Thermographic nondestructive testing techniques have been receiving increasing attentions as one of the effective NDT
techniques, because of its non-contact, remote sensing, time-saving, and cost-saving vision techniques. However, the
defect detecting ability of this technique basically depends on environmental condition such as surrounding temperature,
initial temperature of inspection target, emissivity and so on. Most of thermographic NDT engineers have been
concerned about this problem, also. This paper proposes two reference specimens, aluminum alloy and stainless steel for
evaluating detecting ability of photothermal thermography nondestructive inspection system. This paper will improve on
the reliability of thermographic NDT technique.
In ultrasound excitation thermography, the injected ultrasound to an object is transformed to heat by thermo-structure
effect and internal friction. The advantage of this technique is selectively sensitive to thermally active defects. The
appearance of defects, which can be visualized by thermography camera, depends strongly on the method of excitation.
In preliminary studies, ultrasonic excitation horns of ultrasonic manufacturing process are widely adopted for a polymer
structure. However, it is needed that these horns are modified for improving the defect detection capability. This paper
proposes a new ultrasonic excitation horns with tuning fork shape in NDT of wood material. Geometric conditions are
optimized by FEA and application results by the developed horn are described and compared with those by a previous
Structural components subjected to high frequency vibrations, such as those used in vibrating parts of gas turbine
engines, are usually required to avoid resonance frequencies. Although the operating frequency is designed at more than
resonance frequencies, the structure, when a vibrating structure starts or stops, has to pass through a resonance
frequency, which results in large stress concentration. This paper applies thermography to analyze transient stress
variation of a circular holed plate. In experiment, the finite element modal (FEM) analysis of the specimen was
performed and the surface temperature measured by infrared camera is calculated to the stress of the nearby hole, based
on thermoelastic equation. Stress distributions between 2nd and 3rd vibration mode are investigated with thermography
and also dynamic stress concentration factors according to the change of vibration amplitude are estimated at resonance
The paper proposes an evaluation technique for the elastic modulus of a cantilever beam by vibration analysis based on time average electronic speckle pattern interferometry (TA-ESPI) and Euler-Bernoulli equation. General approaches for the measurement of elastic modulus of a thin film are the Nano indentation test, Buldge test, Micro-tensile test, and so on. They each have strength and weakness in the preparation of the test specimen and the analysis of experimental results. ESPI is a type of laser speckle interferometry technique offering non-contact, high-resolution and whole-field measurement. The technique is a common measurement method for vibration mode visualization and surface displacement. Whole-field vibration mode shape (surface displacement distribution) at resonance frequency can be visualized by ESPI. And the maximum surface displacement distribution from ESPI can be used to find the resonance frequency for each vibration mode shape. And the elastic modules of a test material can be easily estimated from the measured resonance frequency and Euler-Bernoulli equation. The TA-ESPI vibration analysis technique can be used to find the elastic modulus of a material requiring simple preparation process and analysis.