Finite Element Simulation of Crack Propagation Under Mixed Mode Loading Condition Using Element Removing Method

2007 ◽  
Vol 345-346 ◽  
pp. 501-504
Author(s):  
H.S. Kim ◽  
K.S. Kim ◽  
Young Seog Lee
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Finite Element Simulation ◽  
Crack Growth ◽  
Failure Criterion ◽  
Mixed Mode ◽  
Loading Condition ◽  
Crack Tip ◽  
Mixed Mode Loading ◽  
Element Simulation

In this study, we introduce an approach which simulates crack propagation under mixedmode loading condition. In comparison with the conventional element removing method which eliminates any element that satisfies a prescribed failure criterion near the crack tip, the present approach selects a set of elements ahead of the crack tip on the crack growth direction and removes them one by one when the element meets a prescribed failure criterion. Compact tension shear (CTS) specimens of type 304 stainless steel were used for failure testing. Finite element simulation has been carried out to simulate crack profiles and compared with observed ones. Results showed the proposed element removing algorithm is useful for crack growth simulation under mixed mode loading condition. The experimentally measured crack growth profile is in an agreement with the predicted ones.

Finite Element Simulation of Stable Fatigue Crack Growth Using Critical CTOD Determined by Preliminary Finite Element Analysis

2014 ◽  
Vol 891-892 ◽  
pp. 1675-1680
Author(s):  
Seok Jae Chu ◽  
Cong Hao Liu
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Finite Element Simulation ◽  
Crack Growth ◽  
Crack Tip ◽  
Stress Intensity Factor Range ◽  
Crack Tip Opening Displacement ◽  
Element Analysis ◽  
Element Simulation

Finite element simulation of stable fatigue crack growth using critical crack tip opening displacement (CTOD) was done. In the preliminary finite element simulation without crack growth, the critical CTOD was determined by monitoring the ratio between the displacement increments at the nodes above the crack tip and behind the crack tip in the neighborhood of the crack tip. The critical CTOD was determined as the vertical displacement at the node on the crack surface just behind the crack tip at the maximum ratio. In the main finite element simulation with crack growth, the crack growth rate with respect to the effective stress intensity factor range considering crack closure yielded more consistent result. The exponents m in the Paris law were determined.

Finite Element Simulation and Comparison of Hydraulic Splitting Fracturing Test of Concrete

2014 ◽  
Vol 678 ◽  
pp. 551-555
Author(s):  
Xue Zhi Wang ◽  
Hao Fei Zou ◽  
Shu Wen Zheng ◽  
Yuan Li ◽  
Jun Yu Liu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Mixed Mode ◽  
Failure Process ◽  
Crack Tip ◽  
Mixed Mode Fracture ◽  
Test Results ◽  
Mode Fracture ◽  
Element Simulation ◽  
Simulation Results

I-II mixed mode fracture under two kinds of load manners was carried out, and it was also simulated by the ANSYS, and the test results and the simulation results were compared and analyzed, and the reasonableness of the model built and the effectiveness of test were verified. The failure process of fracture under the loading could be judged through the development of the crack tip combined with the stress nephogram and strain nephogram when cracks initiation at crack tip, and it provided the basis for the crack damage judgment.

Hybrid Finite-Discrete Element Simulation of Crack Propagation under Mixed Mode Loading Condition

2006 ◽  
Vol 306-308 ◽  
pp. 495-500
Author(s):  
Ahmad Kamal Ariffin ◽  
Syifaul Huzni ◽  
Mohd Jailani Mohd Nor ◽  
Nik Abdullah Nik Mohamed
Keyword(s):  
Crack Propagation ◽  
Mixed Mode ◽  
Loading Condition ◽  
Discrete Element ◽  
Experimental Result ◽  
Mixed Mode Loading ◽  
Discrete Element Simulation ◽  
Element Simulation ◽  
Proposed Model ◽  
Element Method

This paper describes the numerical modeling based on combination of finite element method (FEM) and discrete element method (DEM) has been employed to simulate crack propagation under mixed mode loading. The work demonstrates the ability of combination finitediscrete element method to simulate the crack propagation that is usually performed through, what is termed, transition from continua to discontinua process. Crack propagation trajectory under selected loading angles (30o & 60o) are presented. The result obtained using the proposed model compare well with experimental result.

scholarly journals Adaptive Finite Element Prediction of Fatigue Life and Crack Path in 2D Structural Components

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1316
Author(s):  
Abdullateef H. Bashiri ◽  
Abdulnaser M. Alshoaibi
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Stress Intensity ◽  
Crack Propagation ◽  
Crack Growth ◽  
Mixed Mode ◽  
Equivalent Stress ◽  
Circumferential Stress ◽  
Mixed Mode Loading ◽  
Linear Elastic

The existence of a hole near a growing fatigue crack can cause the crack trajectory to deviate. Unless the hole is too close to the crack, the crack is arrested at the edge of the hole and does not progress further. The purpose of this paper was to predict the crack propagation and lifetime of two-dimension geometries for linear elastic materials in mixed-mode loading using a finite element source code program written in Visual Fortran language. The finite element mesh is generated using the advancing front method. The onset criterion of crack propagation was based on the equivalent stress intensity factor which provides the most important parameter that must be accurately estimated for the mixed-mode loading condition. The maximum circumferential stress theory was used as a direction criterion. The modified compact tension (MCTS) was studied to demonstrate the influence of the hole’s presence on the direction of crack growth and fatigue life for different configurations. The Paris’ law model has been employed to evaluate the mixed-mode fatigue life for MCTS in different configurations under the linear elastic fracture mechanics (LEFMs) assumption. The framework involves a progressive crack extension study of stress intensity factors (SIFs), crack growth direction, and fatigue life estimation. The results show that the fatigue growth was attracted to the hole either changes its direction to reach the hole or floats by the hole and grows as the hole is missed. The results of the study agree with several crack propagation experiments in the literature revealing similar crack propagation trajectory observations.

Cyclic Plasticity of a Cracked Structure Subjected to Mixed Mode Loading

2007 ◽  
Vol 348-349 ◽  
pp. 105-108 ◽  
Author(s):  
Sylvie Pommier
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Crack Tip ◽  
Cyclic Plasticity ◽  
Loading Conditions ◽  
Mixed Mode Loading ◽  
Crack Tip Plasticity

Cyclic plasticity in the crack tip region is at the origin of various history effects in fatigue. For instance, fatigue crack growth in mode I is delayed after the application of an overload because of the existence of compressive residual stresses in the overload’s plastic zone. Moreover, if the overload’s ratio is large enough, the crack may grow under mixed mode condition until it has gone round the overload’s plastic zone. Thus, crack tip plasticity modifies both the kinetics and the crack’s plane. Therefore modeling the growth of a fatigue crack under complex loading conditions requires considering the effects of crack tip plasticity. Finite element analyses are useful for analyzing crack tip plasticity under various loading conditions. However, the simulation of mixed mode fatigue crack growth by elastic-plastic finite element computations leads to huge computation costs, in particular if the crack doesn’t remain planer. Therefore, in this paper, the finite element method is employed only to build a global constitutive model for crack tip plasticity under mixed mode loading conditions. Then this model can be employed, independently of any FE computation, in a mixed mode fatigue crack growth criterion including memory effects inherited from crack tip plasticity. This model is developed within the framework of the thermodynamics of dissipative processes and includes internal variables that allow modeling the effect of internal stresses and to account for memory effects. The model was developed initially for pure mode I conditions. It was identified and validated for a 0.48%C carbon steel. It was shown that the model allows modeling fatigue crack growth under various variable amplitude loading conditions [1]. The present paper aims at showing that a similar approach can be applied for mixed mode loading conditions so as to model, finally, mixed mode fatigue crack growth.

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