Experimental and numerical investigation of fatigue crack growth in aluminum plates repaired by FML composite patch

2014 ◽  
Vol 5 (4) ◽  
pp. 242-252 ◽  
Author(s):  
M. Rahmani Kalestan ◽  
H. Moayeri Kashani ◽  
A. Pourkamali Anaraki ◽  
F. Ashena Ghasemi
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Strength ◽  
Notched Specimen ◽  
Content Type ◽  
Composite Patch ◽  
Crack Angle

Purpose – The purpose of this paper is to use the fiber metal laminates (FML) composites as a patch for repairing a single notched specimen made of AL1035 aluminum alloy. The FML composite patch was bonded on one side of the cracked specimens by adhesive Araldite 2015. Then the fatigue crack growth tests were conducted on the specimens and the effects of both FML patch lay-up sequence and pre-crack angle on the fatigue life were investigated. Finally, the effect of repairing on the fracture parameters (SIF and crack propagation direction) at the crack front has also been calculated using three-dimensional finite element analysis. Design/methodology/approach – The fatigue crack growth tests were conducted on the specimens and the effects of both FML patch lay-up sequence and pre-crack angle on the fatigue life were investigated. Findings – The results show that the fatigue life of the patched specimens with inclined crack increased approximately 2-6.02 times compared to the un-patched specimens. In addition, the fatigue crack growth rate decreased significantly when the patch was used. Generally, the FML patch with Plate-Fiber-Fiber-AL lay-up has more efficiency than other lay-up sequences. Originality/value – Recently, composite patches are used in the structure repair processes to increase the service life of cracked components. The bonded patch method is one of the efficient methods among repairing methods. Today, the FMLs are used in the aircraft structures as a replacement of high-strength aluminum alloys due to their lightweight and high-strength properties. Many researches have been performed on single and double side repaired panels using composite patches. In this study, the FML composites have been used as a patch for repairing a single notched specimen made of AL1035 aluminum alloy.

Evaluation of the Compatibility of High-Strength Aluminum Alloy 7075-T6 to High-Pressure Gaseous Hydrogen Environments

2018 ◽  
Author(s):  
Yuhei Ogawa ◽  
Dain Kim ◽  
Hisao Matsunaga ◽  
Saburo Matsuoka
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Strength ◽  
Gaseous Hydrogen ◽  
Aluminum Alloy 7075

To develop safer and more cost-effective high-pressure hydrogen tanks used in fuel cell vehicles (FCVs), the metallic materials with the following three key properties, i.e. lightweight, high strength and excellent resistance to hydrogen embrittlement should be explored. In this study, the compatibility of high-strength, precipitation-hardened aluminum alloy 7075-T6 was evaluated according to the four types of mechanical testing including slow-strain rate tensile (SSRT), fatigue life, fatigue crack growth (FCG) and fracture toughness tests in high-pressure gaseous hydrogen environments (95 ∼ 115 MPa) at room temperature. Even though numerous publications have previously reported significant degradation of the mechanical properties of 7075-T6 in some hydrogenating environments, such as moist atmosphere, the understanding with regards to the performance of this alloy in high-pressure gaseous hydrogen environments is still lacking. In SSRT tests, the alloy showed no degradation of tensile strength and ductility. Furthermore, fatigue life, fatigue crack growth and fracture toughness properties were also not degraded in hydrogen gas. Namely, it was first demonstrated that the material has big potential to be used for hydrogen storage tanks for FCVs, according to its excellent resistance to high-pressure gaseous hydrogen.

Micromechanisms of multistage fatigue crack growth in a high-strength aluminum alloy

2007 ◽  
Vol 55 (6) ◽  
pp. 1975-1984 ◽  
Author(s):  
Y. Xue ◽  
H. El Kadiri ◽  
M.F. Horstemeyer ◽  
J.B. Jordon ◽  
H. Weiland
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Strength ◽  
High Strength Aluminum Alloy

scholarly journals Fatigue crack growth in aluminum alloy from cold expanded hole with preexisting crack

2020 ◽  
Vol 99 (3) ◽  
pp. 5-16
Author(s):  
P. Yasniy ◽  
O. Dyvdyk ◽  
O. Semenets ◽  
V. Yasnii ◽  
A. Antonov
Keyword(s):  
Growth Rate ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Residual Lifetime ◽  
Aircraft Structure ◽  
Edge Notch

The fatigue life of aircraft structure elements with operational damage in the vicinity of the hole was investigated. The plates 60 mm wide and 6 mm thick made of D16chT aluminum alloy with a central hole were taken for the study. Fatigue damage was examined with an corner quarter-elliptical fatigue crack with a length of 1,25 mm, which was initiated from an edge notch of 0,5 x 0,5 mm. The fatigue crack growth rate on the surface of the plate after mandrel hole with cold expansion degree i = 2,7% increases up to15 times and residual lifetime in three times compared to the virgin plate.

Fatigue Crack Propagation Experiment and Simulation on 7050 Aluminum Alloy

2011 ◽  
Vol 464 ◽  
pp. 560-563
Author(s):  
Xu Dong Ren ◽  
Yong Zhuo Huangfu ◽  
Yong Kang Zhang ◽  
Da Wei Jiang ◽  
Tian Zhang
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
7050 Aluminum Alloy ◽  
Shock Processing

In this paper, an experiment of fatigue crack propagation in 7050 aluminum alloy was presented. Laser shock processing (LSP) is used to shock the crack surface. Compared with the specimen without LSP, the fatigue life after LSP increased greatly. The simulation of the fatigue crack growth in 7050 aluminum alloy is implemented in FRANC2D. Simulating result is in accordance with the result of the experiment well. Laser shock processing increases the fatigue life and reduce fatigue crack growth rate, it has good prospect on the study of crack arrestment.

Influence of Secondary Ageing on Fatigue Crack Propagation of the AA7050 Aluminum Alloy

2014 ◽  
Vol 891-892 ◽  
pp. 1816-1821
Author(s):  
Sheila Cristina Jacumasso ◽  
Luis Otavio Ribas Lima ◽  
Juliana Paula Martins ◽  
André Luis Moreira Carvalho
Keyword(s):  
Heat Treatment ◽  
Growth Rate ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Strength ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Precipitation Hardening ◽  
Solution Treatment ◽  
High Strength

The AA7050 aluminum alloy is widely used due to its low specific combined with high strength and toughness obtained from the heat treatment which involves solution treatment and ageing. It produces the mechanism of precipitation hardening of a thin phase and disperses. In this context, the present study to investigated three ageing treatments, their influence on fatigue crack growth. In order to find a better condition of precipitation of η' phase, which may increase resistance to fatigue crack growth of AA7050 aluminum alloy. The T614-65 condition was chosen as an alternative treatment in relation to T7451 and T6 conditions of current use in the industry. The fatigue crack growth rate results have shown that T614-65 fatigue strength were up to 14% higher than the shown for T7451 temper.

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