Moritz Wenzel, Oreste S. Bursi, Vincenzo La Salandra, Alessio Bonelli

Transcription

1 15-16/05/2017 Bologna, Italia 3 rd WORKSHOP ON SEISMIC METAMATERIALS 3D LOCALLY RESONANT PERIODIC FOUNDATIONS WITH LOW FREQUENCY BAND GAPS FOR SEISMIC PROTECTION OF FUEL STORAGE TANKS Moritz Wenzel, Oreste S. Bursi, Vincenzo La Salandra, Alessio Bonelli Department of Civil, Environment and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123, Trento, Italy. Contact: moritz.wenzel@unitn.it oreste.bursi@unitn.it

2 O. S. Bursi - Advances in Mechanical Metamaterials Trento Acknowledgements 1.The speaker gratefully acknowledges Alessandro Marzani, Antonio Palermo, Andrea Colombi and Sebastien Guenneau as well as the Local Organizing Committee 2. The author deeply acknowledges the financial support from the European Union through: - the XP-Resilience project (Project Reference: ); The author fully acknowledges master University of Trento for their research activities.

3 OUTLINE Motivation and EU Project XP-Resilience Metamaterial Concept Foundation Design Functionality Check Redesign of the Foundation Vertical component damping SSI Conclusions

4 Motivation Protection of high risk structures No Devices needed Vertical component damping Simplification of design process Damping of multiple frequencies XP-resilience EU Research Project Protection of Petrochemical Plants through Metamaterials

5 Petrochemical Plants Variable liquid level -> variable impulsive frequencies Danger of Domino-Effect

6 Focal depth H Nuclear Power Plants Reduction of Isolators 3. ARCHETYPE PLANT MODELS Vertical component isolation ESCRIPTION OF ISOLATED STRUCTURE AND ISOLATION SYSTEM umerical model is based on the APR 1400, which stands for Advanced Power Reactor. PR 1400 is a pressurized water reactor developed in Korea that produces 1400 MW of ical power. Figure 3-1 shows vertical and horizontal cross sections of the nuclear island. Epicentral distance levation Alluvial deposit Epicenter Hypocentral distance Z Source Hypocentre

7 Earthquake excitation Mode Number Frequency Modal Mass x Modal Mass y Modal Mass z Unitless Hz % % % 1 3,71 06, ,65 01,27 43,3 0, ,6 01,23 0, ,3

8 Metamaterial Concept Band gap Hz Static cracks did not influence the band gap

9 Foundation Design Traditional Foundation Smart Foundation Concrete baseplate Compacted ground Usually no isolation Lattice of unit cells Seismic Isolation Concrete and rubber components

10 Foundation design

11 Functionality evaluation Finite structure performance Modelling of the complete structure in COMSOL Multiphysics Harmonic excitation at base Frequency response analysis

12 Functionality evaluation

13 12m Liquid Height Paper submitted to Frontiers in Materials Journal: Static and Dynamic Protection of Fuel Storage Tanks by means of 3D Structured Foundation

14 Parameters for Finite Foundations Wall thickness 20cm Wall thickness 10cm

15 REDESIGN Optimization of the unit cell

16 Columns replace Walls 4x4x4 cell 67.5 [to] oscillator 2x2x2 cell 6.86 [to] oscillator Significant size reduction

17 Design Variants Sliding Surface Steel Springs Sliding surface Rocking Device Steel Springs Rocking Device

18 Sliding Variant

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21 Rocking Device Rocking motion Stiffness equivalent Vertical component Reduced effect

22 Variation of Springs

23 Analytical Solution Sliding Surface Rocking Device

24 Equations of Motion Dynamic System Matrix form Frequency Response Function

25 Frequency Response Analytical m 1 =2.9 to, m 2 =6.86 to, k 1 =83.3 MN/m, k 2 =3.2 MN/m, c=1.4 kn*s/m Rocking Sliding

26 Periodicity

27 Dispersion Diagram

28 Soil Structure Interaction Soil as linear elastic Spring k s =20 MPa/m (medium dense Sand) Vertical resonance Attenuation Zone Rocking Device

29 FRF for SSI Soil as Spring Softness Attenuation Only One Layer possible

30 Conclusion How small can the unit cell become? Nonlinear plastic Soil Reduction of the System Further improvements 3. ARCHETYPE for the PLANT MODELS Vertical Component 3.1. DESCRIPTION OF ISOLATED STRUCTURE AND ISOLATION SYSTEM This numerical model is based on the APR 1400, which stands for Advanced Power Reactor. The APR 1400 is a pressurized water reactor developed in Korea that produces 1400 MW of electrical power. Figure 3-1 shows vertical and horizontal cross sections of the nuclear island. Elevation

31 Thank You