Single-edge-notched tension

SENT single-edge-notched tension specimen... 

Fig. 12. Testing geometries (a) single-edge notch tension (SENT), (b) single-edge notch three-point bending (SEND), and (c) compact tension (CT).

The measurements are carried out on deeply notched specimens, either single-edge-notched tension (SENT) or double-edge-notched tension (DENT) (see Figure 13.22). The total work of fracture Wf consists of two components. First, there is the work expended in the inner zone We, which is called the essential work of fracture. This relates directly to the energy required to fracture the sample and is therefore proportional to the ligament... 

Brown N, Bhattacharya SK. The initiation of slow crack-growth in linear polyethylene under single edge notch tension and plane-strain. J Mater Sci 1985 20(12) 4553-60. 

Fig. 6. Fracture toughness test specimens (a) single-edge notch (b) center notch (c) compact tension and (d) three-point bend. Terms are defined in text.

Single-edge-notched (SEN) or compact-tension (CT) specimens may be used. Shape factors are tabulated (Williams and Cawood, 1990). 

For the experimental determination of LEFM parameters, compact tension (CT) and single edge notched (SEN) bending specimens are commonly used. According to the European Structural Integrity Society (ESIS) test protocol (59) and standard practices (60,61), A) under mode I can be determined from the load-displacement curves according to the relationship ... 

Tj =2PI TTd). As a final example, consider a single edge notch in a plate under uniaxial tension, as shown in Fig. 8.28. The ordinate of this graph will be equivalent to /[crV(OT)] in the limit of p=0 (/f, is the stress concentration factor, a22 l[Pg.234]

Specimen geometries used to determine K,c (a) compact tension (Cll specimen and (b) single-edge-notched bend (SENS) specimen. 

Fig. 2.19. Fracture toughness specimens, (a) Single-edge notched beam specimen, (b) compact tension specimen.

Figure 12.34 Specific total work of firacture Wf versus ligament length / for deeply double-edge-notched tension (DENT) ( ) and single-edge-notched bend (SENS) ( ) 3 mm thick polypropylene random copolymer samples. (Reproduced with permission firom Fasce, Bernal, Frontini, et al., Polym. Eng. Sci., 41, 1 (2001))...

Figure 9.8 Fatigue crack propagation (FCP) rate v ersus stress intensity range in tension at different temperatures for 0.59 melt index high-density polyethylene (single edge-notched specimen) [3].

The most common test specimen configurations for performing plane-strain fracture toughness test are the single edge notch bend (SENB or three-point bend) and the compact tension specimens. Hence, for an accurate determination of the plane-strain fracture toughness, a specimen whose thickness exceeds a critical size is required. 

A rectangular bar of polymer of thickness B = S mm and width = 20 mm has a central notch of length a = 10 mm. The bar is loaded in a three-point bending test with an 80 mm span, S, at room temperature. The bar fractures when the force applied is 300 N. Calculate (a) Kjc for the polymer and (b) the force needed to fracture in a compact tension test a specimen of dimensions IT = 50 mm, J = 10 mm, having a single-edge sharp crack of = 25 mm. 

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