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X. Wu and J. A. El-Awady
Finally, Tsige and Stevens showed that the density of interfacial bonds determines
the fracture mode of DGEBA/solid surface system, and the tensile and shear stresses
were predicted as functions of interfacial bonds [60].
5 Summary and Conclusions
In summary, all-atom MD and CG-MD simulations are the most common modeling
approaches to investigate the molecular structural and the thermal and mechanical
properties of epoxy bulk materials. However, when the desired simulation length
and time scales are large (e.g., simulations of epoxy-matrix composites), multiscale
simulation methods are required [83].
The most common multiscale approach involves first the utilization of DFT
simulations to quantify the bond breaking conditions (i.e., critical length) [98], as
well as to create molecular force fields [27]. These results provide inputs for allatom MD or CG-MD simulations. All-atom MD simulations are commonly used
to predict epoxy properties at the atomic scale with the goal to use the predicted
values as inputs to larger length/time scale models [44], or to reveal quantify relevant
molecular-scale mechanisms in order to explain macroscale observed phenomena
[43, 61]. However, the common challenges facing all-atom MD simulations is how
to interpret the results in the relevant length/time scales and compare the simulated
properties directly with macroscale experiments. On the other hand, CG-MD
simulations are ideal to create larger simulation domains on the scale of the spacing
between fibers/particles in composites [52, 70, 109]. In plastics, soft matter, and
biomaterial simulations, CG-MD simulations have been very popular in modeling
material mesoscale structures [114–116]; however, it is still in the development
stages for epoxy simulations. Finally, FEM simulations have the advantage of
simulating a microscale material with heterogeneous local properties, with the RVE
method used commonly to help bring atomic information to continuum models.
The advantages of multiscale simulation of epoxy can be summarized as
follows:
1. Provide mechanistic understanding of the molecular-scale origins of observed
macroscopic material properties, which enriches our understanding of epoxy
materials.
2. For specific nanoscale materials, such as nanocomposites, accurate and wellvalidated simulation models provide a less expensive means to study and test
materials than experiments and with a high resolution.
3. Simulation at all scales can be used for examining material response under
extreme condition including temperature and pressure, where lab setup of such
tests can be difficult or time-consuming.
4. For the purpose of screening, design, and optimization of new materials, and
tailoring material properties of existing materials, simulation is a very effective
method and compliments well to experiments.
X. Wu and J. A. El-Awady
Finally, Tsige and Stevens showed that the density of interfacial bonds determines
the fracture mode of DGEBA/solid surface system, and the tensile and shear stresses
were predicted as functions of interfacial bonds [60].
5 Summary and Conclusions
In summary, all-atom MD and CG-MD simulations are the most common modeling
approaches to investigate the molecular structural and the thermal and mechanical
properties of epoxy bulk materials. However, when the desired simulation length
and time scales are large (e.g., simulations of epoxy-matrix composites), multiscale
simulation methods are required [83].
The most common multiscale approach involves first the utilization of DFT
simulations to quantify the bond breaking conditions (i.e., critical length) [98], as
well as to create molecular force fields [27]. These results provide inputs for allatom MD or CG-MD simulations. All-atom MD simulations are commonly used
to predict epoxy properties at the atomic scale with the goal to use the predicted
values as inputs to larger length/time scale models [44], or to reveal quantify relevant
molecular-scale mechanisms in order to explain macroscale observed phenomena
[43, 61]. However, the common challenges facing all-atom MD simulations is how
to interpret the results in the relevant length/time scales and compare the simulated
properties directly with macroscale experiments. On the other hand, CG-MD
simulations are ideal to create larger simulation domains on the scale of the spacing
between fibers/particles in composites [52, 70, 109]. In plastics, soft matter, and
biomaterial simulations, CG-MD simulations have been very popular in modeling
material mesoscale structures [114–116]; however, it is still in the development
stages for epoxy simulations. Finally, FEM simulations have the advantage of
simulating a microscale material with heterogeneous local properties, with the RVE
method used commonly to help bring atomic information to continuum models.
The advantages of multiscale simulation of epoxy can be summarized as
follows:
1. Provide mechanistic understanding of the molecular-scale origins of observed
macroscopic material properties, which enriches our understanding of epoxy
materials.
2. For specific nanoscale materials, such as nanocomposites, accurate and wellvalidated simulation models provide a less expensive means to study and test
materials than experiments and with a high resolution.
3. Simulation at all scales can be used for examining material response under
extreme condition including temperature and pressure, where lab setup of such
tests can be difficult or time-consuming.
4. For the purpose of screening, design, and optimization of new materials, and
tailoring material properties of existing materials, simulation is a very effective
method and compliments well to experiments.