Measuring structure stress distribution using lock-in infrared thermography technique

When the stress of a structure is measured the important effect toward measurement result caused by altering loading frequency was studied through experiment by adopting lock-in infrared thermography technique. The experiment method was given to choose a proper loading frequency, which was an important parameter. The lock-in infrared thermography technique was applied to the research of structure stress distribution of a riveted structure between the skin and framework of aerofoil in aviation industry, and apparent advantage of lock-in infrared thermography technique in structure stress measurement aspect was demonstrated, when comparing with conventional strain gauge electrical measurement technique.