Fracture Mechanics Study on the Effects of Various Notch Radii by Using FE Analysis

2015 ◽  
Author(s):  
Zalikha Murni Abdul Hamid ◽  
Keun-Hyung Bae ◽  
Gyo-Geun Youn ◽  
Dae-Young Lee ◽  
Yun-Jae Kim ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Fracture Strain ◽  
Notch Root ◽  
Damage Model ◽  
Fe Analysis ◽  
Experiment Data ◽  
Apparent Fracture Toughness ◽  
Notch Root Radius ◽  
Plane Strain Deformation

This paper predicts the effects of notch root radius on the ductile fracture behavior of the structure through evaluation based on fracture mechanics concept. To understand the effects of notch radii on structure, FE analysis of J-integral for plane strain deformation fields with various size of notches were predicted. The fracture toughness of the specimens with various notch radii were determined by stress modified fracture strain damage model FE simulation that was established based on notched bar tensile test data. The simulated results were validated by comparison with the experiment data. Findings show that the value of apparent fracture toughness increases with the increase in the notch radii. Therefore, indicates the increase in the resistance to the crack propagation. Similar trend can be shown for both C(T) and M(T) specimen. Thus, shows that the proposed method can be used to obtain effects of various notch radii.

Ductile Tearing Simulation of Circumferential Cracked Pipe Under Cyclic Loading Using Damage Criteria Determined by Monotonic Pipe Test Data

2018 ◽  
Author(s):  
Jin-Ha Hwang ◽  
Gyo-Geun Youn ◽  
Naoki Miura ◽  
Yun-Jae Kim
Keyword(s):  
Fracture Toughness ◽  
Cyclic Loading ◽  
Ductile Fracture ◽  
Test Data ◽  
Strain Energy ◽  
Fracture Strain ◽  
Damage Model ◽  
Fracture Toughness Test ◽  
Ductile Tearing ◽  
Damage Criteria

To evaluate the structural integrity of nuclear power plant piping, it is important to predict ductile tearing of circumferential cracked pipe from the view point of Leak-Before-Break concept under seismic conditions. CRIEPI (Central Research Institute of Electric Power Industry) conducted fracture test on Japanese carbon steel (STS410) circumferential through-wall cracked pipes under monotonic or cyclic bending load in room temperature. Cyclic loading test conducted variable experimental conditions considering effect of stress ratio and amplitude. In the previous study, monotonic fracture pipe test was simulated by modified stress-strain ductile damage model determined by C(T) specimen fracture toughness test. And, ductile fracture of pipe under cyclic loading simulated using damage criteria based on fracture strain energy from C(T) specimen test data. In this study, monotonic pipe test result is applied to determination of damage model based on fracture strain energy, using finite element analysis, without C(T) specimen fracture toughness test. Ductile fracture of pipe under variable cyclic loading conditions simulates using determined fracture energy damage model from monotonic pipe test.

scholarly journals Notch-acuity effects on the fracture toughness of saline ice

1991 ◽  
Vol 15 ◽  
pp. 230-235 ◽  
Author(s):  
S.J Defranco ◽  
Y. Wei ◽  
J. P. D. Dempsey
Keyword(s):  
Fracture Toughness ◽  
Notch Root ◽  
Crack Tip ◽  
Constant Thickness ◽  
Razor Blade ◽  
Mean Values ◽  
Fracture Testing ◽  
Apparent Fracture Toughness ◽  
Band Saw ◽  
Image Position

Dynamic ocean-induced loading of ice has recently prompted interest in the fatigue strength of ice and, consequently, aspects of the fracture testing of ice need to be examined. One aspect in fracture testing, the effects of notch acuity on the apparent fracture toughness (KQ) of saline ice, was investigated in this study using four groups of single-edge notched-bend specimens with different crack-(or notch-) root radii, fabricated by four different methods; namely, drilling a small hole of two different radii at the crack tip, cutting a crack with a band saw and using a hand-held razor blade to scribe a sharp crack. For this study, tests were performed on saline ice using one crack length and orientation, constant thickness and constant temperature (−25°C). The mean values and the standard deviations of the apparent fracture toughness of the specimens with blunt notches were higher than those with sharp cracks. The results presented in a plot of fracture toughness versus where ρ is the crack-tip radius, provide a preliminary estimate of the required notch acuity for fracture-toughness testing of saline ice.

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