Learning Forum

[wei zhang]

Hello, I have a question about autodyn. I would like to ask you how autodyn imports external energy deposition. I built a copper cylinder, and then knew the energy deposition corresponding to each point in it. How can I introduce the energy deposition into the cylinder, and then calculate the density pressure after a certain time, etc. I tried to carry out secondary development of autodyn and found that the EXSIE module in the subroutine can import energy deposition, but it only has one input parameter. I don't know how to input it, so I would like to ask for advice.

 

The picture shows the subroutine EXSIE

The picture shows the energy deposition I want to import. The first and second columns are the coordinates, and the third column is the corresponding energy deposition

[Chris Quan]

EXSIE is called at every cycle for every element.

Basically, you only need to enter DSIE so program will read DSIE and then deposit it to the element which calls the EXSIE. 

If each element has different value of DSIE, you can add IF-THEN statements in EXSIE to calculate the DSIE for the specified element (I = INOW, J = JNOW, K = KNOW).

Density, Pressure, etc, will be calculated outside of EXSIE by other subroutines.

[wei zhang]

May I humbly ask for guidance?

Do I need to read the energy deposition file, compute the internal energy, and then allocate it to the energy of different elements on various grids?

My energy deposition file contains 800,000 lines, but the number of corresponding Autodyn grids is not as high. Should I still use interpolation to distribute energy to the elements on the grid?

Additionally, I would like to know which subroutines are required for calculating density, temperature, and pressure.

[Chris Quan]

As we discussed, EXSIE is called at every cycle for every element. Thus, in EXSIE you need to

1. Get the X/Y/Z of the element based upon the element index (INOW, JNOW, KNOW or IJKNOW),
2. Read this 800,000 lines files, locate the lines based upon the X/Y/Z from #1 and obtain their corresponding energy.
3. Calculate the deposited energy by interpolating the energy from #2. 

Since the program has to read the 800000 line file at every cycle and every element, this may take additional CPU time.

If you can simplify the energy distribution by an analytical expression of X/Y/Z coordinates, you can calculate the deposited energy with the equation, rather than read 800000 lines for every element, that will save running time significantly.

The density and pressure will be calculated by the subroutines that are corresponding to the EOS. For example, if Ideal-Gas EOS is used, density and pressure will be calculated in the subroutine of Ideal Gas EOS. 

If you want to customize the density & pressure calculation, you need to edit the user-subroutine mdeos_user_1.f90. You may not need to edit the EXSIE. You can deposit the energy in the mdeos_user_1.f90.

[wei zhang]

I have just started learning the secondary development of AUTOYDN now, so I don’t understand many issues very well.

What you mean is that when AUTODYN is running, all subroutines such as EXSIE will be called in each cycle.

You said that you can get the X, Y, Z coordinates through element index IJKNOW, but I don't seem to have found the corresponding module.

I have previously tried to directly assign energy to IJK, but the number of grids in the IJK direction of AUTODYN is much smaller, so a lot of approximations have to be made.

What I also want to ask is, is the code for reading external energy deposition files directly written in the EXSIE subroutine?

I have a lot of questions. Can you please write me an example of how to read the TXT file of energy deposition and then assign the read energy deposition to the corresponding grid? I would be very grateful.