scholarly journals Deterministic and Probabilistic Investigation on Multiple Crack Interactions in a Semi-Infinite Domain

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Eui-Keun Kim ◽  
Habeun Choi ◽  
Kyoungsoo Park ◽  
Won-Hee Kang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Shielding Effect ◽  
Multiple Cracks ◽  
Infinite Domain ◽  
Multiple Crack ◽  
Crack Interactions ◽  
Safety And Reliability ◽  
Crack Shielding Effect

The investigation of multiple crack interactions in fracture mechanics is important to predict the safety and reliability of structures. This study aims to investigate the interactions of multiple parallel cracks in a semi-infinite domain in both deterministic and probabilistic ways by using an automated finite element modeling procedure and the Monte Carlo simulation. The stress intensity factor is considered as an indicator of failure and accurately evaluated by using the domain integral technique. The variation of the stress intensity factor according to the position, the length, and the number of cracks is demonstrated. In a probabilistic investigation, the effects of the number of cracks, the random distribution of the crack lengths, and the crack interactions to the failure probability are studied for a semi-infinite domain. The stress redistribution among multiple cracks, the effect of unevenly distributed crack lengths, and the combined effect of crack length uncertainties and a crack shielding effect have been examined.

scholarly journals Stress intensity factor for multiple cracks on curved panels

2018 ◽  
Vol 13 ◽  
pp. 469-474 ◽  
Author(s):  
Gordana Kastratović ◽  
Mustafa Aldarwish ◽  
Aleksandar Grbović ◽  
Nenad Vidanović ◽  
Khalid Eldwaib
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Multiple Cracks ◽  
Curved Panels

Stress intensity factor for bonded dissimilar materials weakened by multiple cracks

2020 ◽  
Vol 77 ◽  
pp. 585-601 ◽  
Author(s):  
K.B. Hamzah ◽  
N.M.A. Nik Long ◽  
N. Senu ◽  
Z.K. Eshkuvatov
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Dissimilar Materials ◽  
Multiple Cracks

Computation of Stress Intensity Factor for Multiple Cracks Using Singular Finite Element

2011 ◽  
Vol 214 ◽  
pp. 75-79 ◽  
Author(s):  
Ruslizam Daud ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Al Emran Ismail ◽  
A. Zulkifli
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Analytical Solution ◽  
Crack Width ◽  
Width Ratio ◽  
Multiple Cracks ◽  
Two Dimensional ◽  
Interval Ratio

The simplification of two dimensional approaches in singular finite elements has promoted the method to be used in the formulation of stress intensity factor (SIF) of multiple cracks in finite body. The effect of shielding and amplification are considered in defining the SIF. As been observed, the current available analytical approximations are more restricted to several assumptions. The more accurate and less restricted method has motivated this study. This paper presents the investigation of singular finite elements applied in two dimensional finite element models subjected to different crack-width ratio and cracks interval ratio. The newly finite element formulations are resulted with good agreement with theoretical statement compared to analytical solution. The weak points of presented analytical solution are discussed regards to the influence of crack width ratio and cracks interval ratio.

Influences of Crack Face Bridging Stress and Microstructure on Fracture Toughness of Toughened Alumina Ceramics

2011 ◽  
Vol 462-463 ◽  
pp. 972-978
Author(s):  
Yoshihisa Sakaida ◽  
Hajime Yoshida ◽  
Shotaro Mori
Keyword(s):  
Fracture Toughness ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Opening ◽  
Stress Shielding ◽  
Crack Tip ◽  
Shielding Effect ◽  
Hot Press ◽  
Crack Face

Three types of polycrystalline alumina, one pressureless and two hot press sintered Al2O3, were used to examine the effects of the characteristics of microstructure and crack face bridging on fracture toughness. The crack opening displacements and microstructures along the pop-in crack of single edge precracked beam (SEPB) specimens were observed in situ at a constant applied stress intensity factor by scanning electron microscopy (SEM). The bridging stress distribution could be determined from the measured crack opening displacement by three-dimensional finite element analysis, and then the stress intensity factor and stress shielding effect at the crack tip could also be determined. Intergranular microcracks of toughened Al2O3 were deflected by a complicated microstructure, and crack closure due to bridging grains was observed near the crack tip. Bridging stress of Al2O3 was compressive perpendicular to the crack face and was distributed behind the crack tip. The maximum bridging stress of two hot press sintered Al2O3 was about twice as large as that of pressureless sintered Al2O3. The fracture toughness of hot press sintered Al2O3 was, therefore, higher than that of pressureless sintered Al2O3, because the total amount of bridging stress and stress shielding effect increased with increasing magnitude of microcrack deflection and the number of interlocking grains.

Review of Technical Basis for ASME Code Section XI Appendix L

2020 ◽  
Author(s):  
Deepak S. Somasundaram ◽  
Dilip Dedhia ◽  
Do Jun Shim ◽  
Gary L. Stevens ◽  
Steven X. Xu
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Crack Growth ◽  
Multiple Cracks ◽  
Single Crack ◽  
Flaw Tolerance ◽  
Asme Code ◽  
The Impact

Abstract Equivalent Single Crack (ESC) sizes are provided in ASME Code, Section XI, Nonmandatory Appendix L, Tables L-3210-1 (for ferritic piping) and L-3210-2 (for austenitic piping). These two tables define initial flaw aspect ratios for use in fatigue flaw tolerance evaluations. These ESC sizes were based on the results of probabilistic fracture mechanics (PFM) evaluations that determined the equivalent single crack size that resulted in the same probability of through-wall leakage as the case when multiple cracks are initiated and grown around the inner circumference of a pipe. The PFM software, pc-PRAISE, used for the evaluation of ESC sizes had fracture mechanics models based on available data and models in the early 2000s. The stress intensity factor solutions used in pc-PRAISE were generated for a pipe radius-to-thickness ratio, Ri/t, of 5, and used a root-mean-square (RMS) averaged methodology. And the crack growth model was based on NUREG/CR-2189, Volume 5. This paper presents the results of evaluations to calculate a limited number of ESC sizes using updated fracture mechanics models for stress intensity factor and fatigue crack growth rates. The effect of crack growth due to stress corrosion cracking (SCC) in determining the ESCs is also discussed. The impact of the revised ESCs by performing two sample fatigue flaw tolerance problems and the associated results are also presented and discussed in this paper.

Probabilistic Fracture Mechanics Analysis of Multiple Cracks in Cylindrical Pressure Vessel

2011 ◽  
Vol 462-463 ◽  
pp. 1314-1318 ◽  
Author(s):  
Tatacipta Dirgantara ◽  
Tuppi Summa Wicaksono ◽  
Thahir Ahmad ◽  
Indra Sadikin ◽  
Djoko Suharto ◽  
...  
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Service Life ◽  
Intensity Factor ◽  
Pressure Vessel ◽  
Initial Crack ◽  
Multiple Cracks ◽  
Cylindrical Pressure Vessel ◽  
Mechanics Analysis

In this work, a probabilistic fracture mechanics analysis of multiple cracks in a cylindrical pressure vessel was conducted. The analysis was performed to predict service life of a pressure vessel with a certain level of reliability if the vessel has a multiple internal surface cracks that interact each other. The stress intensity factor of multiple cracks configuration was determined from the stress intensity factor of a single surface crack in a plate subjected to uni-axial load and the interaction factor between the cracks. In this work, the Swift’s crack link-up criterion was employed. These parameters together with several other stochastic parameters, i.e. initial crack size, Paris’s crack propagation constants and fracture toughness, were then used to calculate the probability of failure with a certain level of reliability. The failure probability was simulated using guided direct simulation, for cycle-by-cycle crack propagation, to find the expected service life and the mode of failure (leak or break). A case study of a high-pressure vessel having different initial crack sizes have been simulated and the service life with 99,99% reliability were determined.

Sign in / Sign up

Export Citation Format

Share Document