Thermal Bolt Pretension
Thermal Bolt Pretension
(OP)
Hi
According thread799-338002: Thermal bolt pretension
Bolts are A490 and 1.25 in. So A=7.91 cm^2
Pt-bolt= 138.7 kips= 62900 kg
E=2.05 e6 kg/cm^2
I’m going to define 70% Pt = 44000 kg
I defined orthotropic expansin as:
0, 0, 2.1e-6
So AEalpha=34.08 and then T= -1290 degrees
So in predefined load I assigned -1290 for surface of shanks in the first step.
(Direct specification> constant through region> Ramp> and propagate for 2nd step)
But they provide the Force only 8000 kg instead of 44000 kg at the end of the step (according to free body force)‼
What’s my fault?
Should I define a bolt load and a Predefined load together for a bolt?
thanks
According thread799-338002: Thermal bolt pretension
Bolts are A490 and 1.25 in. So A=7.91 cm^2
Pt-bolt= 138.7 kips= 62900 kg
E=2.05 e6 kg/cm^2
I’m going to define 70% Pt = 44000 kg
I defined orthotropic expansin as:
0, 0, 2.1e-6
So AEalpha=34.08 and then T= -1290 degrees
So in predefined load I assigned -1290 for surface of shanks in the first step.
(Direct specification> constant through region> Ramp> and propagate for 2nd step)
But they provide the Force only 8000 kg instead of 44000 kg at the end of the step (according to free body force)‼
What’s my fault?
Should I define a bolt load and a Predefined load together for a bolt?
thanks





RE: Thermal Bolt Pretension
but why it won't provide the desired pretension?
thanks in advance
RE: Thermal Bolt Pretension
RE: Thermal Bolt Pretension
Thanks for your reply.
First I defined pretension in BOLT LOAD. But bolts got narrowed during the analys. then I imposed thermal pretensin as i told above and the result of above.
I need to impose 70% of capcity of bolts to them as without any large narrowing. also I expect when I get output as free body diagram, the minimum load after imposing pretension, shows the 70% that I imposed?
what is the best way for it?
RE: Thermal Bolt Pretension