Our research on substructure testing

Currently, we are working on the algorithms for substructure testing, especially stability and accuracy of real time substructure tests of non-linear substructures. The following is the list of projects to develop substructure testing on distributed shaking tables.

The project E-FAST: Design Study of a European Facility for Advanced Seismic Testing (2008-2011)

E-FAST (Design study of a European Facility for Advanced Seismic Testing) is an FP7 European collaborative project under the support EC grant No. 212109 by the European Commission. It deals with the study of all aspects regarding the design of a major testing facility in Europe that would complement and collaborate with the existing ones. Actually, earthquake risk is a major civil protection issue which is related to mitigation measures for protecting citizens, infrastructures, property and the human cultural heritage. Seismic testing plays a key role for the better understanding of physical phenomena, the validation and improvement of analysis and design methods and for the qualification of sensitive equipment. Therefore, the availability of high level experimental facilities is essential to meet the objectives of earthquake mitigation.

Test setup at UNIKA for substructure testing in E-FAST:

The test setup consists of: a hydraulic cylinder (1), the SDOF main structure consisting of the shaking table (3) and leaf spring (2), the Tuned Mass Damper (TMD) (4) with UHYDE- device (5) (Dorka 1995, US Patent no. 5456047); locked leaf spring (below) during substructure testing.

UNIKA testing concepts of the new facility:

Test setup of large and irregular buildings
Test setup of bridge models (scale 1:2)
Test setup for engineering systems
Test setup for substructure tests of soil and structure interaction
The model of the test setup: 2-DOF system for reference tests (a) is decoupled in numerical and experimental parts (b) and used as SDOF substructure for substructure tests (c).

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The project SUBSHAKE: Development of substructure test in real time for hydraulic shaking tables, DFG project, grant number Do 360/22-1,2 (2006 - 2010)

This is a joint project between UNIKA and IZIIS (Institute of Earthquake Engineering and Engineering Seismology in Skopje, Republic of Macedonia) under the support by German Research Foundation (DFG), Project number Do 360/22-1,2. The full structure including a three storey steel frame and a bi-directional TMD with the friction device UHYDE-fbr was tested on the shaking table in IZIIS for producing reference response. Then, the non-linear substructure as the TMD including the friction device UHYDE-fbr was placed on the bi-directional shaking table at UNIKA to perform real-time substructure testing. Different nonlinear effects were tested by controlling air pressure in the friction device UHYDE-fbr device.

The reference model including a half-scale three-storey steel frame and a TMD with the friction device UHYDE-fbr for reference tests using the shaking table at IZIIS
Real-time substructure tests of the TMD with the friction device UHYDE-fbr using the bi-directional shaking table in UNIKA

The project of Common Action CEA and UNIKA (2006-2009)

The project is set up by co-operation of CEA (Commissariat à l’Énergie Atomique, Saclay, France) and UNIKA (Universität Kassel). The aim of research is to develop a control system and technique for substructure testing on distributed shaking tables. With the application of real-time substructure control system developed by UNIKA, it was the first time in the world real-time time substructure tests using distributed shaking tables have been carried out. The formulation of substructure testing within the framework of the project “SubPSD-Algorithmen” for aerospace applications have been applied in the testing system in CEA.

Real time substructure test of TMD on shaking table VESUVE and TOUNERSOL in CEA
Reference test of full model with 2 TMDs on shaking table AZALEE in CEA

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Project “Composite Structures under cyclic loading”: A1 project of special research group SFB 151, Ruhr-Universität Bochum, supported by the German Research Foundation (DFG) (1983-1989)

In 1986, the first continuous Pseudo-Dynamic (PsD) tests in Europe with a time scale factor 10 on stiff-ductile specimen was performed (Roik and Dorka 1989).

Test setup for the first continuous PsD test in Europe
Test was done on a stiff-ductile SDOF specimen with sliding friction connections at Ruhr-Universität Bochum, Germany
Response of the stiff-ductile specimen to the El Centro earthquake: Displacement
Stiff-ductile hysteresis

The project “SubPSD-Algorithmen”: Algorithm for real-time pseudo-dynamic substructure tests, DFG project, grant number Do 360/7-1 (1996 - 1998)

This research was a joint project of Universität Kaiserslautern and the “Deutsches Zentrum für Fluft und Raumfahrt” (DLR) in Göttingen and leaded by Prof. Dr. –Ing. Uwe Dorka. In this project, the basic algorithm for substructure testing was verified and real time tests resembling aerospace applications were conducted.

Bilder zu "SubPSD-Algorithmen"

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