Research Activities and Profile Summaries

Masoud Rais-Rohani: Research Activities and Profile Summaries

Masoud Rais-Rohani is a Professor of Mechanical Engineering at the University of Maine, where he has served as department chair since 2017. His research focuses on structural and multidisciplinary design optimization, composite structures, computational modeling, uncertainty quantification, and engineering education. Previously, he was a faculty member in Aerospace Engineering at Mississippi State University. His work has been supported by NASA, NSF, DOE, DoD, ERDC, and NSSC.

ResearchGate Profile

Computational Modeling & Simulation Research

The goal of this research is to study nonlinear behavior of structures, vehicle crashworthiness, progressive axial crush of thin-walled single- and multi-cell, multi-corner metallic tubes, and integrated process-product, material-product analysis using sequential finite element simulations.

Highlights of research sponsored by DOE and NSF:

  • Finite element simulations of single- and multi-stage sheet forming processes
  • Energy absorption characterization of steel, aluminum, magnesium, and composite crush tubes through nonlinear finite element simulations and analytical modeling
  • Role of manufacturing-induced history effects on performance of sheet-formed components

When a structural component is optimized absent the history effects due to manufacturing, the resulting design may end up either too conservative or lacking the required level of safety.  Through sequentially coupled finite element simulations and appropriate constitutive models, such effects can be captured.

Publications: (*Student, **Postdoc)

  • Bock*, C., Ellis, B., and Rais-Rohani, M., “Process-Informed Simulation of Big-Area Additive Manufacturing (BAAM) of Polymers,” Proceedings of the iMeche, Part C: Journal of Mechanical Engineering Science, 2024. (in press)
  • Bock*, C., Ellis, B., and Rais-Rohani, M., “Fast Analytical Homogenization for Large Scale Additive Manufacturing,” SAMPE Conference and Exposition, Long Beach, CA, May 20-23, 2024.
  • Grant*, A., Ellis, B., Rais-Rohani, M., and Hajiha, R., “Exploring Process-Properties Relationships of 3D-Printed PLA: Towards Process-Informed Simulation and Design,” NanoTech 2019 Conference and Expo, Boston, MA, Jun 17-19, 2019.
  • Islam*, M., Buijk, A., Rais-Rohani, M., and Motoyama, K., “Process Parameter Optimization of Lap Joint Weld Based on FEM-RSM-GA Integration Technique,” Advances in Engineering Software, Vol. 79, pp. 127-136, 2015.
  • Najafi*, A., Acar**, E., and Rais-Rohani, M., “Multi-Objective Robust Design of Energy Absorbing Components Using Coupled Process-Performance Simulations,” Engineering Optimization, Vol. 46, No. 2, pp. 146-164, 2014.
  • Islam*, M., Bujik, A., Rais-Rohani, M., and Motoyama, K., “Simulation-Based Numerical Optimization of Arc Welding Process for Reduced Distortion in Welded Structures,” Finite Elements in Analysis and Design, Vol. 84, pp. 54-64, 2014.
  • Tamasco*, C., Rais-Rohani, M., and Buijk, A., “Coupled Finite Element Simulation and Optimization of Single- and Multi-Stage Sheet-Forming Processes,” Engineering Optimization, Vol. 45, No. 3, pp. 357-373, 2013.
  • Najafi*, A. and Rais-Rohani, M., “Multilevel Decomposition and Optimization of Coupled Process-Performance Systems,” 8th AIAA Multidisciplinary Design Optimization Specialist Conference, Honolulu, HI, Apr 23-26, 2012.
  • Najafi*, A., Acar**, E., and Rais-Rohani, M., “Robust Design of Energy Absorbing Components Considering the Manufacturing Effects,” 14th AIAA Non-Deterministic Approaches Conference, Honolulu, HI, Apr 23-26, 2012.
  • Najafi*, A., Marin, E., and Rais-Rohani, M., “Concurrent Multi-Scale Crush Simulations with a Crystal Plasticity Model,” Thin-Walled Structures, Vol. 53, pp. 176-187, 2012. (Featured online on Advances in Engineering, Sep 16, 2012)
  • Najafi*, A. and Rais-Rohani, M., “Sequential Coupled Process-Performance Simulation and Multi-Objective Optimization of Thin-Walled Tubes,” Materials and Design, Vol. 41, pp. 89-98, 2012.
  • Najafi*, A. and Rais-Rohani, M., “Coupled Sequential Process-Performance Simulation and Multi-Attribute Optimization of Thin-Walled Tubes,” ASME 2011 International Design Engineering Technical Conferences, Washington, D.C., Aug 29-31, 2011.
  • Salehghaffari*, S., Rais-Rohani, M., and Najafi*, A., “Analysis and Optimization of Externally Stiffened Crush Tubes,” Thin-Walled Structures, Vol. 49, pp. 397-408, 2011.
  • Najafi*, A. and Rais-Rohani, M., “Mechanics of Axial Collapse in Multi-Cell, Multi-Corner Crush Tubes,” Thin-Walled Structures, Vol. 49, pp. 1-12, 2011.
  • Najafi*, A., Rais-Rohani, M., and Hammi, Y., “Multi-Attribute Integrated Forming-Crush Simulation Optimization Using Internal State Variable Model,” 1st World Congress on Integrated Computational Materials Engineering, Seven Springs, PA, July 10-14, 2011.
  • Najafi*, A., Marin, E., and Rais-Rohani, M., “Influence of Anisotropic Texture on Crushing Behavior of Square Tubes,” 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Denver, CO, Apr 4-7, 2011.
  • Tamasco*, C., Rais-Rohani, M., and Buijk, A., “Sheet-Stamping Process Simulation and Optimization,” 7th AIAA Multidisciplinary Design Optimization Specialist Conference, Denver, CO, Apr 4-7, 2011.
  • Najafi*, A., Huang*, D., Rais-Rohani, M., Abdi, F., and Heydari, C., “Simulation of Crushing Process in Composite Tubes,” 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Orlando, FL, Apr 12-15, 2010.

Masoud Rais-Rohani: Modeling and Design of Composite Structures Research

The goal of this research is to investigate modeling and optimization techniques ranging from tailoring of ply orientation angle and thickness in design of laminated composite structures to micromechanical modeling of nanofiber enhanced polymer materials.

Highlights of research sponsored by NASA, DOE, and NSWCCD:

  • Computational modeling of extrusion-based additive manufacturing informed by process-structure-property-performance relationships
  • Design, modeling, simulation, and optimization of thick-walled origami-inspired rapidly-deployable foldable shelters
  • Reinforcement layout and sizing optimization of composite submarine sail structures
  • Analytical modeling of buckling and vibration characteristics of composite sandwich plates with elastic rotational edge restraints
  • Micromechanical modeling of nanofiber enhanced polymer composite materials to explore the effects of inhomogeneous, three-dimensional interphase and nanofiber waviness
Stiffener Layout Optimization Technique graphic

Alternative topology optimization techniques are used to determine the optimal layout of the internal stiffeners supporting large composite structures. Significant weight savings can be achieved when sizing optimization follows a stiffener layout optimization.

Publications: (*Student, **Postdoc)

  • Verzoni*, A. and Rais-Rohani, M. “Transition Analysis of Flat-Foldable Origami-Inspired Deployable Shelter Concepts,” Engineering Structures, Vol. 273, 115074, 2022.
  • Rouhi*, M. and Rais-Rohani, M., “Influence of Interphase and Inclusion Waviness on Stiffness Properties of a Nanoenhanced Matrix,” Hybrid Polymer Composite Materials, Properties and Characterisation, V.K. Thakur, M.K. Thakur, and A. Pappu (Eds.), Woodhead Publishing, ISBN 978-08-100787-7, 2017.
  • Rouhi*, M. and Rais-Rohani, M., “Predicting the Elastic Properties of CNF/Thermoset Polymer Composites Considering the Effect of Interphase and Fiber Waviness,” Nanocomposites Characterization: Technology and Industrial Applications, F. Abdi and M. Garg (Eds.), Pan Stanford Publishing, ISBN 978-981-4669-02-3, 2017.
  • DorMohammadi*, S., Rais-Rohani, M., and Rouhi*, M., “A Multilevel Approach for Analysis and Optimization of Nano-Enhanced Composite Structures,” Composite Structures, Vol. 131, pp. 1050-1059, 2015.
  • DorMohammadi*, S., Rais-Rohani, M., and Rouhi*, M., “Hierarchical Analysis and Optimization of Nano-Enhanced Composite Sandwich Plates,” AIAA SciTech 2014: 55th AIAA/ASME/ASCE/ AHS/ASC Structures, Structural Dynamics, and Materials Conference, National Harbor, MD, Jan 13-17, 2014.
  • Rouhi*, M. and Rais-Rohani, M., “Effect of Nano-Inclusions on Probabilistic Design of Components Made of Hybrid Composite Materials,” 9th AIAA Multidisciplinary Design Optimization Specialist Conference, Boston, MA, Apr 8-11, 2013.
  • Najafi*, A., Huang, D., Abdi, F., and Rais-Rohani, M., “Test Validation on the Energy Absorption Behavior of Composite Tubes with Different Ply Architectures,” SAMPE 2012 Conference, Baltimore, MD, May 21-24, 2012.
  • Rouhi*, M. and Rais-Rohani, M., “Modeling and Uncertainty Quantification of Nanofiber Enhanced Polymer Composite Materials with Functionally Graded Interphase Properties,” 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Denver, CO, Apr 4-7, 2011.
  • Rouhi*, M., Rais-Rohani, M., Lacy, T., Garg, M., and Abdi, F., “Mechanical Characterization of Nanofiber Enhanced Polymer with Application to Composite Crush Tubes,” 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Orlando, FL, Apr 12-15, 2010.
  • Sullivan, R., Hwang, Y., Rais-Rohani, M., Lacy, T., “Structural Analysis and Testing of an Ultralight UAV Carbon Composite Wing,” Journal of Aircraft, Vol. 46, No. 3, pp. 814-820, 2009.
  • Eamon, C. and Rais-Rohani, M., “Integrated Reliability and Sizing Optimization of Large Composite Structures,” Marine Structures, Vol. 22, No. 2, pp. 315-334, 2009.
  • Eamon, C. and Rais-Rohani, M., “Structural Reliability Analysis of Composite Advanced Sail for Virginia Class Submarine,” Journal of Ship Research, Vol. 52, No. 3, pp. 165-174, 2008.
  • Rais-Rohani, M. and Lokits*, J., “Reinforcement Layout and Sizing Optimization of Composite Submarine Sail Structures,” Structural and Multidisciplinary Optimization, Vol. 34, No. 1, pp. 75-90, 2007.
  • Thompson*, M., Eamon, C., and Rais-Rohani, M., “Reliability-Based Optimization of Fiber-Reinforced Polymer Composite Bridge Deck Panels,” ASCE Journal of Structural Engineering, Vol. 132, No. 12, pp. 1898-1906, 2006.
  • Rais-Rohani, M. and Lokits*, J., “Comparison of First- and Zeroth-Order Approaches for Reinforcement Layout Optimization of Composite Submarine Sail Structures,” 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, VA, Sep 6-8, 2006.
  • Sullivan, R., Rais-Rohani, M., Lacy, T., and Alday*, N., “Structural Testing of an Ultralight Composite UAV,” 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Newport, RI, May 1-4, 2006.
  • Thompson*, M., Eamon, C., and Rais-Rohani, M., “Reliability-Based Optimization of Fiber-Reinforced Polymer Composite Bridge Deck Panels,” 8th AIAA Non-Deterministic Approaches Conference, Newport, RI, May 1-4, 2006.
  • Rais-Rohani, M., Eamon, C., and Keesecker, A., “Structural Analysis and Sizing Optimization of a Composite-Advanced-Sail Design Concept,” Marine Technology, Vol. 42, No. 2, pp. 61-70, 2005.
  • Smitherman, D.V., Rais-Rohani, M., Dunn, D., and Perkinson, D., “Hybrid Robotic Habitat for Lunar Exploration,” Space Technology and Applications International Forum (STAIF-2005): Conference on Human/Robotic Technology and the National Vision for Space Exploration, Albuquerque, NM, Feb 13-17, 2005.
  • Rais-Rohani, M. and Lokits, J. C., “Pseudo-Topology and Sizing Optimization of a Composite Advanced Sail Structure with Buckling Constraints,” 10th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Albany, NY, Aug 30-Sep 1, 2004.
  • Rais-Rohani, M. and Marcellier*, P., “Buckling and Vibration Analysis of Composite Sandwich Plates with Elastic Rotational Edge Restraints,” AIAA Journal, Vol. 37, No. 5, 579-587, 1999.
  • Deo*, S.K. and Rais-Rohani, M., “Reliability-Based Design of Composite Sandwich Plates with Non-Uniform Boundary Conditions,” AIAA-99-1580, 40th AIAA/ASME/ ASCE/AHS/ ASC Structures, Structural Dynamics and Materials Conference, St. Louis, MO, Apr 12-15, 1999.
  • Marcellier*, P. and Rais-Rohani, M., “Free Vibration and Buckling Analysis of Anisotropic Sandwich Plates with Edges Elastically Restrained against Rotation,” AIAA-98-2084, 39th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Long Beach, CA, Apr 20-23, 1998.
  • Harris*, R.H. and Rais-Rohani, M., “Analysis and Design Optimization of Composite Sandwich Plates Under Axial and Biaxial In-Plane Loads,” Developments in Theoretical and Applied Mechanics, Vol. 18, 8th Southeastern Conference on Theoretical and Applied Mechanics, pp. 599-600, 1996.
  • Bennett, A.G., Rais-Rohani, M., Hall, K.R., Holifield, W., Sullivan, R. and Brown*, S., “Rapid Prototyping of Composite Aircraft Structures,” Invited paper, SAE Aerotech 1993 National Meeting, Costa Mesa, CA, Sep 27-30, 1993.

Masoud Rais-Rohani: Structural & Multidisciplinary Design Optimization Research

The goal of this research is to develop and apply numerical optimization techniques and solution strategies, particularly to problems involving high-fidelity computer simulations.

Highlights of research sponsored by NSF, DOE, ERDC, and NASA:

  • Decomposed multilevel optimization approaches with application to vehicle, material-product, or process-product design problems
  • Element Exchange Method for topology optimization
  • Variable fidelity framework for wing design optimization under static and aeroelastic constraints

Through proper hierarchical decomposition, a complex multidisciplinary system can be divided into a collection of connected, but simpler, optimization problems with improved computational efficiency.

Publications: (*Student, **Postdoc)

  • Ireland*, M., Ellis, B., and Rais-Rohani, M., “Coupled Topology and Process Optimization in Powder Bed Fusion Additive Manufacturing,” SAMPE Conference and Exposition, Long Beach, CA, May 20-23, 2024.
  • Gandikota*, I., Rais-Rohani, M., Kiani*, M., and DorMohammadi*, S., “Multilevel Design Optimization of a Vehicle-Dummy Model Under Crash, Vibration, and Injury Criteria,” International Journal of Vehicle Design, Vol. 70, No. 1, pp. 45-68, 2016.
  • Robinson*, J., Vahedifard, F., Rais-Rohani, M., Mason, G., Priddy, J., “Multi-Objective Traction Optimization of Vehicles in Loose Dry Sand Using the Generalized Reduced Gradient Method,” Journal of Terramechanics, Vol. 64, pp. 46-57, 2016.
  • Gandikota*, I., Rais-Rohani, M., DorMohammadi*, S., Kiani*, M.,“Multilevel Vehicle-Dummy Design Optimization for Mass and Injury Criteria Minimization,” Proceedings of the IMechE, Part D: Journal of Automobile Engineering, Vol. 229, No. 3, pp. 283-295, 2015.
  • Marvasti*, A.K., Fu, Y., DorMohammadi*, S., and Rais-Rohani, M., “Optimal Operation of Active Distribution Grids: A System of Systems Framework,” IEEE Transactions on Smart Grid, Vol. 5, No. 3, pp. 1228-1237, 2014.
  • DorMohammadi*, S., Rais-Rohani, M., and Rouhi*, M., “Multilevel Design Optimization with Application to Material-Product Systems,” AIAA SciTech 2014: 10th AIAA Multidisciplinary Design Optimization Specialist Conference, National Harbor, MD, Jan 13-17, 2014.
  • Rouhi*, M. and Rais-Rohani, M., “Element Exchange Method for Stochastic Topology Optimization,” Metaheuristic Applications in Structures and Infrastructures, A. Gandomi, X-S. Yang, S. Talatahari, and A. Alavi (Eds.), Elsevier, ISBN: 978-0-12-398364-0, 2013.
  • DorMohammadi*, S. and Rais-Rohani, M., “Exponential Penalty Function Formulation for Multilevel Optimization Using the Analytical Target Cascading Framework,” Structural and Multidisciplinary Optimization, 47, No. 4, pp. 599-612, 2013.
  • DorMohammadi*, S. and Rais-Rohani, M., “Comparison of Alternative Strategies for Multilevel Optimization of Hierarchical Systems,” Applied Mathematics (Special issue on optimization), Vol. 3, No. 10A, pp. 1448-1462, 2012.
  • Najafi*, A. and Rais-Rohani, M., “Concurrent Process-Product Design Optimization Using Coupled Nonlinear Finite Element Simulations,” Finite Element Analysis – Applications in Mechanical Engineering, F. Ebrahimi (Ed.), InTech, ISBN: 978-953-51-0717-0, 2012.
  • DorMohammadi*, S. and Rais-Rohani, M., “Analytical Target Cascading Framework Using the Exponential Method of Multipliers,” 14th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Indianapolis, IN, Sep 17-19, 2012.
  • DorMohammadi*, S., Rouhi*, M., and Rais-Rohani, M., “Topology Optimization of Blank Geometry for the Sheet Forming Process,” ASME 2012 International Design Engineering Technical Conferences, Chicago, IL, Aug 12-15, 2012.
  • DorMohammadi*, S. and Rais-Rohani, M., “An Empirical Accuracy and Computational Cost Study of Augmented Lagrangian Method in Analytical Target Cascading,” 8th AIAA Multidisciplinary Design Optimization Specialist Conference, Honolulu, HI, Apr 23-26, 2012.
  • Rouhi*, M., Rais-Rohani, M., and Williams*, T., “Element Exchange Method for Topology Optimization,” Structural and Multidisciplinary Optimization, 42, No. 2, pp. 215-231, 2010.
  • Rouhi*, M. and Rais-Rohani, M., “Topology Optimization of Continuum Structures Using Element Exchange Method,” 4th AIAA Multidisciplinary Design Optimization Specialists Conference, Schaumburg, IL, Apr 7-10, 2008.
  • Martinez*, M., Messac, A., and Rais-Rohani, M., “Manufacturability-Based Optimization of Aircraft Structures Using Physical Programming,” AIAA Journal, Vol. 39, No. 3, pp. 517-542, 2001.
  • Rais-Rohani, M., Haftka, R., Grossman, B., and Unger, E.R., “Integrated Aerodynamic-Structural-Control Wing Design,” International Journal of Computing Systems in Engineering, Vol. 3, No. 6, pp. 639-650, 1992.
  • Unger, E., Hutchison, M., Rais-Rohani, M., Haftka, R., and Grossman, B., “Variable-Complexity Multi-Disciplinary Design of a Transport Wing,” International Journal of Systems Automation: Research & Applications (SARA), Vol. 2, No. 2, pp. 87-113, 1992.
  • Rais-Rohani, M., Haftka, R.T., Grossman, B. and Unger, E.R., “Integrated Aerodynamic-Structural-Control Wing Design,” AIAA-92-4694, 4th AIAA/USAF/ NASA/OAI Symposium on Multidisciplinary Analysis and Optimization, Cleveland, OH, Sep 21-23, 1992.
  • Unger, E.R., Rais-Rohani, M., Hutchison, M. G., Haftka, R.T. and Grossman, B., “Multi-disciplinary Design of a Subsonic Transport Wing,” 3rd USAF/NASA Symposium on Recent Advances in Multidisciplinary Analysis and Optimization, San Francisco, CA, Sep 24-26, 1990.
  • Grossman, B., Haftka, R., Kao, P., Polen, D., Rais-Rohani, M., and Sobieszczanski-Sobieski, J., “Integrated Aerodynamic-Structural Design of a Transport Wing,” Journal of Aircraft, Vol. 27, No. 12, pp. 1050-1056, 1990.
  • Grossman, B., Haftka, R.T., Kao, P.J., Polen, D.M., Rais-Rohani, M. and Sobieszczanski-Sobieski, J., “Integrated Aerodynamic-Structural Design of a Transport Wing,” A paper presented at the AIAA/AHS/ASEE Aircraft Design, Systems and Operations Conference, Seattle, WA, Jul 31-Aug 2, 1989.

Masoud Rais-Rohani: Thin-Walled Structures Research

The goal of this research is to perform computer modeling, failure analysis, and design optimization of structural systems to improve performance, manufacturability, and reliability while reducing weight and production costs.

Highlights of research sponsored by DOE and NASA:

  • Crashworthiness optimization of vehicle structures with magnesium alloy parts
  • Manufacturability-based optimization of aircraft structures using physical programming
  • Product and process coupling in multidisciplinary design of flight vehicle structures
Multi-cell Tubes for Improved Energy Absorption graphic

Energy absorption in multi-corner, multi-cell crush tubes is significantly influenced by the cross-sectional geometry. For the above design concept consisting of two concentric square tubes, bracing the webs of the inner and outer tubes results in 30% greater mean crush force than bracing the corners.

Publications: (*Student, **Postdoc)

  • Watson*, A., Rais-Rohani, M., Belding, J., McGill*, J., and Ellis, B., “Characterization of Laser Ablated Bound Metal Deposition,” Journal of Manufacturing and Materials Processing, Vol. 9, No. 19, 2025. https://doi.org/10.3390/jmmp9040119
  • Alam*, A., Berube, K., Rais-Rohani, M., and Khoda, B., “Mechanical Performance of Three-Dimensional Printed Lattice Structures: Assembled Versus Direct Print,” 3D Printing and Additive Manufacturing, 2022. https://doi.org/10.1089/3dp.2021.0207
  • Kiani*, M., Gandikota*, I., Rais-Rohani, M., and Motoyama, K., “Design of Lightweight Magnesium Car Body Structure under Crash and Vibration Constraints,” Journal of Magnesium and Alloys, Vol. 2, No. 2, pp. 99-108, 2014.
  • Kiani*, M., Motoyama, K., Rais-Rohani, M., and Shiozaki, H., “Joint Stiffness Analysis and Optimization as a Mechanism for Improving Vehicle Structural Design and Performance,” Proceedings of the IMechE, Part D: Journal of Automobile Engineering, Vol. 228, No. 6, pp. 689-700, 2014.
  • Parrish*, A., Rais-Rohani, M., and Najafi*, A., “Crashworthiness Optimization of Vehicle Structures with Magnesium Alloy Parts,” International Journal of Crashworthiness, Vol. 17, No. 3, pp. 259-281, 2012.
  • Parrish*, A., Rais-Rohani, M., and Najafi*, A., “Crashworthiness Optimization of Vehicle Structures Made of a Lightweight Magnesium Alloy,” 7th AIAA Multidisciplinary Design Optimization Specialist Conference, Denver, CO, Apr 4-7, 2011.
  • Rais-Rohani, M., Solanki, K., Acar**, E., and Eamon, C., “Shape and Sizing Optimization of Automotive Structures with Deterministic and Probabilistic Design Constraints,” International Journal of Vehicle Design, Vol. 54, No. 1, pp. 309-338, 2010.
  • Salehghaffari*, S., Rais-Rohani, M., and Najafi*, A., “Analysis and Optimization of Externally Stiffened Crush Tubes,” 6th AIAA Multidisciplinary Design Optimization Specialist Conference, Orlando, FL, Apr 12-15, 2010.
  • Najafi*, A. and Rais-Rohani, M., “Influence of Cross-Sectional Geometry on Crush Characteristics of Multi-cell Prismatic Columns,” 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Schaumburg, IL, Apr 7-10, 2008.
  • Rais-Rohani, M., Solanki, K., and Eamon, C., “Reliability-Based Optimization of Lightweight Automotive Structures for Crashworthiness,” 11th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Portsmouth, VA, Sep 6-8, 2006.
  • Fang, H., Solanki, K., Horstemeyer, M.F., and Rais-Rohani, M., “Multi-objective Crashworthiness Optimization with Full-Scale Finite Element Simulations,” World Congress in Computational Mechanics (in conjunction with APCOM’04), Beijing, China, Sep 5-10, 2004.
  • Xie*, Q. and Rais-Rohani, M., “Probabilistic Design Optimization of Aircraft Structures with Reliability, Manufacturability, and Cost Constraints,” AIAA-2003-1631, 44th AIAA/ASME/ASCE/AHS Structures, Structural Dynamics and Materials Conference, Norfolk, VA, Apr 7-10, 2003.
  • Clements*, T.M. and Rais-Rohani, M., “Design Optimization of a Composite Tilt-Rotor Wing with Stability Approximations,” AIAA-2000-1454, 41st AIAA/ASME/ASCE/AHS/ ASC Structures, Structural Dynamics and Materials Conference, Atlanta, GA, Apr 3-6, 2000.
  • Martinez*, M.P., Messac, A., and Rais-Rohani, M., “Manufacturability-Based Optimization of Aircraft Structures Using Physical Programming,” AIAA-2000-1667, 41st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Atlanta, GA, Apr 3-6, 2000.
  • Rais-Rohani, M. and Huo*, Z., “Analysis and Optimization of Primary Aircraft Structures Based on Strength, Manufacturability, and Cost Requirements,” AIAA-99-1328, 40th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, St. Louis, MO, Apr 12-15, 1999.
  • Rais-Rohani, M. and Greenwood, A.G., “Product and Process Coupling in Multidisciplinary Design of Flight Vehicle Structures,” AIAA-98-4820, 7th AIAA/USAF/ NASA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, St. Louis, MO, Sep 2-4, 1998.
  • Brunson*, S.L. and Rais-Rohani, M., “A Thin Tailored Composite Wing Box for the Civil Tiltrotor Transport Aircraft,” AIAA-96-1378, 37th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Salt Lake City, UT, Apr 15-17, 1996.
  • Rais-Rohani, M. and Dean, E.B., “Toward Manufacturing and Cost Considerations in Multidisciplinary Aircraft Design,” AIAA-96-1620, 37th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Salt Lake City, UT, Apr 15-17, 1996.
  • Clements*, T.M. and Rais-Rohani, M., “Sensitivity Analysis of A Tilt-Rotor Composite Wing Natural Frequencies With Respect to Structural Parameters,” Developments in Theoretical and Applied Mechanics, Vol. 18, 8th Southeastern Conference on Theoretical and Applied Mechanics, pp. 385-398, 1996.
  • Rais-Rohani, M. and Baker, D.J., “Wing Design for a Civil Tilt-Rotor Transport Aircraft: A preliminary Study,” 35th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Hilton Head, SC, Apr 18-20, 1994.

Masoud Rais-Rohani: Uncertainty Quantification, Model Calibration & Structural Reliability Research

The goal of this research is to explore both probabilistic and non-probabilistic methods for representation and propagation of aleatory and epistemic uncertainties, model calibration, and to develop analytical structural reliability techniques for increasing computational efficiency with minimal loss of accuracy.

Highlights of research sponsored by NSF and DOE:

  • Epistemic uncertainty quantification of microstructure-based and phenomenological material models using evidence theory
  • Reliability analysis with dimension reduction and extended generalized lambda distribution
  • Stochastic uncertainty analysis of damage evolution using structure-property relations
Evidence-Based Uncertainty Propagation graphic

When epistemic uncertainty in a variable is represented by a belief structure consisting of multiple focal elements, a joint belief structure of the uncertain variables can be formed through Cartesian products of the individual belief structures. Evidence theory can be used to calculate the cumulative belief and plausibility distributions of the affected uncertain response functions.

Publications: (*Student, **Postdoc)

  • Dettwiller*, I., Vahedifard, F., Rais-Rohani, M., Mason, G., Priddy, J., “Improving Accuracy of Vehicle-Terrain Interface Algorithms for Wheeled Vehicles on Fine-Grained Soils Through Bayesian Calibration,” Journal of Terramechanics, Vol. 77, pp. 59-68, 2018.
  • Dettwiller*, I., Rais-Rohani, M., Vahedifard, F., Mason, G., Priddy, J., “Bayesian Calibration of Vehicle-Terrain Interface Algorithms for Wheeled Vehicles on Loose Sands,” Journal of Terramechanics, Vol. 71, pp. 45-56, 2017.
  • Dettwiller*, I., Rais-Rohani, M., Vahedifard, F., Mason, G., and Priddy, J., “Updating of Selected Vehicle-Terrain Interface Equations Through Bayesian Calibration,” Proceedings of the 8th ISTVS Americas Regional Conference, Troy, MI, Sep 12-14, 2016.
  • Salehghaffari*, S. and Rais-Rohani, M., “Material Model Uncertainty Quantification Using Evidence Theory,” Proceedings of the IMechE, Part C: Journal of Mechanical Engineering Science, Vol. 227, No. 10, pp. 2163-2179, 2013.
  • Salehghaffari*, S., Rais-Rohani, M., Marin, E., and Bammann, D., “A New Approach for Determination of Material Constants of Internal State Variable Based Plasticity Models and Their Uncertainty Quantification,” Computational Materials Science, Vol. 55, pp. 237-244, 2012.
  • Salehghaffari*, S., Rais-Rohani, M., Marin, E., and Bammann, D., “An Evidence-Based Framework for Determination of Material Constants in Advanced Plasticity Models,” 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Denver, CO, Apr 4-7, 2011.
  • Acar**, E., Rais-Rohani, M., and Eamon, C., “Structural Reliability Analysis using Dimension Reduction and Extended Generalized Lambda Distribution,” Handbook of Fitting Statistical Distributions with R, Z.A. Karian and E.J. Dudewicz (Eds.), CRC Press LLC, ISBN: 978-1-58488-711-9, 2010.
  • Acar**, E., Rais-Rohani, M., and Eamon, C., “Structural Reliability Analysis using Dimension Reduction and Extended Generalized Lambda Distribution,” International Journal of Reliability and Safety, Vol. 4, Nos. 2/3, pp. 166-187, 2010.
  • Acar**, E., Solanki*, K., Rais-Rohani, M., and Horstemeyer, M., “Stochastic Uncertainty Analysis of Damage Evolution Computed Through Microstructure-Property Relations,” Journal of Probabilistic Engineering Mechanics, Vol. 25, No. 2, pp. 198-205, 2010.
  • Salehghaffari*, S. and Rais-Rohani, M., “Epistemic Uncertainty Modeling of Johnson-Cook Plasticity Model Using Evidence Theory,” 13th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Fort Worth, TX, Sep 13-15, 2010.
  • Acar**, E., Solanki*, K., Rais-Rohani, M., and Horstemeyer, M., “Uncertainty Analysis of Damage Evolution Computed Through Microstructure-Property Relations,” ASME 2008 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, New York City, NY, Aug 3-6, 2008.
  • Acar**, E., Rais-Rohani, M., and Eamon, C., “Reliability Estimation using Dimension Reduction and Extended Generalized Lambda Distribution,” 10th AIAA Non-Deterministic Approaches Conference, Schaumburg, IL, Apr 7-10, 2008.

Masoud Rais-Rohani: Non-Deterministic Design Approaches Research

The goal of this research is to develop and apply design optimization techniques to structural systems subject to uncertainty with design constraints defined using probability, reliability index or evidence-based plausibility formulation.

Highlights of research sponsored by NSF, DOE, and NASA:

  • Optimization of structures under material parameter uncertainty using evidence theory
  • Aircraft structural optimization under reliability and manufacturability constraints
  • Multi-objective robust design optimization of energy absorbing components using coupled process-performance simulations
Reliability-Based Component graphic Shape Optimization graphic

By modeling the effects of underlying uncertainties in an ISV-based damage model, a reliability-based design optimization approach is used for optimizing the shape and size of a vehicle component under multiple dynamic loading conditions.

Publications: (*Student, **Postdoc)

  • Dettwiller*, I. and Rais-Rohani, M., “Decomposed Multilevel Optimization and Bayesian Uncertainty Quantification of Nano-Enhanced Composite Sandwich Plates,” AIAA SciTech 2017: 19th AIAA Non-Deterministic Approaches Conference, Grapevine, TX, Jan 9-13, 2017.
  • Dettwiller*, I. and Rais-Rohani, M., “Application of Bayesian Theory in Decomposed Multilevel Optimization Under Epistemic Uncertainty,” AIAA SciTech 2016: 18th AIAA Non-Deterministic Approaches Conference, San Diego, CA, Jan 4-8, 2016.
  • Nesbit*, B., Rais-Rohani, M., DorMohammadi*, S., “Decomposed Multilevel Optimization Under Epistemic Uncertainty,” AIAA SciTech 2014: 16th AIAA Non-Deterministic Approaches Conference, National Harbor, MD, Jan 13-17, 2014.
  • Rouhi*, M., Rais-Rohani, M., and Najafi*, A., “Probabilistic Analysis and Optimization of Energy Absorbing Components Made of Nanofiber Enhanced Composite Materials,” Composite Structures, Vol. 100, pp. 144-153, 2013.
  • Salehghaffari*, S., Rais-Rohani, M., Marin, E., and Bammann, D., “Optimization of Structures Under Material Parameter Uncertainty Using Evidence Theory,” Engineering Optimization, Vol. 45, No. 9, pp. 1027-1041, 2013.
  • Rouhi*, M. and Rais-Rohani, M., “Modeling and Probabilistic Design Optimization of a Nanofiber Enhanced Composite Cylinder for Buckling,” Composite Structures, Vol. 95, pp. 346-353, 2013.
  • Salehghaffari*, S. and Rais-Rohani, M., “Evidence-Based Design Optimization of Energy Absorbing Components under Material Field Uncertainty,” 8th AIAA Multidisciplinary Design Optimization Specialist Conference, Honolulu, HI, Apr 23-26, 2012.
  • DorMohammadi*, S. and Rais-Rohani, M., “Reliability-Based Design Optimization Within Analytical Target Cascading Framework,” 8th AIAA Multidisciplinary Design Optimization Specialist Conference, Honolulu, HI, Apr 23-26, 2012.
  • Salehghaffari*, S. and Rais-Rohani, M., “Evidence-Based Design Optimization of Externally Stiffened Crush Tubes,” 13th AIAA Non-Deterministic Approaches Conference, Denver, CO, Apr 4-7, 2011.
  • Solanki*, K., Acar**, E., Rais-Rohani, M., Horstemeyer, M., and Steele, G., “Product Design Optimization Using Microstructure-Property Relations and Associated Uncertainties,” International Journal of Design Engineering, Vol. 2, No. 1, pp. 47-79, 2009.
  • Solanki*, K, Acar**, E., Rais-Rohani, M., and Horstemeyer, M., “Reliability-Based Structural Optimization using a Multiscale Material Model,” 48th AIAA/ASME/ASCE/ AHS Structures, Structural Dynamics and Materials Conference, Honolulu, HI, Apr 23-26, 2007.
  • Rais-Rohani, M. and Xie*, Q., “Probabilistic Structural Optimization under Reliability, Manufacturability, and Cost Constraints,” AIAA Journal, Vol. 43, No. 4, pp. 864-873, 2005.

Masoud Rais-Rohani: Reduced Order & Surrogate Modeling Research

The goal of this research is to facilitate simulation-based design optimization involving computationally expensive and often noisy responses using both parametric and non-parametric surrogate-modeling (metamodeling) techniques and to develop a new approach based on an optimized ensemble of surrogate models.

Highlights of research sponsored by DOE, NASA and ERDC:

  • Surrogate-based optimization of automotive structures under multiple design criteria
  • Ensemble of metamodels with weight factors optimized using alternative cross validation metrics
  • Surrogate modeling in multi-objective optimization
Surrogate Modeling of Crash-Induced Responses graphic

A full-frontal or side impact simulation for estimation of a response function (e.g., peak acceleration, intrusion distance) could take several hours on a computer cluster. Through surrogate modeling, a smooth and computationally efficient representation of each response function can be generated. Such models can be extremely helpful in both trade space exploration and design optimization pursuits.

Publications: (*Student, **Postdoc)

  • Parrish*, J., Rais-Rohani, M., and Janus, M., “Reduced Order Techniques for Sensitivity Analysis and Design Optimization of Aerospace Systems,” AIAA Journal, Vol. 53, No. 12, pp. 3567-3576, 2015.
  • Parrish*, J., Rais-Rohani, M., and Janus, M., “Application of Reduced Order Techniques for Sensitivity Analysis to Multidisciplinary Aerospace Systems,” AIAA SciTech 2015: 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, FL, Jan 5-9, 2015.
  • Parrish*, J., Rais-Rohani, M., and Janus, M., “Reduced Order Techniques for Sensitivity Analysis and Design Optimization of Aerospace Systems,” AIAA SciTech 2014: 10th AIAA Multidisciplinary Design Optimization Specialist Conference, National Harbor, MD, Jan 13-17, 2014.
  • Kiani*, M., Gandikota*, I., Parrish*, A., Motoyama, K., and Rais-Rohani, M., “Surrogate-Based Optimisation of Automotive Structures Under Multiple Crash and Vibration Design Criteria,” International Journal of Crashworthiness, Vol. 18, No. 5, pp. 473-482, 2013.
  • Acar**, E. and Rais-Rohani, M., “Ensemble of Metamodels with Optimized Weight Factors,” Structural and Multidisciplinary Optimization, Vol. 37, No. 3, pp. 279-294, 2009.
  • Acar**, E. and Rais-Rohani, M., “Ensemble of Metamodels with Optimized Weight Factors,” 4th AIAA Multidisciplinary Design Optimization Specialists Conference, Schaumburg, IL, Apr 7-10, 2008.
  • Fang, H., Rais-Rohani, M., Liu*, Z., and Horstemeyer, M., “A Comparative Study of Metamodeling Methods for Multi-objective Crashworthiness Optimization,” Computers and Structures, Vol. 83, pp. 2121-2136, 2005.
  • Rais-Rohani, M. and Singh*, M., “Comparison of Global and Local Response Surface Techniques in Reliability-Based Optimization of Composite Structures,” Structural and Multidisciplinary Optimization, Vol. 26, No. 5, pp. 333-345, 2004.
  • Fang, H., Rais-Rohani, M., and Horstemeyer, M.F., “Multi-objective Crashworthiness Optimization with Radial Basis Functions,” 10th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Albany, NY, Aug 30-Sep 1, 2004.
  • Rais-Rohani, M. and Singh*, M. N., “Efficient Response Surface Approach for Reliability Estimation of Composite Structures,” AIAA-2002-5604, 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Atlanta, GA, Sep 4-6, 2002.
  • Su*, B., Rais-Rohani, M., and Singh, M. N., “Reliability-Based Optimization of Anisotropic Cylindrical Shells with Response Surface Approximations of Buckling Instability,” AIAA-2002-1386, 43rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Denver, CO, Apr 22-25, 2002.

Masoud Rais-Rohani: Engineering Education Research

The goal of this research is to implement experiential and computer-assisted pedagogical approaches and measure their effectiveness in student learning outcomes particularly in mechanics, mechanical engineering, and aerospace engineering courses.

Highlights of projects sponsored by UMaine, Hearin Foundation, Mississippi IHL and NASA:

  • Web-based learning resources for Aircraft Structures and Statics
  • Experiential learning in aircraft structures
  • Design-build-test and design-build-fly projects
Design-Build-Test of Stiffened Panels graphic

Experiential learning can enrich engineering education by engaging and motivating students. In an Aerospace Structural Design course, students conduct a project involving the design, analysis, optimization, fabrication, and testing of stiffened panels under axial compression. The group project culminates with each student team giving an oral presentation that summarizes the project and their written technical reports.

Publications: (*Student)

  • Sullivan, R., Saha, S., and Rais-Rohani, M., “Implementation of a Hands-on Aerospace Design Project During the COVID Pandemic,” Proceedings of the 2024 ASEE Annual Conference and Exposition, Portland, OR, Jun 23 – 26, 2024.
  • Rais-Rohani, M., Rubenstein, D., and Friess, W.A., “Aerospace Initiative at the University of Maine,” Proceedings of the 2018 ASEE Annual Conference and Exposition, Salt Lake City, UT, Jun 24 – 27, 2018.
  • Putzeys, O., Rais-Rohani, M., and Maalouf*, S., “Redesign of an Introduction to Mechanical Engineering Course to Keep Students Engaged and Interested,” Proceedings of the 2018 ASEE Annual Conference and Exposition, Salt Lake City, UT, Jun 24 – 27, 2018.
  • Rais-Rohani, M., “Practical Engineering Experience in Aircraft Structural Design,” Proceedings of the 2015 ASEE Annual Conference and Exposition, Seattle, WA, Jun 14-17, 2015.
  • Messac, A., Warnock, J., and Rais-Rohani, M., “Engineering Education Outside the Classroom: Engagement of Professional Societies,” 3rd Annual ASEE International Forum, Indianapolis, IN, Jun 14, 2014.
  • Rais-Rohani, M. and Walters, A., “Preliminary Assessment of the Emporium Model in a Redesigned Engineering Mechanics Course,” Advances in Engineering Education, Vol. 4, No. 1, pp. 1-19, Winter 2014.
  • Rais-Rohani, M., Walters, A., and Vizzini, A., “Emporium Based Redesign of Statics: An Innovative Approach to Enhance Learning and Reduce Costs,” Proceedings of the 2010 ASEE Annual Conference, Louisville, KY, Jun 20-23, 2010.
  • Sullivan, R. and Rais-Rohani, M., “Design and Application of a Beam Testing System for Experiential Learning in Mechanics of Materials,” Advances in Engineering Education, Vol. 1, No. 4, pp. 1-19, Spring 2009.
  • Sullivan, R. and Rais-Rohani, M., “Design and Application of a Beam Testing System for Experiential Learning in Mechanics of Materials,” Proceedings of the 2008 ASEE Annual Conference, Pittsburgh, PA, Jun 22-25, 2008. (Best Paper Award, ASEE-Mechanics Division, June 2008)
  • Rais-Rohani, M., “Experiential Learning in Aircraft Structures,” Proceedings of the 2003 ASEE Annual Conference, Nashville, TN, Jun 23-25, 2003.
  • Rais-Rohani, M., Koenig, K., and Hannigan, T., “Keeping Students Engaged: An Overview of Three Introductory Courses in Aerospace Engineering,” Proceedings of the 2003 ASEE Annual Conference, Nashville, TN, Jun 23-25, 2003.
  • Rais-Rohani, M., “On Effectiveness of an Online Tutorial to Enhance Statics Instruction,” Computers in Education, Vol. XI, No. 2, pp. 38-43, Apr-Jun 2001.
  • Rais-Rohani, M., “VLSM: An Online Tutorial for Solid Mechanics,” Computers in Education, Vol. XI, No. 1, pp. 38-44, Jan-Mar 2001.
  • Rais-Rohani, M. “On Development, Application and Effectiveness of a Computer Based Tutorial in Engineering Mechanics (Statics),” Proceedings of the 2001 ASEE Annual Conference and Exposition, Albuquerque, NM, Jun 24-27, 2001.
  • Rais-Rohani, M. and Gassaway*, B., “Manufacturing and Testing in Support of Aerospace Structural Design Projects,” Proceedings of the 2000 ASEE Annual Conference and Exposition, St. Louis, MO, Jun 18-21, 2000.
  • Rais-Rohani, M. and Brown, D., “Development of a Virtual Laboratory for the Study of Mechanics,” Proceedings of the 2000 ASEE Annual Conference and Exposition, St. Louis, MO, Jun 18-21, 2000.
  • Rais-Rohani, M. and Hicks*, G., “Multidisciplinary Design and Prototype Development of a Micro Air Vehicle,” Journal of Aircraft, Vol. 36, No. 1, pp. 227-234, 1999.
  • Rais-Rohani, M. and Hicks*, G., “Multidisciplinary Design and Prototype Development of a Very Small Remotely-Piloted Reconnaissance Airplane,” 1997 SAE Transactions: Aerospace Journal, Vol. 106, pp. 1546-1554, Jun 1998.
  • Hall*, K., Brown, S., Bennett, A., and Rais-Rohani, M., “Construction of a One-third Scale Model of the National Aerospace Plane-NASP,” International Journal of Engineering Education, Vol. 13, No. 2, pp. 153-159, 1997.
  • Rais-Rohani, M. and Young*, K.A., “Development of a Multimedia Structural Mechanics Teaching Tool on the World Wide Web,” Proceedings of the 1996 ASEE Annual Conference and Exposition, Washington, D.C., Jun 23-26, 1996.
  • Hall, K., Brown*, S., Bennett, A., and Rais-Rohani, M., “Construction of a One-third Scale Model of the NASP,” Paper no. AIAA-93-0427, presented at the 31st AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, Jan 11-14, 1993.