Failure Response of Two Serial Bolted Joints in Composite Laminates

2011 ◽  
Vol 27 (3) ◽  
pp. 293-307 ◽  
Author(s):  
F. Sen ◽  
O. Sayman
Keyword(s):  
Composite Laminates ◽  
Glass Fibers ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Bolted Joints ◽  
Geometrical Parameters ◽  
Material Parameters ◽  
Joint Geometry ◽  
Parametric Studies ◽  
Plate Width

ABSTRACTIn this study, the failure response of two serial bolted joints in composite laminates was investigated. The composite material was consisted of epoxy matrix and glass fibers. To find out the effects of joint geometry and stacking sequences on the failure response, parametric studies were performed experimentally. Three different geometrical parameters that were the edge distance-to-hole diameter ratio (E/D), plate width-to-hole diameter ratio (W/D) and the distance between two serial holes-to-hole diameter ratio (K/D) were investigated. Hence, E/D, W/D and K/D ratios were considered from 1 to 5, 2 to 5 and 3 to 5, respectively. In addition, the failure tests were carried out for a range of preload moments as 2, 3, 4, 5 Nm and without any preload moments as 0Nm. Tested composite laminates were oriented two different stacking sequences as [0°]8 and [0°/0°/90°/90°]s. Experimental results point out that failure response of two serial bolted composite joints are firmly effected from material parameters, geometrical parameters and the magnitudes of applied preload moments.

Identification of damage stages in bolted metallic joints for different joint geometries and tightening torques using statistical analysis

2019 ◽  
Vol 23 (5) ◽  
pp. 911-923 ◽  
Author(s):  
Amr Abd-Elhady ◽  
Ahmed Abu-Sinna ◽  
Mahmoud Atta ◽  
Hossam El-Din M Sallam
Keyword(s):  
Analysis Of Variance ◽  
Failure Load ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Experimental Results ◽  
Bolted Joints ◽  
Tightening Torque ◽  
Joint Geometry ◽  
Joint Width ◽  
The Impact

The main parameters controlling the structural behavior of bolted joints are the tightening torque ( T) and the joint geometry such as the edge distance ( e) to the bolt hole diameter ( D) ratio ( e/ D) and the joint width ( W) to the hole diameter ratio ( W/ D). In the first part of this study, the effects of W/ D and T, with a constant value of e/ D ( e/ D = 3), have been studied experimentally. Three values of W/ D (2.25, 3, and 3.75) with six values of T (0, 10, 15, 20, 25, and 30 N m) have been chosen to construct 18 assemblies. Experimental results highlighted the impact of W/ D, and T, on the different failure stages of bolted double-lap metallic joints. In the second part of this study, analysis of variance has been adopted to analyze the effects of T and W/ D in addition to the effect of e/ D which has been studied previously by the authors. The present experimental results showed that the value of applied load at which the sticking failure occurred increased by increasing the tightening torque up to T = 25 N m for all values of W/ D. However, the other stages of failure were slightly affected by the value of T. The results obtained from the analysis of variance identified that there is no clear effect of W/ D and e/ D on the sticking failure load. However, their effects are markedly clear for other stages of failure.

Failure Behavior of Two Parallel Pinned/Bolted Composite Joints

2011 ◽  
Vol 27 (1) ◽  
pp. 121-127
Author(s):  
M. Pakdil ◽  
F. Sen ◽  
A. Cakan
Keyword(s):  
Glass Fibers ◽  
Laminated Composite ◽  
Composite Plates ◽  
Diameter Ratio ◽  
Laminated Plates ◽  
Hole Diameter ◽  
Failure Behavior ◽  
Geometrical Parameters ◽  
Composite Joints ◽  
Laminated Composite Plates

ABSTRACTIn this study, the failure behavior of two parallel pinned/bolted composite joints was investigated, experimentally. The laminated composite plates were produced from glass fibers and epoxy matrix. During the tests, various joint geometries and ply orientations were considered to decide the optimum joint geometry and suitable stacking sequence of the laminated composite plates for two parallel pinned/bolted joints. For these reasons, the distance from the free edge of the plate to hole diameter ratio (E/D) was changed from 1 to 5, the distance between two parallel holes to hole diameter ratio (K/D) was selected as 2 and 5, the distance from the lateral edge of the plate to hole diameter ratio (N/D) was taken as 2 and 3. The laminated plates were composed from 8 laminas to stuck onto together with three different orientations as [0°2 / 30°2]s, [0°2 / 45°2]s and [0°2 / 60°2]s. The experiments involved both pinned and bolted joint. Experimental results indicate that failure behaviors of pinned/bolted composite joints are strictly influenced from both orientations of laminated plates and geometrical parameters.

Failure Analysis of Bolted Composite Joint Based on Extended Finite Element

2011 ◽  
Vol 488-489 ◽  
pp. 771-774
Author(s):  
Zhen Qing Wang ◽  
Song Zhou ◽  
Jian Sheng Zhou ◽  
Xiao Di Wu
Keyword(s):  
Finite Element ◽  
Failure Analysis ◽  
Failure Load ◽  
High Strength ◽  
Maximum Principal Stress ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Geometrical Parameters ◽  
Stress Criterion ◽  
Composite Joint

In this paper, the influence of geometrical parameters on failure load of bolted single-lap composite joint was investigated. The composite laminate was manufactured from HTA/6376, a high-strength carbon fiber–epoxy material currently used in primary structures in the European aircraft industry. Two geometrical parameters which were plate width-to-hole diameter ratio (W/D), and the edge-to-hole diameter ratio (E/D) were analyzed. To avoid modeling each ply of the laminates discretely, the laminates were modeled using equivalent linear elastic properties. the failure analysis was modeled by Extend Finite Element Method (XFEM) in ABAQUS. Maximum principal stress criterion (Maxps) was used to determine the failure load.

Design Parameters Effect on Load Distribution Around the Hole in Mechanically Fastened Pinned Connections

2008 ◽  
Author(s):  
Vahid Yavari ◽  
Farshad Daneshvar ◽  
Mohammad-Hassan Kadivar ◽  
Iraj Rajabi
Keyword(s):  
Stress Distribution ◽  
Contact Pressure ◽  
Friction Model ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Design Parameters ◽  
Contact Friction ◽  
Plate Interface ◽  
Peak Contact Pressure ◽  
Plate Width

The pinned connection is a principal joining element in many structures. In this article, we present two-dimensional stress analyses for isotropic plate with a pinned circular hole. A study of the pin and the plate material dissimilarity was done by Iyer [6] but still different aspects of the problem are remained to be mentioned. In this work different issues of mechanical engineering interests such as stress distribution in contact area and the magnitude and location of maximum contact pressure and tangential stress are computed with the aid of commercial software ABAQUS 6.6-1 finite element code [7]. In order to have a good evaluation of the stress distribution around the hole, design factors such as plate width to hole diameter ratio (w/d), edge distance to hole diameter ratio (e/d), clearance at the connection area and the contact friction coefficient (μ) were systematically varied during analyses from 2 to 5, 3 to 6, 5% to 25% and 0 to 0.5 respectively. A Coulomb-type friction model is used to simulate the frictional contact at the pin-plate interface. The results obtained in this paper are compared to those available from the paper published by Iyer [6]. Based on the results, it is observed that higher friction at contact interface makes the joints more safe by reducing the peak contact pressure; the same is concluded by reducing the plate width.

scholarly journals Analytical Study of Two Pin-Loaded Holes in Unidirectional Fiber-Reinforced Composites

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
Mohammad Mahdi Attar
Keyword(s):  
Stress Distribution ◽  
Unidirectional Composite ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Geometrical Parameters ◽  
Fiber Array ◽  
Close Match ◽  
Shear Lag Model ◽  
Lag Model ◽  
Long Fibers

The objective of this paper is to investigate the effects of geometrical parameters such as the edge distance-to-hole diameter ratio {e/d}, plate width-to-hole diameter ratio {w/d}, and the distance between two holes-to-hole diameter ratio {l/d} on stress distribution in a unidirectional composite laminate with two serial pin-loaded holes, analytically and numerically. It is assumed that all short and long fibers lie in one direction while loaded by a force po at infinity. To derive differential equations based on a shear lag model, a hexagonal fiber-array model is considered. The resulting pin loads on composite plate are modeled through a series of spring elements accounting for pin elasticity. The analytical solutions are, moreover, compared with the detailed 3D finite element values. A close match is observed between the two methods. The presence of the pins on shear stress distribution in the laminate is also examined for various pin diameters.

Stress Analysis in Single and Multi Fastened Single-Lap Composite Joints

2006 ◽  
Vol 306-308 ◽  
pp. 823-828
Author(s):  
Heoung Jae Chun ◽  
J.M. Choi ◽  
Joon Hyung Byun
Keyword(s):  
Stress Analysis ◽  
Composite Laminates ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Stacking Sequence ◽  
Stress Distributions ◽  
Engineering Structures ◽  
Adequate Knowledge ◽  
Fabric Composite ◽  
Mechanical Fastening

The use of composite materials in many engineering structures has increased recently. The structures are jointed together by single or multiple bolted mechanical fastening to transfer the loads from one member to another. Applications of such joints require adequate knowledge of stress distribution in the vicinity of the boundary of pin hole. In this study, stress analysis is conducted with finite element method to study the stress distributions in the vicinities of both single-pin and multi-pin loaded holes of multi-axial warp knit fabric composite laminates. The perfect fit condition and contact with friction between the pin and hole without lateral constrain are assumed in the analysis. Effects of friction, stacking sequence, ratio of edge distance over hole diameter, ratio of width over hole diameter, number of pins, number of rows, number of column and hole patterns are evaluated. The results show they have a significant influence on joint performance.

An Improved Stiffness Model for Bolted Joints

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Sayed A. Nassar ◽  
Antoine Abboud
Keyword(s):  
Joint Stiffness ◽  
Effective Area ◽  
Accurate Estimate ◽  
Diameter Ratio ◽  
Bolted Joints ◽  
Plate Material ◽  
Reliable Prediction ◽  
Novel Approach ◽  
Stiffness Model ◽  
Initial Assembly

An improved stiffness model is proposed for bolted joints made of similar and dissimilar plates. A novel approach is used to obtain an expression for the effective area used for determining the joint stiffness. More accurate estimate of the joint stiffness provides a more reliable prediction of the joint behavior both during its initial assembly, as well as under subsequently applied tensile loads in service. The effect of the grip length-to-diameter ratio, joint sizes, underhead contact radii ratio, hole clearance, and plate material/thickness ratio are investigated. Experimental data are used for determining the envelope angle α in the proposed analytical model. Finite element modeling is used for evaluating the accuracy of the proposed stiffness model.

Effects of Hole Pitch to Diameter Ratio P/D of Impingement and Film Hole on Laminated Cooling Effectiveness

2017 ◽  
Author(s):  
Weilun Zhou ◽  
Qinghua Deng ◽  
Wei He ◽  
Zhenping Feng
Keyword(s):  
Mass Flux ◽  
Pressure Loss ◽  
Pressure Ratio ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Heat Transfer Analysis ◽  
Internal Cooling ◽  
Cooling Effectiveness ◽  
System Pressure ◽  
The Difference

The laminated cooling, also known as impingement-effusion cooling, is believed to be a promising gas turbine blade cooling technique. In this paper, conjugate heat transfer analysis was employed to investigate the overall cooling effectiveness and total pressure loss of the laminated cooling configuration. The pitch to film hole diameter ratio P/Df of 3, 4, 5, 6, combined with pitch to impingement hole diameter ratio P/Di of 4, 6, 8, 10, are studied at the coolant mass flux G of 0.5, 1.0, 1.5, 2.0 kg/(sm2bar) respectively. The results show that overall cooling effectiveness of laminated cooling configuration increases with the decreasing of P/Df and the increasing of the coolant mass flux in general. However P/Df smaller than 3 may leads to a serious blocking in first few film holes at low coolant mass flux. The large P/Di that makes the Mach number of impingement flow greater than 0.16 may cause unacceptable pressure loss. The increment of overall cooling effectiveness depends on the difference between the deterioration of external cooling and the enhancement of internal cooling. Pressure loss increases exponentially with P/Di and G, and it increases more slowly with P/Df that compared to P/Di and G. The mixing loss takes up the most pressure loss at low coolant mass flux. With the increasing of the whole pressure loss, the proportion of throttling loss and laminated loss becomes larger and finally takes up the most of the whole pressure loss. When the sum of throttling loss and laminated loss is greater than mixing loss, the increment of system pressure ratio is unreasonable that compared to the increment of overall cooling effectiveness.

Flexural Response of Inorganic Hybrid Composites With E-Glass and Carbon Fibers

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
James W. Giancaspro ◽  
Christos G. Papakonstantinou ◽  
P. N. Balaguru
Keyword(s):  
Carbon Fibers ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Composite Plates ◽  
Carbon Composite ◽  
Primary Objective ◽  
Flexural Capacity ◽  
Compression Failure

By far, carbon and glass fibers are the most popular fiber reinforcements for composites. Traditional carbon composites are relatively expensive since the manufacturing process requires significant heat and pressure, while the carbon fibers themselves are inherently expensive to produce. In addition, they are often flammable and their use is restricted when fire is a critical design parameter. Glass fabrics are approximately one order of magnitude less expensive than similar carbon fabrics. However, they lack the stiffness and the durability needed for many high performance applications. By combining these two types of fibers, hybrid composites can be fabricated that are strong, yet relatively inexpensive to produce. The primary objective of this study was to experimentally investigate the effects of bonding high strength carbon fibers to E-glass composite cores using a high temperature, inorganic matrix known as geopolymer. Carbon fibers were bonded to E-glass cores (i) on only the tension face, (ii) on both the tension and compression faces, or (iii) dispersed throughout the core in alternating layers to obtain a strong, yet economical, hybrid composite laminate. For each response measured (flexural capacity, stiffness, and ductility), at least one hybrid configuration displayed mechanical properties comparable to all carbon composite laminates. The results indicate that hybrid composite plates manufactured using 3k unidirectional carbon tape exhibit increases in flexural capacity of approximately 700% over those manufactured using E-glass fibers alone. In general, as the relative amount of carbon fibers increased, the likelihood of precipitating a compression failure also increased. For 92% of the specimens tested, the threshold for obtaining a compression failure was utilizing 30% carbon fibers. The results presented herein can dictate future studies to optimize hybrid performance and to achieve economical configurations for a given set of design requirements.

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