- In this study, cylindrical or disc specimens were selected for pure mode Ⅲ fracture experiment because they can be prepared more easily from core without additional complex processing such as cutting.
- The loading methods for ENDB and ENDC specimens are different; the former is loaded in bending while the latter is loaded in uniaxial compression. ANDB specimens are also loaded using two rigid plates for diameter compression, but they require the two axial grooves to remain in one plane during machining which makes them difficult to machine and introduces potential errors due to slippage. On the other hand, ENDB specimens can be loaded in the traditional three-point bending mode, making them easier to machine and operate during testing.
- Previous studies have shown that when a crack length to specimen thickness ratio of a/B = 0.4 is reached under pure Mode III loading conditions, t-stress in ENDC specimens becomes negative which increases fracture toughness magnitude, whereas t-stress in ENDB specimens remains close to zero. As a result, fracture toughness obtained with ENDB specimens is more reliable.
Improvements:
- Clarify why cylindrical or disc specimens were chosen by adding a reason and rephrasing the sentence for clarity.
- Restructure sentences for clarity and remove repetition of “loaded”.
- Provide context before stating previous studies’ findings and explain how it relates to the topic at hand.
- Add summary sentence at end of paragraph for cohesion with overall article structure
