Hybrid Stereocorrelation for 3D Thermomechanical Field Measurements

Abstract

Three dimensional displacement fields are measured thanks to an original stereo system made of InfraRed (IR) and visible light cameras. This configuration provides the thermal fields which drive the thermomechanical loading and the 3D surface displacement fields, i.e. the response of the studied material. The calibration of the stereo rig is performed by using a 3D target of known geometry and the large gray level variations that occur on the IR images are accounted for by applying a low-pass filter. Because of a slight disorientation of the target, a further calibration correction step revealed necessary. After correction of the target orientation, the measured displacement fields display a good qualitative agreement (no quantitative comparison has been performed yet) with the expected fields.

Hybrid Multiview Correlation for Measuring and Monitoring Thermomechanical Fatigue Test

“…It was also proposed to perform hybrid SC with one visible light camera and one IR camera for 3D reconstructions of thermal scenes [39], [40]. In order to meet the challenges of high temperature measurements (e.g., ranging from 400°C to 600°C), out-of-plane motions, relatively high frequency (i.e., 1 Hz) of cyclic loading with short duration (50 ms) of thermal pulses, previous works have proven the feasibility of such an approach [41], [42]. The motivation behind the current work is to extend and improve thermomechanical measurements to capture thermomechanical fields of surfaces under laser shock in fatigue tests.…”