Question about linear static analysis in OpenSees

[gooddaytogo]

Hello, everyone,

I have a question about using the following codes to do linear static analysis in OpenSees. The model is linear elastic and if static load of magnitude 5e6 is applied to the model, the output of target displacement is 300mm.

For the load vector, staticload, in the following code:

If "set staticload {5e6 5e6 5e6 5e6 5e6}" was used, the output from OpenSees of the target displacement is {300 600 900 1200 1500} mm, which is understandable;

What I am confused is if "set staticload {0 5e6 0 5e6 5e6}" was used, the output of the target displacement should be {0 300 300 600 900} mm, but it is {0 600 0 1200 1500} mm from the output of OpenSees.

Anyone can help explain why and how to change the code to get the displacement {0 300 300 600 900} mm when "set staticload {0 5e6 0 5e6 5e6}" was used? Thanks a lot.



#####################################################
set i 0

set staticload {0 5e6 0 5e6 5e6}

while {$i < 5} {

set y60 [lindex $staticload $i]

pattern Plain 1 Linear -fact 1 {
load 1098 0.0 $y60 0.0 0.0 0.0 0.0;
}

wipeAnalysis;

constraints Transformation
numberer RCM
system BandGeneral
test NormDispIncr 1e-3 200
algorithm NewtonLineSearch;
integrator LoadControl 1;
analysis Static;
analyze 1;

remove loadPattern 1;

incr i

}