L.E.D.A. Research CentreLaboratory of Earthquake engineering and Dynamic Analysis

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The laboratory

The Laboratory of Earthquake engineering and Dynamic Analysis has been realised in the framework of the National Operational Programme “Research & Competitiveness” (PON “R&C”), 2007-2013 (cod. PONa3_00374), financed to the University of Enna “Kore” to realise an integrated Research, High Training and Innovation Centre with unique characteristics in the European context in the fields of Experimental Dynamics, Materials and Structures and Geotechnics and Soil Dynamics.

The L.E.D.A. Research Centre is located in the new scientific centre of the ‘Kore’ University of Enna, in the district of Santa Panasia in lower Enna.

Presentation

The Laboratory of Earthquake engineering and Dynamic Analysis is equipped with a range of important scientific equipment that allows dynamic tests to be carried out in a wide range of frequencies and payloads, fully involving the civil, mechanical and aeronautical engineering sectors, the transport industry and the energy and defence sectors.

The main research infrastructure of the Experimental Dynamics Laboratory is the system of two six-degree-of-freedom vibration tables measuring 4 m by 4 m (Figure 5), which Bosch-Rexroth built especially for L.E.D.A.

The activities of the Experimental Dynamics Laboratory are aimed at developing research and teaching activities and consultancy services for third parties  in the fields of Structural Science, Structural Engineering, Structural Dynamics and Earthquake Engineering.

Topics of interest include the definition of the dynamic behaviour of traditional and innovative materials and scale and real-life structural models, the development of techniques for seismic risk mitigation and vibration control, the calibration of finite element models of complex structures, the study of methods for structural monitoring and the identification of incipient damage, and the study of intelligent structural systems.

These topics are transversal to all degree courses contained in the Faculty of Engineering and Architecture curriculum of the University of Enna “Kore” and the laboratory facilities are available to students for internships, dissertations, and PhDs.

The Experimental Dynamics Laboratory is also active in providing testing services and technical and scientific advice in Structural Engineering and the fields of Electrical Engineering, Energy, Defence and in support of companies and industries in the Civil Engineering sector.

Organisation

The Experimental Dynamics Laboratory of the L.E.D.A. Research Centre has obtained ISO 9001:2015 certification for the field of activity: “Research, provision of technical and scientific consultancy services, design and provision of multidisciplinary experimental activities in structural testing (IAF34)”.

The Laboratory adopts an organisational model aimed at the constant monitoring and improvement of all aspects related to the quality of the processes that take place there, through the application of a management system organised according to a process approach.

The main objective of the Experimental Dynamics Laboratory is to provide excellent tools for teaching, research and consultancy activities in structural engineering.
The activities of the Laboratory are organised in the following main sections:

  • numerical simulation section;
  • dynamic experimentation section on scale models;
  • dynamic experimentation section on real structures;
  • section for high-frequency and acceleration tests
  • structural monitoring and on-site measurements section.

Research

The Experimental Dynamics Laboratory is engaged in various theoretical, numerical, and experimental research activities briefly described below.

Internships, dissertations or research projects can be carried out on these topics on active PhD courses:

  • Techniques and algorithms for static and dynamic monitoring of critical structures and infrastructures;
  • Structural identification techniques, model updating and damage identification;
  • Vibration control and mitigation strategies in industrial and seismic environments;
  • Aleatory Dynamics techniques and methods on linear and non-linear systems;
  • Analytical modelling and synthesis of accelerograms and power spectral density functions consistent with response spectra;
  • Vibration mitigation and seismic protection of cultural heritage and museum contents;
  • Numerical techniques and theoretical investigations on the measurement and evaluation of structural reliability;

Equipment

The experimental scientific research, teaching support and consultancy activities for third parties of the Experimental Dynamics Laboratory are carried out in various rooms with the scientific equipment described below:

  • Laboratory for dynamic experimentation on real structures;
  • Laboratory for high-frequency and acceleration dynamic testing;
  • Laboratory for small-scale models and numerical simulation;

The main research infrastructure of the Experimental Dynamics Laboratory consists of a system of two identical vibrating tables, 4 metres per side, with six degrees of freedom.

Reduced scale or life-size models can be made for seismic and dynamic analysis and qualification of structural systems, equipment, construction techniques, or devices for seismic risk mitigation.

The high performance of the control system allows both the separate use of the two tables and the joint use for experimentation on large structures subject to synchronous and asynchronous motions. In addition, the two vibrating tables can be rigidly connected to create a single six-degree-of-freedom seismic simulator with dimensions of 10×4 metres and a maximum payload of 100 tonnes.

Main features of the vibrating table system

Feature Single table Coupled table
Dimensions 4 x 4 m 10 x 4 m
Payload  60 tons 100 tons
Operating frequency range 0.01 ÷ 60 Hz 0.01 ÷ 60 Hz
Stroke (horizontal axes) ±400 mm ±400 mm
Stroke (vertical axes) ±250 mm ±250 mm
Speed (horizontal axes) ± 2.2 m/s ± 1.1 m/s
Speed (vertical axes) ± 1.5 m/s ± 0.75 m/s
Acceleration (horizontal axes) ± 1.5 g ± 1.05 g
Acceleration (vertical axes) ± 1.0 g ± 0.7 g
Reversing moment 60 ton∙m (triaxial test)

100 ton∙m (uniaxial test)

100 ton∙m (uniaxial test)

100 ton∙m (uniaxial test)

Inspection system Trio Sistemi RT3-S – 2 kHz position, speed and acceleration control loop

Main features of the Bosch-Rexroth hydraulic power unit:

Feature Value
Installed electrical power 2500 kW
Motor-pump units 8 units of 200 kW (vibrating tables) +
1 unit of 55 kW (pseudo dynamic)
Filtration and recirculation 4 recirculation units for 74 kW
Power exchange cooling 840 kW (ΔT = 10°C), 525 kW (ΔT = 5°C)
Tank size 15000 l
Working pressure 270 bar
Maximum pressure 315 bar
Maximum flow rate (pumps) 3200 l/min
Peak capacity (accumulators) 14000 l/min
Oil cleanliness class (ISO 4406) 17/15/12 l/min
Automated and remotely available central management PLC

The Experimental Dynamics Laboratory is equipped with two systems for testing at high accelerations and frequencies.

A TEAM Cube Model 2-DV-LS six-degree-of-freedom hydraulic test rig is available for multi-axis testing in the automotive, aerospace, transport and energy sectors.

Main features of the six-degree-of-freedom test bench:

Feature Value
Fixing area 813 x 813 mm
Payload 450 kg
Dynamic force 62 kN
Frequency operating range 0 ÷ 250 Hz
Stroke X-axis: 100 mm, Y and Z axis: 50 mm
Acceleration (vacuum system) X-axis: 10.7 g, Y-axis: 9.6 g, Z-axis: 9.7 g (Z)
Acceleration (at maximum payload) X-axis: 9.2 g, Y-axis: 7.0 g, Z-axis: 8.2 g
Inspection system Spectral Dynamics Jaguar MIMO control

For some specialised applications in aerospace or impact testing, or when even higher acceleration and frequency performance is required, the LDS V875LS-440 uniaxial electromechanical shaker can be used.

Main features of the electromechanical shaker:

Feature Value
Payload 600 kg
Dynamic force 35.6 kN
Frequency operating range 5 ÷ 3000 Hz
Stroke 76 mm
Speed 1.8 m/s
Acceleration (sinusoidal) 110 g (sine peak), 100 g (rms random)
Inspection system Brüel & Kjær VC-LAN controller Type 7542

In this section, research activities related to numerical simulation and experimentation on small-scale models are developed, useful for initial validation of the numerical models.

In addition, test benches are available for calibrating velocimeter and accelerometer sensors.

The equipment available in this section is:

  • optical tables with pneumatic active isolation system (dimensions 1800 x 1200 mm and 3000 x 1500 mm);
  • pXI bus data acquisition system for electrical signals, IEPE sensors and electroresistive strain gauges;
  • modal shakers with maximum forces of up to 300 N and a frequency range of up to 18 kHz;
  • instrumented hammers for impulsive testing;
  • piezoelectric load cells;
  • uniaxial or triaxial piezoelectric or MEMS accelerometers with different sensitivities and frequency ranges for structural identification, modal analysis, seismic analysis and shock testing;
  • system for three-dimensional tracking of non-contact movements, consisting of several high-resolution, high-frequency infrared and visible cameras, the workstation and software for real-time data analysis and storage;
  • Spektra APS 129 test bench for calibration of velocimeter and accelerometer sensors.

Selection of experimental activities

  1. Seismic qualification test on a high-voltage hybrid circuit breaker (combined table configuration): test object volume 8.35×7.32×7.64 m3, mass 11.9 t, peak acceleration 0.5 g.
  2. Seismic qualification test on a hybrid high-voltage switch (single-table configuration): volume of test object 5.16×5.50×5.96 m3, mass 5.1 t, peak acceleration 1.0 g.
  3. Seismic qualification tests on measuring transformers (single and combined table configurations): a) height 13.5 m, mass 7.5 t, peak acceleration 0.5 g; b) height 9.5 m, mass 3.5 t, peak acceleration 1.0 g.
  4. Seismic qualification tests for HVAC toxic gas sensors, actuators and fire doors for the Mochovce (SK) nuclear power plant, units 3 and 4.
  5. Vibration test on a high-voltage switchgear for a wind turbine: test object volume 2.37×1.77×2.51 m3, mass 3.1 t, 3D endurance test lasting 2.5 hours with peak accelerations of 2.5 g.

Research products and publications

  • PON Research and Competitiveness 2007-2013 project entitled ‘L.E.D.A.
    (Laboratory of Earthquake engineering and Dynamic Analysis)’ cod. PONa3_00374.
  • PON Research and Competitiveness 2007-2013 project entitled ‘Interoperable cloud platforms for SMART-government – PRISMA’ cod. PON04a2_A/5.
  • PON Research and Competitiveness Project 2007-2013 entitled “Smart Energy Master for the energy government of the territory – SINERGREEN – RES NOVAE” cod. PON04a2_E.
  • PRIN 2017 project entitled “USR342 – Urban safety, sustainability and resilience: 3 paving solutions, 4 sets of modules, 2 platforms’, prot. no. 2017XYM8KC.
  • PON Industrial Research and Experimental Development project entitled ‘E-WAS An early warning system for cultural heritage’, cod. ARS01_00926.
  • PON Industrial Research and Experimental Development project entitled ‘Innovative Technologies and Models for Risk Mitigation in Critical Infrastructures – TARGETED THEMES’, cod. ARS01_00158.
  • ‘CSW – Confined Stone Wall’ project in collaboration with Architecture & Développement (A&D) Association de Solidarité Internationale and École Nationale Supérieure d’Architecture Paris-Malaquais.
  • LO IACONO, F., ALAIMO, A., ESPOSITO, A., NAVARRA, G., ORLANDO, C. (2020), “An anthropometric 4-DOF vibration model with uncertain parameters for air transportation”, AIP Conference Proceedings, 2293, art. no. 200008, DOI: 10.1063/5.0027753.
  • NAVARRA, G., LO IACONO, F., OLIVA, M., ESPOSITO, A. (2020), “Design of a NES device via Efficient Stochastic Linearisation”, AIP Conference Proceedings, 2293, art. no. 200015, DOI: 10.1063/5.0026432.
  • OLIVA, M., BARONE, G., LO IACONO, F., NAVARRA, G. (2020), “Nonlinear energy sink and Eurocode 8: An optimal design approach based on elastic response spectra”, Engineering Structures, 221, art. no. 111020, DOI: 10.1016/j.engstruct.2020.111020.
  • NAVARRA, G., IACONO, F.L., OLIVA, M., ESPOSITO, A. (2020), “Aircraft wings dynamics suppression by optimal NESs designed through an Efficient stochastic linearisation approach”, Advances in Aircraft and Spacecraft Science, 7 (5), pp. 405-423, DOI: 10.12989/aas.2020.7.5.405.
  • NAVARRA, G., LO IACONO, F., OLIVA, M. (2020), “An Efficient Stochastic Linearisation Procedure for the Seismic Optimal Design of Passive Control Devices”, Frontiers in Built Environment, 6, art. no. 32, DOI: 10.3389/fbuil.2020.00032
  • CASCONE, D., NAVARRA, G., OLIVA, M., LO IACONO, F. (2020), “Influence of user-defined parameters using Stochastic Subspace Identification (SSI)”, Lecture Notes in Mechanical Engineering, pp. 1567-1582. DOI: 10.1007/978-3-030-41057-5_127
  • NAVARRA, G., IACONO, F.L., OLIVA, M., CASCONE, D. (2020), “Speeding up the stochastic linearisation for systems controlled by non-linear passive devices”, Lecture Notes in Mechanical Engineering, pp. 1625-1644, DOI: 10.1007/978-3-030-41057-5_131
  • BARONE, G., LO IACONO, F., NAVARRA, G., PALMERI, A. (2019) “Closed-form stochastic response of linear building structures to spectrum-consistent seismic excitations”, Soil Dynamics and Earthquake Engineering, 125, art. no. 105724, DOI: 10.1016/j.soildyn.2019.105724.
  • LO IACONO, F., NAVARRA, G., OLIVA, M. (2017), “Structural monitoring of “Himera” viaduct by low-cost MEMS sensors: characterization and preliminary results”, Meccanica, 52 (13), pp. 3221-3236, DOI: 10.1007/s11012-017-0691-4
  • ARTALE, V., NAVARRA, G., RICCIARDELLO, A., BARONE, G. (2017), “Exact closed-form fractional spectral moments for linear fractional oscillators excited by a white noise”, ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering, 3 (3), art. no. 03090, DOI: 10.1115/1.4036700
  • OLIVA, M., BARONE, G., NAVARRA, G. (2017) “Optimal design of Nonlinear Energy Sinks for SDOF structures subjected to white noise base excitations”, Engineering Structures, 145, pp. 135-152, DOI: 10.1016/j.engstruct.2017.03.027
  • FOSSETTI, M., LO IACONO, F., MINAFÒ, G., NAVARRA, G., TESORIERE, G. (2017) “A new large scale laboratory: The LEDA research centre (Laboratory of Earthquake engineering and Dynamic Analysis)”, International Conference on Advances in Experimental Structural Engineering, 2017-September, pp. 699-717. DOI: 10.7414/7aese.T6.18
  • NAVARRA, G., IACONO, F.L., OLIVA, M. (2017), “Probabilistic optimal design of passive control devices coherently with seismic codes response spectra”, AIMETA 2017 – Proceedings of the 23rd Conference of the Italian Association of Theoretical and Applied Mechanics, 3, pp. 2356-2371.
  • LO IACONO, F., NAVARRA, G., OLIVA, M., CASCONE, D. (2017) “Experimental investigation of the dynamic performances of the LEDA shaking tables system”, AIMETA 2017 – Proceedings of the 23rd Conference of the Italian Association of Theoretical and Applied Mechanics, 5, pp. 897-915.
  • OLIVA, M., BARONE, G., IACONO, F.L., NAVARRA, G. (2017) “Simplified design of nonlinear energy sinks for mdof structures excited by white noise base excitations”, AIMETA 2017 – Proceedings of the 23rd Conference of the Italian Association of Theoretical and Applied Mechanics, 3, pp. 2372-2384.

Services

The Experimental Dynamics Laboratory offers technical and scientific consultancy services for the experimental validation of construction techniques, of devices for the mitigation of vibrations or the seismic protection of structures and components, for the execution of structural response measurements in situ and the Laboratory.

In addition, the laboratory offers certification services according to the following international standards.

  • IEEE Std. 693 IEEE Recommended Practice for Seismic Design of Substations;
  • AC156 Acceptance criteria for seismic certification by shake-table testing of nonstructural components;
  • ASTM D4169 Standard Practice for Performance Testing of Shipping Containers and Systems;
  • CEI 45-86 Guida per la qualifica sismica dei sistemi e dei componenti a bassa tensione;
  • IEC 60068-2 Environmental testing – Part 2: Tests;
  • IEC 60721-3-2 Classification of environmental conditions – Part 3:
  • Classification of groups of environmental parameters and their severities – Section 2: Transportation;
  • IEC 61166 High-voltage alternating current circuit-breakers – Guide for seismic qualification of high-voltage alternating current circuit-breakers;
  • IEC TS 61463 Bushings – Seismic qualification;
  • IEC 61869-1 Instrument transformers – Part 1: General requirements;
  • IEC 62271-207  High-voltage switchgear and controlgear Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV;
  • IEEE Std. C37.98 IEEE Standard for Seismic Qualification Testing of Protective Relays and Auxiliaries for Nuclear Facilities;
  • IEEE Std. 344 IEEE Standard for Seismic Qualification of Equipment for Nuclear Power Generating Stations;
  • IEEE Std. 382 IEEE Standard for Qualification of Safety-Related Actuators for Nuclear Power Generating Stations;
  • IEEE IEC 60980-344 Nuclear facilities – Equipment important to safety – Seismic qualification;
  • ISO 13355 Packaging — Complete, filled transport packages and unit loads — Vertical random vibration test;
  • ISO 4180 Packaging — Complete, filled transport packages — General rules for the compilation of performance test schedules;
  • ISO 2631 Mechanical vibration and shock – Evaluation of human exposure to whole-body vibration;
  • UNI 9614 Measurement of vibrations in buildings and criteria for assessing disturbance;
  • UNI 9916 Criteria for measuring and evaluating the effects of vibrations on buildings;

Customer portfolio and agreements

  • ANAS S.p.A (Azienda Nazionale Autonoma delle Strade), Direzione Regionale per la Sicilia, Via Alcide De Gasperi, 247, Palermo, Italy;
  • Anti-Seismic Innovative Solutions and Materials (ASISM) S.r.l. Spinoff Accademico, Università Mediterranea di Reggio Calabria, Italy;
  • Hitachi ABB Power Grids Italy, Via Vittor Pisani, n.16, Milano, Italy;
  • Hitachi ABB Power Grids Sweden, Lyviksvagen, 4, Dalarnas Lan Ludvika, Sweden;
  • Istituto Italiano di Tecnologia (IIT), Via Morego, 30, Genova, Italy;
  • Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via di Vigna Murata 605, Roma, Italy
  • Monsud S.p.A., Area Industriale Via Pianodardine, Avellino (AV), Italy;
  • Powerflex S.r.l., Via Campitiello, 6, 82030, Limatola, Benevento, Italy;
  • Trench Italia S.r.l. (Siemens Group), Strada Curagnata, 37, Cairo Montenotte, Italy;
  • Trench France S.A.S. (Siemens Group), 16. Rue du Général Cassagnou, Saint-Louis, France;
  • Somma International S.r.l., via Carlo Mirabello, Roma, Italy;

Contacts and where we are

Address: Laboratory of Experimental Dynamics – L.E.D.A. Research Centre – Polo scientifico e tecnologico di Santa Panasia 9400 – Enna, Italy

Telephone: +39 0935 536 770

GPS coordinates: 37°32’23.1 “N 14°17’02.1 “E (37.539750, 14.283917)

Directions to the L.E.D.A. Research Centre:

Reach the Enna exit of the A19 Palermo-Catania motorway (about 120 km from Palermo and 72 km from Catania);