Kinematic transformations for planar multi-directional pseudodynamic testing / Mercan, Oya in Earthquake engineering structural dynamics, Vol. 38 N° 9 (Juillet 2009)  

Kinematic transformations for planar multi-directional pseudodynamic testing [texte imprimé] / Mercan, Oya, Auteur ; James M. Ricles, Auteur ; Sause, Richard, Auteur . - pp. 1093-1119.
Génie Civil
Langues : Anglais (eng)
in Earthquake engineering structural dynamics > Vol. 38 N° 9 (Juillet 2009) . - pp. 1093-1119

Mots-clés :	Error detection  Kinematic correction  Multi-directional testing  Pseudodynamic test method  Test structure
Index. décimale :	624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels
Résumé :	The pseudodynamic (PSD) test method imposes command displacements to a test structure for a given time step. The measured restoring forces and displaced position achieved in the test structure are then used to integrate the equations of motion to determine the command displacements for the next time step. Multi-directional displacements of the test structure can introduce error in the measured restoring forces and displaced position. The subsequently determined command displacements will not be correct unless the effects of the multi-directional displacements are considered. This paper presents two approaches for correcting kinematic errors in planar multi-directional PSD testing, where the test structure is loaded through a rigid loading block. The first approach, referred to as the incremental kinematic transformation method, employs linear displacement transformations within each time step. The second method, referred to as the total kinematic transformation method, is based on accurate nonlinear displacement transformations. Using three displacement sensors and the trigonometric law of cosines, this second method enables the simultaneous nonlinear equations that express the motion of the loading block to be solved without using iteration. The formulation and example applications for each method are given. Results from numerical simulations and laboratory experiments show that the total transformation method maintains accuracy, while the incremental transformation method may accumulate error if the incremental rotation of the loading block is not small over the time step. A procedure for estimating the incremental error in the incremental kinematic transformation method is presented as a means to predict and possibly control the error.
ISSN :	0098-8847
En ligne :	http://www3.interscience.wiley.com/journal/121641476/abstract