OPTICAL NONDESTRUCTIVE INSPECTION METHOD AND OPTICAL NONDESTRUCTIVE INSPECTION DEVICE

摘要

To provide an optical nondestructive inspection method and an optical nondestructive inspection device with which, when determining a joint state between a first member and a second member on the basis of a temperature change at a measurement point that is set to the first member and irradiated with a laser for heating, it is possible to further suppress a variation of the joint state and acquire a more stable joint state for determination.SOLUTION: The optical nondestructive inspection method comprises a heating laser emission step, an information acquisition step for acquiring measurement point information and heating laser information, and a joint state determination step for determining a joint state on the basis of the measurement point information and heating laser information. The optical nondestructive inspection method further includes a preheating step for irradiating, before the heating laser emission step, the measurement point or a preheating range including the measurement point or a preheating point that is set within the preheating range with a preheating laser for which thermal strain generation strength defined as constant output strength and an irradiation time are adjusted, so that a thermal strain is induced without destructing the first member.SELECTED DRAWING: Figure 14