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:

  • 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.