Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Evaluation of the Crack Initiation of Curved Compact Tension Specimens of a Zr-2.5Nb Pressure Tube Using the Unloading Compliance and Direct Current Potential Drop Methods

제하 컴플라이언스법 및 직류전위차법을 이용한 Zr-2.5Nb 압력관 휘어진 CT 시편의 균열시작 평가

  • Published : 2005.08.01
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Abstract

The direct current potential drop (DCPD) method and the unloading compliance (UC) method with a crack opening displacement gauge were applied simultaneously to the Zr-2.5Nb curved compact tension (CCT) specimens to determine which of the two methods can precisely determine the crack initiation point and hence the crack length for evaluation of their fracture toughness. The DCPD method detected the crack initiation at a smaller load-line displacement compared to the UC method. As a verification, a direct observation of the fracture surfaces on the curved compact tension specimens was made on the CCT specimens experiencing either 0.8 to 1.0 mm load line displacement or various loads from $50\%\;to\;80\%$ of the maximum peak load, or $P_{max}$. The DCPD method is concluded to be more precise in determining the crack initiation and fracture toughness, J in Zr-2.5Nb CCT specimens than the UC method.

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References

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