Effect of Interference-Fit on Fatigue Life for Composite Lap Joints

2014 ◽  
Vol 939 ◽  
pp. 39-46 ◽  
Author(s):  
Hong Qian Xue ◽  
Qian Tao ◽  
Emin Bayraktar
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Tests ◽  
Lap Joints ◽  
Finite Element Simulations ◽  
Cyclic Loads ◽  
Lap Joint ◽  
Interference Fit ◽  
3D Finite Element ◽  
Double Shear

The aim of this study is to examine the effect of the clearance and interference-fit on the fatigue life of composite lap joints in double shear, 3D finite element simulations have been performed to obtain stress (or strain) distributions around the hole due to interference fit using FEM package, Non-linear contact analyses are performed to examine the effects of the clearance and interference for titanium and composite lap joint. Fatigue tests were conducted for the titanium and composite lap joints with clearance fit and interference fit with 0.5, 1, and 1.5% nominal interference fit levels at different cyclic loads. The results shows that interference fit increases fatigue life compared to clearance fit specimens, the titanium and composite lap joint with 1% interference fit level has the better fatigue life.

Effect of different temperatures on the fatigue behavior of interference fitted plates of Al-alloy 7075-T6

2017 ◽  
Vol 233 (7) ◽  
pp. 1324-1335
Author(s):  
H Taghizadeh ◽  
TN Chakherlou
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Thermal Cycle ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Al Alloy ◽  
Interference Fit ◽  
Short Period ◽  
Different Temperatures

The effect of short time exposure to thermal cycle on the fatigue life of interference fitted fastener holes was evaluated by experimental and numerical method in Al-alloy 7075-T6. When interference fitted holes are subjected to temperature, the pre-stresses produced by interference fit may be considerably redistributed. To investigate the pre-stresses redistribution and its effect on the fatigue life of interference fitted specimens, two different temperatures (i.e. 60 ℃ and 120 ℃), apart from room temperature, were selected. The fatigue tests were performed to obtain S–N curves. Tangential pre-stress distribution was analyzed by the finite element method. Three-dimensional stress distributions of interference fit process have been determined around the hole at three temperatures: 25 ℃, 60 ℃, and 120 ℃. The finite element analyses justify the experimentally observed fatigue test behavior. The results show that the short period thermal cycle could improve the fatigue life of the prepared samples.

Effect of bolt tightening on the fatigue behavior of GLARE double shear lap joints

2021 ◽  
pp. 002199832110033
Author(s):  
B Abazadeh ◽  
HR Maleki
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Lap Joints ◽  
Clamping Force ◽  
Test Results ◽  
Load Range ◽  
Double Shear ◽  
Aluminum Sheets ◽  
Aluminum Alloy 2024

In this paper, the effect of bolt torque tightening has been investigated on the fatigue behavior of GLARE in double shear lap configuration. To do so, experimental fatigue tests were conducted using GLARE3-5/4-0.4 specimens with applied torques of 0 (finger tightened), 2 and 4 Nm at different cyclic longitudinal load ranges to achieve the stress-life (S-N) curves. The results revealed that applying and increasing the clamping force enhances the fatigue life of the GLARE specimens. Furthermore, comparison of fatigue test results of GLARE and available monolithic aluminum alloy 2024-T3 plates indicated when the applied load range is low, the effect of clamping force is more noticeable in GLARE specimens due to longer fatigue crack growth life of GLARE. Also, the occurrence of fretting fatigue didn’t reduce the fatigue life of GLARE specimens considerably in contrary to aluminum sheets because of the laminated structure of GLARE. The obtained results can provide insights in designing bolted GLARE joints with superior fatigue in-service performance.

Fatigue behavior of interference fitted Al-alloy 7075-T651 specimens subjected to bolt tightening

2018 ◽  
Vol 233 (9) ◽  
pp. 1879-1893
Author(s):  
H Taghizadeh ◽  
TN Chakherlou
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Test ◽  
Failure Modes ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Al Alloy ◽  
Clamping Force ◽  
Interference Fit ◽  
Test Behavior

Interference fit process is extensively used in bolted and pined joints having different fatigue behavior compared to plain hole specimens. In the present research, fatigue behavior of interference fitted specimens subjected to bolt clamping force has been investigated. The objective of the present study is to extend the present knowledge about the fatigue behavior of interference fitted holes by investigating the subsequent bolt clamping force effect based on the experimental and numerical results in Al-alloy 7075-T651 plates. To investigate the effect of bolt tightening on the fatigue life of interference fitted specimens two tightening torque levels were employed. Fatigue tests were performed to obtain S–N curves and failure modes of interference fitted bolt clamped specimens. Circumferential pre-stress distribution created by interference fit and bolt clamping has been analyzed by finite element method. The finite element analyses justify the experimentally observed fatigue test behavior. The fatigue test results demonstrate that bolt clamping force applied on interference fit plays a positive effect on fatigue behavior and prolongs the fatigue life.

Improving Fatigue Life of Riveted Joints by Rivet Hole Sizing

2014 ◽  
Vol 598 ◽  
pp. 141-146
Author(s):  
Adam Lipski ◽  
Zbigniew Lis
Keyword(s):  
Fatigue Life ◽  
Fold Increase ◽  
Fatigue Tests ◽  
Aviation Industry ◽  
Lap Joint ◽  
Riveted Joints ◽  
Riveting Process ◽  
The Difference ◽  
Structural Connection ◽  
The Impact

The aim of this paper is to assess the impact of the rivet hole sizing process on the fatigue life based on the example of the structural connections characteristic for riveted joints used in aviation industry. Test specimens reflected the structural connection consisting in a riveted lap joint of an airplane plating stiffened with a T-bar. Connected plates and the T-bar are made of D16CzATW aluminum alloy. 3 mm diameter oval head solid rivets for aviation-related purposes were made of PA24 aluminum. During fatigue tests, individual specimens with non-sized holes and with sized holes were subjected to uniaxial, one-sided, fixed-amplitude loading (R = 0). It can be concluded from the fatigue life comparison that introduction of an additional operation in the riveting process, i.e. the hole sizing, results in significant, about two-fold increase of the fatigue life of the riveted structural connection, even at slight sizing degree. The difference of the specimen damage nature was observed between specimens with sized and non-sized holes.

scholarly journals 3D finite element simulations of high velocity projectile impact

2015 ◽  
Vol 94 ◽  
pp. 04029
Author(s):  
Joško Ožbolt ◽  
Barış İrhan ◽  
Daniela Ruta
Keyword(s):  
Finite Element ◽  
High Velocity ◽  
Finite Element Simulations ◽  
3D Finite Element ◽  
Projectile Impact

A Hybrid Supervised Deep Learning and Nonlinear Finite Element Framework for Efficient Fatigue Life Predictions of Rotary Shouldered Threaded Connections

2020 ◽  
Author(s):  
Fei Song ◽  
Ke Li
Keyword(s):  
Finite Element ◽  
Deep Learning ◽  
Fatigue Life ◽  
Learning Algorithm ◽  
Fatigue Tests ◽  
Full Scale ◽  
Remaining Useful Life ◽  
Nonlinear Finite Element ◽  
Threaded Connections ◽  
Life Predictions

Abstract In this paper, a hybrid computational framework that combines the state-of-the art machine learning algorithm (i.e., deep neural network) and nonlinear finite element analysis for efficient and accurate fatigue life prediction of rotary shouldered threaded connections is presented. Specifically, a large set of simulation data from nonlinear FEA, along with a small set of experimental data from full-scale fatigue tests, constitutes the dataset required for training and testing of a fast-loop predictive model that could cover most commonly used rotary shouldered connections. Feature engineering was first performed to explore the compressed feature space to be used to represent the data. An ensemble deep learning algorithm was then developed to learn the underlying pattern, and hyperparameter tuning techniques were employed to select the learning model that provides the best mapping, between the features and the fatigue strength of the connections. The resulting fatigue life predictions were found to agree favorably well with the experimental results from full-scale bending fatigue tests and field operational data. This newly developed hybrid modeling framework paves a new way to realtime predicting the remaining useful life of rotary shouldered threaded connections for prognostic health management of the drilling equipment.

Effect of specimen crack lengths on stress intensity factor for Al6061-TiC composites using experimental and 3D numerical methods

2017 ◽  
Vol 8 (5) ◽  
pp. 506-515 ◽  
Author(s):  
Raviraj M.S. ◽  
Sharanaprabhu C.M. ◽  
Mohankumar G.C.
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Length ◽  
Finite Element Simulations ◽  
Experimental Results ◽  
Crack Mouth Opening Displacement ◽  
3D Finite Element ◽  
Content Type

Purpose The purpose of this paper is to present the determination of critical stress intensity factor (KC) both by experimental method and three-dimensional (3D) finite element simulations. Design/methodology/approach CT specimens of different compositions of Al6061-TiC composites (3wt%, 5wt% and 7wt% TiC) with variable crack length to width (a/W=0.3-0.6) ratios are machined from as-cast composite block. After fatigue pre-cracking the specimens to a required crack length, experimental load vs crack mouth opening displacement data are plotted to calculate the KC value. Elastic 3D finite element simulations have been conducted for CT specimens of various compositions and a/W ratios to compute KC. The experimental results indicate that the magnitude of KC depends on a/W ratios, and significantly decreases with increase in a/W ratios of the specimen. Findings From 3D finite element simulation, the KC results at the centre of CT specimens for various Al6061-TiC composites and a/W ratios show satisfactory agreement with experimental results compared to the surface. Originality/value The research work contained in this manuscript was conducted during 2015-2016. It is original work except where due reference is made. The authors confirm that the research in their work is original, and that all the data given in the article are real and authentic. If necessary, the paper can be recalled, and errors corrected.

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