scholarly journals Failure Strength of E-Glass/Epoxy Composite Pinned Joints: Effect of Geometry, Clamping Torque and Laminate Orientation

2007 ◽  
Vol 16 (3) ◽  
pp. 096369350701600 ◽  
Author(s):  
Yeliz Pekbey
Keyword(s):  
Composite Plate ◽  
Failure Modes ◽  
Failure Load ◽  
Epoxy Composite ◽  
Experimental Investigations ◽  
Failure Behavior ◽  
Displacement Curve ◽  
Failure Strength ◽  
Bearing Strength ◽  
Specimen Width

The experimental investigations described in this paper were conducted in order to study the strength and failure behavior of composite plate with pin-loaded conditions. The main objective of the present paper was to investigate the influence of certain factors on the strength of the pin-loaded in E-GLASS/EPOXY composite plate with different orientations such as [0/90/±30]s and [0/90/±60]s. These factors included the preload moment (M=0, 2 Nm), the ratio of the edge distance to the pin diameter ( E/ D), and the ratio of the specimen width to the pin diameter ( W/ D). The mechanical properties and failure strengths of E-GLASS/EPOXY composite were obtained with experimental measurements. Based on experiments, the effects of laminate orientation, and preload moment on joint strengths were systematically investigated. In addition, geometrical configurations of specimens were suitably varied in order to observe all possible failure modes. A total of 150 different pin-loaded composite plate specimens were tested under static loading conditions. The specimen tested exhibited different failure modes, consisting of bearing, net-tension and shear-out, depending on the geometry adopted. Guidelines for effective laminate orientations, geometrical configurations and preload moment for mechanically pin connected E-GLASS/EPOXY composite plate were specified based on ultimate bearing strength. From the experiments, it was also found that glass-epoxy with [0/90/±30]s yielded the highest bearing strengths. Bearing strengths reached when E/D and W/D ratios were equal or greater than 4 both [0/90/±30]s and [0/90/±60]s orientations. Besides, the experimental results showed that the load-displacement curve of specimen with M=0, had the lowest the failure strength. M=2Nm preload moment, had the maximum failure load.

The Effects of Seawater Immersion on the Bearing Strength of Woven-Glass–Epoxy Prepreg Pin-Loaded Joints

2011 ◽  
Vol 21 (2) ◽  
pp. 153-170 ◽  
Author(s):  
AyŞe Öndürücü
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Natural Seawater ◽  
Bearing Strength ◽  
Specimen Width ◽  
Bearing Load ◽  
Mechanically Fastened ◽  
Ultimate Failure

This study considers the bearing strengths and failure modes of woven-glass–epoxy prepreg composite mechanically fastened joints. For the study, the specimens were immersed in natural seawater in the laboratory for over 1 year. The edge distance-to-hole diameter ( E/ D) ratio and the specimen width-to-hole-diameter ratio ( W/ D) were systematically altered during experiments. Failure modes were determined by observing the failure regions on the specimens. Damage progression in pin-loaded specimens prepared from woven-glass–epoxy prepreg was also examined using a scanning electron microscopy for three different percentages of ultimate failure load. According to the experimental investigation results, it was observed that the bearing load values obtained from the specimens immersed in seawater decreased considerably in comparison to unimmersed specimens.

scholarly journals Experimental Characterization of An E-Glass/Epoxy Composite Plate in Pin-Loaded Joints

2007 ◽  
Vol 16 (2) ◽  
pp. 096369350701600
Author(s):  
Yeliz Pekbey
Keyword(s):  
Failure Mode ◽  
Composite Plate ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Width Ratio ◽  
Tension Stress ◽  
Bearing Failure ◽  
Experimental Characterization ◽  
Bearing Strength ◽  
Edge Distance

Because of increased use of composites, understanding the failure behaviour of composites is important for effective structural designs. In this study, an experimental investigation was carried out to study the behaviour of pin connected E-GLASS/EPOXY composite joints under static loading conditions. Several specimens were fabricated by varying width and hole-to-edge distance and tested in pin bearing. Details of the test-setup were given and the joint configurations were used in a series of 75 such tests on single bolt joints. The results of this study were presented as experimental characterization. The effects of geometric parameters such as ratio between end distance-hole diameter (E/D) and width ratio (W/D) were evaluated. Three failure modes were observed, net-tension, bearing and shear-out failure at the bolt, depending on the geometry adopted. Under single bolt-bearing conditions, the load-displacement curve labelled for E-GLASS/EPOXY composite with [0/90/45/-45/-45/45/90/0] stacking sequence. In addition, bearing strength, shearing and net-tension stress at failure data were presented as functions of the geometric ratios. The results provided useful information for the structural design with this material against joint failures. From the experimental results obtained, it was concluded that the edge distance ratio (E/D) of the specimen strongly affected the bearing strength of composites. In addition, width ratio (W/D) remarkably affected the failure mode. Bearing failure occurred if (E/D) and (W/D) were large enough. Bearing failure mode was thought as the desirable mode since it generally gave a higher strength and failure was less brittle. Net-tension and shear-out failure modes were catastrophic and not progressive. Therefore, the geometry of the composite plate in pin-loaded joints was designed to undergo bearing failure only.

Rainwater effect on bearing strength of glass–epoxy laminated composite pinned joints

2016 ◽  
Vol 50 (30) ◽  
pp. 4269-4278 ◽  
Author(s):  
Onur Sayman ◽  
Ümran Esendemir
Keyword(s):  
Room Temperature ◽  
Failure Modes ◽  
Failure Load ◽  
Weight Ratio ◽  
Laminated Composite ◽  
Hole Diameter ◽  
Plastic Container ◽  
Specimen Width ◽  
Bearing Load ◽  
Pinned Joints

Composite materials are used in areas that have varying environmental conditions due to their advantages such as generally higher stiffness- and strength-to-weight ratio, and corrosion resistance compared to metallic alloys. This experimental study is carried out to investigate the bearing strengths and failure modes of woven glass–epoxy composite pinned joints subjected to rainwater. The specimens were immersed in rainwater in a closed plastic container indoors for 20 month periods at room temperature. The ratio of edge-distance-to-hole diameter (E/D) and the ratio of the specimen width-to-hole-diameter (W/D) were selected as parameters. Failure modes were determined by observing the failure regions on the specimens. Damage of immersed and unimmersed specimens was examined using scanning electron misroscopy for the same failure load. Experimental results showed that the bearing load values obtained from the specimens immersed in rainwater decreased in comparison to unimmersed specimens.

scholarly journals Failure Analysis of Woven Glass- Epoxy Prepreg Bolted Joints under Different Clamping Moments

2008 ◽  
Vol 17 (5) ◽  
pp. 096369350801700 ◽  
Author(s):  
Ümran Esendemi̇r
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Failure Analysis ◽  
Failure Modes ◽  
Bolted Joints ◽  
Geometrical Parameters ◽  
Bearing Strength ◽  
Strength Failure ◽  
Specimen Width ◽  
Standard Tests

In this study, an experimental investigation was carried out, in order to study pin- bearing strength, failure modes under various clamping moments depending on the geometrical parameters. Two different geometrical parameters were investigated. For that reason, the ratio of the distance from the pin centre to the top edge top in diameter (E/D), and the ratio of the specimen width to the pin diameter (W/D) were suitably varied, in order to verify their influence on the failure modes consisting of net-tension, cleavage and bearing. Totally, 160 specimens were tested. The mechanical properties of prepreg composite were obtained from standard tests. Experimental results showed that failure modes and bearing strengths were strictly influenced from increasing value of applied clamping moments and geometrical parameters.

Effect of Ply Orientation on Strength and Failure Mode of Pin Jointed Unidirectional Glass-epoxy Nanoclay Laminates

2015 ◽  
Vol 65 (6) ◽  
pp. 489 ◽  
Author(s):  
Manjeet Singh ◽  
H. Bhunia ◽  
J. S. Saini
Keyword(s):  
Failure Mode ◽  
Composite Laminates ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Free Edge ◽  
Bearing Strength ◽  
Failure Theory ◽  
Unidirectional Glass ◽  
Curve Method ◽  
Ply Orientation

In the present work the effect of the different ply orientations and nano filler on the bearing strength and failure mode of the pin joints is investigated both experimentally and numerically. Glass-epoxy composite laminates were prepared with [0°/45°/90°], [0°/45°/0°] and [0°/90°/0°] ply orientations. Nanoclay filler with 1, 2, 3, 4 and 5wt% were added in the epoxy for the said orientations to prepare the pin joints. Results show that the strength of the pin joints is drastically dependent on both ply orientations and nanofiller wt%. The joint geometry i.e., the distance from the free edge of specimen to the diameter of the hole (E/D) ratio and width of the specimen to the diameter of the holes (W/D) ratio were also investigated which effected the failure mode of the joints. Tsai-Wu failure theory along with the characteristics curve method was used for the prediction of failure modes numerically.

scholarly journals Compression Shear Properties of Bonded–Bolted Hybrid Single-Lap Joints of C/C Composites at High Temperature

2020 ◽  
Vol 10 (3) ◽  
pp. 1054
Author(s):  
Yanfeng Zhang ◽  
Zhengong Zhou ◽  
Zhiyong Tan
Keyword(s):  
High Temperature ◽  
Failure Modes ◽  
Shear Failure ◽  
Shear Loading ◽  
Lap Joints ◽  
Failure Behavior ◽  
Displacement Curve ◽  
Analysis Model ◽  
Single Lap Joints ◽  
Hybrid Joints

Based on previous research, in this paper, the compressive shear failure behavior and mechanical properties of bonded–bolted hybrid single-lap joints of C/C composites at high temperature were studied. The compression shear test was performed on the joints at 800 °C to obtain the load–displacement curve and failure morphology. The failure modes of joints were observed by digital microscopy and scanning electron microscopy. A numerical analysis model was implemented in finite element code Abaqus/Explicit embedded with the user material subroutine (VUMAT). The numerical results were compared with the test results to verify the correctness of the model. The interrelationship of the compression shear loading mechanism and the variations in stress distribution between bonded joints and bonded–bolted hybrid joints at high temperature were explored. The progressive damage of hybrid joints and the variations in the ratio of the bolt load to the total load with displacement were obtained.

Finite Elemental Simulation on Flexural Process of Carbon Fiber/Epoxy Composite Laminates

2011 ◽  
Vol 332-334 ◽  
pp. 1105-1108 ◽  
Author(s):  
Ling Fei Chen ◽  
Li Chen ◽  
Guo Li Zhang
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Tensile Failure ◽  
Experimental Result ◽  
Displacement Curve ◽  
Finite Element Software ◽  
Carbon Fiber Epoxy

A 3D finite element model of three-point flexure test of carbon fiber/epoxy composite laminates is developed and analyzed with the finite element software ANSYS. Based on the Hashin criterion, a stiffness degradation method is adopted to predict the progressive failure properties of the carbon fiber/epoxy composite laminates. For carbon fiber/epoxy composite, five failure modes: fiber tensile failure, fiber compressive failure, matrix tensile cracking, matrix compressive cracking and fiber-matrix shear-out failure are included in the present model. The calculated load-displacement curve and the final flexural failure strength are compared with the experimental result, and the finite element results are in good agreement with the experimental values.

scholarly journals Fatigue Resistance and Failure Behavior of Penetration and Non-Penetration Laser Welded Lap Joints

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xiangzhong Guo ◽  
Wei Liu ◽  
Xiqing Li ◽  
Haowen Shi ◽  
Zhikun Song
Keyword(s):  
Fatigue Resistance ◽  
Failure Modes ◽  
Plate Thickness ◽  
High Stress ◽  
Lap Joints ◽  
Failure Behavior ◽  
Passenger Cars ◽  
Plate Fracture ◽  
The Difference ◽  
Railway Passenger

AbstractPenetration and non-penetration lap laser welding is the joining method for assembling side facade panels of railway passenger cars, while their fatigue performances and the difference between them are not completely understood. In this study, the fatigue resistance and failure behavior of penetration 1.5+0.8-P and non-penetration 0.8+1.5-N laser welded lap joints prepared with 0.8 mm and 1.5 mm cold-rolled 301L plates were investigated. The weld beads showed a solidification microstructure of primary ferrite with good thermal cracking resistance, and their hardness was lower than that of the plates. The 1.5+0.8-P joint exhibited better fatigue resistance to low stress amplitudes, whereas the 0.8+1.5-N joint showed greater resistance to high stress amplitudes. The failure modes of 0.8+1.5-N and 1.5+0.8-P joints were 1.5 mm and 0.8 mm lower lap plate fracture, respectively, and the primary cracks were initiated at welding fusion lines on the lap surface. There were long plastic ribs on the penetration plate fracture, but not on the non-penetration plate fracture. The fatigue resistance stresses in the crack initiation area of the penetration and non-penetration plates calculated based on the mean fatigue limits are 408 MPa and 326 MPa, respectively, which can be used as reference stress for the fatigue design of the laser welded structures. The main reason for the difference in fatigue performance between the two laser welded joints was that the asymmetrical heating in the non-penetration plate thickness resulted in higher residual stress near the welding fusion line.

scholarly journals Analytical Investigation of Tension Loaded Deformed Rebar Anchors in Concrete

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 442-458
Author(s):  
Sandip Chhetri ◽  
Rachel A. Chicchi
Keyword(s):  
Test Data ◽  
Parametric Study ◽  
Failure Modes ◽  
Experimental Testing ◽  
Analytical Investigation ◽  
Failure Behavior ◽  
Capacity Design ◽  
Simulation Results

Experimental testing of deformed rebar anchors (DRAs) has not been performed extensively, so there is limited test data to understand their failure behavior. This study aims to expand upon these limited tests and understand the behavior of these anchors, when loaded in tension. Analytical benchmark models were created using available test data and a parametric study of deformed rebar anchors was performed. Anchor diameter, spacing, embedment, and number of anchors were varied for a total of 49 concrete breakout simulations. The different failure modes of anchors were predicted analytically, which showed that concrete breakout failure is prominent in the DRA groups. The predicted concrete breakout values were consistent with mean and 5% fractile concrete capacities determined from the ACI concrete capacity design (CCD) method. The 5% fractile factor determined empirically from the simulation results was kc = 26. This value corresponds closely with kc = 24 specified in ACI 318-19 and ACI 349-13 for cast-in place anchors. The analysis results show that the ACI CCD formula can be conservatively used to design DRAs loaded in tension by applying a kc factor no greater than 26.

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