modeling a constant strain rate test
modeling a constant strain rate test
(OP)
Hello,
I am trying to model a constant strain rate test. My model is very simple block with the bottom area held constant and a load placed on the top area. I tried a constant displacement load but it changes the strain rate considerably over the loading time- which is understandable- but unwanted in my modeling.
Does anyone have a simple constant strain rate test procedure they can share?
Thank you
I am trying to model a constant strain rate test. My model is very simple block with the bottom area held constant and a load placed on the top area. I tried a constant displacement load but it changes the strain rate considerably over the loading time- which is understandable- but unwanted in my modeling.
Does anyone have a simple constant strain rate test procedure they can share?
Thank you





RE: modeling a constant strain rate test
This is my advice:
For constant strain analysis I use an uniform temperature loading.
Please see:
eps=alfa*deltaT
where:
eps is the constant strain that I need
alfa is the thermal expansion coefficient
deltaT is the uniform temperature
so if I know eps I could put
deltaT=eps/alfa
and I will obtain a constant strain eps in my model
For constant strain rate you need to apply not a constant temperature but a linear one (depending on time). So you need a transient analysis and put a linear temperature:
T = T0 + Trate*time
where:
T0 = 0 (I have no initial deformation)
time = will vary from 0 to endtime (the time at the end of your loadstep in transient analysis)
Trate = epsrate/alfa
epsrate = constant strain rate
The strain will be linear too and of course the strain rate will be constant.
Good luck,
Juzz
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Justin Onisoru
Researcher
Romanian Academy - Institute of Solid Mechanics
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