Fastening and Joining Research Institute (FAJRI)

FAJRI research objective is to advance the science and technology, develop, and to disseminate new knowledge of material joining for load-bearing structural and mechanical joint systems that may be made of similar and/or mixed materials.  This includes metals, composites, polymers, and plastics that are joined by mechanical fastening, adhesive bonding, welding, riveting, hybrid or other advanced joining methods.

FAJRI Research Philosophy
In its material joining research, FAJRI follows a systems approach that would simultaneously investigate the relative significance of single and multiple variable interactions, which would affect the overall system performance and reliability.  Those variables are divided into six groups that belong to:  1) the joint,    2) the joining element,   3) the joining tool,   4) process control method,   5) in-service loads, and   6) environmental effects.

FAJRI Research Methodology
A combination of analytical and mathematical modeling, numerical and computer simulation, experimental testing and validation methods are used.

FAJRI Facility and Test Equipment
FAJRI dedicated lab space and graduate student office occupy a 4,000 sq. ft secure suite on the second floor of Dodge Hall on the main campus of Oakland University. Dedicated FAJRI equipment include MTS fatigue testing system with high temperature chamber and grip rating (100kN), 5-spindle DC-nut runner with controls, Junker machine for Vibration loosening, two Torque-tension-angle research systems (up to 1,000 ft-lb), Wyko optical profiler for surface roughness measurement, Dynamic Mechanical Analyzer (DMA), Environmental Chamber with controls, Cyclic salt-fog corrosion chamber, Autoclave with Process Controls for film adhesive bonding, Vibration-isolation table, NDE equipment (ultrasonic and optical), FEA software and computer work stations, secure storage space and conference room facility for ITAR projects, ...etc. Several specialty labs in various engineering and science departments also support FAJRI research; this includes the Optics and NDE lab, Chemistry labs, and a well-equipped machining center for test fixture design and sample manufacturing.

NSF Initiative for Composite Joining Research at OU

https://www.nsf.gov/awardsearch/showAward?AWD_ID=1822028

Dr. Nassar and his interdisciplinary research team at Oakland, in partnership with their counter parts at Georgia Institute of Technology (GT), and The University of Tennessee-Knoxville (UTK)], have been recently awarded respective NSF Planning grants to develop a full proposal for Phase 1 ($4.5 million) of an IUCRC (Industry-University Cooperative Research Center).  The three-phase ($13.5m total) NSF initiative would establish three closely coordinated sites for a new research centers for Digital Composite Joining and Repair (D-CJAR) at OU, GT, and UTK.  A research team of 30 faculty experts, from the three partnering universities, would lead the research at the three respective D-CJAR sites, in close partnership with interested industry and other government research agencies. An NSF-led Planning meeting between respective academic and industrial partners is scheduled at Georgia Tech during the first quarter of 2019 for the 3-partnering universities to plan NSF proposal for Phase 1. NSF requires the formation of an Industrial Advisory Board (IAB) at each of the three D-CJAR sites to select and fund research projects. The OU site of D-CJAR would have an automotive/ground vehicle thrust, while the GT and UTK sites would respectively have Aerospace, and Energy/infrastructure thrusts. Subsequent to review, and hopeful award, by NSF, the start date for the 3 D-CJAR sites would be during the last quarter of 2019.

FAJRI research outcome benefits both the civilian and defense sectors of the US economy, by disseminating new fastening and joining technology to the automotive, ground vehicle, aerospace, infrastructure, energy sectors of the US economy. This is accomplished through technology transfer and work force training that ultimately lead to improved vehicle and component performance, weight reduction and energy savings, improved product safety and reliability, and reduced emissions.

FAJRI has been primarily funded by the US Congress, US Army CCDC Ground Vehicle Systems Center (formerly TARDEC), National Science Foundation (SBIR), and the US automotive OEMs.

Sample Funded Research Projects and Topics: 

• Adhesive bonding of lightweight materials
• Process optimization of autoclave film adhesive bonding
• Damage modeling and simulation
• Adhesive bonding and mechanical fastening of composite and polymeric joints
• Phenomenon modeling of vibration-induced loosening of threaded fasteners
• Ultrasonic control of bolt elongation during bolted joints assembly
• Tribology of threaded fasteners
• Clamp load loss due to cyclic service loads
• Non-destructive testing and inspection of composite and metallic joints
• Elastic interaction between fasteners in gasketed bolted joints
• Modeling of spine screw joints
• Finite element modeling and analysis of composite, polymer and metallic joints
• Reliability of bolted assemblies
• Torque specifications 

Headed by the PI and Founding Director (Professor Sayed Nassar), FAJRI has a strong interdisciplinary team of expert faculty who supervise graduate research of Ph.D./MS students, secure and conduct externally sponsored research projects from industry. In addition to using state of the art research equipment at FAJRI, each faculty researcher has his/her specialty lab dedicated to the specific sub-area of expertise.  FAJRI faculty come from the Departments of Mechanical Engineering, Electrical and Computer Engineering, Computer Science, Chemistry, and Mathematics and Statistics, at Oakland University:

• Composite fastening and Joining - Dr. S. Nassar
• Data Analytics, Machine Learning - K. Malik, Ph.D.
• Human-robotics interaction, automation - Dr. W-Y. G. Louie
• Fasteners and bolted joints - Dr. S. Nassar
• VOC and Chemistry - Dr. R. Dembinski
• NDT/NDE (optics and ultrasonics) - Dr. L. Yang, Dr. S. Nassar
• Tribology of threaded fasteners - Dr. S. Nassar
• FEA simulation, mechanical testing - Dr. Z. Wu
• Analytical, numerical and experimental stress analysis - Dr. S. Nassar
• Applied mathematics and statistics - Dr. M. Shillor
• Other collaborating faculty from other US and European institutions

A partial list of recent journal publications by FAJRI team includes: 

• Jagatap, S., Nassar, S., Abbas, R., Belingardi, G., “Process Variable Effect on the Strength of Autoclave-Bonded Film Adhesive Joints”, 2019, Journal of Adhesion Science and Technology”, JAST-2018-00304.
• Jagatap, S., Nassar, S.A., Tardito, M., “Effect of Autoclave Cure Pressure and Temperature on Polycarbonate Single Lap Joints with Polyurethane Film Adhesive”, 2018, Journal of Adhesion Science and Technology, in press.
• Mazhari, E., Nassar, S.A., “A Coupled Peel and Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints”, 2017, Journal of Manufacturing Science and Engineering-ASME Transactions, in press (accepted).
• Nassar, S.A., Mazhari, E., “A Coupled Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints”, 2016, Journal of Applied Mechanics- ASME Transactions, vol. 83(10), pp. 101006-1~7.
• Zaki, A.M., Nassar, S.A., Shillor, M., “Inverse Problem Solution for Bolt Preload Using Measured Surface Deformation”, 2016, Journal of Pressure Vessels Technology - ASME Transactions, accepted (in press).
• Sakai, K, Nassar, S. A., “Failure Analysis of Composite-Based Lightweight Multimaterial Joints after Cyclic Heat at High Relative Humidity”, 2016, Journal of Manufacturing Science and Engineering-ASME Transactions, vol. 139 (4), pp. 041007-1~11.
• Nassar, S. A., Mao, J., Yang, X., and Templeton D., “A Damage Model for Adhesively Bonded Single-Lap Thick Composite Joints”, 2012, Journal of Engineering Materials and Technology-ASME Transactions, vol. 134, no. 4, pp. 041004-1~7
• Yang, X., Nassar, S.A., and Wu, Z., “Criterion for Preventing Self-Loosening of Preloaded Cap Screws Under Transverse Cyclic Excitation”, 2011, Journal of Vibrations and Acoustics-ASME Transactions, vol. 133, no. 4, pp. 041013-1~11.
• Nassar, S.A., Yang, X., “A Mathematical Model for Vibration-Induced Loosening of Preloaded Threaded Fasteners”, 2009, Journal of Vibrations and Acoustics- ASME Transactions, vol.131, no. 2, 021009-1~13.
• Nassar, S.A., and Virupaksha, V., “Effect of Adhesive Thickness and Properties on the Biaxial Interfacial Shear Stresses in Bonded Joints Using a Continuum Mixture Model”, 2009, Journal of Engineering Materials and Technology-ASME Transactions, vol.131, no. 2, pp. 021015-1~9.
• Nassar, S. A., Tardito, M., Belingardi, G., “Effect of Autoclave Heating and Cooling Rate Adhesively-Bonded Lightweight Material Joints”, 2017, Proceedings of the ASME-IMECE2017.
• Nassar, S.A., Jagatap, S., Tardito, M., “Effect of Cure Temperature and Pressure on Autoclave-Bonded Polycarbonate Single Lap Joints”, 2016, Symposium on Material Fastening and Joining Technology, Proceedings of the ASME International Mechanical Engineering Congress & Exposition (IMECE2016), November 11-17, Phoenix, AZ.
• Wu, Z., Diab, M., Nassar, S.A., “Effect of Elevated Temperature on Adhesively Bonded Lightweight Material Single Lap Joints”, 2015, American Society for Composites 30th Technical Conference, September 28-30, East Lansing, MI.
• Nassar, S.A., Mazhari, E., “Cyclic Corrosion of Composite-Based Lightweight Material Single Lap Joints”, 2015, American Society for Composites 30th Technical Conference, September 28-30, East Lansing, MI.
• Housari, B. A., and Nassar, S.A., “Effect of Thread and Bearing Friction Coefficients on the Vibration-Induced Loosening of Threaded Fasteners Under Cyclic Transverse Loads”, 2007, ASME Journal of Vibrations and Acoustics-ASME Transactions, Vol. 129, pp. 484-494.
• Nassar, S.A. and Housari, B. A., “Study of the Effect of Hole Clearance and Thread Fit on the Self-Loosening of Threaded Fasteners Due to Cyclic Transverse Loads”, 2007, ASME Journal of Mechanical Design, Vol. 129, Issue 6, pp. 586-594.
• Nassar, Sayed A. and Alkelani, A.A., “Elastic Interaction and Creep Relaxation in Bolted Gasketed Joints”, 2006, ASME Journal of Pressure Vessels Technology, Vol. 128, pp. 394-401.
• Nassar, S.A. and Matin, P., “Clamp Load Loss Due to Fastener Elongation Beyond its Elastic Limit”, 2006, ASME Journal of Pressure Vessels Technology, Vol. 128, Nov. 2006, pp. 379-387.
• Nassar, Sayed A. and Veeram, Aditya B., “Ultrasonic Control of Fastener Tightening using Variable Wave Speed”, 2006, ASME Journal of Pressure Vessels Technology, Vol. 128, pp. 427-432.
• Nassar, Sayed A. and Housari, B. A., “Effect of Thread Pitch on the Self-Loosening of Threaded Fasteners Due to Cyclic Transverse Loads”, 2006, ASME Journal of Pressure Vessels Technology, Vol. 128, pp. 590-598.
• Nassar, S.A. and Matin, P. H., and G. C. Barber, “Thread Friction in Bolted Joints”, 2005, Journal of Pressure Vessels Technology- ASME Transactions, Vol. 127, pp. 387-393.
• Nassar, S.A., El-Khiamy, H., Barber, G.C., Zou, Q., Sun, T.S., “Bearing and Thread Friction in Fasteners”, 2005, Journal of Tribology, ASME Transactions, Vol. 127, pp. 263-272.
• Nassar, S.A., Barber, G.C., and Zuo, D., “Bearing Friction Torque in Bolted Joints”, 2005, STLE Tribology Transactions, Vol. 48, pp. 69-75.
• Nassar, Sayed A., and Matin, P. H., “Non-Linear Strain Hardening Model for Predicting Clamp Load Loss in Bolted Joints”, 2006, ASME Journal of Mechanical Design, Vol.128, Issue 6, pp.1328-1336.
• Nassar, S.A., Andrews, K.T., Kurk, S., and Shillor, M., “Modeling and Simulation of a Bonded Rod”, 2005, Journal for Mathematical and Computer Modeling, Vol. 42, pp. 553-572.
• Yang, X. and Nassar, S. A., “Constitutive Modeling of Time-Dependent Cyclic Straining for Solder Alloy 63Sn-37Pb”, 2005, Journal of Mechanics of Materials, vol. 37, pp. 801-814.
• Zou, Q., Sun, T.S., Nassar, S., Barber, G.C., El-Khiamy, H., “Contact Mechanics Approach to Determine Effective Radius in Bolted Joints”, 2005, Journal of Tribology-ASME Transactions, Vol. 127, pp. 30-36.
• Nassar, S.A. and Virupaksha, V.L., Ganeshmurthy, S., “Effect of Bolt Tightening and Joint Material on the Strength and Behavior of Composite Joints”, 2007, ASME Journal of Pressure Vessels Technology, Vol. 129, pp. 43-51.
• Nassar, S. A. and Matin, P.H., “Cumulative Clamp Load Loss Due to a Fully Reversed Cyclic Load Acting on an Initially Yielded Joint System”, 2006, ASME Journal of Mechanical Design, Vol. 129, pp. 421-433.
• Alkelani, A.A., Housari, B., Nassar, S.A., “A Proposed Model for Evaluating Gasket Creep Relaxation in Bolted Flanges”, 2007, in press, Journal of Pressure Vessels Technology-ASME Transactions.
• Nassar, S.A. and Meng, A., “Optical Monitoring of Bolt Tightening Using 3-D Electronic Speckle Pattern Interferometry (ESPI)”, 2007, ASME Journal of Pressure Vessels Technology, Vol. 129, pp. 89-95.