Rani Elhajjar

Dr. Elhajjar is a Fulbright scholar and professor. His experiences include senior positions in composite quality, certification, and build reliability engineering at Boeing and SpaceX. Dr. Elhajjar was a structural analyst on the Boeing 787 Dreamliner program where he was the lead engineer on the effects of the composite manufacturing defects program for the 787-fuselage structure. He developed various approaches for the structural assessment of composite structures with manufacturing defects. More recently in 2018, he led a similar role with SpaceX to build reliability of composite structures used in the Falcon 9 and Falcon Heavy Vehicles. Dr. Elhajjar was selected as a Fulbright Scholar to the Università Degli Studi di Trento in Italy in 2016 at the Department of Industrial Engineering for a teaching and research appointment in composite materials.  He is the author of the book Composite Structures: Effects of Defects.

Education

• PhD, Civil Engineering, Georgia Institute of Technology, 2004
• MS, Civil Engineering, University of Texas at Austin, 2000
• BS, Civil Engineering, University of Nebraska Lincoln-Omaha, 1998

Research Interests

• Effects of defects in polymer based composite structures, sustainable composite materials from renewable and fully recyclable systems
• Full field non-destructive testing methods
• Fracture mechanics (micro and nano composites)
• Smart composites for stress sensing
• Dielectric elastomer composites
• Magnetostrictive composites
• Coupled mechanics of composites
• Composites for infrastructure applications

Journal Publications

Google Scholar link

• Law, C.T., Yermakov, A., Thompson, A., Coaty, C., Sabo, R., and Elhajjar, R., Flexible Magnetostrictive Nanocellulose Membranes for Actuation, Sensing and Energy Harvesting Applications. Frontiers in Materials, 2020. 7: p. 38. https://doi.org/10.3389/fmats.2020.00038
• Rigotti, D., Elhajjar, R., & Pegoretti, A. (2019). Adiabatic effects on the temperature and rate dependency of the fracture toughness of an ethylene-fluoroethylene film. Engineering Fracture Mechanics, vol. 24, pp.260-269.
  https://doi.org/10.1016/j.engfracmech.2019.03.005
• Elhajjar, R., Law, C.T. and Pegoretti, A., (2018), Magnetostrictive polymer composites: recent advances in materials, structures and properties. Progress in Materials Science, vol. 97, pp 204-229.
  https://doi.org/10.1016/j.pmatsci.2018.02.005
• Yang, P., Law, C.T., Elhajjar, R., (2017) Full-Field Infrared Phase Sensitive Thermography for Microstructural Investigation of Giant Magnetostrictive Materials,  Mechanics of Advanced Materials and Modern Processes, vol. 3, no.1 p.10.
  https://doi.org/10.1186/s40759-017-0026-0
• Ning Z., Liu, R., ElHajjar, R., Wang, F.,(2017) Micro-modeling of thermal properties in carbon fibers reinforced polymer composites with fiber breaks or delamination. Composites B, v.114, pp.247-255.
• Van Dyke, S., Titi, H., & El-Hajjar, R. (2017). Comparison of California Bearing Ratio and Pin Puncture Strength Testing Used in the Evaluation of Geotextiles. Transportation Research Record: Journal of the Transportation Research Board, (2656), 1-11.
• Paneerselvam, S., Samad, W., Venkatesh, R., Song, K., Elhajjar, R, and Rowlands, R., (2017) Displacement-based experimental stress analysis of a circularly-perforated asymmetrical isotropic structure, Experimental Mechanics, 57 (1), pp 129-142.
  DOI: 10.1007/s11340-016-0218-2
• Sabo, R., Yermakov, A., Law, C., and Elhajjar, R., (2016) Nanocellulose enabled electronics, energy harvesting devices, smart materials and sensors:  a review. Journal of Renewable Materials, 4(5): 297-312.
• Tabandeh-Khorshid, M., Schultz, B., Rohatgi, P., Elhajjar,R., (2016) The diametrically loaded cylinder for the study of nanostructured aluminum-graphene and aluminum- alumina nanocomposites using digital image correlation. Frontiers in Materials, 09 May 2016 | http://dx.doi.org/10.3389/fmats.2016.00022
• Al-Hajjeh, A., Lynch, E., Law, C. T., & El-Hajjar, R. (2016). Characteristics of a Magnetostrictive Composite Stress Sensor. IEEE Magnetics Letters, 7, 1-4.
• Elhajjar, R., and Shams, S. (2016).  A new method for limit point determination in composite materials containing defects using image correlation. Composites Science and Technology. 122, 140-148,
  doi: 10.1016/j.compscitech.2015.11.026
• Shams, S., Yang, P., and Elhajjar, R. (2016). Damage Initiation and Fatigue Behavior of Carbon-Fiber Composite Disk Springs. SAE Int. J. Mater. Manf. 9(1):181-186,
  doi:10.4271/2015-01-9084.
• Elhajjar, R. F., Shams, S. S., Kemeny, G. J., & Stuessy, G., (2016), A hybrid numerical and imaging approach for characterizing defects in composite structures. Composites Part A: Applied Science and Manufacturing. 2016, 81, 98-104,
  doi: 10.1016/j.compositesa.2015.10.027
• Erfanian-Naziftoosi, H. R., Shams, S. S., & Elhajjar, R. (2016). Composite wave springs: Theory and design. Materials & Design, 95, 48–53
  doi:10.1016/j.matdes.2016.01.073
• Elhajjar, R. and Haj-Ali, R., (2016), “Thermoelastic stress analysis for detecting wrinkles and associated resin pockets in polymer composites,” Challenge Journal of Structural Mechanics, 2 (4), 246–247

Books

• 2013 - co-edited along with Dr. Valeria La Saponara and Dr. Anastasia Muliana, Smart Composites – Mechanics and Design, by CRC Press. The book addresses the current progress in the mechanics and design of smart composites and multifunctional structures.
• Elhajjar, R., Grant, P., and Ashforth, C., Composites Structures: Effects of Defects, Wiley, Hoboken, NJ. 2018

 Awards, Honors and Societies

• Tau Beta Pi Engineering Honor Society
• Phi Kappa Phi Honor Society