hnng
Civil/Environmental
- Aug 17, 2007
- 38
Hello Everyone,
I am having a weird problem, and I am pretty sure I have some wrong understanding. In this problem I have a rectangular beam, which is to be subjected to convection and radiation boundary condition in Thermal physics and then to stress analysis in Strucutral physics.
I have attached the input file. In the file remove ! marks from the lines enclosed by:
!****************** Remove the comments to replicate the problem *********
I have 3 types of elements in thermal environment SOLID90, SURF152 (Radiation), SURF152 (Convection). I do a static thermal analysis (to calculate initial condition) followed by transient thermal analysis (use LDREAD to apply static solution as initial conditio), I keep the temperature bulk temperature (10 deg C) same for both static and transient anlysis for checking my code. After the transient analysis I see that temperature through out the body is 10 deg C. Which is intutive and right.
Now if I define one more element (say no. 10) as a shell element (SHELL181) in structural physics (Translates to SHELL131 in thermal physics). The initial conditions calculated in static analysis do not apply as initial condition of transient analysis. This happens particularly with SHELL181 if I keep it type to SOLID95 then there is no problem. But I need a SHELL element as I want to apply a thin layer of material havin thermal and physical property.
I will highly appreciate if you could point an error in my thinking/code.
Regards
I am having a weird problem, and I am pretty sure I have some wrong understanding. In this problem I have a rectangular beam, which is to be subjected to convection and radiation boundary condition in Thermal physics and then to stress analysis in Strucutral physics.
I have attached the input file. In the file remove ! marks from the lines enclosed by:
!****************** Remove the comments to replicate the problem *********
I have 3 types of elements in thermal environment SOLID90, SURF152 (Radiation), SURF152 (Convection). I do a static thermal analysis (to calculate initial condition) followed by transient thermal analysis (use LDREAD to apply static solution as initial conditio), I keep the temperature bulk temperature (10 deg C) same for both static and transient anlysis for checking my code. After the transient analysis I see that temperature through out the body is 10 deg C. Which is intutive and right.
Now if I define one more element (say no. 10) as a shell element (SHELL181) in structural physics (Translates to SHELL131 in thermal physics). The initial conditions calculated in static analysis do not apply as initial condition of transient analysis. This happens particularly with SHELL181 if I keep it type to SOLID95 then there is no problem. But I need a SHELL element as I want to apply a thin layer of material havin thermal and physical property.
I will highly appreciate if you could point an error in my thinking/code.
Regards