Learning Forum

[Amrith Mariappan]

 

Hello everyone,

I am working on developing a coupled thermo-mechanical user material for LS-DYNA R14 (MPP, double precision, using the Intel ifx compiler). My goal is to create an entropy-based material model where the thermal subroutine (thumat12) calculates an entropy generation term based on heat transfer and passes it to the mechanical subroutine (umat41) via a COMMON block.

I have run into a compilation error that I haven't been able to solve, and I would appreciate some guidance.

The Problem:

My build process fails when compiling my dyn21tumat.f file. The specific error message is:
dyn21tumat.F(321): error #5102: Cannot open include file 'bk01.inc'

This error is then followed by a cascade of "undeclared variable" errors because the necessary pointers and variables are not being defined.

Detailed Explanation of Why I Need bk01.inc:

To correctly calculate the entropy generation due to heat transfer, my thumat12 subroutine needs to compute the temperature gradient within an element. I have written a helper subroutine called compute_temperature_gradient to do this, which follows the standard FEM procedure:

1. It gets the global node numbers for the element from the COMMON /aux33loc/ block.

2. It uses these node numbers to get the temperature at each node.

3. It then uses the shape function derivatives from COMMON /tsbsis/ to calculate the gradient (gradT) at the integration point.

The critical step is #2. To get the nodal temperatures, my code needs to access the main LS-DYNA data array a() using the pointer ntmp0, like this:
temp_nodes(i) = a(ntmp0 + node_ids(i))

I have determined from documentation and other source files that the pointer ntmp0 is defined in the COMMON /bk01/ block, which is located in the file bk01.inc.

My Issue:

I downloaded the user material package for LS-DYNA R14 MPP Double Precision from the official LSTC/Ansys FTP site (https://ftp.lstc.com/objects/download_page.html), and the file bk01.inc is not included in this package. My directory listing confirms it is missing.

My Questions:

1. Could someone please provide the standard bk01.inc file for a double-precision MPP build, or confirm its contents?

2. Is there a different, official location where these essential include files (like bk01.inc) are stored that I might have missed?

3. As a fallback, if direct access to this file is not the intended method for this type of customization, is there an alternative function or a different set of common blocks I should be using to access nodal temperatures within a thusrmat user subroutine?

Thank you in advance for any help or guidance you can provide. Your expertise would be greatly appreciated!

Best regards,

Amrith