| 摘要 |
PURPOSE:To reduce the labor of measurement and to perform a processing quickly by obtaining two stress picture data different in load phase by 90 deg. to reduce the number of times of scan and measurement. CONSTITUTION:A rotation load having a sine waveform where compression and tension are changed periodically is applied to the point P1 of a sample 1. Consequently, the load at a point P2 shifted from the point P1 by 90 deg. phase angle is different from the load at the point P1 in phase by 90 deg.. In accordance with a signal generated by a timing generating circuit 7, a data processor 6 reads an infrared detection signal when the maximum value of the compressive load is impressed to the point P1 and a signal when the maximum value of the tensile load is impressed to the point P1 an obtains the difference of intensity between both signals at every point of the sample to store stress picture data in a storage device 8. Similarly, the difference of intensity between compressive and tensile load signals of the point P2 is obtained in accordance with the signal from the circuit 7. Data of individual corresponding points are squared and added with respect to all data to obtain square roots, thereby calculating stress picture data corresponding to a maximum stress load at each point. |
