Abstract: Composite materials are nowadays finding increasing utilisation in transportation, energy and health sectors. With a wide range of microstructures and properties, they are promising for future load-bearing components or shape-morphing structures, as diverse as aircraft drag control systems, deployable space structures and flexible electronics. One of the primary challenges facing new composite structures is the desire to understand the mechanics of material microstructures upon their macroscopic mechanical behaviour. To address this challenge, substantial development of new theories and multiscale models for composite materials is required.
In this talk, I will firstly present a bottom-up multiscale computational framework to model different entities (fibre/matrix, ply, laminate and component) in load-bearing composite structures. The framework starts by measuring the material properties of fibre, matrix and interface using nano-indentation techniques. Various computational methods such as phase field fracture, continuum damage mechanics and cohesive zone models were then used to model the failure behaviour of composite materials. This framework enables carrying out multiscale modelling by computing the properties of individual ply and homogenizing the results into a constitutive model, followed by the transfer of information to the next length scale. The multiscale models are further validated by experimental results from impact and crush loading conditions.
Then, I will present a novel inverse-design framework of morphing structures using functionally graded composites. By harnessing the non-linear beam buckling theory and composite micromechanics, we are able to transform flat 2D sheets (with cuts) into desired 3D axisymmetric structures. We have proposed a voxel-based method to manufacture Functionally Graded Composites (FGC). The use of FGC in the manufacturing of morphing structures enables a seamless transition from one state to another. It grants precise control of the modulus profile of materials within the component, unlike traditional single-phase homogeneous material, hence specific morphing requirements can be achieved.
Overall, our multiscale virtual test platform opens a new avenue to the efficient design, testing and certification of future composite structures.
School of Engineering and Materials Science, Queen Mary University London, Mile End Road, London, E1 4NS, UK
Biography: Dr Wei Tan is a Lecturer (Assistant Professor) at Queen Mary University London and the head of the research group on “Mechanics of Composite Materials” since January 2020. He received his Bachelor in Mechanical Engineering and Physics (double major) at Central South University, followed by his PhD in Aerospace Engineering at Queen’s University Belfast. After his PhD study, he spent 2 months as a visiting research fellow at IMDEA material institute. He then worked as a Research Associate at University of Cambridge. He has published over 30 papers in leading journals of composite materials. Other recognitions include the EPSRC New Investigator Award, Cambridge CAPE BlueSky Research Award and Royal Aeronautical Society Bronze Award.
His research interests lie in the mechanics of multifunctional composite materials from load-bearing, energy-storage to shape-morphing. His research is focused on understanding and predicting the mechanical response of composite materials via experimental, analytical and computational methods. Particularly, his current research projects include: (1) proposing novel characterisation method to reveal the microstructures and deformation/failure mechanisms of composites operating over different length scales; (2) developing novel computational models or data-driven methods for predicting the mechanical response of composites under impact or crush loading; (3) promoting a new generation of damage tolerant and multifunctional composites, such as energy-storage and shape-morphing structures.