Single-specimen evaluation of tearing resistance in SENT testing

Abstract

Please cite this article as: Verstraete, M.A., De Waele, W., Van Minnebruggen, K., Hertelé, S., Single-specimen evaluation of tearing resistance in SENT testing, Engineering Fracture Mechanics (2015), doi: http://dx.doi.org/ 10. 1016/j.engfracmech.2015.07.067 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract The evaluation of CTOD tearing resistance is required by several strain based defect assessment procedures. To that extent, the use of SENT testing is widely advised as the constraint matches that of pressurized pipes. This indicates the need for well validated testing methods. This paper discusses two single specimen techniques for the evaluation of tearing resistance using clamped SENT specimens: the unloading compliance (UC) and the direct current potential drop (DCPD) technique. From the results of tests carried out on a variety of both base metal and welded specimens, both methods show a comparable accuracy and scatter. Single-specimen evaluation of tearing resistance in SENT testing

Comparison of girth weld tearing resistance obtained from Curved Wide Plate and Single Edge Notch Tensile testing

“…10b). These natural defects contribute to the crack extension as measured by the nine point average method, though do not increase the potential drop across the crack during the test [25]. …”

“…To obtain a sufficient amount of ductile crack extension, the tests are continued until the force drops back to 80% of the maximum recorded value. For a detailed description of the SENT testing procedure, the reader is referred to [25].…”

“…The width of the scatter band, d s , is determined from the 95% confidence interval considering the same reduced set of data points [25].…”

Strain Capacity of Girth Welded Joints in HSAW Pipes

“…Tearing resistance is described by following equation which relates the crack tip opening displacement (CTOD) to the crack extension (Δa): CTOD = δ1*Δa δ2 In Figure 7, an example of a tearing resistance curve is provided for weld condition SB4. The tearing resistance curve was experimentally determined by a single-specimen technique using the direct current potential drop technique, as detailed by Verstraete et al [12]. …”

Experimental and numerical analysis of deformation patterns in notched heterogeneous welds

“…Crack driving force is represented by means of crack tip opening displacement (CTOD) [8,9,6]. Quantification of CTOD is performed by the usage of two clip gauges, mounted over the notch at different heights using the procedure described by BS8571:214 [10].…”