Polymer and polymeric composite materials are now widely used in automotive, transportation, aerospace, oil and gas sectors where their low density, coupled with durability, stiffness and strength makes them an attractive weight saving option. One of the advantages for the use of composite materials includes weight saving as well as dimensional stability in support structures to withstand large temperature variation. This seminar aims to raise greater awareness of current research work in developing novel polymeric composite processing and their various industrial applications.
1.35pm Presentation 1: Composite Materials by Dr Shantanu Bhowmik
2.05pm Presentation 2: Composite Materials Manufacturing by Dr Yuan Xiaowen
2.35pm Coffee/Tea break and networking
3.00pm Presentation 3: Composite Repair Techniques by Dr Sunil C Joshi
3.30pm Presentation 4: Non Destructive Evaluation of Composite Materials by Dr Stephen Wong
About the Speakers
Dr Shantanu Bhowmik received his PhD in Mechanical Engineering from Indian Institute of Technology, Roorkee in 2002 and presently, he is Senior Scientist at Singapore Institute of Manufacturing Technology, Singapore and Associate Professor (Adjunct) at Department of Aerospace Engineering, Delft University of Technology, The Netherlands. Dr Bhowmik has been honored by number of international research awards: DST-DAAD PPP-2000 research award during doctoral research and part of the doctoral research was carried out at Technical University of Berlin, Germany; NSERC Visiting Fellow (Research Award of Government of Canada as one of the most promising and emerging scientists) and the work was carried out at National Defence of Canada; and The Research Award of Prestigious National Academies (National Research Council of USA), for NASA’s Vision of Space Exploration at NASA-MSFC. Dr Bhowmik has published 86 research articles in international journals and international conferences, 2 book chapters and filed 3 patents and 4 invention disclosures.
Composite Materials: Emerging Technologies for Automotive, Aviation, Space and Electro Magnetic Interference Shielding
Recent technological scenario reveals that there is also significant demand of polymer for automotive, transfortation, aviation, electromagnetic interference (EMI) shielding etc. This presentation will highlight basic understanding of ionizing and nonionising radiations and properties of high-performance polymers and adhesives when exposed to radiations. As a case study, performance of space durable polymer such as polybenzimidazole (PBI) modified by low pressure plasma and atmospheric-pressure plasma and fabrication of the polymer by ultrahigh temperature-resistant epoxy adhesive (DURALCO 4703) will be addressed. Surface characterization of the unmodified and modified PBI sheets is carried out by contact-angle measurements by which surface energy is calculated. It is observed that polar component of surface energy leading to total surface energy of the polymer increases significantly when exposed to low-pressure plasma. X-ray Photoelectron Spectroscopy (XPS) reveals that the polymer surface becomes hydrophilic, resulting in increase in surface energy. High-energy radiation is simulated with mixed-field radiation generated by SLOWPOKE-2 (safe low power critical experiment) nuclear reactor. Therefore, in order to see the performance of the adhesive joint of PBI under radiation, the joint is exposed to SLOWPOKE-2 nuclear reactor up to a dose of 444 kGy and critically analysed.
Dr Xiaowen Yuan is a Senior Scientist at the Singapore Institute of Manufacturing Technology in Singapore. Her research strength lies in the development of advanced composite materials, including the manufacture and characterisation of hybrid polymer composites using natural resources, such as natural fibres, mineral fibres, cellulose and bioceramic materials. She has worked on manufacturing and characterisation of natural fibre composites, nano-cellulose composites, biomedical composite materials and biomorphic inorganic composites, and has also researched fibre surface modification.
Composite Materials: Manufacturing, Applications and Challenges
Composite materials date from the use of straw-reinforced clay in Egypt about three thousand years ago. Advanced composite materials emerged in the sixties with glass fibre composite resins being produced on a large scale. Today, composite materials are used widely in the aerospace, automotive, marine, and renewable energy industries and for a variety of civil infrastructure applications. Since the last decade, natural fibres have attracted renewed interest as a substitute for glass fibres, due to their inherent advantages of lightness, affordability, recyclability, and degradability. This talk will focus on the manufacturing and application of composite materials in the aerospace and automotive industries. The challenges associated with developing composites using natural fibres will be discussed.
Dr Sunil C. Joshiis currently an Associate Professor at the faculty in Aerospace Engineering Division, School of Mechanical and Aerospace Engineering, Nanyang Technological University. He received his doctorate in 1999 from Monash University, Australia, for his work on simulation of composites manufacturing processes. Prior to that, he worked as Scientist for 6 years at National Aerospace Laboratories in India, on various composites related tasks. His current research interests include reinforced composites, numerical simulation and optimisation of composites manufacturing processes, development of specialty composite material systems, curing and repair of composites, analysis and testing of thermal controls for micro-satellites, and thermo-mechanical analysis of coated and composite structures. Besides being actively involved in various research projects and administrative committees, he is an area editor for an Elsevier journal. To date he has more than 80 research publications to his credit.
Composites Repair Techniques
The increasing use of composite materials in various applications has raised a question as to how the repair technology be pitched to make these composites and their structures reliable and sustainable. This talk is intended to highlight the various composite-intensive applications, unique damage modes to composites and the repair required. It will touch upon the repair techniques available at hand and the conventional repair practices adopted for composites. Current developments in the area of composites repairs will also be discussed. Typical case studies on laminates and sandwich panels will be included. Finally, the talk will be concluded with remarks on various issues and related challenges in composite repairs.
Dr Stephen Wong has recently been appointed as a Senior Research Fellow with Nanyang Technological University, Singapore. Previously he was a lecturer with NTU for 23 years, with the School of Mechanical and Aerospace Engineering, where he presented course modules and conducted research in Non-Destructive Testing. Prior to this he worked for 11 years in the UK, conducting research and development and auditing sub-contractors in NDT. During this latter period he worked 2 years for Clarke Chapman - International Combustion Plc Ltd, a pressure vessel fabrication company and 9 years for Rolls Royce Plc Ltd, a gas turbine engine fabrication company. He has a PhD in Physics from the University of Manchester Institute of Science and Technology, UK and has published over 90 papers in various journals and conferences mainly in non-destructive testing. He is a Member of the Overseas Advisory Panel for the British Institute of NDT for Singapore and is a Technical NDT auditor for the Singapore Laboratory Accredition Service. He has collaborated with various companies (including RSAF and GE, USA) on NDT projects for many years.
Developments in Non-Destructive Testing of Fibre Reinforced Composite (FRC) Materials
Mechanical Impedance Inspection
The technology and equipment will be described. The ability to profile delamination and sizes shapes by probe movement and the ability to size defects from resonant frequencies will be discussed.
Results illustrating the resolution capability of conventional pulse echo immersion will be presented along with interpretation of ultrasonic signals. The ability to detect all delamination defects from 1 to 11 mm at almost any layer in the composite will be presented. A novel procedure to defect small delamination defects 0.15mm from the specimen surface using interfered signals will be described. Impact damage defects on honeycomb specimens will be presented along with the ability to detect the honeycomb and any damage to this structure. Ultrasonic results and sensitivites will also be compared with the results from the next section on Lock-in Thermographic Inspection.
Lock-in Thermographic Inspection
The principles of Lock-in Thermographic Inspection will be presented. The results of the PhD of Dr Bai Weimin will be presented. This work contained the development of a mathematical model and also a finite element model to predict the correct frequency to be used for any specimen. This frequency would give the maximum phase contrast and hence sensitivity between a defect and its surrounding region. The model was novel because it contained the convention current component due to the surrounding air which has not been considered by previous workers. Impressive correlation between the experimental, finite element and mathematical was achieved showing the correctness of the models.
Who Should Attend
Researchers, R&D managers and engineering staff with special focus on polymer related materials and relevant technology.
This is a non-chargeable seminar and seats are available on a first-come, first-served basis. To attend the seminar, please register online.
For technical enquiries: Dr Shantanu Bhowmik, Senior Scientist, Email: shantanub@SIMTech.a-star.edu.
For general enquiries: Alice Koh, Email: email@example.com