16.1.2. Example
A simple example shows how to use this post-analysis toolkit. Figure 16.7 shows the modeling.
Figure 16.7 An example for the Eigen Movement
A rigid body is supported by four spring-damper forces. The left side two springs (Spring1 and 2) are stiffer than the right side (Spring3 and 4).
All spring are set with Y direction. The stiffness of the left side is stiffer than the right side. Therefore, the displacement of the left side is smaller than the right side.
After the eigenvalue analysis, we can check the 4th mode moves along the Y-axis with absolute eigen vector and eigen animation result.
Figure 16.8 The absolute eigenvector result on the OUT file
The marker 1, 2, 3, and 4 are selected in order to check the displacement on the Eigen Movement Dialog. The marker 1, 2, 3, and 4 is connected the Spring 1, 2, 3, and 4, respectively.
Therefore, we can expect followings
The displacements of the left side two markers (the marker 1 and 2) are the same.
The displacements of the right side two markers (the marker 3 and 4) are the same.
The displacement of the left side is smaller than the right side.
The below figure shows the result. And the expectations are confirmed.
Figure 16.9 Result of the Eigen Movement