Partial Differential Equation Toolbox |

pdesmech

Calculate structural mechanics tensor functions

Syntax

-     ux=pdesmech(p,t,c,u,'PropertyName',PropertyValue,...)

Description

`ux=pdesmech(p,t,c,u,p1,v1,...)` returns a tensor expression evaluated at the center of each triangle. The tensor expressions are stresses and strains for structural mechanics applications with plane stress or plane strain conditions. `pdesmech` is intended to be used for postprocessing of a solution computed using the structural mechanics application modes of the `pdetool` GUI, after exporting the solution, the mesh, and the PDE coefficients to the MATLAB workspace. Poisson's ratio, `nu`, has to be supplied explicitly for calculations of shear stresses and strains, and for the von Mises effective stress in plane strain mode.

Valid property name/property value pairs include the following.

Property Name | Property Value/Default | Description
`tensor` | `ux|uy|vx|vy|exx|eyy|exy|sxx|syy|sxy|e1|e2|s1|s2|`{`von Mises`} | Tensor expression
`application` | {`ps`}|`pn` | Plane stress|plane strain
`nu` | Scalar or string expression {0.3} | Poisson's ratio

The available tensor expressions are

- `exx`, the x-direction strain (x)
- `eyy`, the y-direction strain (y)
- `exy`, the shear strain (xy)
- `sxx`, the x-direction stress (x)
- `syy`, the y-direction stress (y)
- `sxy`, the shear stress (xy)
- `e1`, the first principal strain (1)
- `e2`, the second principal strain (2)
- `s1`, the first principal stress (1)
- `s2`, the second principal stress (2)
- `von Mises`, the von Mises effective stress, for plane stress conditions

- or for plane strain conditions

Examples

Assuming that a problem has been solved using the application mode "Structural Mechanics, Plane Stress," discussed in Structural Mechanics -- Plane Stress, and that the solution `u`, the mesh data `p` and t, and the PDE coefficient `c` all have been exported to the MATLAB workspace, the x-direction strain is computed as

-     sx=pdesmech(p,t,c,u,'tensor','sxx');

To compute the von Mises effective stress for a plane strain problem with Poisson's ratio equal to 0.3, type

-     mises=pdesmech(p,t,c,u,'tensor','von Mises',...
      'application','pn','nu',0.3);

| pdesdp, pdesde, pdesdt |  | pdesurf |