Periodic Reporting for period 4 - MiniMasonryTesting (Seismic Testing of 3D Printed Miniature Masonry in a Geotechnical Centrifuge)
Reporting period: 2023-10-01 to 2025-03-31
Earthquakes are responsible for more than half of the human losses due to natural disasters. Masonry structures have been proven the most vulnerable both in the developing and in the developed world. Even though Masonry is one of the oldest building materials, our understanding of its behavior at the level of the structure (system level) is limited. In fact, when global experts are invited to blindly predict the results of shake table tests of whole structures, they blatantly fail. This is partly due to the errors and uncertainties induced by the “global level assumptions” that numerical models make, i.e. the assumptions that dictate how individual components dynamically interact to form the whole structure.
Therefore, there is a need for extended shake table testing. But shake table tests are expensive and full-scale system-level testing of large buildings is only possible in a handful of shake tables in the globe – and at a huge cost. We propose to take advantage of research developments in 3D printing and develop a method to perform system-level testing at a small scale using 3D printers and a geotechnical centrifuge (to preserve similitude). The key is to print materials with behavior controllable and similar to masonry. This project testing proposes to control the properties of masonry via controlling the geometry of a 3D printed “meta”-mortar. The method will be developed via typical static masonry tests performed on the 3D printed parts. Then, multiple shaking table tests (in a centrifuge) of small scale physical models of masonry structures will be performed with the aim of creating extended datasets to be used for the validation of the global level assumptions of numerical models, for given and experimentally obtained component level behavior. As a case study, the method will be applied to explore the behavior of a low-cost seismic isolation method that has been proposed for masonry structures in developing countries.
With the rapid evolution of 3D printing, it will be possible to scale-up the methods developed in this project, so that other Civil Engineering materials can be tested faster and cheaper than now. This is a game changer in structural testing, as it will enable researchers to test structures that up to now it was impossible or very expensive to test at a system level.
Therefore, there is a need for extended shake table testing. But shake table tests are expensive and full-scale system-level testing of large buildings is only possible in a handful of shake tables in the globe – and at a huge cost. We propose to take advantage of research developments in 3D printing and develop a method to perform system-level testing at a small scale using 3D printers and a geotechnical centrifuge (to preserve similitude). The key is to print materials with behavior controllable and similar to masonry. This project testing proposes to control the properties of masonry via controlling the geometry of a 3D printed “meta”-mortar. The method will be developed via typical static masonry tests performed on the 3D printed parts. Then, multiple shaking table tests (in a centrifuge) of small scale physical models of masonry structures will be performed with the aim of creating extended datasets to be used for the validation of the global level assumptions of numerical models, for given and experimentally obtained component level behavior. As a case study, the method will be applied to explore the behavior of a low-cost seismic isolation method that has been proposed for masonry structures in developing countries.
With the rapid evolution of 3D printing, it will be possible to scale-up the methods developed in this project, so that other Civil Engineering materials can be tested faster and cheaper than now. This is a game changer in structural testing, as it will enable researchers to test structures that up to now it was impossible or very expensive to test at a system level.
Up to now, we have focused on two tasks: a) We are finishing characterizing the mechanical properties of the bulk 3D printed material and b) We are studying the behavior of a low-cost rolling isolation system at a component level.
Until the end of the project, we expect to
a) Have developed a novel methodology for the physical modelling of masonry structures, applicable to seismic testing. This will allow for a better understanding of their seismic behavior and for the improvement of the numerical models that the engineering community uses for design and analysis.
b) Have demonstrated the effectiveness of the above method by performing an feasibility study on a low cost seismic isolation system that can be used for the isolation of masonry structures in low-income countries.
a) Have developed a novel methodology for the physical modelling of masonry structures, applicable to seismic testing. This will allow for a better understanding of their seismic behavior and for the improvement of the numerical models that the engineering community uses for design and analysis.
b) Have demonstrated the effectiveness of the above method by performing an feasibility study on a low cost seismic isolation system that can be used for the isolation of masonry structures in low-income countries.