Nastran and Hypermesh bdf/fem reader

version 1.0.2 (277 KB) by Eric Trudel
Read and print out custom bdf or fem files. They can be sent to the solver of your choice for analysis.


Updated 27 Mar 2022

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%This description/tutorial outlines how to upload and print hypermesh fem or NASTRAN bdf files.
clear all
%% First step is to upload the file testp.fem or .bdf
%path name
path_name = 'testp.fem';
%upload the .fem file
fem_struct = read_fem(path_name); %use read_bdf for a .bdf file
%% Second step is to inspect the data
%bulk data and Subcase data are seperated by fields
%from here you can view all your data
%data for subcase with ID 1 is accesed this way
fem_struct.SUBCASE(1) %ID 5 for example would be fem_struct.SUBCASE(5)
%to see the first card for CQUAD4 (or any card in the .fem/.bdf BULK data)
fem_struct.BULK.CQUAD4{1} %is organized as a card nx9 cell structure, n is the number of rows
%% Third step is to modify any cards or insert additional data
%data is stored as a string in all cells
%to convert to numeric use fem_cell2num()
fem_mat = fem_cell2num(fem_struct); %only bulk data is transfered over
%fields are given an extra _MAT at the end to show it is a matrix. You may
%modify the function to remove the additional appended text.
%To revert back to string format from matrix form use fem_num2cell()
fem_cell = fem_num2cell(fem_mat,'fem'); %'bdf' for bdf files
%a parfor is in the above function, you may modify it to be a regular for loop
%depending on the size of the input structure
%To remove the "_MAT" from the fields, use the code below
map = containers.Map(fieldnames(fem_cell),strrep(fieldnames(fem_cell),'_MAT',''));
tmp = reshape(values(map,fieldnames(fem_cell)),1,[]);
tmp(2,:) = num2cell(permute(struct2cell(fem_cell),[3,1,2]),1);
print_cell.BULK = reshape(struct(tmp{:}),size(fem_cell));
%% The fourth step is to print out the file
%you may print out the cell structure after modifications
%append the old subcase data to the new structure, then print the file
print_cell.SUBCASE = fem_struct.SUBCASE;
print_fem(print_cell,'testp2.fem',0) %print_bdf for bdf file
%% The final step is to upload your finite element model to nastran or optistruct directly using MATLAB.
%Refer to the code below for examples
%FEM file
loc_opti='C:\\Program Files\\Altair\\2019\\hwsolvers\\scripts\\optistruct.bat';
command_string1 = char(strcat('"',loc_opti,'" "',path_fem,'" -ncpu 4 -monitor'));
answer = system(command_string1);
%BDF file (no white spaces in path)
loc_Nastran = "C:\\Program Files\\MSC.Software\\MSC_Nastran\\2020\\bin\\nastran.exe";
path_bdf = "C:\Users\XXX\Documents\Matlab\MATLAB_File_Exchange_Contributions\NASTRAN_and_Hypermesh_Connectivity\testp.bdf";
command_string1_Nas = char(strcat('"',loc_Nastran,'" "',path_bdf,'" old=no scr=yes smp=4 '));
%*Some of these functions rely on num2nasSFFstr() written by Coon Timothy which has been slightly modified to suit the applications of this submission.

Cite As

Eric Trudel (2022). Nastran and Hypermesh bdf/fem reader (, MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2020b
Compatible with R2020b to R2022a
Platform Compatibility
Windows macOS Linux

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