Rais-Rohani: Computational modeling and simulation - Mechanical Engineering

Masoud Rais-Rohani: 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, Vol. 238, No. 20, 10012-10025, 2024.
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,” 8^th 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,” 14^th 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,” 1^st 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,” 52^nd 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,” 7^th 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,” 51^st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Orlando, FL, Apr 12-15, 2010.