How to set up time in transient thermal analysis?

aagallardo

Hello!

I want to simulate a thermal cycling with time depending. Temperature goes: 20°C (12 hrs), 40°C (14 hrs), 80°C (6hrs), -40°C(6 hrs), 40°C(14 hrs) and 20°C(4 hrs).

I know it might be defined through step controls, however I am not pretty sure about the right set up for time.

Could you help me to clarify that please?

Thank you!

peteroznewman

@aagallardo What is the Initial temperature of the parts? If it is 20C, then step 1 is irrelevant.

ANSYS computes in seconds. The 40C is 14 hours = 50,400 seconds.

Under Analysis Settings, change Auto Time Stepping to On.

Initial Time Step = 500 seconds or about 1%

Minimum Time Step = 50 seconds or about 0.1%

Maximum Time Step = 5000 seconds or about 10%

Use a similar pattern for the other steps.

peteroznewman

@aagallardo Change your Step End Time to the correct value first, then you can set the Maximum Time Step to a smaller value.

peteroznewman

@aagallardo What is the Initial temperature of the parts? If it is 20C, then step 1 is irrelevant.

ANSYS computes in seconds. The 40C is 14 hours = 50,400 seconds.

Under Analysis Settings, change Auto Time Stepping to On.

Initial Time Step = 500 seconds or about 1%

Minimum Time Step = 50 seconds or about 0.1%

Maximum Time Step = 5000 seconds or about 10%

Use a similar pattern for the other steps.

aagallardo

Hello Peter!

Yes, the initial temp of the parts if 20°C.

Understood, that was my doubt, it is clear now

Thank you so much, I really appreciate your help!

aagallardo

HI Peter, I tried to set up the time step controls as you suggest, however I get an error: "Invalid maximum time step"

How can I to overcome this issue?

Thank you!

peteroznewman

@aagallardo Change your Step End Time to the correct value first, then you can set the Maximum Time Step to a smaller value.

aagallardo

Thanks Peter, it's working now! :D