Numéro |
J. Phys. IV France
Volume 115, June 2004
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Page(s) | 11 - 20 | |
DOI | https://doi.org/10.1051/jp4:2004115002 |
J. Phys. IV France 115 (2004) 11
DOI: 10.1051/jp4:2004115002
Experimental investigations on the damping behaviour of superelastic NiTi
I. Schmidt and R. LammeringUniversity of the Federal Armed Forces Hamburg, Institute of Mechanics, Holstenhofweg 85, 22043 Hamburg, Germany
Abstract
A set of experimental investigations on the micro- and macromechanical
transformation behaviour of superelastic NiTi as well as on elementary
structures with integrated NiTi components has been undertaken with
respect to damping. At low frequencies the transformation process during
tensile tests has been observed and documented using in-situ optical
microscopy [1]. For an estimation of the attainable
damping capacity, experiments on a pre-strained string were performed.
Pre-strained to approximately 25% martensite the damping capacity of
NiTi for low amplitudes is in the range of steel. Increasing amplitudes
lead to much higher damping values for NiTi. In the completely transformed
stage NiTi exhibits an amplitude independent damping behaviour
with values that are smaller than those observed in experiments
with steel [2]. Further experiments have been performed with
coil springs made from NiTi. These springs were used to increase
the damping capability in a vibrating system compared to the
same system with steel springs. Again increasing pre-stress as
well as increasing vibration amplitudes lead to a stronger damping
of the NiTi springs and the vibrating system. The calculated
damping values result from a linear analysis.
© EDP Sciences 2004