Composite elements are recently commonly used in many industrial branches like aviation, marine or civil engineering. One of the problems that can influence on material durability are contaminations (e.g. water, oil, dust) that can be introduced into elements structure during manufacturing process or can diffuse into its internal part during exploitation. Such intrusions locally change material characteristics, affect its durability and can be a damage origin significantly decreasing mechanical properties of a composite object. Due to this it is important to have a non-destructive method to inspect an internal structure of elements just after manufacturing or in intervals during its exploitation. One of the techniques is THz spectroscopy that can be applied for non-conductive materials. This method can be used for identification of discontinuities or material structural disintegrations that results in changes of absorption, refractive index or scattering of THz waves propagating throughout the material structure. The paper presents an application of THz spectroscopy for detection and localization of different contaminations (like water, oil or dust) that were introduced into composite material during its manufacturing process or were an effect of exploitation faults. During analysis the limitations of proposed method will be determined.
|