“…Erdogan & Sih (1963), Williams & Ewing (1972) and Theocaris (1984) used a rectangular plate containing an inclined center crack subjected to a uniform far field tension in their mixed mode fracture studies. The symmetric and asymmetrically loaded three or fourpoint bend specimens were also employed by researchers for investigating mode I and mixed mode brittle fracture (Fett et al, 1995;Xeidakis et al, 1996;Suresh et al, 1990, Aliha et al 2009Razavi et al, 2017Bahmani et al 2017;Heidari-Rarani et al, 2014), Disc type specimens including the centrally cracked Brazilian disk (BD) specimen, centrally cracked/notched ring specimen subjected to diametrall compression, edge notch disc bend (ENDB) and the semi-circular bend (SCB) specimen have been frequently employed for determining the mixed mode fracture resistance of various engineering materials such as rocks, graphite, concretes and polymers (Awaji & Sato, 1978;Ayatollahi et al, 2006;Ameri et al 2012Ameri et al ,2016Razmi & Mirsayar, 2017;Alhasan 2013;Fakhri et al 2017, Aliha et al 2008,2015a,c, 2017, Abd-Elhady 2013Al-Hdabi et al 2014;Dehghany et al 2017. However, some of these specimens have certain shortcomings.…”