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rotationaxis [2020/06/05 18:13] marijn.nijenhuis |
rotationaxis [2020/06/05 18:13] marijn.nijenhuis |
* If the specified node does not actually rotate in the specified eigenmode, there is no rotation and there will be no effective axis. Calls to ''getPoleAxis'' in that case may //not// produce an //error// and probably just lead to incorrect numbers being returned. The same holds in the case that the rigid body is moving as a pure translation: even though there is no effective rotation axis, the script may not produce an error, and just return erroneous numbers, without a warning. | * If the specified node does not actually rotate in the specified eigenmode, there is no rotation and there will be no effective axis. Calls to ''getPoleAxis'' in that case may //not// produce an //error// and probably just lead to incorrect numbers being returned. The same holds in the case that the rigid body is moving as a pure translation: even though there is no effective rotation axis, the script may not produce an error, and just return erroneous numbers, without a warning. |
* Simulation results in general may be displayed in various load steps (e.g. if a command like ''nprops(i).force'' or ''nprops(i).displ_x'' is used, rather than ''nprops(i).force_initial'' or ''nprops(i).displ_x_initial''). The number of load steps in a simulation result is indicated in the Spavisual window by means of the large horizontal load step slider at the bottom. For each load step, a new set of eigenmodes is shown. The ''getPoleAxis'' script, used in this example, uses the eigenmodes that correspond with the //first load step//. Again, there is no interaction between the Spavisual buttons and this visualization script, so take care to look at the correct eigenmode and the load step. | * Simulation results in general may be displayed in various load steps (e.g. if a command like ''nprops(i).force'' or ''nprops(i).displ_x'' is used, rather than ''nprops(i).force_initial'' or ''nprops(i).displ_x_initial''). The number of load steps in a simulation result is indicated in the Spavisual window by means of the large horizontal load step slider at the bottom. For each load step, a new set of eigenmodes is shown. The ''getPoleAxis'' script, used in this example, uses the eigenmodes that correspond with the //first load step//. Again, there is no interaction between the Spavisual buttons and this visualization script, so take care to look at the correct eigenmode and the load step. |
* It is possible that the motion of a rigid body consists of //both// a rotation about an effective axis //and// a simultaneous translation along that same axis: the rigid body then makes a screw motion. In this case, the script //will return// the effective axis corresponding with the screw motion. | * It is possible that the motion of a rigid body consists of //both// a rotation about an effective axis //and// a simultaneous translation along that same axis: the rigid body then makes a screw motion. In this case, the script //will return// the effective axis. |
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