Dynamic characterization of bi-material cantilevers
de Vreugd, J.
Sadeghian Marnani, H.
In this paper, an experimental-theoretical method is proposed to accurately determine the thermal diffusivity, characteristic time constant and layer thicknesses of a bimaterial cantilever using a transient, non-destructive and noncontact measurement. The technique is based on the wellknown optical beam deflection method. A time dependent, sinusoidal heat load is locally applied to induce a time varying thermal profile over the length of the beam, resulting in a mismatch-strain between the two layers that bends the cantilever. A measurement of the phase difference between the thermo-mechanical response and the input signal can be used to extract the thermal diffusivity, characteristic time constant and the location of the heat source. For this reason a closedform analytical solution for the thermo-mechanical response is presented. The dynamic response of the system is characterized using the transfer function in the Laplace domain. The analytical solution includes a Gaussian distributed, time-dependent heat source of known width at a location along the beam. A constant convective heat transfer coefficient can be included to allow measurement in ambient conditions. A combination of a measurement of the thermal diffusivity and the effective conductance are used to calculate the mutual layer thicknesses of the two layers.
Mechatronics, Mechanics & Materials
To reference this document use:
OM - Opto-Mechatronics
TS - Technical Sciences
High Tech Systems & Materials
SENSORDEVICES 2013, 4th International Conference on Sensor Device Technologies and Applications, Barcelona, Spain, August 25-31, 2013