SIMULATION OF JOINT STRENGTH OF SINGLE LAP JOINT OF COMPOSITE PLATES BASED ON VARIATIONS OF PLATE THICKNESS AND OVERLAP LENGTH

In this study, in situ monitoring of single lap joint of woven glass fabric reinforced epoxy composites modified with multi-walled carbon nanotubes (MWCNTs) is presented. Woven glass fibre reinforced/epoxy composite plates modified with 3% wt. highly electrically conductive MWCNTs were manufactured by hand lay-up process for obtaining adherends. MWCNTs were used in 1% and 2% by weight in order to investigate the effect of the MWCNTs level on the shear lap joint strength and the self-sensing sensitivity of bonded area. One, four, and seven plies of adhesive woven cloths were employed for bonding adherends to examine the thickness effect on both the shear lap joint strength and the self-sensing sensitivity of bonded area. In order to provide low electrical contact resistance, woven carbon fibres were placed on the top and bottom of the glass fibre layer during production. Results indicate that the health monitoring of lap joints in the woven glass reinforced epoxy composites can be successfully achieved.

Download Full-text

Free Vibration Analysis and Design of an Adhesively Bonded Composite Single Lap Joint

Volume 1: Advances in Aerospace Technology ◽

10.1115/imece2007-41378 ◽

2007 ◽

Author(s):

M. Kemal Apalak ◽

Recep Ekici ◽

Mustafa Yildirim

Keyword(s):

Fiber Volume Fraction ◽

Natural Frequencies ◽

Volume Fraction ◽

Plate Thickness ◽

Mode Shapes ◽

Lap Joint ◽

Adhesively Bonded ◽

Fiber Volume ◽

Fiber Angle ◽

Single Lap Joint

In this study the three dimensional vibration analysis of an adhesively bonded cantilevered composite single lap joint was carried out. The first four bending natural frequencies and mode shapes were considered. The back-propagation Artificial Neural Network (ANN) method was used to determine the effects of the fiber angle, fiber volume fraction, overlap length and plate thickness on the bending natural frequencies and the mode shapes of the adhesive joint. The bending natural frequencies and modal strain energies of the composite adhesive lap joint were calculated using the finite element method for random values of the fiber angle, the fiber volume fraction, the overlap length and the plate thickness. Later, the proposed neural network models were trained and tested with the training and testing data. The fiber angle was more dominant parameter than the fiber volume fraction on the natural bending frequencies and corresponding bending mode shapes, and the plate thickness and the overlap length were also important geometrical design parameters whereas the adhesive thickness had a minor effect. In addition, the present ANN models were combined with Genetic Algorithm to search a joint design satisfying maximum natural frequency and minimum modal strain energy conditions for each natural bending frequency and mode shape.

Download Full-text

Study on the Adhesive Joint Strength of 2060-T8 Al–Li Alloy Single Lap Joint with Different Adhesives

Frontiers in Materials Processing, Applications, Research and Technology ◽

10.1007/978-981-10-4819-7_22 ◽

2017 ◽

pp. 257-267

Author(s):

Xiaohong Zhan ◽

Cheng Gu ◽

Hongliang Wu ◽

Hongbing Liu ◽

Jie Chen ◽

...

Keyword(s):

Adhesive Joint ◽

Joint Strength ◽

Lap Joint ◽

Single Lap Joint

Download Full-text

JOINT STRENGTH OF MIXED SILYL MODIFIED POLYMER-EPOXY ADHESIVE ON SINGLE LAP JOINT ETCHED ALUMINUM

Jurnal Teknologi ◽

10.11113/jt.v79.11873 ◽

2017 ◽

Vol 79 (7-2) ◽

Cited By ~ 1

Author(s):

Sri Hastuti ◽

Neng Sri Suharty ◽

Triyono Triyono

Keyword(s):

Failure Mode ◽

Adhesive Joint ◽

Joint Strength ◽

Epoxy Adhesive ◽

Experimental Result ◽

Aluminum Surface ◽

Lap Joint ◽

Single Lap Joint ◽

Modified Polymer ◽

Bus Body

Currently, aluminum alloy is widely used in an automotive structure such as bus body materials due to decreasing the structure weight and fuel consumption. In this structure, there are tens or even hundreds of joints to meet the engineering design. Because of its advantages, the adhesive joint is usually chosen. Aluminum is stiff enough, but it can deform easily. Due to its deformability, cracks will occur easily on the aluminum adhesive joint if it is joined using strong and stiff adhesive. Otherwise, it will be very weak if it is joined using flexible adhesive. The mixture of the strong adhesive, epoxy (EP) and the ductile adhesive, silyl modified polymer (SMP) was proposed for joining aluminum. This study aims to evaluate the effect of the composition of mixed adhesive and its thickness on the strength of single lap joint (SLJ) etched aluminum. Before joining process, the aluminum surface was treated by sandpapering (SDP), and then chromic-sulphuric acid (CSA) etch. The composition variations of mixed adhesive were 100%EP, 75%SMP:25%EP, 50%SMP:50%EP, 25%SMP:75%EP, and 100%SMP. Mixed adhesives were prepared by using a stirrer with a spatula for 4-6 minutes at 60 rpm. SLJ specimens were manufactured through bonding of two aluminum sheets surface with an adhesive and giving 0.1 MPa pressure. The thickness adhesive was varied of 0.2 mm, 0.4 mm, and 0.6 mm. Specimens got a post-curing process at 100oC for 100 minutes. The shear tests were performed to evaluate the strength of SLJ. The experimental result showed that the surface treatments of SDP and CSA give higher porosity on the adherend surface. The highest strength and elasticity modulus were achieved by joint of 25%SMP:75%EP mixed adhesive joints. The addition a few of SMP adhesive in EP adhesive and adherend surface treatment increases the joint strength. All of the joints have mixed failure mode except the 100%EP adhesive joint has an adhesive failure mode.

Download Full-text

STRESS DISTRIBUTION OF SECONDARY BENDING IN SINGLE-LAP BOLTED JOINTS WITH DISSIMILAR JOINING PLATES AND PLATE TYPES

Jurnal Teknologi ◽

10.11113/jt.v78.8567 ◽

2016 ◽

Vol 78 (5-5) ◽

Author(s):

Hilton Ahmad

Keyword(s):

Fuel Efficiency ◽

Plate Thickness ◽

Stress Gradient ◽

Lap Joints ◽

Lap Joint ◽

Single Lap Joints ◽

Single Lap Joint ◽

Joint Construction ◽

Composite Joint ◽

Composite Steel

Single-lap joints are an important class of bolted joint in the aerospace and civil engineering sectors. This type of joint is preferred as it can reduce weight and hence help to optimize fuel efficiency. However, bolted single-lap joints exhibit secondary bending due to eccentricity of the applied loads. Flexural of plates during tensile loading alters the contact regions in the single-lap joint significantly, resulting in more non-linear behaviour and a stress gradient across the plate thickness. 3-D bolted single-lap joint were modelled in ABAQUS CAE incorporating the effect of the bolt tension from application of a tightening torque. Current 3-D model used elastic properties based on smeared-out properties, the effect of joint construction is considered further by examining the stress in a composite-composite joint and comparing with a composite-steel joint. In a related investigation the effect of varying composite thickness in the composite-steel joints is also studied.

Download Full-text