LDFEM is a simple code for Large Deformations hyperelastic solids analysis using the Finite Element Method and Fortran90.
The code recieves as input a gmsh legacy file and a specific .inp file and, after solving using the Newton-Raphson method, generates results and VTK files.
The code was developed between 2014 and 2015 by Jorge Pérez Zerpa (@jorgepz), with contributions (on stress tensors output and compressible case tangent matrix) made by Pablo Castrillo (@pablocgp) in December 2014, at the Instituto de Estructuras y Transporte de la Facultad de Ingeniería de la Universidad de la República, Uruguay.
To compile the code you need to have installed gcc's fortran compiler and also the BLAS libraries in a linux environment. You can execute the script build.sh to generate the ldfem.lnx binary.
LDFEM uses a specific .inp format file and
Example terminal output:
====================================
------- Welcome to LDFEM -------
Los factores de carga a resolver son: 0.20000000000000001 0.26666666666666666 0.26666666666666666 0.26666666666666666
barra.msh
Totales:
nodos: 14
tetra: 24
trian: 24
-------------------------------
Control node number 1/ 1
Closest node to coordinates entered is: 2 distance: 0.000E+00
Coordinates: 0.100E+01 0.000E+00 0.000E+00
boundary condtitions: nneumdofs: 22 Ndiridofs: 20
Nnonzero diridofs: 5
0.00 0.00 0.00 0.00 0.00 0.00 0.00
0.00 1.00 0.00 0.00 0.00 0.00 0.00
0.00 0.00 1.00 0.00 0.00 0.00 0.00
0.00 0.00 0.00 1.00 0.00 0.00 0.00
0.00 1.00 0.00 0.00 0.20 0.00 0.00
------- New time step: -------
indtime: 1 factor: 0.20E+00 (delta: 0.27E+00)
--- Starts Newton-Raphson --------
#it | gradient norm | residual load norm |
---------------------------------------------------
1 | 0.134159445656E-01 | 0.612370188774E-17 |
2 | 0.371405878766E-01 | 0.207104676539E-16 |
3 | 0.668707674562E-03 | 0.207542086232E-18 |
4 | 0.120980990213E-05 | 0.299251950680E-21 |
5 | 0.656169760904E-11 | 0.361196727392E-26 |
linear system solver: 1 time: 5.00400085E-03 seconds
--- Loop end --------
------- New time step: -------
indtime: 2 factor: 0.47E+00 (delta: 0.27E+00)
--- Starts Newton-Raphson --------
#it | gradient norm | residual load norm |
---------------------------------------------------
1 | 0.193503906761E-01 | 0.729300710064E-17 |
2 | 0.560448879535E-01 | 0.195827276197E-16 |
3 | 0.123638868363E-02 | 0.556945901834E-18 |
4 | 0.387333163243E-05 | 0.116767435777E-20 |
5 | 0.651562152966E-10 | 0.163256883516E-25 |
linear system solver: 1 time: 4.48699854E-03 seconds
--- Loop end --------
------- New time step: -------
indtime: 3 factor: 0.73E+00 (delta: 0.27E+00)
--- Starts Newton-Raphson --------
#it | gradient norm | residual load norm |
---------------------------------------------------
1 | 0.213966727814E-01 | 0.812549298955E-17 |
2 | 0.627522074871E-01 | 0.332441647205E-16 |
3 | 0.128510063193E-02 | 0.372833076419E-18 |
4 | 0.411804510961E-05 | 0.113233744743E-20 |
5 | 0.720892904071E-10 | 0.169831873709E-25 |
linear system solver: 1 time: 4.38899919E-03 seconds
--- Loop end --------
------- New time step: -------
indtime: 4 factor: 0.10E+01 (delta: 0.27E+00)
--- Starts Newton-Raphson --------
#it | gradient norm | residual load norm |
---------------------------------------------------
1 | 0.235520435462E-01 | 0.624624186222E-17 |
2 | 0.697852729115E-01 | 0.223404664773E-16 |
3 | 0.133280761750E-02 | 0.524033484032E-18 |
4 | 0.436388479103E-05 | 0.217358638487E-20 |
5 | 0.792851238956E-10 | 0.222906112046E-25 |
linear system solver: 1 time: 7.38699734E-03 seconds
--- Loop end --------
All files written, ldfem finished. Go and open the vtks with Paraview!