Trigonometric Function after static loading

[suusie]

Hello,

I want to know if trigonometric function can be used to simulate sinusoidal displacement- and velocity- controlled analysis AFTER static loading (ex. dead load) is imposed. I want to impose sinusoidal motion in the same direction as static load is imposed. It seems trigonometric function governs and statically imposed displacement is removed before sinusoidal motion is imposed.

In this case, what can I do ?

- - - - - - - - - - - .tcl (static load > sinusoidal load)
model basic -ndm 2 -ndf 3

node 2 0 1 0
node 1 0 0 0

pattern Plain 1 Linear {
load 2 0. [expr -$W] 0.
}

timeSeries Trig 1 1 2 3 -factor $Amp; # displace control
timeSeries Trig 2 1 2 3 -factor [expr 2*$pi/$Tdur*$Amp]; # velocity control

pattern MultiSupport 2 {
groundMotion 2 Plain -disp 1 -vel 2
imposedMotion 2 2 2
}
----------------------

[fmk]

yes it is possible .. just do an analysis with the gravity loads, then issue a loadConst command and reset the time in the domain to 0 and then introduce your multisupport patterns and finally do the transient analysis, i.e.


model basic -ndm 2 -ndf 3

node 2 0 1 0
node 1 0 0 0

pattern Plain 1 Linear {
load 2 0. [expr -$W] 0.
}

analysis Static
analyze 1
loadConst -time 0.0

timeSeries Trig 1 1 2 3 -factor $Amp; # displace control
timeSeries Trig 2 1 2 3 -factor [expr 2*$pi/$Tdur*$Amp]; # velocity control

pattern MultiSupport 2 {
groundMotion 2 Plain -disp 1 -vel 2
imposedMotion 2 2 2
}

analysis Transient
analyze 2000 .02