Interlaminar Crack Growth in Fiber Reinforced Composites During Fatigue

1979 ◽  
Vol 101 (1) ◽  
pp. 34-41 ◽  
Author(s):  
S. S. Wang ◽  
H. T. Wang
Keyword(s):  
Crack Propagation ◽  
Crack Growth ◽  
Practical Importance ◽  
Crack Tip ◽  
Fatigue Loading ◽  
Fiber Reinforced Composites ◽  
Crack Growth Behavior ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Interlaminar Crack

This paper presents an investigation of interlaminar crack growth behavior in fiber-reinforced composites subjected to fatigue loading. In the experimental phase of the study, interlaminar crack propagation rates and mechanisms were determined for the cases of various geometries, laminate parameters and cyclic stress levels. An advanced singular hybrid-stress finite element method was used in conjunction with the experimental results to examine the local crack-tip behavior and to characterize the crack propagation during fatigue. Results elucidate the basic nature of the cyclic delamination damage and relate the interlaminar crack growth rate to the range of mixed-mode crack-tip stress intensity factors. The study provides fundamental insight into the problem, reveals several important features of the interlaminar fatigue failure, and should be of practical importance in selection, testing and design of composite materials.

Study of the Crack Propagation for Particles Reinforced Composite Materials with Different Inclusion Distribution

2012 ◽  
Vol 461 ◽  
pp. 338-342 ◽  
Author(s):  
Da Zhao Deng ◽  
Ji Xiang Luo
Keyword(s):  
Composite Materials ◽  
Crack Propagation ◽  
Engineering Application ◽  
Reference Value ◽  
Voronoi Cell ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Reinforced Composite ◽  
Inclusion Distribution

Based on the Voronoi cell finite element can also reflect fiber reinforced composites interface to take off the layer and matrix crack propagation of the new cell (X-VCFEM cell)[1]. Combined with the re-mesh strategy and grid dynamic technology, Simulated analysis in different inclusion distribution, interface crack propagation for fiber reinforced composites, the results show that for the model with multiple Voronoi cell, The horizontal tension was the largest; For only a Voronoi cell, The size of the horizontal tension was little change.The result was very important reference value for manufacturing process and engineering application of fiber reinforced composite materials.

Effects of Loading Spectra on High pH Crack Growth Behavior of X65 Pipeline Steel

CORROSION ◽  
10.5006/3472 ◽  
2020 ◽  
Vol 76 (6) ◽  
pp. 601-615 ◽  
Author(s):  
Hamid Niazi ◽  
Karina Chevil ◽  
Erwin Gamboa ◽  
Lyndon Lamborn ◽  
Weixing Chen ◽  
...  
Keyword(s):  
Free Surface ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Strain Rate ◽  
Crack Growth ◽  
Pipeline Steel ◽  
Crack Tip ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
Secondary Crack

The effects of mechanical factors on crack growth behavior during the second stage of high pH stress corrosion cracking in pipeline steel were investigated by applying several loading scenarios on compact tension (CT) specimens. The main mechanism for stage 2 of intergranular crack propagation is anodic dissolution ahead of the crack tip which is highly dependent on crack-tip strain rate. The maximum and minimum crack growth rates were 3 × 10−7 mm/s and 1 × 10−7 mm/s, respectively. It was observed that several factors such as mean stress intensity factor, amplitude, and frequency of loading cycles determine the crack-tip strain rate. Low R-ratio cycles, particularly high-frequency ones, enhance secondary crack initiation, and crack coalescence on the free surface. This mechanism accelerates crack advance on the free surface which is accompanied with an increase in mechanical driving force for crack propagation in the thickness direction. These findings have implications for pipeline operators and could be used to increase the lifespan of the cracked pipelines at stage 2. For those pipelines, any loading condition that increases the strain rate ahead of the crack tip enhances anodic dissolution and is detrimental. Additionally, secondary crack initiation and coalescence could be minimized by avoiding internal pressure fluctuation, particularly rapid large pressure fluctuations.

scholarly journals An Integral Formulation of Two-Parameter Fatigue Crack Growth Model

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Jianguo Wu ◽  
Shan Jiang ◽  
Wei Zhang ◽  
Zili Wang
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Crack Closure ◽  
Crack Tip ◽  
Integral Form ◽  
Crack Growth Behavior ◽  
Crack Growth Model ◽  
Two Parameter

A two-parameter fatigue crack growth algorithm in integral form is proposed, which can describe the continuous crack growth process over the time period. In this model, the fatigue crack propagation behavior is governed by the temporal crack-tip state including the current applied load and the physical condition due to the previous load sequence. The plasticity-induced crack closure, left by the historical loading sequence, controls the following fatigue crack growth behavior and typically leads to the interaction effects. In the proposed method, a modified crack closure model deriving from the local plastic deformation is employed to account for this load memory effect. In general, this model can simulate the fatigue crack growth under variable amplitude loading. Additionally, this model is established on the physical state of crack tip in the small spatial and temporal scale, and it is used to evaluate the macroscopic crack propagation and fatigue life under irregular tension-tension loading. A special superimposed loading case is discussed to demonstrate the advantage of the proposed model, while the traditional two-parameter approach is not proper functional. Moreover, the typical various load spectra are also employed to validate the method. Good agreements are observed.

Micro Crack Transverse Propagation Simulation of Carbon Fiber Reinforced Composites

2014 ◽  
Vol 1004-1005 ◽  
pp. 505-508
Author(s):  
Yuan Sha ◽  
Cheng Hong Duan ◽  
Da Huang
Keyword(s):  
Carbon Fiber ◽  
Crack Propagation ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Dissipation Energy ◽  
Crack Propagation Direction ◽  
Carbon Fiber Reinforced Composites ◽  
Carbon Fiber Reinforced ◽  
Transverse Propagation

The XFEM was used to forecast the sub-interface crack propagation paths of carbon fiber reinforced composites, and the simulation results were compared with the SEM photos. The change of strain energy and damage dissipation energy in this process was also investigated. The results indicated that the existence of fiber had a certain influence on the crack propagation direction. And the structure energy changed along with the crack propagation.

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