画像表示によるスポット溶接部の超音波測定

• 里中

  熊本大学

• 立川 逸郎

  熊本大学 (現)(財)大分県高度技術開発研究所

• 山本 光治

  熊本大学

書誌事項

タイトル別名

• Ultrasonic Measurement for Nugget Geometry of Resistance Spot Welds of Thin Plates with Imaging Techniques

抄録

This study proposes a ultrasonic measurement of nugget geometry in resistance spot welding of two-plate lap joint of thin plate below 1 mm in thickness. This measurement is immersion method with point focussed probe and is based on the composite effects of convergence of ultrasonic beam and attenuation due to the multiple reflection. Under the condition which the focus of ultrasonic beam places beneath the backwall, there appears a echo from the backwall within the weld region or from the faying surface with an observable time delay behind the surface echo. Since the time delay of backwall echo is as same as that of interface echo but these two echoes provide different amplitude, the weld region is distinguished from unbonded zones. According to the line scanning, three distinct patterns appear ; the flat pattern peculiar to the faying surface, decreasing pattern at the vicinity of nugget boundary and increasing or flat pattern at weld region. The nugget size is determined by the distance between two points changing from the decreasing pattern to increasing or flat one, from which the measurement of nugget size is performed with the accuracy of 0.3 mm. A series of parallel line scanning with aid of personal computer provide the configuration of nugget, which is displayed on the CRT with two methods, that is, colour mode and white-black mode evaluated by the amplitude and gradient of amplitude, respectively.

収録刊行物

• 本会論文集

  本会論文集 7 396-400, 1989

  社団法人溶接学会

キーワード

• Resistance spot welding
• Nugget
• Ultrasonic testing
• Multiple reflection
• Scanning detection
• Imaging technique
• C-scan display

詳細情報

• CRID: 1570009752463523328
• NII論文ID: 110003422990
• NII書誌ID: AN1005067X
• ISSN: 02884771
• 本文言語コード: ja
• データソース種別:
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