전단간섭법을 이용한 압력배관 면외변형 정량측정

Abstract

At Non-contact and Non-destructive testing technique like ESPI Digital holography. Recently, The study about deformation measurement of defect in specimen is actively being done by using speckle pattern like digital holography and shearing interferometry. Of the optical interferometers typically using a laser, Measurement method to measure the deformation amount is an electronic speckle pattern interferometry process (ESPI). However, ESPI can be measured precisely by the strain generated in the object but, may be disturbed at the industry without the anti-vibration table which decrease external vibration. Therefore, we don’t encourage experts to use it at the industry. Another way, Shearing interferometry known as one of laser interferometers is usefully being used in the way of Non-destructive test to quantitatively analyze defects and structural of machine because it is relatively less sensitive to vibrations and external impacts. In this study, we tested pressure pipe defect length and the internal pressure change to figure out the out-of-plane deformation. Prior to the pressure pipe defect detection test, we organized a shearing interferometer to use the optical component. To carry out the reliability test of a shearing interferometer composed of optical components, The measurement of pressure pipe’s out-of-plane deformation and an experiment of defect detection were carried out after the shearography system and out-of-plane deformation testing of rubber were conducted and secured the reliability of development equipment. In addition, to test the out-of-plane deformation of the pressure vessel, The out-of-plane deformation was measured, after we produced a test piece in straight form and differed from size and shape of the defects that have been produced in the inside of each specimen. The pipe specimens are adopted from SS400 which is used for pipe line system. The defect remaining in material was quantitatively determined for the extracted objects by developing the program for Image enhancement and deformation information. Using the measured defect and deformation information presented interworking with finite element analysis. Findings, The conventional shearing interference method are referred to as shearing amount in the upper surface shear amount is applicable to any values of distance units, in this paper, the shearing amount by applying the image processing techniques to apply the shearing amount by the number of pixels it was confirmed that the can. In addition, lateral shearing interferometer and compared results with commercial equipment interferometer Shearography system configured based on the out-of-plane deformation measurements of commercial equipment in the measurement with the interferometer configured for measuring deformation of the rubber flat plate showed an average error of 2.4%. The lateral pressure pipe via a change of pressure results in deformation measurement 0.05~0.25Mpa experiment was to detect the respective maximum out-of-plane deformation. Increase the amount of deformation due to the pressure difference between each specimen were similar, when compared to the specimen, this was the biggest flaw is the amount of deformation of the SS-1-1-1 most common defect is the smallest amount of deformation of the SS-1-1-4 this showed the smallest. Pipelines pressure sizing experiment to obtain the installation, the image in the object surface of the transparent character immediately before the experiment, using the number of pixel for the 5mm proposed a method to infer the length and width of the defect. For the experiments, the size of the longest defect SS-1-1-1 showed the actual processing of the length and approximately 4.1% error when the smallest SS-1-1-4 was an error of 2.9%. The lateral size of the defect obtained from the deformation amount and the defect detection test using the shearing interferometer, width and depth of the information could be used by the FEM tool such as finite element analysis to know the maximum pressure and maximum defect length by deformation.