Fatigue Life Estimation of Adhesively Bonded Lap Joints

1988 ◽  
Vol 110 (4) ◽  
pp. 350-354 ◽  
Author(s):  
Makato Imanaka ◽  
Yusuke Fukuchi ◽  
Waichiro Kishimoto ◽  
Kozo Okita ◽  
Hideaki Nakayama ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Load Condition ◽  
Tensile Load ◽  
Adhesive Layer ◽  
Maximum Tensile Stress ◽  
Lap Joints ◽  
Thin Wall ◽  
Adhesively Bonded ◽  
Butt Joints

This paper describes a method of estimating the fatigue life of adhesively bonded lap joints on the basis of the stress analysis in adhesive layer with finite element method. First, cyclic tensile fatigue tests were conducted for adhesively bonded lap joints with different lap length and adhesive layer thickness. The results were evaluated from the viewpoint of the maximum values of both tensile and shear stress obtained numerically, instead of the apparent stress. Then these standardized fatigue strength were compared with those of adhesively bonded butt joints of a thin wall tube under cyclic tensile and fully reversed torsional load conditions. The results indicate that fatigue strength of lap joints evaluated from the maximum tensile stress of the adhesive layer agrees well with the fatigue strength of adhesively bonded butt joints of thin wall tube under cyclic tensile load condition. It is confirmed that fatigue strength of lap joints can be estimated adequately based on the fatigue strength of the butt joint of thin wall tube and the numerical results for the stress state of adhesive layer.

Effect of Adhesive Thickness on the Impact Toughness of Butt-Joints

2011 ◽  
Vol 230-232 ◽  
pp. 1350-1354 ◽  
Author(s):  
Min You ◽  
Jing Rong Hu ◽  
Xiao Ling Zheng ◽  
Ai Ping He ◽  
Cun Jun Chen
Keyword(s):  
Impact Toughness ◽  
Adhesive Layer ◽  
Curing Temperature ◽  
Curing Time ◽  
Optimum Thickness ◽  
Adhesively Bonded ◽  
Butt Joints ◽  
Notched Specimen ◽  
Adhesive Thickness ◽  
The Impact

The effect of the adhesive thickness on the impact toughness of the adhesively bonded steel joint under impact loading is studied using the experimental method. The results obtained show that the impact toughness increases when the adhesive thickness increased then it decrease as the adhesive thickness increase. When the curing time is set as a constant, the higher the curing temperature is, the lower the impact toughness of the joint. The optimum thickness of the adhesive layer for the specimen of impact toughness test cured at 60 C for 1 h is 0.6 mm and it is 0.4 mm to 0.6 mm for the specimen cured 1 h at temperature of 90 C or higher than it. It is recommended using the notched specimen to decrease the testing deviation.

scholarly journals Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1437 ◽  
Author(s):  
Yanfeng Zhang ◽  
Zhengong Zhou ◽  
Zhiyong Tan
Keyword(s):  
Composite Materials ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Experimental Result ◽  
Shear Stresses ◽  
Test Results ◽  
Adhesively Bonded ◽  
Finite Element Software ◽  
Joint Structure ◽  
Simulation Results

The performance of joint structure is an important aspect of composite material design. In this study, we examined the compression shear bearing capacity of the adhesively bonded single-lap joint structure of high-temperature-resistant composite materials (C/C composite materials). The test pieces were produced in accordance with the appropriate ASTM C1292 standard, which were used for the compression shear test. The failure morphology of the layer was observed by a digital microscopic system and scanning electron microscope. The experimental result shows that the load on the test piece increased nonlinearly until the failure occurred, and most of the adhesive layer exhibited cohesive failures at three temperature points (400, 600, and 800 °C), while the interface failures occurred in a small part of the adhesive layer. A numerical analysis model was established using ABAQUS finite element software. The simulation results were compared with the test results to verify the correctness of the model. On the basis of correctness of the model verified by comparing the simulation results and the test results, the influences of temperature and overlapped length on the joint compression shear performance were studied through the validated simulation method. Numerical results showed that the ultimate load of the joint decreased with increases in temperature and that the distribution trends of the shear stresses in the overlapped length direction were substantially the same for joints of different overlapped lengths.

Effect of interface non-flatness on the fatigue behavior of adhesively bonded single lap joints

2017 ◽  
Vol 233 (7) ◽  
pp. 1277-1286 ◽  
Author(s):  
SMJ Razavi ◽  
MR Ayatollahi ◽  
M Samari ◽  
LFM da Silva
Keyword(s):  
Fatigue Life ◽  
Bearing Capacity ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Lap Joints ◽  
Lap Joint ◽  
Adhesively Bonded ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Single Lap Joints

This paper addresses numerical and experimental examination of the role of zigzag interface shapes on the load bearing capacity and fatigue life of adhesively bonded single lap joints. Aluminum adherends with non-flat zigzag interfaces were tested under both quasi-static and fatigue loading conditions. The quasi-static test results revealed that the non-flat adhesive joints have higher load bearing capacity compared to the conventional flat single lap joints. Comparative fatigue tests with different loading levels revealed that the non-flat zigzag single lap joint had considerably higher fatigue life than the conventional lap joint.

Simplified stiffness analysis for degraded single lap joints in the space sector – Comparative analytical and finite element analysis

2020 ◽  
Vol 234 (13) ◽  
pp. 1956-1966
Author(s):  
Jannik Zimmermann ◽  
Josef Weiland ◽  
Mohammad Zamaan Sadeghi ◽  
Alexander Schiebahn ◽  
Uwe Reisgen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Ionizing Radiation ◽  
Coefficient Of Thermal Expansion ◽  
Closed Form Solution ◽  
Adhesive Layer ◽  
Lap Joints ◽  
Polymer Chains ◽  
Adhesively Bonded ◽  
European Organization

Considering the aerospace sector, the use of adhesively bonded joints is constantly increasing over the last decades. Due to its lightweight and capability of joining various materials with different coefficient of thermal expansion, this joining technique offers many benefits over conventional methods like rivets, screws and welding. On the other hand, structural adhesives consists of polymer chains that can be severely affected by the environment. An example of such an environmental effect is the interaction of the polymer chains of the adhesive with ionizing radiation in space. Nevertheless in the literature, the influence of ionizing radiation on the mechanical properties of epoxides is covered but not well understood. The present work describes a method of determining the stiffness of an adhesively bonded single lap joint (SLJ) using closed form solution equations. This analytical approach is compared with a numerical model. The mechanical properties of the adhesive in both models is degraded due to irradiation, based on experiments conducted by the European Organization for Nuclear Research (CERN). The results show that the degradation of the mechanical properties of the adhesive layer has a significant influence on the joint stiffness. This effect increases with growing adhesive layer thickness. Comparing the results with a finite element model, it is shown that the developed calculation scheme overestimates the stiffness of the SLJ. This is caused by the neglection of bending stresses within the adherends.

MECHANICAL BEHAVIOR OF ADHESIVELY-BONDED JOINTS UNDER HIGH LOADING RATES

2021 ◽  
Author(s):  
MEHMET EMIN ERCAN ◽  
FERHAT KADIOGLU
Keyword(s):  
Adhesive Layer ◽  
Experimental Tests ◽  
Lap Joints ◽  
Adhesively Bonded ◽  
Case Scenario ◽  
Worst Case ◽  
Adhesive Film ◽  
Package Program ◽  
Set Up ◽  
Static Conditions

This work aims to investigate the dynamic behavior of adhesively-bonded Single Lap Joints (SLJs) under ballistic conditions. For this purpose, the joints with clamped-clamped boundary conditions were modelled using a Finite Element Method (FEM) via ABAQUS package program. The numerical model is based on the joint subjected to a projectile with a mass of 1.25 gr, a density of 11.3 gr/cm3, and an impacting velocity of 100 m/s. The experimental tests conducted in a specially designed set-up were performed via an air-pressurized gun. 6061 aluminum adherends and an adhesive film were used to manufacture the bonded structure. Curves of the velocity and dynamic load against time were predicted for the joint under the impacting projectile. Failure and stress distributions in the adherend as well as in the adhesive layer were predicted that was validated via the experimental results. The prediction was made according to the worst case scenario that accounts the input data obtained from the quasi-static conditions.

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