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variable = const after a time t

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Hello,

is there a posibility to define a variable in that way that it cant be changed after a time t1.
somehow like this:

"variable = if(t<t1,(T2<273), const)"

after the time t1 the variable should have the value of t1, which was defined by (T2<273)

3 Replies Last Post Nov 26, 2015, 5:46 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Oct 10, 2014, 7:27 a.m. EDT
Hi

if you build your variable (i.e. via a global equation) as a time integration variable, you can set the increment to "0" after a certain time by a boolean equation, else I see only the saturation to a given (and previously known) value as you write it out.

--
Good luck
Ivar
Hi if you build your variable (i.e. via a global equation) as a time integration variable, you can set the increment to "0" after a certain time by a boolean equation, else I see only the saturation to a given (and previously known) value as you write it out. -- Good luck Ivar

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Posted: 1 decade ago Oct 10, 2014, 8:16 a.m. EDT
Thanks Ivar for the good idea.

i used
on1=(t<t1)*(T2<T_krit)-on1t (global equation)

and

a = on1/t1 (variable)
if a==1 then i am fine
Thanks Ivar for the good idea. i used on1=(t

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Posted: 9 years ago Nov 26, 2015, 5:46 a.m. EST
hello,
i ve again a similar problem.
a variable var should be ve a constant value t1 after the time t1.
but t1 is not known before. it should depend on a variable var2. t1 should be at that time on which var2 is changing its value. (d(var2,t)!=0)
but the problem here is that var2 is changing like a stepfunction.
does anyone ve any idea?
hello, i ve again a similar problem. a variable var should be ve a constant value t1 after the time t1. but t1 is not known before. it should depend on a variable var2. t1 should be at that time on which var2 is changing its value. (d(var2,t)!=0) but the problem here is that var2 is changing like a stepfunction. does anyone ve any idea?

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