force-deflection curve

[esi_opensees]

in the hysteretic material command we can assign only 3 points for the negative direction and 3 points for the positive direction.if we want define more points,how can we do it?
i used the example which imancivil mentioned above, the opensees gives error. would you please help me?

uniaxialMaterial Hysteretic 1 0 0 0.458 2525.76 2e 2525.76 -5 -2140 -8 -1100 -16e -800 -24 -550 -36 -460 -60 -360 -100 -250

[silvia]

first of all, if you define the third slope negative, the envelope actually has a fouth zero tangent beyond the maximum strain defined in eps3....
beyond that, you have to use a parallel material.
have you looked at pinching4?

[WhiteNoise]

Hello,
I've read the manual however, I couldn't find the proper material to model a only tension element.
The material I want to model has the following stress-strain relationship:
eps= -0.005 0 stress= 75.0
eps= -0.0025 stress=100.0
eps= -0.0000 stress=300.0
eps= 0.0025 stress=600.0
eps= 0.0050 stress=800.0
Could you kindly give me an advise?
Thanks in advance.

[silvia]

try playing with the hysteretic material.

[WhiteNoise]

[quote="silvia"]try playing with the hysteretic material.[/quote]

I omitted to mention that I did try with hysteretic material but the results seem to be weird. Another suggestion?
If not, I'll keep trying with hysteretic material.
Thank you.

[silvia]

don't know enough about what you are trying to.
play around with a simple case, but remember, the more complicated you make it, the more likely it is to cause problems.