Boundary conditions
Image
The solution to the wave equation
$\displaystyle\frac{\partial^2 u}{\partial t^2}= c ^2\displaystyle\frac{\partial^2 u}{\partial x^2}$ |
is of the form
$ z = z_0 e^{ i( k s - \omega t )}$ |
but it must satisfy the conditions of free or fixed edge. In the edge case
- free wave can move but has no support so the stress and thus the deformation must be zero.
- fixed the wave cannot move but it can generate tension and with it deformation
Graphically, we have
ID:(14186, 0)
Standing waves
Image
The equation
It means that there are two solutions.
$\omega = \pm c k$
so the solution is of the form
$x_0 e^{ikx}(e^{i\omega t)}+e^{-i\omega t})$
or with Euler's relation the real part is
$2x_0 \cos(kx)\cos(\omega t)$
In other words, a function of the position oscillates in the same place without moving:
This is called a standing wave.
ID:(14205, 0)
Solution modes
Image
Las condiciones de borde permiten soluciones que tienen mas nodos como se ve en el ejemplo fijo-libre
ID:(14190, 0)
Model
Top
Parameters
Variables
Calculations
Calculations
Calculations
Equations
$ z = z_0 e^{ i( k s - \omega t )}$
z = z_0 * exp( %i *( k * s - omega * t ))
$\displaystyle\frac{\partial^2 u}{\partial t^2}= c ^2\displaystyle\frac{\partial^2 u}{\partial x^2}$
@DIF( u , t , 2) = c ^2*@DIF( u , x , 2)
ID:(15583, 0)
Wave equation
Equation
La ecuación de movimiento
$\displaystyle\frac{\partial^2 u_i}{\partial t^2}=\displaystyle\frac{ E }{ \rho }\displaystyle\frac{\partial^2 u_i}{\partial x^2}$ |
con la relación
$ c ^2 = \displaystyle\frac{ E }{ \rho }$ |
representa la ecuación de onda del solido
$\displaystyle\frac{\partial^2 u}{\partial t^2}= c ^2\displaystyle\frac{\partial^2 u}{\partial x^2}$ |
ID:(14180, 0)
General solution of the wave equation
Equation
The general solution of the wave equation
$\displaystyle\frac{\partial^2 u}{\partial t^2}= c ^2\displaystyle\frac{\partial^2 u}{\partial x^2}$ |
can be written in the complex space as
$ z = z_0 e^{ i( k s - \omega t )}$ |
ID:(14187, 0)