DOI: 10.5281/zenodo.17035636
title: Reactive coarse-grained MD models to capture interphase formation in  epoxy-based structural adhesive joints - dataset

description:  

Abstract:from [1]

Polymer nanocomposites (PNCs) have shown great potential to meet the ever-growing requirements of modern engineering applications. Nowadays, molecular dynamics (MD) simulations are increasingly employed to complement experimental work and thereby gain a deeper understanding of the complex structure–property relations of PNCs. However, with respect to the thermoplastic’s mechanical behavior, the role of its average molar mass is rarely addressed, and many MD studies only consider uniform (monodispersed) polymers. Therefore, this contribution investigates the impact that and the dispersity Đ have on the stiffness and strength of PNCs through coarse-grained MD. To this end, we employed a Kremer–Grest bead–spring model and observed the expected increase in the mechanical performance of the neat polymer for larger . Our results indicated that the unimodal molar mass distribution does not impact the mechanical behavior in the investigated dispersity range Đ. For the PNC, we obtained the same -dependence and Đ-independence of the mechanical properties over a wide range of filler sizes and contents. This contribution proves that even simple MD models can reproduce the experimentally well researched effect of the molar mass. Hence, this work is an important step in understanding the complex structure–property relations of PNCs, which is essential to unlock their full potential.

Contact:

Maximilian RiesInstitute of Applied MechanicsFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 591058 Erlangen

Software:

All MD simulations were performed with LAMMPS [2,3], version: 2 Aug 2023 - Update 3, with REACT package [4,5]

Compiled withCompiler: GNU C++ 11.2.0 with OpenMP not enabledC++ standard: C++11

Post-processing Matlab R2023b

License:

Creative Commons Attribution 4.0 International

Context:

Data set supplementing  journal paper:[1] V. Dötschel, E. M. Richter, G. Possart, P. Steinmann, M. Ries,  "Reactive coarse-grained MD models to capture interphase formation in epoxy-based structural adhesive joints." European Journal of Mechanics-A/Solids (2025): 105801.

Content:

structure of data set (follows sections of [1]):

    - 3.1 Adherend-adhesive interaction parameters    - 3.2.1 Grafting bond density    - 3.2.2 Grafting bond heterogeneities    - 3.3 Adhesive layer thickness    - A2 Case III: no grafting

       

naming convention for simulation folders

    - case_I, case_II, case_III:     refers to the different force field parameter sets discussed in the paper    - surf_react:                    gives the grafting density in percent    - hole05:                        indicates an inert region of 50percent    - EQ:                            contains equilibration files    - UT:                             contains uniaxial tensile files    - _double, _half:                indicates the adhesive joint thickness, double or half of the standard presented in 3.1    - _01 to _05:                    number of the replica    - bins

 

Each simulation directory contains:

    data files (*.data) containing the sample configuration in LAMMPS data format    dat files (*.dat)   containing simulation output, format explained below

    LAMMPS_out:            simulation results                 - ReadyForCuring.data                            sample configuration directly before curing        - Sandwich_Sim_Curing1.data                        sample configuration after curing stage I        - Sandwich_Sim_Curing2.data                        sample configuration after curing stage II        - Sandwich_Sim_Curing3.data                        sample configuration after curing stage III        - Sandwich_Sim_Curing4.data                        sample configuration after curing stage IV (end of curing)        - Sandwich_Sim_finalEquil_afterBC_change.data    sample at end of equilibration, i.e., ready for deformation        - Sandwich_Sim_afterDeformation.data            sample after deformation                - thermo.dat                                    tabulated thermodynamic output during equilibration in columns, containing            TimeStep                     timestep            c_thermo_temp                 temperature in K            c_thermo_press[1]             pressure component pxx in atm            c_thermo_press[2]             pressure component pyy in atm                 c_thermo_press[3]             pressure component pzz in atm             c_thermo_press[4]             pressure component pxy in atm             c_thermo_press[5]             pressure component pxz in atm             c_thermo_press[6]             pressure component pyz in atm             v_PACM_react                 fraction of reacted PACM (linear and network reactions)            v_DC                         fraction of reacted DGEBA excluding grafting reactions            v_DGEBA_react                 fraction of reacted DGEBA including grafting reactions            v_Surf_react                 fraction of reacted substrate surface atoms            v_Etot                         total energy in kcal/mol            v_Epair                     nonbonded energy in kcal/mol            v_Ebond                     bond energy in kcal/mol            v_Eangle                     angle energy in kcal/mol            v_Epot                         potential energy in kcal/mol            v_Ekin                         kinetic energy in kcal/mol            v_Stress_xx_MPa             stress component in xx direction in MPa            v_Density                     density of simulation box in g/cm^3            v_Lx                         length of simulation box in x direction            v_Ly                         length of simulation box in y direction            v_Lz                         length of simulation box in z direction            v_Stress_yy_MPa             stress component in yy direction in MPa             v_Stress_zz_MPa             stress component in zz direction in MPa             v_Stress_xy_MPa             stress component in xy direction in MPa             v_Stress_xz_MPa             stress component in xz direction in MPa             v_Stress_yz_MPa             stress component in yz direction in MPa                - thermo_UT.dat                             tabulated thermodynamic output during deformation in columns, containting             TimeStep                     timestep            c_thermo_temp                 temperature in K            c_thermo_press[1]             pressure component pxx in atm            c_thermo_press[2]             pressure component pyy in atm                 c_thermo_press[3]             pressure component pzz in atm             c_thermo_press[4]             pressure component pxy in atm             c_thermo_press[5]             pressure component pxz in atm             c_thermo_press[6]             pressure component pyz in atm             v_Etot                         total energy in kcal/mol            v_Epair                     nonbonded energy in kcal/mol            v_Ebond                     bond energy in kcal/mol            v_Eangle                     angle energy in kcal/mol            v_Epot                         potential energy in kcal/mol            v_Ekin                         kinetic energy in kcal/mol            v_Stress_xx_MPa             stress component in xx direction in MPa            v_Density                     density of simulation box in g/cm^3            v_Lx                         length of simulation box in x direction            v_Ly                         length of simulation box in y direction            v_Lz                         length of simulation box in z direction            v_Strain_xx                 strain component in xx direction            v_Strain_yy                  strain component in yy direction            v_Strain_zz                  strain component in zz direction            v_Strain_xy                  strain component in xy direction            v_Strain_xz                  strain component in xz direction            v_Strain_yz                  strain component in yz direction            v_Stress_xx_MPa                 stress component in xx direction in MPa            v_Stress_yy_MPa                 stress component in yy direction in MPa            v_Stress_zz_MPa                 stress component in zz direction in MPa            v_Stress_xy_MPa                 stress component in xy direction in MPa            v_Stress_xz_MPa                 stress component in xz direction in MPa            v_Stress_yz_MPa                 stress component in yz direction in MPa            v_Volume_Epoxy1                 polymer volume via substrate volume in A^3            v_Volume_Epoxy2                 polymer volume via box lenghts in A^3            v_Cauchy_xx_MPa_Epoxy1             stress component in xx direction in MPa with respect to Volume_Epoxy1 (only polymer)            v_Cauchy_yy_MPa_Epoxy1             stress component in yy direction in MPa with respect to Volume_Epoxy1 (only polymer)            v_Cauchy_zz_MPa_Epoxy1             stress component in zz direction in MPa with respect to Volume_Epoxy1 (only polymer)            v_Cauchy_xy_MPa_Epoxy1             stress component in xy direction in MPa with respect to Volume_Epoxy1 (only polymer)            v_Cauchy_xz_MPa_Epoxy1             stress component in xz direction in MPa with respect to Volume_Epoxy1 (only polymer)            v_Cauchy_yz_MPa_Epoxy1             stress component in yz direction in MPa with respect to Volume_Epoxy1 (only polymer)            c_ForceLeft                     resulting force acting on left substrate in kcal/(mol A)            c_ForceRight                     resulting force acting on right substrate in kcal/(mol A)            c_ForceBothSurfaces             resulting force acting on both substrates in kcal/(mol A)            v_NominalStressLeft             nominal tensile stress via force acting on left substrate in MPa            v_NominalStressRight             nominal tensile stress via force acting on right substrate in MPa            v_TrueStressLeft                 true tensile stress via force acting on left substrate in MPa                v_TrueStressRight                 true tensile stress via force acting on left substrate in MPa            v_Cauchy_xx_MPa_Epoxy2             stress component in xx direction in MPa with respect to Volume_Epoxy2 (only polymer)            v_Cauchy_yy_MPa_Epoxy2             stress component in yy direction in MPa with respect to Volume_Epoxy2 (only polymer)            v_Cauchy_zz_MPa_Epoxy2             stress component in zz direction in MPa with respect to Volume_Epoxy2 (only polymer)            v_Cauchy_xy_MPa_Epoxy2             stress component in xy direction in MPa with respect to Volume_Epoxy2 (only polymer)            v_Cauchy_xz_MPa_Epoxy2             stress component in xz direction in MPa with respect to Volume_Epoxy2 (only polymer)            v_Cauchy_yz_MPa_Epoxy2            stress component in yz direction in MPa with respect to Volume_Epoxy2 (only polymer)                - Bins*.dat                         output for spatial binning of atom type *, i.e, 3, 5, 8, 9, 10, or 11; containing                Chunk                            ID for ith binning            Coord1                            center coordinate of binning            Ncount                            number of atom of atom type * in current bin            density/number                    number density of atom type * in current bin                

References:

[1] V. Dötschel, E. M. Richter, G. Possart, P. Steinmann, M. Ries,  "Reactive coarse-grained MD models to capture interphase formation in epoxy-based structural adhesive joints." European Journal of Mechanics-A/Solids (2025): 105801.

[2] S. Plimpton, “Fast parallel algorithms for short-range molecular dynamics,” Journal of computational physics, 1995, 117, 1-19.

[3] A. P. Thompson et al., “LAMMPS - a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales,” Computer Physics Communications, vol. 271, p. 108171, 2022.

[4] J. R. Gissinger, B. D. Jensen, and K. E. Wise, “Modeling chemical reactions in classical molecular dynamics simulations,” Polymer, vol. 128, pp. 211–217, 2017.

[5] J. R. Gissinger, B. D. Jensen, and K. E. Wise, “Reacter: A heuristic method for reactive molecular dynamics,” Macromolecules, vol. 53, no. 22, pp. 9953–9961, 2020.