Mixed mode I/III fracture parameters for edge‐notched diametrically compressed disc specimen

Abstract

The applicability of a recently proposed test specimen named the edge‐notched diametrically compressed (ENDC) disc was assessed for mixed mode I/III fracture toughness studies. The specimen benefits from simple geometry and does not require complicated test configuration. The finite element analyses of this specimen revealed that pure modes I and III, as well as various intermediate mixed mode I/III deformations, are easily achieved by changing the direction of edge crack relative to the applied diametral compressive load. The modes I and III stress intensity and geometry factors were numerically computed in the midsection of the ENDC specimen using several 3D finite element analyses for different crack depths and inclination angles. Pure mode III angle was also obtained for each crack depth ratio. These assessments showed that the ENDC specimen can be a suitable candidate for studying mixed mode I/III fracture toughness.

Contribution of Interface Fracture Mechanism on Fracture Propagation Trajectory of Heterogeneous Asphalt Composites

“…Afterwards, some experimental testing methods and test samples including the edge cracked rectangular beam specimen subjected to four-point bend loading and the semi-circular bend (SCB) specimen were employed by Molennar et al [11,12] for investigating the mode I fracture of the asphalt mixtures. Other test configurations such as the modified indirect tensile disc (MITD) specimen [13], disc-shape compact-tension specimen [14], single edge notch beam (SENB) subjected to three-point bend [9,15], wedge splitting disc (WSD) [16], edge notch disc bend (ENDB) [17][18][19][20][21][22][23][24], edge notch disc diametral compression (ENDC) [25][26][27], center cracked Brazilian disc subjected to diametral compression [28], semi-circular bend (SCB) specimen [29][30][31][32][33][34], and hollow disc (or ring shape) specimen containing center crack and loaded diametrically [35] are some of the test configurations employed in the literature for investigating the fracture resistance of asphalt mixtures. Any of these test samples are suitable for simulating and conducting specific modes of fracture.…”

Specimen type effect on measured low‐temperature fracture toughness of asphalt concrete

“…Hence, disc shape samples in the form of circular and semi-circular specimens seems to be good candidate configurations for conducting the fracture toughness experiments on asphalt concrete materials. Review of extensive research works in this regard indicates that a number of disc shape samples including centre-cracked Brazilian disc loaded by diametral compression, 12 single-edge cracked disc loaded by diametral compressive load, 13,14 V-shaped notch disc loaded by wedge splitting load, 15 edge-cracked disc specimen loaded by symmetric three-point bending, [16][17][18][19][20][21][22] edgecracked disc shape sample subjected to tensile pin loading, [23][24][25][26] edge-cracked semi-circular specimen loaded by symmetric three-point bending [27][28][29][30][31][32][33][34][35][36][37] and modified indirect tension disc 38 have been employed in the past for conducting mode I fracture experiments on asphalt mixtures. Figure 1 presents and introduces the overall geometry and experimental setup employed for testing the mentioned specimens.…”

KIcandKIIcmeasurement for hot mix asphalt mixtures at low temperature: Experimental and theoretical study using the semicircular bend specimen with different thicknesses

“…These two parameters can be determined experimentally by means of appropriate laboratory testing methods. Some test specimens usually in the shape of circular discs including diametral compact-tension (DCT) specimen, [1][2][3][4] centre cracked Brazilian disc specimen, 5 semicircular bend (SCB) specimen, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] edge notch disc bend (ENDB) specimen [20][21][22][23][24][25][26] and edge notch disc diametral compression (ENDC) specimen 27,28 are usually used for conducting the fracture toughness experiments on asphalt mixtures. In addition, beam shape specimens such as rectangular beam specimen containing an edge crack and subjected to three-point bending (TPB) or four-point bending (FPB) [29][30][31][32][33][34][35] or wedge-splitting cube (WSC) 36,37 samples are among the other miscellaneous fracture test specimens employed by the asphalt and bituminous researchers.…”

“…Stewart et al 3 investigated the thickness effect on mode I fracture behaviour of HMA material manufactured in the shape of DCT specimen. Using the ENDB and ENDC specimens, authors in the previous studios [21][22][23][24]27,28 determined the mode I fracture toughness value at low-temperature condition for different HMA, WMA and stone mastic asphalt (SMA) materials containing different types of modifiers, additive and fibres including, styrene-butadiene-styrene (SBS), CR, polyphosphoric acid, sasobit and antistripping agent, carbon nanofiller, natural jute fibre and synthetic forta fibre. Also Fakhri et al 39 and Mansourian et al 24 investigated the effect of reclaimed asphalt pavement (RAP) and CR content on mode I and mixed mode fracture behaviour of roller compacted concrete mixture and HMA mixture using the SCB and FPB specimens.…”