Effect of Adhesive Thickness and Properties on the Biaxial Interfacial Shear Stresses in Bonded Joints Using a Continuum Mixture Model

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Sayed A. Nassar ◽  
Vinayshankar L. Virupaksha
Keyword(s):  
Material Properties ◽  
Interfacial Shear ◽  
Shear Stresses ◽  
Bonded Joints ◽  
Proposed Model ◽  
Bonded Joint ◽  
Continuum Mixture Model ◽  
Adhesive Thickness ◽  
Adhesive Bonded Joints ◽  
Selection Of

In this work, an analytical model based on continuum mixture theories is developed to study the biaxial interfacial shear stresses in adhesive-bonded joints due to thermomechanical loading. The model predicts the effect of adhesive thickness and properties on the interfacial shear stresses. Two sets of governing partial differential equations are solved for the displacement field in each layer of the joint. The interfacial shear stresses between the adhesive and each adherend are determined using the constitutive equations. Numerical results show that both the adhesive thickness and the material properties have a significant effect on the thermomechanically induced interfacial shear stresses between the adherends and the adhesive. The proposed model inherently has the capacity for optimizing the selection of the adhesive thickness and material properties that would yield a more reliable bonded joint.

The Effect of Geometry and Material Properties on the Load Capacity of Single-Strapped Adhesive Bonded Joints

2008 ◽  
Vol 399 ◽  
pp. 89-96 ◽  
Author(s):  
Marin Sandu ◽  
Adriana Sandu ◽  
Dan Mihai Constantinescu ◽  
Ştefan Sorohan
Keyword(s):  
Adhesive Bonding ◽  
Load Capacity ◽  
Dissimilar Materials ◽  
Adhesive Layer ◽  
Adhesive Bond ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesive Bonded Joints ◽  
Major Factors ◽  
Selection Of

Adhesive bonding is a particularly effective method of assembling complex structures, especially those made from dissimilar materials. If the joint is well designed and correctly executed, the adhesive bond ought to be one of the strongest components of the structure and most certainly should not be the reason for reducing the load capacity or fatigue life. The major factors determining the integrity of an adhesive bond are selection of the most appropriate adhesive, joint design, preparation of the bonding surfaces, strict quality control in production and monitoring in service. This work focuses on the evaluation of the load capacity of some configurations of adhesively bonded single-strapped joints based on finite element analyses. The adhesive layer thickness, the overlap length, the adherent and strap thicknesses were varied as well as the materials properties.

Experimental and Analytical Investigations of the Dynamic Analysis of Adhesively Bonded Joints for Composite Structures

2009 ◽  
Vol 147-149 ◽  
pp. 663-675 ◽  
Author(s):  
S.M. Ghoneam ◽  
A.A. Hamada ◽  
M.I. El-Elamy
Keyword(s):  
Dynamic Analysis ◽  
Composite Structures ◽  
Damping Capacity ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Line Configuration ◽  
Bonded Joint ◽  
Adhesive Bonded Joints ◽  
Adhesively Bonded Joint

Adhesively bonded joints are used extensively in various industries. Some imperfections like holes, thermal residual stresses occurring in the bolted, welded, riveted, and soldered joints don't take place in adhesively bonded joints. Hence, the main advantages of bonded joint are lightness, sealing, corrosion resistance, heat and sound isolation, damping, and quickly mounting facility which have been highly proved. This paper introduces an attempt to study the dynamic analysis of adhesively bonded joint for composite structures to investigate mainly the influences of lamina code number, bonded adhesive line configuration and boundary condition on the dynamic behavior of the test specimens containing composite assembly. The numerical based on the use of finite element model (FEM) modified by introducing unified mechanical properties are represented and applied to compute efficiently the Eigen-nature for composite bonded structures. The experimental tests are conducted to investigate such adhesive bonded joints using two different techniques. The first technique includes an ultrasonic technique in which the magnetostractive pulse echo delay-line for material characterization of composite material is used. The second technique is bassed on the use of the frequency response function method (FRF) applying the hammering method. The comparison between the numerical and experimental results proves that the suggested finite element models of the composite structural beams with bonded joints provide an efficient by accurate tool for the dynamic analysis of adhesive bonded joints. The damping capacity is inversely proportional to the stiffness of the bonded joint specimens. The type of the proportionality depends mainly on the bond line configuration type, lamina orientation, and boundary conditions. This in turn enables an accurate evaluation for selecting the proper characteristics of the specimens for controlling the present damping capacity and the proper resistance against deformation during the operating process. The present study provides an efficient non-destructive technique for the prediction of dynamic properties for an adhesive bonded joint for the studied composite structure systems. The coordination of the experimental and numerical techniques makes it possible to find an efficient tool for studying the dynamic performance of adhesively bonded joint for composite structures.

Stress Determination in an Adhesive Bonded Joint by X-Ray Diffraction

1983 ◽  
Vol 27 ◽  
pp. 251-260 ◽  
Author(s):  
Paul Predecki ◽  
Charles S. Barrett
Keyword(s):  
X Rays ◽  
Bonded Joints ◽  
Lap Joint ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Lap Joint ◽  
Structural Applications ◽  
Bonded Joint ◽  
Adhesive Bonded Joints ◽  
Gain Access

At the present time there is considerable interest in the use of adhesive bonded joints for structural applications. The design of such joints is based mostly on finite element calculations and failure tests rather than on strain or stress measurements. To our knowledge no measurements have been made of stresses at or near the adhesive/adherend interface (where many bond failures occur) because of difficulties with accessibility. The purpose of this work was therefore to try to make such measurements using X-ray diffraction.The approach taken was to gain access to the bond by making one of the adherends in a single lap joint to be relatively transparent to X-rays and the cither relatively opaque. Incident X-rays then penetrated the first adherend and the adhesive and were diffracted from gains in the second adherend adjacent to the adhesive/adherend interface. Stresses resulting from curing of the adhesive were determined first, after which a load was applied and the stresses redetermined.

Bioluminescent proteins prediction with voting strategy.

2020 ◽  
Vol 15 ◽  
Author(s):  
Shulin Zhao ◽  
Ying Ju ◽  
Xiucai Ye ◽  
Jun Zhang ◽  
Shuguang Han
Keyword(s):  
Amino Acid ◽  
Model Building ◽  
Prediction Method ◽  
Pair Composition ◽  
Proposed Model ◽  
Counting Rules ◽  
Significant Phenomenon ◽  
Voting Strategy ◽  
Improved Accuracy ◽  
Selection Of

Background: Bioluminescence is a unique and significant phenomenon in nature. Bioluminescence is important for the lifecycle of some organisms and is valuable in biomedical research, including for gene expression analysis and bioluminescence imaging technology.In recent years, researchers have identified a number of methods for predicting bioluminescent proteins (BLPs), which have increased in accuracy, but could be further improved. Method: In this paper, we propose a new bioluminescent proteins prediction method based on a voting algorithm. We used four methods of feature extraction based on the amino acid sequence. We extracted 314 dimensional features in total from amino acid composition, physicochemical properties and k-spacer amino acid pair composition. In order to obtain the highest MCC value to establish the optimal prediction model, then used a voting algorithm to build the model.To create the best performing model, we discuss the selection of base classifiers and vote counting rules. Results: Our proposed model achieved 93.4% accuracy, 93.4% sensitivity and 91.7% specificity in the test set, which was better than any other method. We also improved a previous prediction of bioluminescent proteins in three lineages using our model building method, resulting in greatly improved accuracy.

scholarly journals Adhesively bonded joints of jute, glass and hybrid jute/glass fibre-reinforced polymer composites for automotive industry

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
H. F. M. de Queiroz ◽  
M. D. Banea ◽  
D. K. K. Cavalcanti
Keyword(s):  
Automotive Industry ◽  
Failure Load ◽  
Natural Fibre ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Reinforced Polymer ◽  
Fibre Composites ◽  
Bonded Joint ◽  
Fibre Reinforced Polymer

AbstractNatural fibre-reinforced composites have attracted a great deal of attention by the automotive industry mainly due to their sustainable characteristics and low cost. The use of sustainable composites is expected to continuously increase in this area as the cost and weight of vehicles could be partially reduced by replacing glass fibre composites and aluminium with natural fibre composites. Adhesive bonding is the preferred joining method for composites and is increasingly used in the automotive industry. However, the literature on natural fibre reinforced polymer composite adhesive joints is scarce and needs further investigation. The main objective of this study was to investigate experimentally adhesively bonded joints made of natural, synthetic and interlaminar hybrid fibre-reinforced polymer composites. The effect of the number of the interlaminar synthetic layers required in order to match the bonded joint efficiency of a fully synthetic GFRP bonded joint was studied. It was found that the failure load of the hybrid jute/glass adherend joints increased by increasing the number of external synthetic layers (i.e. the failure load of hybrid 3-layer joint increased by 28.6% compared to hybrid 2-layer joint) and reached the pure synthetic adherends joints efficiency due to the optimum compromise between the adherend material property (i.e. stiffness and strength) and a diminished bondline peel stress state.

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