2D).

The key to FEA/FEM is the "mesh discretization of a continuous domain into a set of discrete sub-domains."

Here is some background -
FEA - http://en.wikipedia.org/wiki/Finite_element_analysis

FEM - http://en.wikipedia.org/wiki/Finite_element_method

I work with two guys who were FEM pioneers at Berkeley during the 1960's.

5. Nov 4, 2008

### vend

can anyone teach me what is fem and pde? i am newbie on it.. i've read so many article about it.. but i'm still confuse.. can anyone give me explanation about it? thanks a lot..

6. Nov 4, 2008

### HallsofIvy

Staff Emeritus
So you want someone to teach you a full course? I don't think that's going to happen. Ask specific questions and you will get specific answers.