Comparative study on mechanical properties of aluminum alloy and BFRP single lap joints with hygrothermal aging

The influence of both preload and the presence of shim types on the mechanical properties of composite-aluminium single-bolt, single-lap joints were studied in this paper. The load-displacement curve and surface strain field of joints in different shim types and preloads were obtained through tensile experiments. A progressive damage model was established using the UMAT subroutine in ABAQUS. A hybrid failure criterion and a linear continuous degradation model were used to describe the progressive damage of composite laminates. The results show that for joints with no shim and for those with various types of shims, the tensile stiffness, peak load and initial damage load could be reduced when the preload is insufficient or too large. Compared with joints with no shims or with peelable fibreglass shims, joints with liquid shims required a larger preload to achieve the best mechanical properties. As the proportion of peelable fibreglass shim increased, the tensile stiffness and peak load continued to increase in joints with a mixed shim of liquid and peelable fiberglass shim. Shims can serve as tension bearings, but have little effect on the initiation and development of bearing failure.

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Microscale Evaluation of Mechanical Properties and the Interfacial Microstructures of Friction Stir Welded Aluminum Alloy/Stainless Steel Dissimilar Lap Joints

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.2786 ◽

2014 ◽

Vol 783-786 ◽

pp. 2786-2791 ◽

Cited By ~ 4

Author(s):

Tomo Ogura ◽

Taichi Nishida ◽

Hidehito Nishida ◽

Mitsuo Fujimoto ◽

Akio Hirose

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Aluminum Alloy ◽

Aluminum Matrix ◽

Amorphous Layer ◽

Interfacial Microstructure ◽

Lap Joints ◽

Friction Stir ◽

Microtensile Test ◽

Alloying Effects

The mechanical properties and interfacial microstructure of slices of friction stir welded aluminum alloy/stainless steel dissimilar lap joints were characterized. In an FSWed A3003 aluminum alloy/SUS304 steel lap joint, the strength on the advancing side was larger than that at the retreating side. TEM observation indicated that a sound joint that fractured at the base metal can be obtained from the stage of the formation of the amorphous layer owing to the mechanical alloying effects before the formation of intermetallic compounds. This lap joining technique was also successfully applied to A6061/T6 aluminum alloy-grooved SUS304 plates. Equiaxed aluminum grains were observed at the interface of the specimen after it was fractured, indicating that the interface deformed only slightly during the microtensile test. It was found that tensile strength of the joint was increased by aging at 433K, considering that precipitation occurred at this temperature. In addition, it was confirmed that the joint heated at 723K for 1.8ks still fractured at the aluminum matrix, assuming that intermetallic layers at the interface would slightly grow in this heating condition.

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Analysis and modelling of fatigue failure of friction stir welded aluminum alloy single-lap joints

Engineering Fracture Mechanics ◽

10.1016/j.engfracmech.2007.04.013 ◽

2008 ◽

Vol 75 (3-4) ◽

pp. 790-803 ◽

Cited By ~ 39

Author(s):

D. Fersini ◽

A. Pirondi

Keyword(s):

Aluminum Alloy ◽

Fatigue Failure ◽

Lap Joints ◽

Friction Stir ◽

Single Lap Joints

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Effect of Recessing in Bondline on Stress in Co-Axial Lap Joint

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.952 ◽

2010 ◽

Vol 97-101 ◽

pp. 952-955

Author(s):

Xiao Ling Zheng ◽

Mei Rong Zhao ◽

Min You ◽

Zhi Li ◽

Jia Ling Yan

Keyword(s):

Finite Element Method ◽

Aluminum Alloy ◽

Elastic Modulus ◽

Middle Part ◽

Lap Joints ◽

Lap Joint ◽

Single Lap Joints ◽

Single Lap Joint ◽

Significant Difference ◽

Peel Stress

The effect of recessing on the stresses distributed along the mid-bondline in both standard single lap joints and co-axial ones were analyzed using elasto-plastic finite element method (FEM). The results obtained show that the values of the peak stresses of all the stresses distributed in the mid-bondline were changed greatly as the preformed angle in over lap zone was about 10 0 when the high elastic modulus adhesive is used. The effect of the elastic modulus level on the stress distribution (especially the peak stresses) is small in the middle part of the lap zone. When taken the stress distributed in the middle part of the lap zone into account, there is nearly no significant difference between the peel stress distributed in the standard joint and co-axial single lap joint when the adhesives with lower elastic modulus was used. It is recommended that a co-axial joint is suitable for the recessing joint made by aluminum alloy and a higher elastic modulus adhesive.

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