scholarly journals Tensile behaviour of Bolted Joints in Low Temperature Cure CFRP Woven Laminates

1997 ◽  
Vol 6 (6) ◽  
pp. 096369359700600 ◽  
Author(s):  
N. Andréasson ◽  
C. P. Mackinlay ◽  
C. Soutis
Keyword(s):  
Low Temperature ◽  
Failure Modes ◽  
Bolted Joints ◽  
Tensile Behaviour ◽  
Bolted Joint ◽  
Dimensional Finite Element ◽  
The Difference ◽  
Observed Damage ◽  
Good Agreement ◽  
Low Temperature Cure

In this work, the stress results of a two-dimensional finite element (FE) analysis are used to understand failure modes of a bolted joint in low temperature cure CFRP woven laminates loaded in tension and predict the bearing strength. Good agreement with experimentally observed damage modes and strengths is achieved; in some cases the difference is less than 10%.

Load Transfer Analysis of Cracked Bolted Joints

2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.

Gasket Catastrophic Failure Modes

2018 ◽  
Author(s):  
Warren Brown ◽  
Nathan Knight
Keyword(s):  
Failure Modes ◽  
The Body ◽  
Bolted Joints ◽  
Test Results ◽  
Bolted Joint ◽  
Critical Factors ◽  
Test Set ◽  
Set Up ◽  
Industry Experience ◽  
Corrugated Metal

This paper outlines how, under certain scenarios, gaskets may catastrophically blow out of pressure boundary bolted joints. Supporting the observations on industry occurrences of such failures, attempts were made to re-create one of the failure modes in a test set-up. The tests managed to highlight critical factors for blow out of Corrugated Metal with Covering Layer (CMCL) gaskets. A summary of the known industry experience with gasket blow out and the CMCL test results are included in the body of this paper. Conclusions and recommendations for considering these failure modes in both pressure boundary bolted joint design and also risk assessment are made.

Fracture Pattern Comparison Research of Different Types of All-Ceramic Crown

2013 ◽  
Vol 699 ◽  
pp. 480-483
Author(s):  
Cheng Fan
Keyword(s):  
Failure Modes ◽  
Process Analysis ◽  
Failure Process ◽  
Element Model ◽  
Fracture Pattern ◽  
All Ceramic ◽  
Dimensional Finite Element ◽  
The Difference ◽  
Analysis System ◽  
Ceramic Crown

All-ceramic crown restorations are more widely used. The mechanical properties of different type of all-ceramic crown are evident different because of the differences of materials and production process. To study the failure pattern of different all-ceramic crown under load, two dimensional finite element model of three different all-ceramic crown models are constructed using the RFPA (realistic failure process analysis) system in this paper. Due to the difference of stress mismatch between different porcelain layers, it is found that the failure modes of different all-ceramic crown model are significantly different in the study. The advantage of this system is that the crack initiation, propagation and failure process of all-ceramic crown can be clearly observed and the research results provide guidance for clinical application.

Parametric Analysis Mechanical Properties of Bolted Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3924-3927 ◽  
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Zhong Hu Jia ◽  
Yong Gao ◽  
Wen Lin Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of surface strains and load transfer ratio(LTR) were compared with results from finite element analysis. The results show that three-dimensional finite element model of bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of different parameters on the mechanical behaviour of single lap bolted joints. The results show that straight hole, small bolt diameter, and big hole pitch are selected first for bolted joint if other conditions allowed, and effect of bolt material on LTR of joint is small for small load. Interference and pre-stress should be strictly controlled for bolted joints in order to attain the best fatigue capability of lap joint.

Bolted Joints Modeling Techniques, Analytical, Stochastic and FEA Comparison

2012 ◽  
Author(s):  
Yosef Amir ◽  
S. Govindarajan ◽  
Saravanakumar Iyyanar
Keyword(s):  
Analytical Method ◽  
Failure Modes ◽  
Extreme Values ◽  
Bolted Joints ◽  
Critical Parameters ◽  
Stochastic Methods ◽  
Bolted Joint ◽  
Advantages And Disadvantages ◽  
Parameter Variations ◽  
Modeling Techniques

Bolted joints Design analyses are in general, very complex and it is very difficult to find a single technique to study the complete behavior of the bolted joints. The most popular analytical method is the well-known VDI 2230 which addresses most of the cases very well. This analytical method uses extreme values for critical parameter variations and is considered to be conservative, but the quickest method. Stochastic analysis is a more advanced method where variations in critical parameters are modeled as statistical distributions and Monte Carlo simulations allow predicting the behaviors of bolted joints through selective parameter variations. Finite element analysis of bolted joints is another methodology to analyze complex bolted joint designs. Though advances in FE modeling techniques help to model bolted joints more accurately, different failure modes require different modeling techniques. For practical complex bolted joints design analysis, a hybrid of analytical and different FEA models is needed for a full analysis; but a combination of FEA techniques can be used to study any bolted joint in detail for all the failure modes. Hence, it is important to study and understand the limitations of each of the modeling techniques. This paper looks at analytical and stochastic methods of bolted joints as well as three different FEA methods — 3D, Axisymmetric and Beam & Rigid Spider — to study different failure modes. Parametric (DOE) FEA simulation technique for variation parameters bolted joint behavior prediction was investigated; this paper examined the DOE parameter of coefficient of friction. A general case study is used as benchmark for comparison between the techniques and to quantify the advantages and disadvantages of each method.

Fatigue and fretting fatigue life prediction of double-lap bolted joints using continuum damage mechanics-based approach

2016 ◽  
Vol 26 (1) ◽  
pp. 162-188 ◽  
Author(s):  
Ying Sun ◽  
George Z Voyiadjis ◽  
Weiping Hu ◽  
Fei Shen ◽  
Qingchun Meng
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Fretting Fatigue ◽  
Bolted Joints ◽  
Continuum Damage ◽  
Bolted Joint

Fatigue and fretting fatigue are the main failure mode in bolted joints when subjected to cyclic load. Based on continuum damage mechanics, an elastic–plastic fatigue damage model and a fretting fatigue damage model are combined to evaluate the fatigue property of bolted joints to cover the two different failure modes arisen at two possible critical sites. The predicted fatigue lives agree well with the experimental results available in the literature. The beneficial effects of clamping force on fatigue life improvement of the bolted joint are revealed: part of the load is transmitted by friction force in the contact interface, and the stress amplitude at the critical position is decreased due to the reduction in the force transmitted by the bolt. The negative effect of fretting damage on the bolted joint is also captured in the simulation.

Mechanical Behavior of Rotational Screw Thread Loosening in Bolted Joints Under Repeated Temperature Changes

2008 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsutoshi Ishimura ◽  
Yasumasa Shoji ◽  
Yusuke Fukuba
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Experimental Results ◽  
Bolted Joints ◽  
Screw Thread ◽  
Bolted Joint ◽  
Temperature Changes ◽  
Thermal Changes ◽  
The Difference

Bolted joints have been used in mechanical structures. However, loosening accidents sometimes happen under several types of loadings. Recently, some studies have been conducted on the screw thread loosening in bolted joints. It is verified that bolted joints are loosened when transverse repeated loadings are applied. A lot of parts for preventing the loosening in the joints have been proposed. Among these parts, eccentric nut is especially expected to be the solution for preventing the loosening. Some studies on no rotational loosening in bolted joints under thermal changes have also conducted. However, few studies on rotational screw thread loosening in bolted joints have conducted. In our previous study, mechanism of rotational screw thread loosening in bolted joint under repeated temperature changes was examined. However, the difference in the loosening mechanism between the FEM results and the experimental results was substantial. In this study, the effect of the incline at the bearing surfaces was taken into consideration on the loosening. In addition, the loosening in the bolted joint with the eccentric nut under repeated temperature changes was examined using finite element method (FEM) calculations. Discussion is made on the mechanism and a solution of rotational screw thread loosening in the bolted joints under the repeated temperature changes. The results show that a reduction in axial bolt force was increased when the incline at the bearing surfaces was taken into consideration and the eccentric nut was shown for preventing the bolt loosening.

scholarly journals Modeling Bolt Load Retention of Ca Modified AS41 Using Compliance-Creep Method

2011 ◽  
Vol 690 ◽  
pp. 278-281
Author(s):  
Okechukwu Anopuo ◽  
Yuan Ding Huang ◽  
Norbert Hort ◽  
Karl Ulrich Kainer ◽  
Petra Maier
Keyword(s):  
Elevated Temperature ◽  
Creep Behaviour ◽  
Test Sample ◽  
Al Alloys ◽  
Mg Alloys ◽  
Bolted Joints ◽  
Bolted Joint ◽  
The Past ◽  
Good Agreement ◽  
Made In

Adequate quantification of the degree of fastener clamp load retained at bolted joint of Mg-Al alloys is crucial to develop new elevated temperature resistant Mg-alloys. Several attempts have been made in the past to model Bolt Load Retention (BLR) behaviour of Mg-alloys using different approaches. It must be mentioned that whereas these models attempt to predict BLR of the alloys investigated, the results of the models differ in most cases with the experiments by great margin. The BLR behaviour of Mg-alloy is geometry and material dependent. This means that, the configuration of the test sample, the compliance of the bolt/joint and creep response of the material under investigation play important role in determining the joint response under load and temperature. In this work, BLR and creep behaviour of Ca modified AS41 is investigated and compared to that of Mg4Al and AS41. A compliance-creep approach is used to model the response of these Mg-Al alloys at bolted joints. The model prediction of the BLR response and experimental results as obtained in this work are in good agreement. AS41+0.15 % Ca shows improved creep and BLR properties up to 175 °C. A correlation between the microstructures, creep and BLR results reveal that the formation of a ternary CaMgSi phase is responsible for the improved elevated temperature behaviour.

Strength Prediction of Double-Lap Bolted Joints of Woven Fabric CFRP Composite Plates Using Hashin Formulations

2015 ◽  
Vol 802 ◽  
pp. 290-294
Author(s):  
Hilton Ahmad ◽  
Mustafa Abbas Abed
Keyword(s):  
Failure Modes ◽  
Composite Plates ◽  
Bolted Joints ◽  
Woven Fabric ◽  
Strength Prediction ◽  
Bearing Failure ◽  
Bolted Joint ◽  
Element Analysis ◽  
Bearing Failures ◽  
Cfrp Composite

Failure modes in composite plates with bolted joint configuration include net-tension, shear-out and bearing failures. Few analytical and numerical approaches in strength prediction frameworks of composite plates with bolted joints were reported in the literatures. Present works are dealing with strength prediction in bearing failure of woven fabric CFRP plates with double lap bolted joint configurations by modeling 3D finite element analysis framework. The pre-processing stage is modeled using commercial ABAQUS CAE package and takes into account all parts interactions, clamping pressure and friction contact. Testing series are following the experimental works found from the literatures with variation of plate width to hole diameter (W/d) ratios and incorporated with finger-tight clamp-up. Hashin failure criterion was implemented as constitutive modeling in current analysis, based on ply-by-ply approaches found to be more appropriate phenomenon in bearing failure. The strength prediction results demonstrated good agreement with all experimental datasets particularly with bearing failures as compared with previously reported work, used stress concentration approach found to be accurate in net-tension failure only.

Behaviour of Coir-Glass/Epoxy Double Lap Bolted Joint under Tensile Loading

2018 ◽  
Vol 923 ◽  
pp. 29-34
Author(s):  
Asad A. Khalid
Keyword(s):  
Failure Modes ◽  
Epoxy Composite ◽  
Tensile Load ◽  
Composite Plates ◽  
Maximum Load ◽  
Tensile Behaviour ◽  
Bolted Joint ◽  
Number Of Layers ◽  
Chopped Strand Mat ◽  
Steel Bolts

Experimental work on tensile behaviour and failure mechanism of composite double lap bolted joint has been carried out. Chopped strand mat (CSM) coir, glass and coir-glass/epoxy composite plates were fabricated by hand lay-up method. The bolted joint specimens were of 155 mm length and 48 mm width. Steel bolts of 4 mm and 8 mm diameters were used. Effect of material type, number of layers and width to diameter ration (w/d) on tensile load, bearing strength and failure behaviour were examined. Results show that, the maximum load obtained from the glass/epoxy, coir/epoxy and coir-glass/epoxy specimens increased with the increase in the number of layers and (w/d) ratio. Maximum load obtained from the six layers glass/epoxy with w/d ratio of 12 is found higher respectively 15.2% and 50.14% than that obtained from hybrid coir-glass and coir/epoxy composite specimens. The percentages of difference were 14.2% and 42.97% for the specimens with w/d ratio of 6. It has been found that the maximum strength of the six layers glass/ epoxy specimens was found higher in the range between 17.5% to 18.46 % and 51.67% to 57.74 % than the hybrid coir-glass and coir/epoxy specimens respectively. Net tension failure and cleavage failure modes were observed for the two and four layers coir/ epoxy specimens with w/d ratios of 6 and 12. Bearing failure mode was observed for the six layers coir, glass and hybrid coir-glass/epoxy specimens.

Sign in / Sign up

Export Citation Format

Share Document