STRESS MEASUREMENT

摘要

The absolute values of biaxial stresses in a ferromagnetic material (16) are measured using a probe (12) which comprises an electromagnet (26), a sensor (32) for stress-induced magnetic anisotropy (SMA) and a sensor (30) for directional effective permeability (DEP). The DEP sensor (30) enables absolute values of stress to be determined; the SMA sensor (32) enables the directions of the principal stress axes to be accurately determined, and improves the accuracy of the stress measurements.