scholarly journals Efficiency and Stiffness of the Single Lap Bolt Joints in Glass Epoxy Composites

2019 ◽  
Vol 69 (3) ◽  
pp. 280-289
Author(s):  
Jaspreet Singh ◽  
Kulwinder Singh ◽  
J. S. Saini
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Characteristic Curve ◽  
Joint Stiffness ◽  
Failure Criteria ◽  
Hole Diameter ◽  
Outer Diameter ◽  
Joint Efficiency ◽  
Failure Loads ◽  
Joint Characteristic

The present work deals with the investigations on the joint efficiency and the joint stiffness of the single lap bolt joint made of two dimensional woven glass fibre reinforced composite materials. The effect of joint geometry, bolt pretension and washer has been determined on the bolt joint performance. To estimate the effect of geometric parameters; the edge-to-hole diameter (e/d) and width-to-hole diameter (w/d) ratios are varied from 3 to 4 and 3 to 5, respectively. To study the worst loading conditions; the bolt pre-tension is set to zero, whereas 5 Nm torque is applied to investigate the joint in fully clamped conditions. Two different sizes of washer i.e., the outer diameter of 12 mm and 16 mm have been studied to estimate the effect of the washer on failure load, joint stiffness, and joint efficiency. Progressive damage analysis has been performed on the single lap bolt joint. Characteristic curve method along with Tsai-Wu failure criteria has been used for the prediction of the failure loads and failure modes. The joint stiffness and the failure load of the joint are increased with the increase of w/d ratios. However, the joint efficiency was negatively influenced by w/d ratio.

Investigations to increase the failure load for joints in glass epoxy composites

2018 ◽  
Vol 233 (6) ◽  
pp. 2074-2090 ◽  
Author(s):  
Kulwinder Singh ◽  
JS Saini ◽  
H Bhunia ◽  
Jaspreet Singh
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Failure Criteria ◽  
Hole Diameter ◽  
Glass Fiber Reinforced ◽  
Failure Loads ◽  
Ultimate Failure ◽  
Nanoclay Content ◽  
Woven Glass Fiber ◽  
Fiber Reinforced Laminates

The present work aims to increase failure loads of pin joints through nanofillers and metal inserts. Pin joints were prepared from woven glass fiber-reinforced laminates with nanoclay as filler material along with metal inserts fitted in holes. To investigate the effect of nanoclay content, 1–5 wt.% of nanoclay was mixed in epoxy. The increase in tensile strength up to 3 wt.% of nanoclay was observed which was due to increase in the specific surface area of the nanocomposite material. Dispersed nanoclay filler particles act as mechanical interlocking between fiber and epoxy matrix which creates a high friction coefficient. The optimal nanoclay content of 3 wt.% was finally used to prepare nanocomposite laminates. The geometric parameters, i.e. edge distance to hole diameter (E/D) ratio and width to hole diameter (W/D) ratio were varied from 2 to 5 and 3 to 6, respectively. Progressive damage analysis along with Hashin failure criteria was performed to predict failure loads and failure modes in pin joints, numerically. Metal inserts reduced the stress concentration around the hole and redistributed stresses at the pin/hole interface, which eventually increased the ultimate failure load of the joint.

To study the contribution of different geometric parameters on the failure load for multi holes pin joints prepared from glass/epoxy nanoclay laminates

2017 ◽  
Vol 52 (5) ◽  
pp. 629-644 ◽  
Author(s):  
Manjeet Singh ◽  
JS Saini ◽  
H Bhunia
Keyword(s):  
Taguchi Method ◽  
Failure Modes ◽  
Failure Load ◽  
Characteristic Curve ◽  
Free Edge ◽  
Failure Criteria ◽  
Geometric Parameters ◽  
Unidirectional Glass ◽  
Curve Method ◽  
Parameters Analysis

The present work aims to analyze the strength and failure modes for the multi holes pin joint configurations made from unidirectional glass/epoxy nanoclay laminates. The geometric parameters, i.e. the distance from the free edge of the specimen to the diameter of the first two holes (E/D) ratio, the distance between two holes along the length of the specimen to the diameter of the hole (F/D) ratio, the distance between the two holes along the width of the specimen to the diameter of the hole (P/D) ratio and side width to diameter (S/D) ratio were studied for their effect on strength and failure modes of the joint. Design of experiment with Taguchi method was used for the optimization of different geometric parameters. Analysis of variance was applied to determine the influence of individual geometric parameter on the strength of the joint. The results demonstrate that the E/D and F/D ratios are the most significant parameters to increase the strength of multi holes pin joint configurations. Their percentage contributions were about 62% to 65% and 23% to 26%, respectively. Thereafter, the characteristic curve method along with Tsai–Wu failure criteria was applied to compare the numerical and experimental predictions.

Effect of Metallic Inserts on the Strength of Pin Joints Prepared from Glass Fiber Reinforced Composites

2017 ◽  
Vol 67 (5) ◽  
pp. 592 ◽  
Author(s):  
Kulwinder Singh ◽  
J. S. Saini ◽  
H. Bhunia
Keyword(s):  
Glass Fiber ◽  
Failure Modes ◽  
Failure Criteria ◽  
Hole Diameter ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Failure Loads ◽  
Experimental Findings

The present study deals with the failure analysis of pin joints by varying different geometric parameters i.e., edge distance to hole diameter (E/D) ratio and width to hole diameter (W/D) ratio. Pin joints were prepared from the glass fiber reinforced laminates incorporating the metal inserts. A range of 2 to 5 and 3 to 6 was considered for E/D and W/D ratios, respectively. The stress around the hole was redistributed by incorporating the metal inserts in the hole to increase the load carrying capacity. To predict the failure loads and failure modes numerically, progressive damage analysis along with Hashin failure criteria was used in the pin joints. Strength of the pin joints increased in the range of 65 per cent to 92 per cent with metal insert due to the redistribution of the stresses around the hole. Progressive damage analysis gave a good correlation with experimental findings. Thereafter, the strength of the joint was predicted by varying the thickness of the metal inserts.

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.

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.

Progressive failure analysis of fiber-reinforced laminated composites containing a hole

2017 ◽  
Vol 27 (7) ◽  
pp. 963-978 ◽  
Author(s):  
Hadi Bakhshan ◽  
Ali Afrouzian ◽  
Hamed Ahmadi ◽  
Mehrnoosh Taghavimehr
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Progressive Failure ◽  
Composite Plates ◽  
Failure Criteria ◽  
Element Analysis ◽  
Progressive Failure Analysis ◽  
Numerical Predictions ◽  
Open Hole ◽  
Failure Loads

The present work aims to obtain failure loads for open-hole unidirectional composite plates under tensile loading. For this purpose, a user-defined material model in the finite element analysis package, ABAQUS, was developed to predict the failure load of the open-hole composite laminates using progressive failure analysis. Hashin and modified Yamanda-Sun’s failure criteria with complete and Camanho’s material degradation model are studied. In order to achieve the most accurate predictions, the influence of failure criteria and property degradation rules are investigated and failure loads and failure modes of the composites are compared with the same experimental test results from literature. A good agreement between experimental results and numerical predictions was observed.

scholarly journals Failure Load and Fatigue Behavior of Monolithic Translucent Zirconia, PICN and Rapid-Layer Posterior Single Crowns on Zirconia Implants

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1990
Author(s):  
Frank A. Spitznagel ◽  
Sara Röhrig ◽  
Robert Langner ◽  
Petra C. Gierthmuehlen
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Fatigue Behavior ◽  
Load To Failure ◽  
Failure Loads ◽  
Application Data ◽  
Monolithic Zirconia ◽  
Post Hoc ◽  
Single Crowns ◽  
Zirconia Implants

This laboratory study aimed to evaluate the thermo-mechanical fatigue behavior and failure modes of monolithic and rapid-layer posterior single-crowns (SCs) supported by zirconia implants. Methods: 120 all-ceramic crowns supported by one-piece zirconia implants (ceramic.implant; vitaclinical) were divided into five groups (n = 24 each): Group Z-HT: 3Y-TZP monolithic-zirconia (Vita-YZ-HT); Group Z-ST: 4Y-TZP monolithic-zirconia (Vita-YZ-ST); Z-XT: 5Y-TZP monolithic-zirconia (Vita-YZ-XT); Group E: monolithic-polymer-infiltrated ceramic network (PICN,Vita-Enamic); Group RL (rapid layer): PICN-“table-top” (Vita-Enamic), 3Y-TZP-framework (Vita-YZ-HT). Half of the specimens of each group (n = 12) were exposed to fatigue with cyclic mechanical loading (F = 198N, 1.2-million cycles) and simultaneous thermocycling (5–55 °C). Single-load-to-failure testing (Z010, Zwick) was performed for all specimens without/with fatigue application. Data analysis was performed using ANOVA, Tukey’s post-hoc test, two-sample t-test and Bonferroni correction (p < 0.05). Results: All specimens survived fatigue exposure. Significant differences in failure loads were detected among groups (p ≤ 0.004). Materials Z-HT and Z-ST showed the highest failure loads followed by Z-XT, RL and E. The influence of fatigue was only significant for material RL. Conclusions: All types of tested materials exceeded clinically acceptable failure load values higher than 900N and can be recommended for clinical use. Z-HT and Z-ST appear to be highly reliable towards fatigue. Rapid-layer design of PICN and YZ-HT might be an interesting treatment concept for posterior implant SCs.

Finite element analyses and experimental considerations of the deflection and failure behaviour of an asymmetric laminate composite bicycle handlebar

2002 ◽  
Vol 216 (4) ◽  
pp. 207-218 ◽  
Author(s):  
R R Chang
Keyword(s):  
Failure Modes ◽  
Laminate Composite ◽  
Failure Load ◽  
Laminated Composite ◽  
Experimental Results ◽  
Optimal Angle ◽  
Maximum Stiffness ◽  
Theoretical Predictions ◽  
Failure Loads ◽  
Experimental Approaches

The deformation and first-ply failure load of an asymmetric laminate composite bicycle handlebar have been studied via both theoretical and experimental approaches. The composite bicycle handlebar tube is fabricated with outer main fibre layers and inner reinforcing fibre layers and is designed to predicted first-ply failure loads. Optimal angle-ply orientations of antisymmetric [θ-θ…]-s laminated tubes designed for maximum stiffness were investigated. A number of laminated composite bicycle handlebars were fabricated and subjected to static transverse bend testing. The first-ply failure loads of laminated composite bicycle handlebars tubes were determined using acoustic emission (AE). The failure modes of the bicycle handlebars were studied, and experimental results were used to verify the theoretical predictions. The experimental results have been proved to be efficient and effective in the theoretical prediction of first-ply failure loads of laminated composite bicycle handlebars.

Mechanical and failure behavior of three-dimensional six-directional braided composites bolted joint

2017 ◽  
Vol 36 (10) ◽  
pp. 739-753 ◽  
Author(s):  
Yuling Tang ◽  
Zhengong Zhou ◽  
Shidong Pan ◽  
Zhiyong Tan ◽  
Hongwei Wu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Characteristic Curve ◽  
Damage Model ◽  
Three Dimensional ◽  
Reference Value ◽  
Failure Criteria ◽  
Failure Behavior ◽  
Bolted Joint ◽  
Braided Composites

Experiments and finite element simulation were used to investigate the influence of geometric parameters on failure response of a single-lap bolted joint. Single- and double-bolt joints in three-dimensional six-directional braided composites were tested. The failure modes and mechanisms of the joints were evaluated. To accurately predict bearing strength, a three-dimensional composite damage model was used, which included the Yamada–Sun failure criteria based on the characteristic curve method. The finite element method (FEM) was validated by experimental results. The geometric reference value and failure envelope for the single-lap bolted joint were obtained. The results showed that the carrying capacity of the single-lap bolted joint decreased and the failure mode also changed owing to the secondary bending. It can also be obtained that increased the number of bolt rows can effectively reduce the secondary bending of the plates and thus generated less severe net tensile stresses.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

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