FPCM-15
Flow Processes in Composite Materials
June 27–29, 2023
Keynote Speakers
Session I Morning Keynote
Fiber Orientation Descriptors: How we got here and what comes next
Tuesday, 6/27 8:00a-8:45a
Charles Tucker III
Professor Emeritus
University of Illinois at Urbana-Champaign
Abstract
For discontinuous fiber composites, various models are regularly used to relate flow during processing to fiber orientation, and fiber orientation to rheological and mechanical properties. Any such model relies on some mathematical descriptor of fiber orientation, the most common being the second-order orientation tensor. Orientation tensors are also a standard way to report predictions of local microstructure and to report experimental measurements of orientation.
The choice of an orientation descriptor has a major influence on the accuracy of any model, whether for flow-induced orientation, rheological behavior, or solid-state properties. This talk will review the path by which orientation tensors came to be widely used, summarize their advantages, and highlight some limitations that may not be widely understood, particularly the limitation to orthotropic material symmetry. I will then discuss ways to overcome these limitations and improving the accuracy of predictive models. Options from the literature include using the orientation distribution function as the descriptor, and directly simulating multiple fibers. An option from my own work is to retain the second-order orientation tensor as the primary descriptor and use a non-orthotropic closure approximation for the fourth-order orientation tensor. The orientation distribution function, which is required for predicting nonlinear mechanical properties, can then be reconstructed using the non-orthotropic fourth-order tensor. This scheme is fully developed for planar orientation and can recovers the distribution function much more accurately than any previous tensor-based model.
Biography
Charles Tucker earned bachelor’s, master’s and Ph.D. degrees in mechanical engineering from the Massachusetts Institute of Technology. Since 1978 he has been on the faculty of the Department of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign, where he is currently the Alexander Rankin Professor Emeritus.
Dr. Tucker’s research focuses on manufacturing processes for polymers and composite materials. His models for predicting flow-induced fiber orientation are used worldwide in all software packages for simulating injection molding, and his seminal paper on orientation tensors has over 1,000 citations. He has also studied compression mold filling, resin transfer molding, microstructure development in polymer blends, and mixing in chaotic laminar flows. He has advised 50 master’s, Ph.D., and post-doctoral students.
Dr. Tucker is a Fellow of the American Society of Mechanical Engineers and was one of the first three researchers to be named a Fellow of the Polymer Processing Society. He edited the book Fundamentals of Computer Modeling for Polymer Processing and, with his colleague Jonathan Dantzig, wrote, Modeling in Materials Processing. He recently published his third technical book, Fundamentals of Fiber Orientation: Description, Measurement and Prediction (Hanser, 2022).
From 2013 to 2017 Dr. Tucker served his university as Vice Provost for Undergraduate Education and Innovation. In that role he provided campus-wide leadership in undergraduate education; increased enrollments, student diversity, and financial aid; and supported innovations in classroom and online instruction.
Session II Afternoon Keynote
Flow and Transient Phenomena in Large Scale Additive Manufacturing
Tuesday, 6/27 1:30p-2:15p
Dr. Eduardo Barocio
Asst. Director of Additive Manufacturing
Composites Manufacturing and Simulation Center
Purdue University
Abstract
Although extensive demonstrations of the Large-Scale Additive Manufacturing (LSAM) process have been made across different industries, there is a need for fundamental understanding of the contributions of phenomena including anisotropic flow, transient heat transfer, viscoelasticity, thermoelastic and crystallization shrinkage, and polymer crystallization to the residual stresses and deformation of printed geometries. Insights on the contributions of these phenomena gained through experimental and numerical studies will be shared in this presentation. Numerical studies have been carried out with Additive3D, a physics-based simulation workflow for additive manufacturing that captures, in addition to the phenomena listed above, interactions with the substrate, interlayer adhesion, heat transfer due to material compacter, and local convection and radiation conditions. Similarly, experimental studies have been carried out in the CAMRI system developed at Purdue and the Thermwood LSAM system. The primary industrial application for LSAM has been tooling due to the limited structural characteristics inherent to the short-fiber reinforced polymers used for printing. Hence, this presentation will conclude discussing the outlook for emerging methods to enhance the structural characteristics of printed materials.
Biography
Dr. Eduardo Barocio is the Director of the Composites Additive Manufacturing and Simulation Consortium at the Purdue Composites Manufacturing and Simulation Center. He obtained a Ph.D. from Purdue University and a BSc in Mechatronics Engineering from Tecnologico de Monterrey. Dr. Barocio research interest is in modeling and simulation of composites manufacturing processes as well as in developing hybrid manufacturing processes for composites. His work is primarily in the field of extrusion deposition additive manufacturing with fiber reinforced polymers. During his Ph.D., Dr. Barocio led the development of the composites additive manufacturing research instrument (CAMRI) and codeveloped a comprehensive physics-based process simulation workflow for additive manufacturing called Additive3D.
Session III Morning Keynote
Processing of Powder-Epoxy Composite Materials for Large Structures in Marine Renewable Energy
Wednesday, 6/28 8:00a-8:45a
Professor Conchúr Ó Brádaigh
Head of School of Engineering
University of Edinburgh
Abstract
This keynote lecture discusses the ongoing work at the University of Edinburgh on the processing, design and testing of thick-section composites for large structures such as offshore renewable energy wind and tidal turbine blades. Heat-activated, single component epoxy powders are widely used in the powder coating industry due to their low cost, long out-life, and minimal VOC emissions. They can be formulated to achieve low viscosities at elevated temperatures and then cure rapidly while producing a relatively small total exothermic reaction. The potential to use these materials as a resin matrix for glass-fibres has been identified for manufacturing thick section parts in which it is often difficult to control the heat of cure e.g. the root section of wind and tidal turbine blades. The potential of ocean renewable energy is tremendous. Further development of tidal turbine blades is required, however, due to the harsh marine environment, large cyclic forces and high cost of installation. Numerical simulations of the heat transfer, consolidation flow and cure process allow for a better understanding of the manufacturing process, and how thick sections can be processed more efficiently with epoxy powders. Carbon fibre reinforced polymers are also promising materials for marine applications; hence, it is vital to understand fully their material properties and failure mechanisms. The effect of water immersion on the properties of glass and carbon-fibre reinforced composites is discussed and a novel tape-line for production of low cost carbon and basalt fibre prepreg and semi-preg materials is presented. Thermal modelling and experimental investigation of the tape line enables an understanding of the key physical processes involved and the potential to optimise the process in terms of quality and cost.
As composite blades are the prime movers in tidal stream turbines, they will need to be mechanically tested and certified in dedicated fatigue testing facilities. A typical tidal turbine blade will see 10 million loading cycles in a 15-20 year lifetime, which will take over 3 years to fatigue test using standard hydraulic loading technologies. The FastBlade facility, located in Rosyth Dockyard, Fife has been funded by the EPSRC and the University of Edinburgh. It opened in 2022 and employs novel, regenerative hydraulic technologies to accelerate the fatigue testing of tidal turbine blades by a factor of 10, reducing the lifetime fatigue testing time to only 4 months, which makes the facility unique in the world.
Biography
Prof. Conchúr Ó Brádaigh is Chair of Materials Engineering and Head of the School of Engineering at The University of Edinburgh. He is an elected Fellow of the Royal Academy of Engineering and the Royal Society of Edinburgh, and is a Fellow of the Institute of Material, Minerals and Mining and of the Institution of Mechanical Engineers.
His research interests include manufacturing, testing, modelling and sustainability of composite materials for renewable energy (wind and ocean), aerospace and automotive applications. He is Principal Investigator for the University’s FastBlade tidal turbine blade fatigue testing facility in Rosyth, Scotland.
Conchúr was previously Professor of Energy Engineering at University College Cork, Ireland, where he was also Director of the SFI Marine Renewable Energy Ireland (MaREI) Research Centre. He lectured at the University of Galway from 1990 to 2014, during which time he was also a Co-Founder and Joint Managing Director of two Irish composite materials companies.
Conchúr received a Bachelors in Mechanical Engineering in 1985 from the University of Galway, followed by a Masters Degree in 1987. This was followed by a PhD in composite materials from the University of Delaware, USA in 1991.
Session IV Afternoon Keynote
An Integrated Multi-Physics Modeling Approach to Liquid Composite Molding Simulation
Wednesday, 6/28 1:30p-2:15p
Professor Dianyun Zhang
Assistant Professor, Aeronautics and Astronautics
Purdue University
Abstract
Liquid Composite Molding (LCM) techniques, including Resin Transfer Molding (RTM) and Vacuum Assisted Resin Transfer Molding (VARTM), are increasingly used for fabricating structural components due to their ability to produce complex parts at low costs. The processes involve placing layers of dry fabrics onto a mold, infusing the fabrics with a reactive resin, and curing and consolidation of the part under elevated temperatures and pressures. Due to the property change of a curing resin, the hierarchical nature of composite materials, and mismatch of the thermo-chemo-mechanical properties between the fiber and matrix, unintended defects, such as voids, dry spots, fiber wrinkling, residual stresses, and geometric distortions, are developed in final products, greatly affecting their stiffness, strength, and dimensional stability.
This talk will focus on the development of an integrated multi-physics and multiscale model for predicting manufacturing-induced defects and the resulting variability in structural performance. The processing model predicts dry fabric deformation, resin flow movement, residual stress generation, and dimensional changes of composite panels. A coupled flow-compaction model is developed to predict the movement of flow front and the resulting fabric deformation. The result is subsequently subjected to a curing simulation, which incorporates resin cure kinetics in the heat transfer analysis. Micromechanics is implemented at the subscale to capture the temperature and curing degree distributions at the fiber–matrix level. The curing history is then passed to the stress analysis through the incorporation of a cure constitutive model that includes cure-dependent mechanical properties, thermal strains, and cure shrinkage.
Multiple examples will be used to illustrate the predictive capability and advantages of the proposed modeling tool. Special focus will be given to the effect of dual-scale porosity and the coupling of draping–infusion and infusion–curing simulations. The physics-based model will be further integrated into a Gaussian process modeling framework to quantify the uncertainty associated with composites manufacturing. In-process monitoring and incorporation of residual stresses in composite progressive damage analysis will also be discussed in this talk.
Biography
Dr. Dianyun Zhang joined Purdue University in 2020 as an Assistant Professor in the School of Aeronautics and Astronautics. Prior to that, she was an assistant professor in the Department of Mechanical Engineering at the University of Connecticut from 2015–2020. Dr. Zhang received her dual bachelor degrees in Mechanical Engineering and Aerospace Engineering in 2009, and Ph.D. degree in Aerospace Engineering in 2014, all from the University of Michigan. Her broad area of research interest is in experimental characterization and computational modeling of lightweight materials. The focus is on the composite process models, multiscale modeling methods, and progressive damage analyses across different material length scales. Her research has been funded by several federal agencies and private companies. She is also the recipient of the 2020 NSF CAREER award.
Session V Morning Keynote
Fiber length and orientation dependent flow modeling in macroscopic injection molding simulations
Thursday, 6/29 8:00a-8:45a
Dr. Florian Wittemann
Group Leader
Karlsruhe Institute of Technology (KIT) - Institute of Vehicle System Technology (FAST)
Abstract
For manufacturing of discontinuous fiber reinforced polymer parts, injection molding is today’s most important process. During the injection of the molten fiber-matrix-suspension, the fibers orientate depending on the flow field, leading to anisotropic thermo-mechanical properties of the final part. However, the fiber-induced anisotropy due to re-orientation is also present during the mold filling and thus influences the flow behavior of the suspension. Furthermore, the flowable matrix shows a shear-rate and temperature dependent viscous behavior, also affected by solidification processes like crystallization or curing. Due to this overlap of phenomena, discontinuous fiber reinforced polymers are complex materials, which are challenging to model. However, process simulation is crucial in guaranteeing the manufacturability of a part and providing information for subsequent structural analysis.
To enable more detailed process simulations at part level, enhanced macroscopic approaches for viscosity and fiber breakage modeling are presented. The viscosity is modeled by a fourth-order tensor, considering fiber orientation, length, and volume fraction as well as non-Newtonian matrix behavior [Wittemann et al., 2019]. A recently published approach for fiber breakage, based on hydrodynamic forces, describes the shortening of fibers during filling, depending on flow field and fiber orientation state [Wittemann et al., 2022]. The coupling of the viscosity tensor and the fiber breakage creates a transient anisotropic modeling approach, in which shortening of the fibers directly influences the flow modeling and hence the predicted cavity pressure. The simulated cavity pressure and fiber lengths are in good agreement with experimental data.
Biography
Dr. Florian Wittemann is a mechanical engineer from Karlsruhe, Germany. He earned his doctorate in 2021 from Karlsruhe Institute of Technology (KIT) at the Institute of Vehicle System Technology – Lightweight Design Division, developing novel simulation approaches for injection molding simulations to consider the influence of fiber orientation and length in the mold filling simulation. Dr. Wittemann continues his work as Group Leader at KIT, leading a 7-member team of scientific researchers.
Conference Banquet Welcome/Opening Remarks
Wednesday, 6/28 6:30p
Dr. Arvind Raman
John A. Edwardson Dean of Purdue University’s College of Engineering
Robert V. Adams Professor of Mechanical Engineering
Purdue University
Biography
Dr. Arvind Raman is the John A. Edwardson Dean of Purdue University’s College of Engineering and the Robert V. Adams Professor of Mechanical Engineering. His research focuses on exploiting nonlinear dynamics for innovations in diverse interdisciplinary areas such as nanotechnology, biomechanics and appropriate technologies for sustainable development. He is the co-founder of the Shah Family Global Innovation Lab in the College of Engineering that supports technology development and translation of technologies for sustainable development and the PI of the $70M USAID funded LASER PULSE center that convenes and catalyzes a global network of Universities, government agencies, non-governmental organizations, and the private sector for research-driven practical solutions to critical development challenges in Low- and Middle- Income Countries.
Raman is an ASME fellow, an ASME Gustus Larson Memorial Award recipient, Keeley fellow (Oxford), College of Engineering outstanding young investigator awardee, and an NSF CAREER awardee. Professor Raman joined Purdue University in 2000 as an Assistant Professor following a PhD in Mechanical Engineering from the University of California at Berkeley advised by Prof. C. D Mote Jr. (1999), MS in Mechanical Engineering from Purdue University (1993), and a B. Tech in Mechanical Engineering from the Indian Institute of Technology, Delhi (1991).
Conference Banquet Guest Speaker
Wednesday, 6/28 6:30p
Dr. Sangtae Kim
Distinguished Professor and Head of the School of Chemical Engineering
Purdue University
Biography
Sangtae “Sang” Kim is the Jay and Cynthia Ihlenfeld Head and Distinguished Professor of Chemical Engineering at Purdue University where he is engaged in rational computer-aided drug discovery research. A native of Seoul who was raised in Montreal, Dr. Kim earned simultaneous BSc/MSc degrees (1979) in chemical engineering from the California Institute of Technology and a PhD (1983) from Princeton. He started his career at the Department of Chemical Engineering at UW-Madison in computational microhydrodynamics, rising to the rank of Wisconsin Distinguished Professor in eight years. In 1997, Dr. Kim left Madison to work in the pharmaceutical industry as Vice President of R&D Information Technology, first with Warner Lambert Company’s Parke-Davis Pharmaceutical Research Division and then later with the Lilly Research Laboratories of Eli Lilly. He returned to academia in 2003 to become a distinguished professor at Purdue University and to serve at the National Science Foundation as the inaugural Division Director for the national cyberinfrastructure programs (2004-2005). Dr. Kim is a fellow of AICHE and AIMBE and among many other honors, Dr. Kim has received AICHE’s Allan P. Colburn Award, was inducted in 2001 as a member of the National Academy of Engineering and received the 2013 Ho Am Prize in Engineering from the Samsung/Ho Am Foundation.