Please find below a description of some of the codes that I have developed during my research. In most cases the source code is also provided. Please remember to cite the corresponding paper(s) if you use any of these codes for research or industrial purposes. Do not hesitate to contact me if you have any further doubts.
Codes
MATLAB code to predict H uptake using lumped integration
Finite element MATLAB code for electrochemical reactions, using lumped integration for efficiency and robustness, and particularised to the case of hydrogen uptake.
Paper: T. Hageman, E. Martínez-Pañeda. Stabilising effects of lumped integration schemes for the simulation of metal-electrolyte reactions. Journal of The Electrochemical Society 170, 021511 (2023)
Download code (.zip file)

COMSOL-MATLAB Link to determine H diffusivity from isothermal TDS tests
COMSOL-MATLAB files to fit the output of an isothermal TDS experiment so as to obtain the diffusivity of hydrogen in metals.
Paper: A. Zafra, Z. Harris, E. Korec, E. Martínez-Pañeda. On the relative efficacy of electropermeation and isothermal desorption approaches for measuring hydrogen diffusivity. International Journal of Hydrogen Energy 48, 1218-1233 (2023)
Download code (.zip file)

ABAQUS UMAT FOR PHASE FIELD FRACTURE WITH A DRUCKER-PRAGER CRITERION
ABAQUS UMAT user subroutine for implementing a generalised version of phase field fracture allowing for any fracture driving force split (including Drucker-Prager) and any choice of crack density function.
Paper: Y. Navidtehrani, C. Betegón, E. Martínez-Pañeda. A general framework for decomposing the phase field fracture driving force, particularised to a Drucker-Prager failure surface. Theoretical and Applied Fracture Mechanics 121, 103555 (2022)
Download code (.zip file)

COMSOL PHYSICS BUILDER MODULE TO PREDICT HYDROGEN UPTAKE IN METALS
COMSOL Physics builder to predict hydrogen uptake through an electro-chemo-mechanics framework that resolves the HER.
Paper: T. Hageman, E. Martínez-Pañeda. An electro-chemo-mechanical framework for predicting hydrogen uptake in metals due to aqueous electrolytes. Corrosion Science 208, 110681 (2022)
Download code (.zip file)

BrazVal: A MATLAB APP TO ASSESS THE VALIDITY OF THE BRAZILIAN TEST
MATLAB App that enables assessing the validity of the Brazilian test and provides the material strength from test data.
Paper: Y. Navidtehrani, C. Betegón, R.W. Zimmerman, E. Martínez-Pañeda. Griffith-based analysis of crack initiation location in a Brazilian test. International Journal of Rock Mechanics and Mining Sciences 159, 105227 (2022)
Download code (.zip file)

COMSOL MODEL FOR PHASE FIELD FATIGUE IN LI-ION BATTERY MATERIALS
COMSOL implementation of a coupled deformation-diffusion-fracture/fatigue model with application to cracking in Li-Ion battery electrode particles.
Paper: W. Ai, B. Wu, E. Martínez-Pañeda. A generalised phase field model for fatigue crack growth in elastic-plastic solids with an efficient monolithic solver. Journal of Power Sources 544, 231805 (2022)
Download code (.zip file)

ABAQUS UELMAT FOR PHASE FIELD FRACTURE
ABAQUS UELMAT subroutine to implement the phase field fracture method in combination with any material model available in ABAQUS.
Papers: Z. Khalil, A.Y. Elghazouli, E. Martínez-Pañeda. A generalised phase field model for fatigue crack growth in elastic-plastic solids with an efficient monolithic solver. Computer Methods in Applied Mechanics and Engineering 388, 114286 (2022)
M. Simoes, C. Braithwaite, A. Makaya, E. Martínez-Pañeda. Modelling fatigue crack growth in Shape Memory Alloys. Fatigue & Fracture of Engineering Materials & Structures 45, 1243-1257 (2022)
Download code (.zip file)

ABAQUS UEL FOR PHASE FIELD MODELLING OF CORROSION
ABAQUS user-element subroutine (UEL) to use the phase field method to predict corrosion, pitting corrosion, the pit-to-crack transition and stress corrosion cracking.
Paper: C. Cui, R. Ma, E. Martínez-Pañeda. A phase field formulation for dissolution-driven stress corrosion cracking. Journal of the Mechanics and Physics of Solids 147: 104254 (2021)
Download code (.zip file)

ABAQUS UMAT SUBROUTINE TO IMPLEMENT PHASE FIELD FRACTURE
ABAQUS UMAT user subroutine for implementing phase field fracture without the need for user elements by taking advantage of the heat transfer equation.
Papers: Y. Navidtehrani, C. Betegón, E. Martínez-Pañeda. A unified Abaqus implementation of the phase field fracture method using only a user material subroutine. Materials 14(8): 1913 (2021).
Y. Navidtehrani, C. Betegón, E. Martínez-Pañeda. A simple and robust Abaqus implementation of the phase field fracture method. Applications in Engineering Science 6: 100050 (2021).
Download code (.zip file)

ABAQUS UMATHT SUBROUTINE FOR COUPLED HYDROGEN DIFFUSION
ABAQUS user material (mechanical UMAT and thermal UMATHT) subroutines for implementing hydrogen diffusion coupled with mechanical deformation, suitable for multiple traps.
Paper: R. Fernández-Sousa, C. Betegón, E. Martínez-Pañeda. Analysis of the influence of microstructural traps on hydrogen assisted fatigue. Acta Materialia 199: 253-263 (2020)
Download code (.zip file)

ABAQUS UEL SUBROUTINE FOR DISTORTION GRADIENT PLASTICITY
ABAQUS user-element subroutine (UEL) for Gurtin (2004) distortion gradient plasticity formulation, incorporating the role of the plastic spin as well as dissipative and energetic higher order contributions.
Paper: S. Fuentes-Alonso, E. Martínez-Pañeda. Fracture in distortion gradient plasticity. International Journal of Engineering Science 156: 103369 (2020)
Download code (.zip file)

ABAQUS UMAT FOR POWER LAW HARDENING PLASTICITY
ABAQUS user-material subroutine (UMAT) with a plane strain/3D implementation of von Mises plasticity with isotropic power law hardening. Includes documentation.
Paper: E. Martínez-Pañeda, S. Fuentes-Alonso, C. Betegón. Gradient-enhanced statistical analysis of cleavage fracture. European Journal of Mechanics – A/Solids 77: 103785 (2019)
Download code (.zip file)

ABAQUS UEL FOR PHASE FIELD FATIGUE + QUASI-NEWTON
ABAQUS user-element subroutine (UEL) with phase field fatigue (and fracture). Includes an input file for using Quasi-Newton to run in a robust monolithic manner and a document with detailed instructions.
Paper: P.K. Kristensen, E. Martínez-Pañeda. Phase field fracture modelling using quasi-Newton methods and a new adaptive step scheme. Theoretical and Applied Fracture Mechanics 107: 102446 (2020)
Download code (.zip file)

PHASE FIELD FRACTURE IMPLEMENTATION IN FENICS
FEniCS Python script with a staggered implementation of the phase field fracture method, suitable for 2D and 3D case studies. Includes a document with detailed instructions.
Paper: Hirshikesh, S. Natarajan, R. K. Annabattula, E. Martínez-Pañeda. Phase field modelling of crack propagation in functionally graded materials. Composites Part B: Engineering 169: 239-248 (2019)
Download code (.zip file)

ABAQUS UEL SUBROUTINE FOR STRAIN GRADIENT PLASTICITY
ABAQUS user-element subroutine (UEL) for Gudmundson (2004) higher order strain gradient plasticity formulation, including both energetic and dissipative length scales.
Paper: E. Martínez-Pañeda, V.S. Deshpande, C.F. Niordson, N.A. Fleck. The role of plastic strain gradients in the crack growth resistance of metals. Journal of the Mechanics and Physics of Solids, 126: 136-150 (2019)
Download code (.zip file)

ABAQUS UEL SUBROUTINE FOR PHASE FIELD FRACTURE AND HYDROGEN DIFFUSION
ABAQUS user-element subroutine (UEL) for the coupled deformation – hydrogen transport – phase field fracture scheme presented in the associated paper.
Paper: E. Martínez-Pañeda, A. Golahmar, C.F. Niordson. A phase field formulation for hydrogen assisted cracking. Computer Methods in Applied Mechanics and Engineering, 342: 742-761 (2018)
Download code (.zip file)

ABAQUS UEL SUBROUTINE FOR PHASE FIELD FRACTURE
ABAQUS user-element subroutine (UEL) with a robust phase field formulation for fracture. Several integration schemes are available, as detailed in the accompanying documentation.
Paper: E. Martínez-Pañeda, A. Golahmar, C.F. Niordson. A phase field formulation for hydrogen assisted cracking. Computer Methods in Applied Mechanics and Engineering, 342: 742-761 (2018)
Download code (.zip file)

CONTROL ALGORITHM FOR CONVERGENCE PROBLEMS IN CRACK PROPAGATION STUDIES
ABAQUS input files with a control algorithm to overcome convergence problems in cohesive zone modelling of crack propagation. The code is largely inspired by the work by Segurado and Llorca (2004) on particle fracture in composites.
Paper: E. Martínez-Pañeda, S. del Busto, C. Betegón. Non-local plasticity effects on notch fracture mechanics. Theoretical and Applied Fracture Mechanics, 92: 276-287 (2017)
Download code (.zip file)

MATLAB SCRIPT FOR HYDROGEN ASSISTED CRACKING PREDICTIONS
Matlab script to predict the variation with the applied potential of the cracking threshold and the stage II crack growth rate. The model builds on Gerberich’s decohesion dislocation-based model, strain gradient plasticity and advanced electrochemistry. See details in the associated paper.
Paper: E. Martínez-Pañeda, C.F. Niordson, R.P. Gangloff. Strain gradient plasticity-based modeling of hydrogen environment assisted cracking. Acta Materialia, 105: 9-16 (2017)
Download code (.zip file)

ABAQUS2MATLAB: A SUITABLE TOOL FOR FINITE ELEMENT POST-PROCESSING
A toolbox to connect Abaqus and Matlab, enabling the usage of the statistical analysis, image processing, integrated graph-plotting and mathematical optimization capabilities of Matlab to post-process the outcome of advanced finite element calculations. See www.abaqus2matlab.com
Paper: G. Papazafeiropoulos, M. Muñiz-Calvente, E. Martínez-Pañeda. Abaqus2Matlab: a suitable tool for finite element post-processing. Advances in Engineering Software, 105: 9-16 (2017)
Download code (.zip file / Matlab app / Version 2.0)

ABAQUS USDFLD SUBROUTINE FOR FUNCTIONALLY GRADED ELEMENTS
ABAQUS USDFLD Subroutine for the implementation of a continuous variation of the material elastic properties between integration points.
Paper: E. Martínez-Pañeda. On the finite element implementation of functionally graded materials. Materials, 12(2): 287 (2019)
Download code (.zip file)

NON-LINEAR X-FEM CODE FOR MSG PLASTICITY
Non-linear eXtendend Finite Element code developed in MATLAB including the following material models: linear elasticity, von Mises plasticity and conventional mechanism-based strain gradient (CMSG) plasticity. Particularly appealing to capture the singularity intrinsic to MSG plasticity.
Paper: E. Martínez-Pañeda, S. Natarajan, S. Bordas. Gradient plasticity crack tip characterization by means of the extended finite element method. Computational Mechanics, 59: 831-842 (2017)
Download code (.zip file)

FORTRAN CODE FOR DISTORTION GRADIENT PLASTICITY
Finite Element implementation of Gurtin (2004) Distortion Gradient Plasticity (DGP) theory by following and extending the Minimum Principles established by Fleck and Willis (2009). Code developed entirely in Fortran.
Paper: E. Martínez-Pañeda, C.F. Niordson, L. Bardella. A finite element framework for distortion gradient plasticity with applications to bending of thin foils. International Journal of Solids and Structures, 96: 288-299 (2016)

ABAQUS UEL SUBROUTINE FOR COHESIVE ELEMENTS
ABAQUS user-element subroutine (UEL) with a cohesive zone formulation. Includes the dependence of the cohesive strength on the total hydrogen concentration and the effect of cyclic loading.
Paper: S. del Busto, C. Betegón, E. Martínez-Pañeda. A cohesive zone framework for environmentally assisted fatigue. Engineering Fracture Mechanics, 185: 210-226 (2017)
Download code (.zip file)

ABAQUS UMAT SUBROUTINE FOR CMSG PLASTICITY
ABAQUS User Material (UMAT) subroutine with the constitutive formulation of the conventional mechanism-based strain gradient (CMSG) plasticity theory.
Paper: E. Martínez-Pañeda and C. Betegón. Modeling damage and fracture within strain-gradient plasticity. International Journal of Solids and Structures, 59: 208-215 (2015)
Download code (.zip file)
