For a model with a single segment on one axis (X-axis) with no bends, why are the R1 inertial forces in X directions {FX(Point 10) = 350.87 N and FX(Point 100) = 360.91 N}, are greater than zero, if the total modal captured mass in X direction is 0?
When reviewing the output report the participation values may be 0.00 but the actual value is much smaller than can be reported. See the following procedure:
1. Open the model2. Analyze the model3. Select Results> Grids4. Select Frequency Tab in the grid5. Select any cell in the Particip. Factor X column, note that the value is not 0.00 but much smaller, ex: -5.2860372e-011. AutoPIPE output report is not able to show such small values.
Note: The anchor reaction is more for the model with higher cut-off frequency as it has higher level of discretization and thus able to capture higher modes better.
"Mode Shape" sub report
Bentley AutoPIPE