Fatigue Crack Growth In T-Joints; Out-Of-Plane Bending

2004 ◽

Vol 126 (2) ◽

pp. 192-198 ◽

Cited By ~ 9

Author(s):

C. N. Duong ◽

C. H. Wang

Keyword(s):

Fatigue Crack ◽

Stress Intensity ◽

Fatigue Crack Growth ◽

Crack Growth ◽

Stress Intensity Factors ◽

Load Path ◽

Intensity Factors ◽

Analytical Work ◽

Out Of Plane ◽

Plane Bending

An unsupported cracked plate repaired with a reinforcement bonded on one side may experience considerable out-of-plane bending due to the load-path eccentricity. This out-of-plane bending causes the stress intensity factor at the crack tip to vary significantly through the plate’s thickness with a maximum value attained at the un-patched side of the crack. Even though significant analytical work has been done in the past to evaluate these thickness-varying stress intensity factors, however, to the authors’ knowledge, little work has been done to characterize the fatigue crack growth in a plate with a single-sided repair. The purposes of the present work are to (i) assess the accuracy of the available analytical methods for predicting the stress intensity factors of the panels with a single-sided repair and more importantly, and (ii) characterize the fatigue crack growth in these panels, using test results generated recently under the Composite Repair of Aircraft Structures (CRAS) program.

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Modeling fatigue crack growth for a through thickness crack: An out-of-plane constraint-based approach considering thickness effect

International Journal of Mechanical Sciences ◽

10.1016/j.ijmecsci.2020.105625 ◽

2020 ◽

Vol 178 ◽

pp. 105625 ◽

Cited By ~ 1

Author(s):

He Liu ◽

Xiaoguang Yang ◽

Shaolin Li ◽

Duoqi Shi ◽

Hongyu Qi

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Growth ◽

Thickness Effect ◽

Out Of Plane

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A New Approach for Modeling of Fatigue Crack Growth in Welded Cruciform and Curve T Joint Structures

Applied Mechanics ◽

10.1115/imece2005-81535 ◽

2005 ◽

Author(s):

Mohammad S. Alam ◽

Muhammad A. Wahab

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Propagation ◽

Crack Growth ◽

Bonding Strength ◽

Computer Time ◽

Interface Element ◽

Interface Debonding ◽

T Joints ◽

New Approach

A new approach for the simulation of fatigue crack growth in welded joint has been developed and the concept has been applied to welded cruciform and curve T-joints. The phenomena of crack propagation and interface debonding can be regarded as the formation of new surface. Thus, it is possible to model these problems by introducing the mechanism of surface formation. In the proposed method, the formation of new surface is represented by interface element based on the interface potential energy. The properties of this interface element represent the bonding strength of the material. As the cyclic load continues, the bonding strength decreases between the interacting surfaces and the crack propagates slowly. Based on this concept, an ANSYS code has been written for the simulation of crack propagation. Using this code, fatigue crack growth rate and fatigue crack propagation life of 2-D FEM models of welded cruciform and curve T-joints for different stress/load ratios have been analyzed and presented in this paper. The method is relatively simple compared to other conventional FEM method and save computer time significantly. The predicted results are compared with experimental results and good agreement has been achieved.

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