VO-Notches Subjected to Tension-Torsion Loading: Experimental and Theoretical Fracture Study on Polymeric Samples

Area of Science:

• Materials Science
• Mechanical Engineering
• Fracture Mechanics

Background:

• Brittle materials are susceptible to fracture, especially when weakened by geometric discontinuities.
• Understanding fracture behavior in components with V-shaped notches and end holes (VO-notches) is crucial for structural integrity.

Purpose of the Study:

• To experimentally and theoretically investigate the fracture behavior of brittle specimens with VO-notches.
• To evaluate the influence of notch end-hole size on fracture resistance.
• To develop and validate stress-based criteria for predicting fracture in VO-notched components under mixed-mode loading.

Main Methods:

• Experimental testing of VO-notched PMMA samples under various mixed-mode loading conditions (I, III, and combinations).
• Systematic variation of notch end-hole radii (1, 2, and 4 mm) to assess geometric effects.
• Development and application of the Maximum Tangential Stress (MTS) and Mean Stress (MS) criteria for VO-notches.
• Comparison of theoretical predictions with experimental fracture data.

Main Results:

• Experimental data revealed the impact of VO-notches and end-hole size on fracture behavior.
• The developed VO-MTS and VO-MS criteria were established for mixed-mode I/III loading.
• The VO-MTS criterion predicted fracture resistance with approximately 92% accuracy.
• The VO-MS criterion achieved approximately 90% accuracy in predicting fracture resistance.

Conclusions:

• The study successfully characterized the fracture behavior of VO-notched brittle specimens.
• The developed VO-MTS and VO-MS criteria provide reliable predictions for fracture conditions in these geometries.
• These criteria enhance the ability to estimate fracture resistance, contributing to safer material design and application.