If you attempt to pole radially a cylindrical element to get the acoustic properties, the cylinder will have to be broken into many smaller elements and individually poled.
Here's how to do it.
Section 1: How to pole radially a cylindrical model
So, first, the model does need to be broken into smaller elements that all have their own poling direction but this can be automated to a certain extent by passing a custom coordinate system to the material.
Here's a video showing how to do that
Here's an example file with cylindrical poling implemented for a cylinder:
Section 2: Step by step process for radial poling
Let's see step by step how to create a new cylinder poling axis and how to assign it to the material.
Step 1- Create a new cylinder Axis
In the Axis command, add the 2 following commands:
axis form vctr defn posx car2 0. 0. 0. 1. 0. 0. 0. 1. 0. defn negx car2 0. 0. 0. -1. 0. 0. 0. 1. 0. defn posy car2 0. 0. 0. 0. 1. 0. 0. 0. 1. defn negy car2 0. 0. 0. 0. -1. 0. 0. 0. 1. defn posz car2 0. 0. 0. 0. 0. 1. 1. 0. 0. defn negz car2 0. 0. 0. 0. 0. -1. 1. 0. 0. form angl defn cylnaxis cyln 0. 0. 0. 90. 0. 0. end
Step 2 - Associate this axis in the material
Find the Axis command in the material definition and modify it like this:
axis aln cylnaxis plusr 0. 360. 120. /* relate materials local system to global system
The convention used here is the following:
axis matname axisname option thetabeg thetaend ntheta phibeg phiend nphi
The parameters are the following:
option: Enter PLUSR for poling in the radial direction (i.e. the z’ axis of the material coincides with the local radial direction). MINUSR for poling in the negative radial direction
thetabeg, thetaend, ntheta: ntheta orientations will be defined between thetabeg, thetaend. Theta should be input in degrees
phibeg, phiend, nphi: For spherical systems, nphi orientations will be defined between phibeg, phiend. phi should be input in degrees.
Note: For cylindrical or spherical systems, multiple materials with the same basic properties but different orientations may be automatically generated. These will be assigned names matname:1, matname:2, etc. As a shortcut, PLUSR & MINUSR map the z’ direction of the defined material to radial in AXISNAME.
Section 3: More details
If you want to know more, check the documentation of the matr-axis command.
- Right-click on the command axis within the matr command
- Click on "Show-Help for matr-axis"