Crack propagation and threshold strength of fissured clays subjected to cyclic loading

2013 ◽  
pp. 415-422
Keyword(s):  
Cyclic Loading ◽  
Crack Propagation ◽  
Threshold Strength

Crack initiation and crack propagation under thermal cyclic loading

1990 ◽  
Vol 8 (2) ◽  
pp. 98-104 ◽  
Author(s):  
K. Bethge ◽  
D. Munz ◽  
J. Neumann
Keyword(s):  
Cyclic Loading ◽  
Crack Initiation ◽  
Crack Propagation

Crack Propagation Prediction Using Haensel Damage Model

2012 ◽  
Author(s):  
Piotr Bednarz ◽  
Jaroslaw Szwedowicz
Keyword(s):  
Cyclic Loading ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Damage Model ◽  
Lifetime Prediction ◽  
Dissipated Energy ◽  
Mathematical Approach ◽  
Loading Conditions ◽  
Stored Energy ◽  
Tensile Stresses

The Haensel damage model correlates lifetime of a component until crack initiation to the dissipated and stored energy in the material during cyclic loading. The crack initiation is influenced by mean stresses. The Haensel damage model considers the mean stress effect by including compressive and tensile stresses in calculations of elastic strain energy during cyclic loading conditions. The goal of the paper is to extend the above model to predict crack propagation under large cyclic plasticity and non-proportional loading conditions. After voids initiation onset of necking, voids growth and linking takes place among them. During this process a mesocrack is created. This stage of fracture involves the same amount of released energy for new crack surface creation as dissipated energy for mesocrack initiation. The amount of dissipated and stored energy is related to the process zone size and to the number of cycles. Ilyushin’s postulate is used to calculate the amount of dissipated energy. In order to consider a contribution of tensile stresses only during loading to crack propagation, tensile/compressive split is performed for the stress tensor. One of the key drivers of this paper is to provide a straightforward engineering approach, which does not require explicit modelling of cracks. The proposed mathematical approach accounts for redistribution of stresses, strains and energy during crack propagation. This allows to approximate the observed effect of distribution of dissipated energy on the front of a crack tip. The developed approach is validated through FE (Finite Element) simulations of the Dowling and Begley experiment. The Haensel lifetime prediction of Dowling’s experiment is in good agreement with the experimental data and the explicit FE results. Finally, the proposed mathematical approach simplifies significantly the engineering effort for Nonlinear Fracture Mechanics lifetime prediction by avoiding the requirement to simulate real crack propagation using node base release methods, XFEM or remeshing procedures.

Effect of heat treatment on the resistance to crack propagation during cyclic loading of low-carbon steels

1978 ◽  
Vol 20 (10) ◽  
pp. 811-815
Author(s):  
M. N. Georgiev ◽  
V. N. Danilov ◽  
N. Ya. Mezhova ◽  
I. V. Nikitin ◽  
P. S. Sokolov
Keyword(s):  
Heat Treatment ◽  
Cyclic Loading ◽  
Crack Propagation ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels

Simulation of Cracks in Fiber Reinforced Composite Plate

2011 ◽  
Vol 471-472 ◽  
pp. 892-897 ◽  
Author(s):  
Pramod Kumar ◽  
Ashish Kakyal
Keyword(s):  
Cyclic Loading ◽  
Crack Propagation ◽  
Crack Growth ◽  
Fem Analysis ◽  
Strain Energy Release ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Fiber Reinforced ◽  
Automotive Parts ◽  
Mechanical Approach

Material flaws, pre-cracks and crack initiation due to cyclic loading often lead to undetected crack propagation in commercial structures like aircraft components, automotive parts and computer motherboard. Cyclic loading can make the crack grow large into any shape with an arbitrary orientation, depending on the structure geometry, boundary and loading conditions. Since crack propagation in many cases may lead to catastrophic failure with human and monetary loss as a result, it is important to enable crack growth prediction at all stages of development and during maintenance in order to prevent such scenarios. Micro mechanical approach is used for modelling the crack in composite materials. Crack propagation in a single edge crack plate is carried out by using FEM analysis. 2D model is analysed to determine the crack growth. The crack propagation rate, stress intensity factor and strain energy release rate are predicted by varying the crack length in fiber reinforced epoxy composite using NISA/ENDURE.

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