ENAC Seminar Series by Prof. M. Vassiliou
Event details
| Date | 25.08.2021 |
| Hour | 09:00 › 10:00 |
| Speaker | Prof. Michalis Vassiliou |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
09:00 – 10:00 – Prof. Michalis Vassiliou
Assistant professor, ETH Zürich
Novel testing techniques for the innovative design and rational evaluation of structures
Shake table blind prediction contests show that numerical models fail to predict the test results with a reasonable accuracy. This directly questions the scientific value of our analysis and design methods. Moreover, it leads to conservative design philosophies and to a consequent waste of material. This does not contribute to sustainable design.
The “non-predictability” is one of the most important arguments against designing bridge piers that can uplift and sustain rocking motion during an earthquake – a strategy that could lead to more economical and sustainable seismic design.
This presentation will show that trying to predict the response of a structure to a single ground motion is too strict of a validation test and often a meaningless procedure. Alternatively, it will suggest a weaker but sufficient validation methodology where numerical models are evaluated based on their performance in predicting the statistics of the response to ensembles of ground motions.
The presentation will discuss how the above statistical validation approach has been used to show that 3D rocking motion is “predictable enough” for the scope of earthquake engineering – hence engineers can take advantage of it for design. It will present tests of a rocking bridge-like large-scale specimen comprising reusable precast elements connected dryly with flexible restrainers. After 180 excitations, the specimen presented negligible damage.
Finally, this presentation will claim that a statistical validation approach can and should be used to evaluate the system-level assumptions of RC and masonry numerical models. Since this is impossible at a full scale, small scale (1:10-1:40) physical models of both RC and masonry structures should be manufactured using 3D printing technologies and tested in a geotechnical centrifuge to preserve similitude of stresses. This is the main idea behind our recently awarded ERC and ETH grants and this presentation will discuss some first results.
Short bio:
Michalis Vassiliou is currently an Assistant Professor and holds the Chair of Seismic Design and Analysis, at the Institute of Structural Engineering (IBK) of ETH Zürich. He is a Civil Engineer and has studied in NTU Athens (Diploma 2004), UC Berkeley (MSc 2006), and University of Patras (PhD 2010). Between 2012 and 2019 he was a Postdoc and a Senior Assistant in the ETH. In 2019, he was hired as an Assistant Professor in the ETH after receiving an ERC Starting Grant. His research interests lie in the fields of Structural Engineering with a special focus in Seismic Engineering using both experimental and analytical methods. At the ETH, he is teaching courses on Structural Dynamics and Seismic Isolation.
Assistant professor, ETH Zürich
Novel testing techniques for the innovative design and rational evaluation of structures
Shake table blind prediction contests show that numerical models fail to predict the test results with a reasonable accuracy. This directly questions the scientific value of our analysis and design methods. Moreover, it leads to conservative design philosophies and to a consequent waste of material. This does not contribute to sustainable design.
The “non-predictability” is one of the most important arguments against designing bridge piers that can uplift and sustain rocking motion during an earthquake – a strategy that could lead to more economical and sustainable seismic design.
This presentation will show that trying to predict the response of a structure to a single ground motion is too strict of a validation test and often a meaningless procedure. Alternatively, it will suggest a weaker but sufficient validation methodology where numerical models are evaluated based on their performance in predicting the statistics of the response to ensembles of ground motions.
The presentation will discuss how the above statistical validation approach has been used to show that 3D rocking motion is “predictable enough” for the scope of earthquake engineering – hence engineers can take advantage of it for design. It will present tests of a rocking bridge-like large-scale specimen comprising reusable precast elements connected dryly with flexible restrainers. After 180 excitations, the specimen presented negligible damage.
Finally, this presentation will claim that a statistical validation approach can and should be used to evaluate the system-level assumptions of RC and masonry numerical models. Since this is impossible at a full scale, small scale (1:10-1:40) physical models of both RC and masonry structures should be manufactured using 3D printing technologies and tested in a geotechnical centrifuge to preserve similitude of stresses. This is the main idea behind our recently awarded ERC and ETH grants and this presentation will discuss some first results.
Short bio:
Michalis Vassiliou is currently an Assistant Professor and holds the Chair of Seismic Design and Analysis, at the Institute of Structural Engineering (IBK) of ETH Zürich. He is a Civil Engineer and has studied in NTU Athens (Diploma 2004), UC Berkeley (MSc 2006), and University of Patras (PhD 2010). Between 2012 and 2019 he was a Postdoc and a Senior Assistant in the ETH. In 2019, he was hired as an Assistant Professor in the ETH after receiving an ERC Starting Grant. His research interests lie in the fields of Structural Engineering with a special focus in Seismic Engineering using both experimental and analytical methods. At the ETH, he is teaching courses on Structural Dynamics and Seismic Isolation.
Practical information
- General public
- Invitation required
- This event is internal
Organizer
- ENAC
Contact
- Cristina Perez