Multi-Scale Modeling of Metal-Composite Interfaces in Titanium-Graphite Fiber Metal Laminates Part I: Molecular Scale

Abstract

This study presents the first stage of a multi-scale numerical framework designed to predict the non-linear constitutive behavior of metal-composite interfaces in titanium-graphite fiber metal laminates. Scanning electron microscopy and x-ray diffraction techniques are used to characterize the baseline physical and chemical state of the interface. The physics of adhesion between the metal and polymer matrix composite components are then evaluated on the atomistic scale using molecular dynamics simulations. Interfacial mechanical properties are subsequently derived from these simulations using classical mechanics and thermodynamics. These molecular-level property predictions are used in a companion study to parameterize a continuum-level finite element model of the interface by means of a traction-separation constitutive law. Extension of the proposed approach to other dissimilar metal-or metal oxide-polymer interfaces is also discussed.

Prediction of Interfacial Properties of High-Performance Polymers and Flattened CNT-Reinforced Composites using Molecular Dynamics

“…1. Epoxy: Tetraglycidyl methylenedianiline (TGMDA or TGDDM) and 4,4'-diaminodiphenyl sulfone (DDS) [27] 2. BMI: Bismaleimidodiphenylmethane (BMPM) and O,O'-diallyl bisphenol A (DABPA) [28] 3.…”

“…These three polymer systems are thermosets that are specifically used for structural applications [12,29,[31][32][33][34][35]. Molecular modeling studies exploring the thermo-mechanical properties have been previously performed on these specific polymers [27,28,[36][37][38][39]. However, the influence of the molecular structure on the overall mechanical properties and reinforcement interface characteristics remains largely unexplored.…”

“…Figure 1 shows the molecular structures of all the modelled monomers, and Figure 2 shows the equilibrated conformations. 1:1 molar ratios of BMPM to DABPA and TGMDA to DDS were used for the BMI and epoxy polymers, respectively [22,27,28,36]. and (e) Benzoxazine after molecular minimization in LAMMPS.…”

“…3. The monomers were densified to target mass densities, shown in Table 1, for the BMI, epoxy, and benzoxazine resins [27,28,37,38]. These density values were chosen as initial guesses, with the final mass densities achieved at the end of this step [21,22,46].…”

Interfacial characterization of functionalized graphene-epoxy composites

“…18 Several methodologies have been presented in recent years relating to the extraction of traction-separation curves through MD simulations in different materials interface like aluminium, 18,19 but also in nanocomposites with polymer matrices including, e.g. graphite, [20][21][22] carbon nanotubes [23][24][25][26][27] and graphene. [28][29][30] In the present study, the behaviour of a mode 1 crack is modelled through the opening mode of separation of an epoxygraphene composite material by step-wise separating the epoxy and the graphene as indicated in Figure 1.…”