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Initial Velocity in Local Coordinate System


In several loading situations, initial velocities are often defined along directions that do not coincide with the global coordinate system. In such cases it is very cumbersome to determine the directional components along global axes when the vector direction does not coincide the global system. In such instances, the easiest modeling approach would be to define the velocities along any global direction and then use INCLUDE_TRANSFORM to rotate the coordiate axes. A simple example is shown below where the intent is to define an initial velocity along a vector which is at an angle of 45 degrees to the global-x axis. To accomplish this, the velocity is first defined along the global ‘x’ direction in the included file which is then included in the main input file using the INCLUDE_TRANSFORM that used DEFINE_TRANSFORMATION keyword to perform rotation about the origin at an angle of 45 about the global ‘y’ axis (0, 1, 0).

Main Input File
*keyword
*define_transformation
1,
rotate, 0, 1, 0, 0, 0, 0, 45
*include_transform
initial_velocities_in_global_x.i
 
 
 
1
*end

Included File (to be transformed)
*keyword
*initial_velocity_generation
1
100,
*end

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