Stress and strain measurements by image correlation and Thermoelasticity
In this paper image correlation and thermoelaticity are proposed as joint measurement techniques to perform a “full field” characterization of materials and mechanical components. The very interesting possibilities offered by using both these non contact measurements techniques is the ability to obtain, by measuring both stress and strain, distributions of mechanical parameters on the surface of a dynamically loaded mechanical component, made, in general, of any material. This kind of results can be very useful for non homogeneous, composite or complex materials, or for complex shapes or loading conditions of the mechanical component under analysis, nowadays largely used for machine and structure realizations. In the work a proper coating, useful to perform measurements by both the techniques, is developed and tested. The coating act as a stressstrain distributed gauges.
Laser vibrometry and stress measurement by thermoelasticity on mechanical heart valve
In this paper a measurement method for the analysis of the structural behavior of heart valves is presented by the use of the thermoelasticity and laser Doppler vibrometry. A special experimental test bench has been realized with the purpose to fix the body of the valve and to excite the parts of remarkable importance from the structural point of view by means of a shaker. The vibrational measurements have been adopted as boundary condition for the FEM simulations and the relative maps in terms of stress have subsequently been validate through the employment of the thermoelasticity.
Quantitative stress analysis by means of the thermoelastic effect
Abstract A new non-contact, full-field, stress analysis technique based on the measurement of the intensity of infra-red radiation emitted from the surface of a cyclically loaded body is applied to series of metallic specimens (including beams in bending, the ‘Brazilian’ disc, and a simple pure-shear testpiece) and critically appraised.