Advanced computational models for structural mechanics
Event details
| Date | 01.05.2015 |
| Hour | 12:15 › 13:15 |
| Speaker | Prof. Dr Mohammed HJIAJ, INSA Rennes, France |
| Location | |
| Category | Conferences - Seminars |
Devising practical design rules requires both experimental results and rigorous computational models that are first validated and next used to explore other situations by performing extensive parametric study that cover all possible cases. This presentation will touch on two very different problems (buckling of hybrid columns and impact of steel beam) and show how computational models can be used to derive design rules particularly for problems where tests are expensive.
The first part of the talk deals with numerical investigations on second-order effects in slender RC columns reinforced by several steel sections, namely hybrid columns, subjected to combined axial load and uniaxial bending moment. New expressions for the correction factors involved in the determination of the effective flexural stiffness EI are proposed and calibrated by the results of the extended parametric study with 2960 data sets.
In the second part of the talk, we develop a computational model for the analysis of a column impacted by a projectile. The formulation of impact problems can be divided into two groups: smooth and non-smooth approaches, which we will compare. For both formulations, we use a newly developed energy-momentum time integration scheme to ensure conservation of the total energy and the momentum of the system during and after the impact.
Bio : Professor Mohammed HJIAJ is head of the Structural Engineering Research Group at INSA de Rennes (FRANCE). He graduated with honors from Ecole Centrale des Arts & Métiers (Brussels) in 1990 with a B.S. in Civil Engineering. He obtained an M.Sc. degree in Mechanics of Solids and Structures from Faculté Polytechnique de Mons (Belgium) in 1992. In 1994, he joined the Civil Engineering Department at Ecole des Mines de Douai in France as a lecturer. There he conducted research on computational plasticity, error analysis and adaptive strategies. After receiving his Ph.D. degree from Faculté Polytechnique de Mons in 1999 with the highest distinction, he joined the CNRS as a Research Scientist, where he pursued research on computational mechanics dealing with non-smooth problems. In Fall 2000, he moved to the University of Newcastle (Australia) where he pursued research on computational limit and shakedown analysis with application to foundation engineering and soil-structure interaction. In 2002, he was awarded the Australian Post-Doctoral Fellowship from the Australian Research Council to work on a variety of topics related to computational geomechanics. In September 2004, he was appointed Professor at INSA de Rennes, where he conducts experimental and computational research on steel and composite steel-concrete structures, including seismic behavior and robustness. He serves on various technical committees within the ECCS, is on the editorial board of the French journal Construction Métallique and an associate editor for the ASCE Journal of Structural Engineering.
The Group research ID:
The Structural Engineering Research Group has a long tradition of research in steel and composite structures. Much of our research projects involve a combination of experimental, theoretical and computational work. The group has extensive expertise and knowledge in both computational structural mechanics including its theoretical foundations and advanced testing of structures. Over the years, the group was at the forefront of developing Finite elements for high nonlinear and sophisticated structural problems able to closely reproduce the behavior of structure as observed experimentally with the aim to provide engineers with appropriate tools for advanced design (pre-normative research). Elastic and inelastic time-independent as well as time-dependent problems have been addressed.
The first part of the talk deals with numerical investigations on second-order effects in slender RC columns reinforced by several steel sections, namely hybrid columns, subjected to combined axial load and uniaxial bending moment. New expressions for the correction factors involved in the determination of the effective flexural stiffness EI are proposed and calibrated by the results of the extended parametric study with 2960 data sets.
In the second part of the talk, we develop a computational model for the analysis of a column impacted by a projectile. The formulation of impact problems can be divided into two groups: smooth and non-smooth approaches, which we will compare. For both formulations, we use a newly developed energy-momentum time integration scheme to ensure conservation of the total energy and the momentum of the system during and after the impact.
Bio : Professor Mohammed HJIAJ is head of the Structural Engineering Research Group at INSA de Rennes (FRANCE). He graduated with honors from Ecole Centrale des Arts & Métiers (Brussels) in 1990 with a B.S. in Civil Engineering. He obtained an M.Sc. degree in Mechanics of Solids and Structures from Faculté Polytechnique de Mons (Belgium) in 1992. In 1994, he joined the Civil Engineering Department at Ecole des Mines de Douai in France as a lecturer. There he conducted research on computational plasticity, error analysis and adaptive strategies. After receiving his Ph.D. degree from Faculté Polytechnique de Mons in 1999 with the highest distinction, he joined the CNRS as a Research Scientist, where he pursued research on computational mechanics dealing with non-smooth problems. In Fall 2000, he moved to the University of Newcastle (Australia) where he pursued research on computational limit and shakedown analysis with application to foundation engineering and soil-structure interaction. In 2002, he was awarded the Australian Post-Doctoral Fellowship from the Australian Research Council to work on a variety of topics related to computational geomechanics. In September 2004, he was appointed Professor at INSA de Rennes, where he conducts experimental and computational research on steel and composite steel-concrete structures, including seismic behavior and robustness. He serves on various technical committees within the ECCS, is on the editorial board of the French journal Construction Métallique and an associate editor for the ASCE Journal of Structural Engineering.
The Group research ID:
The Structural Engineering Research Group has a long tradition of research in steel and composite structures. Much of our research projects involve a combination of experimental, theoretical and computational work. The group has extensive expertise and knowledge in both computational structural mechanics including its theoretical foundations and advanced testing of structures. Over the years, the group was at the forefront of developing Finite elements for high nonlinear and sophisticated structural problems able to closely reproduce the behavior of structure as observed experimentally with the aim to provide engineers with appropriate tools for advanced design (pre-normative research). Elastic and inelastic time-independent as well as time-dependent problems have been addressed.
Practical information
- General public
- Free
Organizer
- Prof. Dr Nikolas Geroliminis & Katrin Beyer
Contact
- Prof. Dr Alain Nussbaumer