#### Comments, Questions, and Answers:

Note: see additional comments about Time history analysis in AutoPIPE on the following WIKI's:

## Item #1:

On the Load> Time History Location dialog screen, change value at node (ex. C14 N) from Dy = -1 to Dy = -10 and there is no change in the results, but if change Dy = 0, there is a change in the results. Why?

**Answer:** From the online help:

` DX/DY/DZ`

`Specify the direction cosines or offsets of the time history`

load (i.e., values of 1,0,0 would specify the X-direction as the direction at

which the time history load is applied.

Therefore, changing Dx =0, Dy = -1, Dz = 0, to Dx =0, Dy = -10, Dz = 0, has no affect on the direction cosines, the load is still going to be applied in the -ve Dy direction regardless if Dy in this case is any number -1 to -infinity.

In addition, by setting Dx =0, Dy = -1, Dz = 0, to Dx =0, Dy = 0, Dz = 0, will have a significant change on the results as there is now no directional cosine specified for the load.

If there was another direction with a value, Dx =1, Dy = -1, Dz = 0, to Dx =1, Dy = -10, Dz = 0, is a significant change in the directional cosine. Thus changing the results.

.

# See Also

**Bentley AutoPIPE**