It is well-known that residual stresses can originate in composite laminates during the manufacturing process. These stresses are caused by resin shrinkage and differential thermal contraction between the matrix and reinforcement. Not only are these residual stresses difficult to experimentally measure, but they are also difficult to predict computationally. Predictive models of the laminate curing process require detailed knowledge of the resin thermo-mechanical properties as a function of cure conversion, which cannot be directly determined through traditional continuum-scale modeling methods. Therefore, molecular modeling methods need to be incorporated into the process modeling to effectively predict residual stresses and develop optimal manufacturing techniques to minimize these stresses.
An Integrated Computational Material Engineering (ICME) approach is used to predict the effect of the cure cycle on the design and manufacturing of a carbon/epoxy composite (DGEBA-polyoxypropylene diamine resin). Molecular Dynamics (MD) is employed to predict the resin elastic properties, strength, glass transition, and thermal expansion as a function of the degree of cure at the corresponding curing hold temperatures. The molecular models (Figure 1) are developed using the Interface Forcefield (IFF), and the properties are computed as a function of the crosslink density. The predicted resin properties are subsequently used in micro-scale models that account for random fiber distribution using the Finite Element Method (FEM). Commercial solvers, Abaqus/Standard and Abaqus/Explicit supplemented with user-written subroutines, are employed to model the curing and subsequent loading until failure. The residual stress build-up during cure is predicted using a converged Representative Volume Element (RVE). The effect of residual stress on composite transverse strength is then investigated. Results indicate successful implementation of the two-scale method for process modeling of thermosets using the ICME approach.


Multiscale Modeling of the Cure Process in Thermoset Polymers using ICME

The Virtual Technical Meeting of the Society of Engineering Science 2020 is the first fully virtual meeting of the SES community to envision and connect during the hiatus created by Covid-19, providing a platform for the exchange of ideas, and to showcase the latest research in the field of engineering science.

[Visit the Programme](https://drive.google.com/file/d/1BoCPBzrr1IQFANuzQI8a-paXCJoOcCkB/view?usp=sharing) | [Visit the Prerecorded Video/Poster List](https://drive.google.com/file/d/1XHLeEXJxEFjCSsNScuLDfMwy1X7oy7oJ/view?usp=sharing) | [View the Session Grid](https://drive.google.com/file/d/1VeDOC-Ev5m_ymYjXnjaXSZHR3_DARiLt/view?usp=sharing)