An insight into mode II fracture toughness testing using SCB specimen. Issue 9 (18th June 2019)

• Record Type: Journal Article
• Authors: Bahrami, Bahador; Ayatollahi, Majid R.; Sedighi, Iman; Yazid Yahya, Mohd
• Other Names: Hong Youshi guestEditor.; Susmel Luca guestEditor.; Berto Filippo guestEditor.; Neu Richard W. guestEditor.; Endo Masahiro guestEditor.
• Is Part Of: Fatigue & fracture of engineering materials & structures. Volume 42:Issue 9(2019)
• Page Start: 1991
• Page End: 1999
• Publication Date: 2019-06-18
• Subjects: fracture test -- mode II fracture toughness -- semicircular bending -- support friction effect -- T‐stress; Materials -- Fatigue -- Periodicals; Fracture mechanics -- Periodicals; 620.1123
• DOI: 10.1111/ffe.13069
• Languages: English
• ISSNs: 8756-758X

Abstract

Abstract: The effect of friction forces between the test specimen and its bottom supports on the mode II fracture toughness values obtained using the semicircular bend (SCB) specimen is investigated. First, a number of experiments were conducted on SCB specimen in order to determine the mode II fracture toughness of polymethyl methacrylate (PMMA) according to the conventional approaches available in the literature. Three different types of supports that have been frequently employed by researchers in recent years were used to evaluate the effect of support type on the fracture loads. It was found that the friction forces between the supports and the SCB specimen have a significant effect on the value of mode II fracture toughness measured using the SCB samples. Then, the specimen was simulated using finite element method for more detailed investigation on the near crack tip stress field evolution when friction forces increase between the supports and the SCB specimen. The finite element results confirmed that the type of support affects not only the stress intensity factors K I and K II but also the T‐stress. The experimental and numerical results showed that the use of the crack tip parameters available in literature for frictionless contact between the supports and the SCB specimen can result in significant errors when the mode II experiments are performed by using the fixed or roller‐in‐grove types of supports.