thermo-chemical transient problem using explicit time integration method

[double]

Dear FEAPers,

I am runing a 2-d transient thermo-chemical problem, below are the input file description:

Problem Define: transient mechanical equations + transient heat equation
Material Model: elasto-plastic model, mixed formulation
Element: 9-node quadrilateral
Time Integration: all equations with explicit method
Boundary Conditions: a cyclic loading and a specified temperature are applied on the top of the domain, the specified temperature suddenly applied at time zero and held constant afterwards

But the result shows some strange with the temperature field, could anyone tell me if there is something wrong with the input file?

Thanks a lot for your helping!

[Prof. S. Govindjee]

Seems marginally ok for the very short times that you are running.  Have you computed the thermal diffusivity to determine the penetration depth to expect for the boundary conditions you are using?  Note I ran the problem implicitly with Newmark since I was not sure if central differences has a first order option built in (check in program/duyna08.f).

Also for explict runs with plasticity you should use the material card 'start inelastic'

[Yaakov]

Dear Prof. Govindjee,

from this input file, I would like to ask, can the latest Version of FEAP also solve thermoplasticity Problems (Finite)?

Kind regards,
Yaakov

[double]

Dear Prof. Govindjee,

thanks a lot for your reply. I checked the dyna08.f and you are right, the central difference option didn't build the first order ODE. If I want to apply the explicit method to solve both 1st and 2nd order ODE, could I use the PARTITION provided by FEAP? The commands maybe look like below,

PARTitions
1 1 1 0
0 0 0 1

BATCH
PART,,1
TRAN, CENT
...
PART,,2
TRAN GEN1 0

So the heat equation and mechanical euqations could be slove simultaneously at each time step, right?