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accounting_for_inertia [2023/06/08 16:34] marijn.nijenhuis |
accounting_for_inertia [2023/06/08 16:35] (current) marijn.nijenhuis |
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- the position of the center of mass (note: these numbers are given with respect to the selected coordinate system) | - the position of the center of mass (note: these numbers are given with respect to the selected coordinate system) | ||
- | ** Important: ** Depending on the version of SolidWorks, different conventions are used for the crossproducts (the off-diagonal components of the inertia tensor). With version 2021 and later, you can set the convention: we want the positive tensor notation. You can set this in the Options panel within the Mass Properties window. For older versions of SolidWorks where you don't have this option, be very wary of what SolidWorks returns. | + | ** Important: ** Depending on the version of SolidWorks, different conventions are used for the crossproducts (the off-diagonal components of the inertia tensor). With version 2021 and later, you can set the convention: we want the positive tensor notation. You can set this in the Options panel within the Mass Properties window. For older versions of SolidWorks where you don't have this option, be very wary of what SolidWorks returns. |
$$ \begin{bmatrix} I_{xx} & -I_{xy} & -I_{xz} \\ -I_{xy} & I_{yy} & -I_{yz} \\ -I_{xz} & -I_{yz} & I_{zz} \end{bmatrix} $$ | $$ \begin{bmatrix} I_{xx} & -I_{xy} & -I_{xz} \\ -I_{xy} & I_{yy} & -I_{yz} \\ -I_{xz} & -I_{yz} & I_{zz} \end{bmatrix} $$ | ||
+ | If it's unclear, check the manual for your version to see which sign convention is being used for the off-diagonal terms. | ||
{{ : | {{ : | ||
===== Adding mass and inertia properties to Spacar ===== | ===== Adding mass and inertia properties to Spacar ===== | ||
- | For this example a single leafsprings is simulated between node 1 ([0,0,0]) and node 2 ([0 0.1 0]), with one end of the wrench attached to node 2 (which coincides with the position of the coordinate system in SolidWorks). Furthermore, | + | For this example, a single leafsprings is simulated between node 1 ([0,0,0]) and node 2 ([0 0.1 0]), with one end of the wrench attached to node 2 (which coincides with the position of the coordinate system in SolidWorks). Furthermore, |
** Check the full syntax list for the correct use of '' | ** Check the full syntax list for the correct use of '' |