Reserach areas
Multi-functional lattice structures fabricated by the AM processes
Bio-inspired composites based on triply periodic minimal surfaces (TPMS) and lattices are desirable in many engineering disciplines because of their topology-driven properties. These natural materials have inspired the development and expansion of synthetic architected materials for innovative applications. This research study explores the process-structure-property-performance relationship between different TPMS, and lattices fabricated by the composite fabrication method, primarily through AM. Specific interest is understanding the deformation mechanism and computational modeling of such structures. Understanding the fatigue and fracture properties of the lattices is part of the project.
Designed gyroid structures with different relative densities and gradients
Functionally Graded Additive Manufacturing
A key driver for my research interest and passion is the capability of additive manufacturing in fabricating functionally gradient materials (FGMs). Prior research in at Tennessee Tech University (TTU) focused on designing and developing FGMs, including synthesis, characterization, and computational modeling. The first research project was to design and fabricate FGMs using the low-cost fused filament fabrication (FFF) process. This project has the impact of creating materials with more robust interfaces than the direct material joints—the interfaces of multi-materials characterized by microstructural analysis and mechanical testing methods. I performed numerical homogenization to verify the underlying failure mechanism of the multi-material fabricated parts.
One of the main goals of the project is the multi-scale modeling of functionally graded composite materials manufactured by the FFF process. Three-scale homogenization was used to capture composite materials' microscale and mesoscale effects. Effective macroscale material properties were computed using the graded finite element method with the isoparametric formulation. According to the study, the mechanical performance of the test samples was greatly affected by the fiber morphology and distribution in the microscale and mesostructure formation of the deposited beads. Computational modeling methods confirmed that direct interface joint created stress concentrations which prone to stress cracking and delamination at the interface region. The approach employed in this research significantly reduced the stress concentrations at the interface region, which promises the fabrication of multi-functional parts in potential applications such as aerospace, biomedical, and automotive.
Fiber Reinforced Additive Manufacturing
Prediction of material properties using homogenization methods
Another project titled "Three-scale asymptotic homogenization of short fiber reinforced additively manufactured polymer composites" was accomplished to perform the computational modeling on material extruded parts. To understand their mechanical behavior under various processing conditions and parameters, I investigated the multiscale nature of 3D printed composite materials, including fiber distribution and orientation.
Fiber Reinforced Additive Manufacturing
Development of high-temperature polymer matrix composites
The surface and fracture morphology and mechanical properties of additively manufactured high-temperature polymer samples were analyzed through a project in collaboration with research team members titled, "Processing, mechanical characterization, and micrography of fiber-reinforced composite parts." This research examined morphological properties and fracture morphology of additively manufactured high-temperature composites. Fibers reinforcement inside the matrix helped increase the strength, stiffness, hardness of the overall composite material, which makes it useful in applications like wind turbines, lightweight automotive products, armor, and satellite components.
Multi-Material Additive Manufacturing
The objective of this project is the design, fabrication, and computational modeling of thermo-mechanical properties of additively manufactured metal-ceramic-polymer composites.
Functionally Gradient Composite Materials
Normal stress distribution at the interface of the tensile samples, (a) direct transition from ABS to CF/ABS, (b) gradient transition within 5% of total length, (c) gradient transition within 10% of total length, (d) gradient transition within 30% of total length, (e) 100% linear transition throughout the specimen
