Mixed Mode Fatigue Fracture Criteria for the Plates With an Inclined Semi-Elliptical Crack

2000 ◽  
Author(s):  
Lichun Bian ◽  
Ai Kah Soh
Keyword(s):  
Fatigue Crack ◽  
Mixed Mode ◽  
Yield Criterion ◽  
Axial Loading ◽  
Maximum Tensile Stress ◽  
Core Region ◽  
Elliptical Crack ◽  
Mixed Mode Fracture ◽  
Fracture Criteria ◽  
Von Mises

Abstract The behaviour of fatigue crack propagation of rectangular steel plates, each consisting of an inclined semi-elliptical crack, subjected to axial loading was investigated both experimentally and theoretically. The inclined angle of the crack with respect to the axis of loading varied between 0° and 90°. In the present investigation, the Von Mises yield criterion was applied to define the core region, instead of a core region with a constant distance r from the crack tip. Based on Von Mises elasto-plastic boundary, the two commonly used fracture criteria, the maximum tensile stress and the minimum strain energy density criteria, were modified. The results obtained using the two improved fracture criteria were compared with those obtained using the commonly used mixed mode fracture criteria and experimental results. A mixed mode fatigue crack criterion has been established based on the experimental data.

Fatigue Fracture Behavior of Steel Pipes With a Pre-Crack

2002 ◽  
Author(s):  
Jae-Kyoo Lim ◽  
Lichun Bian
Keyword(s):  
Fatigue Crack ◽  
Yield Criterion ◽  
Axial Loading ◽  
Potential Drop ◽  
Maximum Tensile Stress ◽  
Core Region ◽  
Fracture Criteria ◽  
Steel Pipes ◽  
Inclined Angle ◽  
Von Mises

The behaviour of fatigue crack propagation of mild steel pipes, each consisting of an inclined semi-elliptical crack, subjected to axial loading was investigated both experimentally and theoretically. The inclined angle of the crack with respect to the axis of loading varied between 0° and 90°. In the present investigation, the gowth of the fatigue crack was monitored using the AC potential drop technique. The Von Mises yield criterion was applied to define the core region, instead of assuming a core region with a constant distance r from the crack lip. The two commonly employed fracture criteria, i.e., the maximum tensile stress and the minimum strain energy density criteria, were modified by adopting Von Mises elasto-plastic boundary. The results obtained using the innproved fracture criteria are, in most cases, in better agreement with test results as compared with those obtained using the commonly employed fracture criteria.

The Effect of Discontinuity Size on the Initiation of Shattered Rim Defects

2000 ◽  
Author(s):  
Daniel H. Stone ◽  
Geoffrey E. Dahlman
Keyword(s):  
Fatigue Crack ◽  
Mixed Mode ◽  
Crack Surface ◽  
Fatigue Cracks ◽  
Rolling Direction ◽  
Mixed Mode Fracture ◽  
Mode Fracture ◽  
Clam Shell ◽  
Shear Component ◽  
Mechanics Analysis

Abstract Shattered rim defects are the result of large fatigue cracks that propagate roughly parallel to the wheel tread surface. They form and grow 12 to 20 millimeters (1/2 to 3/4 in.) below the tread surface. A typical shattered rim is shown in Figure 1. The clamshell pattern of the fracture surface is also typical of shattered rims. The clamshell pattern is formed because fatigue cracks at this depth in wheels have a shear component and, when the rolling direction is opposite, the cracks grow in a different direction forming a series of ridges and valleys. Miezoso, et alia have presented a mixed mode fracture mechanics analysis of the process of forming a clam-shell fatigue crack surface in wheels.

Comparison of mixed mode fracture criteria in finite element analysis for matrix crack density estimation of laminated composites

2020 ◽  
Vol 55 (2) ◽  
pp. 277-289
Author(s):  
Mingqing Yuan ◽  
Haitao Zhao ◽  
Li Tian ◽  
Boming Zhang ◽  
Yanzhi Yang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Density Estimation ◽  
Mixed Mode ◽  
Crack Density ◽  
Mode I ◽  
Mixed Mode Fracture ◽  
Fracture Criteria ◽  
Element Analysis ◽  
Mode Fracture

A mixed mode crack density estimation method based on the finite element analysis (FEA) for laminated composites is proposed and verified in this paper. The damaged properties of cracked ply are obtained using semi-analytical micro-mechanical method for the first time. The piecewise functions of the mode I and mode II energy release rates involving crack density are given based on Griffith’s energy principle and discrete damage mechanics (DDM). Any mixed mode fracture criteria could be simply applied to the FEA of the structure to calculate the initiation and evolution of the micro-cracks in the laminate. Mode I criterion, power law and B-K criterion are applied in the numerical examples to compare their performances in the crack density estimation. It has been concluded that the accuracy of the fracture toughness is more important than the choice of fracture criterion in crack density estimation.

Mobilization of Fully Plastic Moment Capacity for Pressurized Pipes

1999 ◽  
Vol 121 (4) ◽  
pp. 237-241 ◽  
Author(s):  
M. Mohareb ◽  
D. W. Murray
Keyword(s):  
Internal Pressure ◽  
Axial Force ◽  
Yield Criterion ◽  
Axial Loading ◽  
Experimental Results ◽  
Moment Capacity ◽  
Interaction Diagram ◽  
Von Mises ◽  
Force Pressure ◽  
Good Agreement

An analytical expression is derived for the prediction of fully plastic moment capacity of pipes subjected to axial loading and internal pressure. The expression is based on the von Mises yield criterion. The expression predicts pipe moment capacities that are in good agreement with full-scale experimental results. A universal nondimensional moment versus effective axial force-pressure interaction diagram is developed for the design of elevated pipe lines.

Mixed-Mode Fracture Criteria for Reliability Analysis and Design With Structural Ceramics

1987 ◽  
Vol 109 (3) ◽  
pp. 282-289 ◽  
Author(s):  
D. K. Shetty
Keyword(s):  
Fracture Mechanics ◽  
Reliability Analysis ◽  
Mixed Mode ◽  
Linear Elastic Fracture Mechanics ◽  
Time Dependent ◽  
Mixed Mode Fracture ◽  
Fracture Criteria ◽  
Mode Fracture ◽  
Linear Elastic ◽  
Elastic Fracture

Increasing use of ceramics in structural applications has led to the development of a probabilistic design methodology that combines three elements: linear elastic fracture mechanics theory that relates strengths of ceramics to size, shape, and orientation of critical flaws, a characteristic flaw size distribution function that accounts for the size effect on strength via the weakest-link concept, and a time-dependent strength caused by subcritical crack growth or other mechanisms. This paper reviews recent research that has been focused on the first of the above three elements, the investigation of fracture criteria for arbitrarily oriented flaws in ceramics, i.e., the mixed-mode fracture problem in linear elastic fracture mechanics theory. Experimental results obtained with two-dimensional through cracks and three-dimensional surface (indentation) cracks are summarized and compared to mixed-mode fracture criteria. The effects of material microstructure and the stress state on mixed-mode fractures are discussed. The application of mixed-mode fracture criteria in reliability analysis is illustrated for several simple stress states in the absence of time-dependent strength degradation.

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