Bearing failure of single-/double-shear composite bolted joints: An explicit finite element modeling

2018 ◽  
Vol 37 (14) ◽  
pp. 933-944 ◽  
Author(s):  
Fangzhou Lu ◽  
Deng’an Cai ◽  
Ju Tang ◽  
Wenlong Li ◽  
Jian Deng ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Failure Modes ◽  
Three Dimensional ◽  
Bolted Joints ◽  
Bearing Failure ◽  
Fiber Failure ◽  
Explicit Finite Element ◽  
Double Shear ◽  
Propagation Law

A three-dimensional explicit finite element method was presented to investigate the bearing failure of single- and double-shear composite bolted joints. To predict the various failure modes of composite laminates, three-dimensional solid elements accompanied by mixed-mode failure criteria considering nonlinear shear behavior were employed in the model. A linear damage propagation law based on the fracture energy and the characteristic length was adopted to alleviate the mesh dependency. In addition, reduced integration elements were used in the models of single- and double-shear joints to avoid the overstiffness. The simulated models were implemented in the Abaqus/Explicit solver with a user-defined material subroutine. The numerical analysis run successfully without any convergence issues. The predictions of mechanical behavior agreed well with the experimental results, with typical damages in the laminates including matrix crack and fiber failure. The effect of secondary bending in the single-shear bolted joint was also analyzed in the explicit modeling.

A Finite Element Assessment of Clamping Effects in Composite Bolted Joints

1989 ◽  
Vol 203 (1) ◽  
pp. 39-45 ◽  
Author(s):  
W S Arnold ◽  
I H Marshall ◽  
J Wood
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Three Dimensional ◽  
Contact Analysis ◽  
Bolted Joints ◽  
Composite Joints ◽  
Fastener Hole ◽  
Stress Levels ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The problem of clamp-up in bolted composite joints has been studied using three-dimensional finite element techniques. In contrast to previous work, a contact analysis has been incorporated enabling both the pin and washer to be modelled. Friction and clamp-up distribution have been shown to significantly effect stress levels in the vicinity of a fastener hole. The results have shown reasonable correlation with experimentally observed strengths and failure modes.

On-site monitoring of bearing failure in composite bolted joints using built-in eddy current sensing film

2020 ◽  
pp. 002199832097973
Author(s):  
Qijian Liu ◽  
Hu Sun ◽  
Yuan Chai ◽  
Jianjian Zhu ◽  
Tao Wang ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Eddy Current ◽  
Failure Modes ◽  
Bolted Joints ◽  
Bearing Failure ◽  
Monitoring Method ◽  
Current Sensing ◽  
Site Monitoring ◽  
Array Sensing ◽  
Bearing Damage

Bearing damage is one of the common failure modes in composite bolted joints. This paper describes the development of an on-site monitoring method based on eddy current (EC) sensing film to monitor the bearing damage in carbon fiber reinforced plastic (CFRP) single-lap bolted joints under tensile testing. Configuration design and operating principles of EC array sensing film are demonstrated. A series of numerical simulations are conducted to analyze the variation of EC when the bearing failure occurs around the bolt hole. The results of damage detection in the horizontal direction and through the thickness direction in the bolt hole with different exciting current directions are presented by the finite element method (FEM). Experiments are performed to prove the feasibility of the proposed EC array sensing film when the bearing failure occurs in CFRP single-lap bolted joints. The results of numerical simulations and experiments indicate that bearing failure can be detected according to the variation of EC in the test specimen.

Progressive fatigue behavior of single-lap bolted laminates under different tightening torque magnitudes

2020 ◽  
Vol 234 (10) ◽  
pp. 1303-1312
Author(s):  
M Feyzi ◽  
S Hassanifard ◽  
A Varvani-Farahani
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Behavior ◽  
Damage Model ◽  
Three Dimensional ◽  
Bolted Joints ◽  
Element Analysis ◽  
Damage And Failure ◽  
Experienced Fatigue ◽  
Three Dimensional Finite Element

The present paper studies fatigue damage and life of single-lap bolted joints tightened with different torque magnitudes subjected to uniaxial load cycles. The adherends were constructed from E-glass/epoxy layers using a hand layup technique and assembled by 1.5, 3, and 8 N m of applied torques. Increasing the torque magnitude benefitted the final fatigue life of the joints so that the high-cycle fatigue life of the joint sample tightened with 8 N m was as high as 10 times that of the joint tightened with 1.5 N m. In the numerical section of this study, a three-dimensional finite element analysis was employed, and the impacts of applied torques were included in the progressive damage model to assess damage and failure in the bolted joints. For the joints tightened with higher torque levels, numerical results revealed higher fatigue lives but at the cost of more delamination at the vicinity of the hole. Laminate fracture surface was investigated through scanning electron microscopy and more cracking/damage progress was evidenced in matrix, fiber, and matrix–fiber interface as composite joints experienced fatigue cycles. Experimental life data of tested joints agreed with those anticipated through the use of finite element analyses indicating the developed model as an appropriate tool in evaluating the effects of applied torques on the fatigue fracture behavior of bolted laminates.

A Damage Model for Prediction of the Open-Hole Strength of Glare Laminates

2013 ◽  
Vol 325-326 ◽  
pp. 123-127
Author(s):  
Zi Zhen Cao ◽  
Ji Feng Zhang ◽  
Yun Wan ◽  
Yong Gang Xie
Keyword(s):  
Failure Modes ◽  
Damage Model ◽  
Three Dimensional ◽  
Matrix Cracking ◽  
Failure Behavior ◽  
Cohesive Elements ◽  
Fiber Failure ◽  
Solution Approach ◽  
Present Solution ◽  
Open Hole

A three-dimensional progressive damage model is proposed to predict the open-hole tensile strength of Glare laminates. For the glass fiber reinforced epoxy the user subroutine UMAT is employed for description of the failure modes, such as matrix cracking and fiber failure. Behavior of the delamination between plies of the laminate is described using cohesive elements. Laminates with a rhombic hole, a square hole and a circular hole are taken into consideration separately. The results obtained by the present solution approach are validated with those available in the literatures.

Strength Analysis of Composite Laminates with Non-Penetrating Damage Repaired by Two Kinds of Bonding Methods

2010 ◽  
Vol 160-162 ◽  
pp. 81-86
Author(s):  
Feng Liu
Keyword(s):  
Finite Element ◽  
Composite Laminates ◽  
Principal Direction ◽  
Tensile Force ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surface Patch ◽  
Damage Mode ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the stress state of the composite laminates under unidirectional tensile force is analyzed. The strength criterion and damage mode are given based on the stresses of material principal direction. The three dimensional finite element models of the same laminates with non-penetrating damage repaired by two kinds of bonding methods are built. The strength criterion and the damage mode of the two kinds of repaired models are also given. The influence of the interlaminar stress is considered in these analysis models. It is showed that the three dimensional models can simulate the geometric and physical features of the real composite laminates. It is concluded that the original composite laminates and the repaired ones both damage first in the laminar whose second material principal direction coincides with the axial tensile force. The damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the mother laminates. After scarf bonding repair, the strength of the damaged laminates recovers up to about eighty-four percent. With additional surface patch, the strength of the damaged laminates recovers up to about eighty-nine percent. Surface patch can improve the strength of damaged laminates.

Behaviour of hollow concrete masonry walls with one-course bond beams subjected to concentric and eccentric concentrated loading

2003 ◽  
Vol 30 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Three Dimensional ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Concentrated Load ◽  
Concrete Masonry ◽  
Out Of Plane ◽  
Concentrated Loading ◽  
Concrete Masonry Walls

Three-dimensional finite element models of unreinforced hollow concrete masonry walls with one-course bond beams subjected to concentrated loading have been analyzed. The walls were modelled with different loading plate sizes, different loading locations along the wall (at the midpoint of the wall, at the end of the wall, and between these points), and different out-of-plane eccentricities (e = 0, t/6, and t/3). The hollow block units, mortar, grout, and bond beam blocks in the walls were modelled separately. Both smeared and discrete cracking methods have been utilized for predicting cracking under load. Geometric and material nonlinearities and damage due to progressive cracking were taken into account in the analyses. The predicted failure modes and ultimate capacities of the walls with the concentric concentrated load applied at the midpoint or at the end of the wall compared very well with the experimental results. When the load was between the midpoint and the end of the wall, the predicted ultimate capacity was between those for the load at the midpoint and at the end. The strength of the walls decreases with increasing out-of-plane eccentricities.Key words: finite element models, hollow masonry, smeared and discrete cracking models, concentrated load, loading locations, out-of-plane eccentricities.

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