[PDF] Effect Of Preforming Adherends On Static And Fatigue Strength Of Bonded Composite Single Lap Joints eBook

Author : James Wayne Sawyer
Publisher :
Page : 24 pages
File Size : 12,4 MB
Release : 1984
Category : Joints (Engineering)
ISBN :

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An analytical and experimental investigation was conducted on bonded composite single-lap joints with the adherends preformed to reduce the angle between the line of action of the applied in-plane force and the bondline. A classical closed-form solution was used to analyze the composite joints with various preform angles and overlap lengths. The adherends of the test specimens were preformed before bonding, during the layup and curing process. Static tests were conducted for preform angles of 0 deg, 5 deg, 10 deg, and 15 deg and overlap lengths of 0.75, 1.75, 2.75, and 3.75 in. A limited fatigue study was conducted for specimens with a 2.75-in. overlap and a preform angle of 5 deg. Results of the analysis showed that preforming the adherends of bonded composite single-lap joints significantly reduced the shear and peel stress concentrations in the adhesive. Experimental results showed that preforming the adherends significantly increased their static and fatigue strength and thus increased the load level for which bonded composite single-lap joints can be designed. (MM).

Author : Mariam Majid
Publisher :
Page : 0 pages
File Size : 48,30 MB
Release : 2018
Category :
ISBN :

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The scope of this research is limited to develop fundamental knowledge on mechanically bolted, adhesively bonded, and hybrid SLJ mechanism and provide knowledge of the know-how of joining similar and dissimilar adherends of AA7075 and GRE composites. Thus, new mechanical fasteners have been introduced and explored the mechanical strength on the joining that will provide affordable techniques when joining the materilas. The materials adherendsof GRE were fabricated with a vacum infusion technique (VIT) and single GRE composite dumbbell shape was examined to obtain the mechanical properties for overlap length (bond length) determination. The tensile testing method for the GRE composites dumbbell shape was in accordance with the ASTM D638 standard. The specimen used in the experiment was exposed in two conditions, dry (RT) and wet for SLJ specimens. Under wet condition, the adhesively bonded and hybrid SLJ specimens were hydrothermally aged in the tap water. In order to estimate their long-term performance, an ageing process was performed on both joint configuration at constant water temperature of 50 C with variable immersion periods (20, 40, 60, 80, 100 and 120 days). Experimental tests were perfomed under tensile load to evaluate the ultimate tensile strength to be used for fatigue resistance of mechanically bolted, adhesively bonded and hybrid SLJs for both conditions. Different amplitude ranges of 30, 40, 50, 60, 70, 80 and 90% and constans stress ratio, R=0.1, were implemented. Meanwhile, the frequency of 5Hz was used on fatigue testing. The fatigue testing. The fatigue test was performed to obtain the S-N and fatigue crack/propagation before and after being exposed to the environmental effects of water absorption.

Author : W. James Renton
Publisher :
Page : 69 pages
File Size : 18,61 MB
Release : 1978
Category :
ISBN :

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Recent experiments have shown that significant improvements can be made in the structural efficiency of single lap joints through several modifications. Tests have been conducted in which the adherends were linearly tapered from full panel thickness to practically zero thickness over the length of the bondline in the load direction. Further, tests were conducted to examine the effects of introducing small grooves on the adhesive side of the adherends, perpendicular to the load direction. Similarly, grooves only over the thicker half of the tapered adherend were investigated, because these grooves do introduce stress concentrations. In each case, significant improvements in joint efficiency were made under either static or fatigue loadings. Additionally, specific observations are made pertaining to the residual strain effect due to joint fabrication on the fatigue life of strain effect due to joint fabrication on the fatigue life of the joint. Second, studies were made on the effects of using hybrid adherends and their effect on joint efficiency.

Author : Raul D. S. G. Campilho
Publisher : CRC Press
Page : 670 pages
File Size : 43,27 MB
Release : 2017-05-25
Category : Science
ISBN : 1315353687

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Adhesively-bonded joints provide many advantages over conventional mechanical fasteners and are increasingly receiving attention as an alternative to mechanical joints in engineering applications. The traditional fasteners usually result in the cutting of fibers and hence the introduction of stress concentrations, both of which reduce structural integrity. By contrast, bonded joints are more continuous and have potential advantages of strength-to-weight ratio, design flexibility, and ease of fabrication. This book provides an overview of available analytical methods as well as numerical methods.

Author :
Publisher :
Page : 155 pages
File Size : 31,81 MB
Release : 2019
Category : Adhesive joints
ISBN :

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Adhesively bonded joints provide several benefits, such as uniform stress distribution than conventional methods such as mechanical fastening. Hence, the knowledge of stresses inside the adhesive layer of an adhesively-bonded joint is essential for design analysis and joint strength prediction. In this thesis, the effect of strain rate on adhesively bonded single lap joints of similar and dissimilar adherends (Aluminum and Carbon fiber composites) with a number of adhesives was investigated.