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Computation Method in Failure Analysis of Mechanically Fastened Joints at Layered Composites

Computation Method in Failure Analysis of Mechanically Fastened Joints at Layered Composites

This paper considers a computation method in failure analysis of layered composites containing pin-loaded holes. The investigation is focused on developing a reliable computation procedure to analyze initial failure load for pin-loaded holes at layered composite structures. Finite element method (FEM) is used to determine stress distribution around the fastener hole. Combining Chang-Scott-Springer characteristic curve model and Tsai-Wu initial failure criterion are used to determine joint failure. Special attention in this work is paid to pin-load distributions and its effect on the load level of failure and its location. In previous work initial failure analysis was carried out using cosine distribution between pin/lug mechanically fastened joint. Here contact finite element pin/lug model is analysed. The influence of stacking sequences of layered composites containing pin-loaded holes is also investigated. Special attention is paid to failure load and mode analyses in composites with stacking sequence [0/(±45) 3 /90 3 ] S . The computation results are compared with available experimental results. Good correlations between
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The prediction of viscoelastic properties of layered composites on example of cross ply carbon reinforced plastic

The prediction of viscoelastic properties of layered composites on example of cross ply carbon reinforced plastic

Structure-phenomenological model based on hereditary mechanics relationships allows the viscoelastic properties of the layered composites to be predicted on viscoelastic properties of the unidirectional layer. The anisotropy of viscoelastic properties of layered plates, and particularly, cross-ply carbon reinforced plastic can be described the derived constitutive equations. Operator expressions of creep and relaxation moduli by means of correspondence principle can be used to solve boundary value problems of viscoelasticity. The analysis of nonlinear viscoelastic properties can be made by modification of the proposed model. An example of model application to prediction of viscoelastic properties of cross-ply carbon reinforced plastic was demonstrated. Satisfactory agreement of cal- culated values and test results was shown.
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Investigation of Literature in E-Glass / Epoxy Layered Composites

Investigation of Literature in E-Glass / Epoxy Layered Composites

However, the response to the impact is also determined by the material itself. That is, the metal and metal alloys result in the impact of the impact and the surface exposed to the impact. In composite materials, the damage caused by the impact can occur on the surface which is not exposed to the impact according to the type of impact. It can be seen as the delamination between the layers in the interior structure. Although the impact response in metals is a rupture or fracture as a result of the plastic k deformation, the composites can be damaged in many different modes and in these damage modes there is no significant change in the structural integrity of the part.
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Shock wave propagation in periodically layered composites

Shock wave propagation in periodically layered composites

IX 3 Experimental Systems for Shock Compression of Solids C-l 3.1 High Velocity Planar Impact Loading System C-l 3.2 Experimental Techniques: Diagnostic Systems C-3 3.2.l Arrival Time De[r]

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Finite Element Modeling and Mechanical Testing of Metal Composites Made by Composite Metal Foil Manufacturing

Finite Element Modeling and Mechanical Testing of Metal Composites Made by Composite Metal Foil Manufacturing

production of large molds but the process has some critical issues. For the handling of the metal sheet contours, a sufficient self-stiffness of the sheet is necessary. Therefore, the thickness has to be more than approximately 0.5 mm. As a consequence of the relatively thick metal foils, parts made from this process suffer from a significant staircase effect [10]. On the other hand, CMFM can work with foils of various thickness and does not face the same issues [11]. The surface quality of the parts made by metal foil LOM is not good, and the products require post processing such as milling, build-up welding, or shot peening where necessary [12]. On the other hand, the parts produced by CMFM have good surface finish and require minimal post-processing to improve their aesthetics. CMFM has also manufactured functional products such as spanners made from similar (aluminum) as well as dissimilar metals (aluminum/copper) to demonstrate its effectiveness [13,14]. It has the capability to produce complex geometries which might not have been possible using traditional manufacturing techniques, such as undercuts, channels through sections, tubes within tubes, and internal voids etc. It can also be used to produce large molds with grooves as well as complex cooling systems with cavities and sliders. Generally, in such cases the cost for tooling or injection molding is very high and CMFM can provide cost-effective means of production. Plates press brazing (PPB) is an AM method that also uses metal foils and has been aimed at the manufacturing of large metallic molds with customized temperature control. Like metal foil LOM, this process also cannot use metal foils of various thickness values and relies heavily on pre/post processes for appropriate adhesion which reduces its efficiency [15]. Ultrasonic consolidation (UC) is another method that makes use of metal foils and has demonstrated its capabilities to produce metal and metal composites. The bonding largely depends on the ultrasonic oscillations to induce plastic flow in the metal foils being bonded. However, the setup is expensive, time-consuming, and difficult for the manufacture of high-quality composites [16–18]. On the other hand, CMFM is easy to setup and works well with a variety of different metal foils with no surface treatment to manufacture layered composites [19,20].
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Layered Metal Composites: Newest Generation of Radiation Protective Materials

Layered Metal Composites: Newest Generation of Radiation Protective Materials

So, at the stage of preliminary testing experimentally several important facts were established. First, it was obtained experimental confirmation of theoretical predictions of higher RPE of layered composites compared to their homogeneous components. Secondly, it is shown that at equal values of surface density ( χ = 0.5) RPE of composites significantly exceeds the characteristics of its components and is different for composites which has a different scheme of their structure. These indicate of that the composites are inherent to the phenomenon of RPE sensitivity to the parameters of their internal architecture.
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Erosion Wear Behaviour of Bamboo-Glass Hybrid Fiber Reinforced Polymer

Erosion Wear Behaviour of Bamboo-Glass Hybrid Fiber Reinforced Polymer

Figure 4 shows the influence of impingement angle (α) on the erosion rate of bamboo-E-glass epoxy composites under 48 m/s impact velocity. It is observed that the peak of erosion rate is around 60° impingement angle for different layered composites and BBBB epoxy composite shows minimum wear as compared to other composite. According to literature if the maximum erosion occurring in the angular range 45°-60° then the composite material possesses semi ductile behaviour.

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Layered effects on soil displacement around a penetrometer

Layered effects on soil displacement around a penetrometer

related to the tendency of the soil to dilate, with the well-known consequence of a non-linear increase of penetration resistance with stress level. Layered soil tests show a clear difference of soil deformation patterns compared to uniform tests, especially for vertical displacements. The peak value of ver- tical displacement of the soil occurs at dense-over-loose interfaces, while a local minima occurs at loose-over-dense interfaces. Parameters are proposed to quantitatively evaluate the layered effects on soil deformations and a de- formation mechanism is described for penetration in layered soils based on the transition of displacement profiles.
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Investigation On Flexural And Morphological Characteristics Of Novel Hybrid Oil Palm Empty Fruit Bunch/ Kenaf Reinforced High Density Polyethylene Composite For Automotive Application

Investigation On Flexural And Morphological Characteristics Of Novel Hybrid Oil Palm Empty Fruit Bunch/ Kenaf Reinforced High Density Polyethylene Composite For Automotive Application

Oil palm empty fruit bunch (OPEFB) fibers are classified as natural fibers which are environmental friendly. These fibers are renewable, abundance, non-toxic, and low cost making them popular. However, the disadvantages of OPEFB fibers are the moisture absorption properties, and incompatibility with some polymer matrix. Polyethylene (PE) is the most frequently used thermoplastic in the production of natural fiber plastic composites due to its general availability, low melting point and low cost (Ewulonu & Igwe, 2012).

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Characteristics of modal layering in the Round Valley Peak Granodiorite, eastern Sierra Nevada, California

Characteristics of modal layering in the Round Valley Peak Granodiorite, eastern Sierra Nevada, California

Detailed mapping of the modally layered Round Valley Peak Granodiorite and surrounding non-layered unit indicate varying relationships between the two distinct units (Fig. 1). Modal layering ranges from concordant to highly discordant to contacts. Orientation of foliation defined by hornblende alignment and mafic enclave flattening in the non-layered granodiorite varies widely, but is generally steep and E- to NE-striking (Fig. 4). Foliation defined by modal layering also varies dramatically, but generally dips to the SW at moderate to high angles (31°-76°) (Fig. 4). A breccia pipe lies near the center of the modally layered rock, and within a few meters of the pipe the orientation of layering is extremely erratic. Copper staining and fine-grained, dark xenoliths were found near the breccia pipe, but were not observed in other areas of the pluton. Lineation defined by hornblende elongation in the modally layered granodiorite generally trends south and plunges between 21°-58° (Fig. 4).
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Synthesis of (cinnamate-zinc layered hydroxide) intercalation compound for sunscreen application

Synthesis of (cinnamate-zinc layered hydroxide) intercalation compound for sunscreen application

ZLH: Zinc layered hydroxide; CA: Cinnamic acid; ZnO: Zinc oxide; HDF: Human dermal fibroblast; UV: Ultraviolet; LHS: Layered hydroxide salt; ZCA: Cinnamate- zinc layered hydroxide interc[r]

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Drilling of TiO2 and Zns Filled Gfrp Composites

Drilling of TiO2 and Zns Filled Gfrp Composites

Composites can be joined with the help of fasteners, preferably mechanical fastening, and to do so, it is nec- essary to drill holes on the composite plates. Hence in the present work drilling is considered as the machining op- eration and carried-out on filled and unfilled composites. Drilling holes in composites can cause failures that are different from those encountered when drilling metals. Delamination, fracture, break-out and separation are some of the most common failures. Delamination (sur- face and internal) is the major concern during drilling composite laminates as it reduces the structural integrity, results in poor assembly tolerance, adds a potential for long term performance deterioration and may occur at both the entrance and exit plane. Delamination can be
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Layered spatial modulation

Layered spatial modulation

The proposed L-SM scheme is a combination of a multi-layered coding scheme and the spatial modulation. The codeword of the multi-layered coding scheme contains a number of layers with the same number of active transmit antennas. A number of phase shifts are inserted in the codeword among the layers and symbols to maximize the diversity and coding gains. When all transmit antennas are active, one codeword is transmitted over one codeword period. When the total number of transmit antennas is greater than or equals twice the number of active transmit antennas, two codewords are transmitted from different
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Pharmacognostical studies of apamarga (achyranthesaspera linn.)  and it’s tikshna kshara

Pharmacognostical studies of apamarga (achyranthesaspera linn.) and it’s tikshna kshara

Transverse section of root showed single layered epidermis, 19 layered, rectangular, tangentially, elongated, walled cork cells. Conjunctive parenchymatous tissues and Arcas or patches of phloem were much smaller and hence appear d in the xylem mass in the stem. Pith was absent and Xylem composed of tracheids, fibers and parenchyma; vessels with both simple and bordered pits.

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Finite Element Simulation of Ballistic Impact on Composite Plates

Finite Element Simulation of Ballistic Impact on Composite Plates

Abstract: In this study, effect of reinforcement type and different numerical composite damage material models are investigated in high velocity impact applications. Aramid and carbon-aramid hybrid fibers are used as a reinforcement material and epoxy is used as matrix in the composite plate. Numerical methods are performed for understanding energy absorption mechanisms. For numerical study, ANSYS is used as pre-processor and LS-Dyna is used as solver. Two failure models are used for composite materials which are MAT 22 (Mat_Composite_Damage) and MAT 59 (Mat_Composite_Failure_Solid_Model). Three different numerical models are created; MAT 22 with layered composite which is modeled as solid plies, MAT 59 with a layered composite which is modeled as solid plies and MAT 59 with single layer. Layered modeling technique is preferred because of weave style of composites. For modeling delamination, contact with tie-break option is used between composite layers. Experiment results are used for comparison of numerical results. 7.62 M61 type AP (Armor Piercing) projectiles were used in experimental procedure as strikers. Residual velocities were measured by velocity measurement traps. Six different velocities were used for both composites which have different reinforcements. After performing numerical procedure, comparison is done with experimental results and good agreement is obtained in terms of ballistic limit velocities and residual velocities of projectile between experimental and numerical methods.
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Manufacturing Process of Polymer Matrix Composite with different description Process

Manufacturing Process of Polymer Matrix Composite with different description Process

The feature common to all composite processes is the combining of a resin, a curing agent, some type of reinforcing fiber, and in some cases a solvent. Typically, heat and pressure are used to shape and "cure" the mixture into a finished part. In composites, the resin acts to hold the fibers together and protect them, and to transfer the load to the fibers in the fabricated composite part. The curing agent, also known as hardener, acts as a catalyst and helps in curing the resin to a hard plastic. The reinforcing fiber imparts strength and other required properties to the composite [3]. Solvents may serve three purposes:
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External capabilities and the limits to social policy

External capabilities and the limits to social policy

If the capability approach is to elude latent individualism, it should be rooted in a layered or stratified social theory that has structural layers as well as individual ones and considers how they influence capabilities. Layers should be interdependent but conceptually distinct, with no reductionism that gives primacy to one layer and relegates the rest to subordinate rank. Unlike orthodox economics, which is committed to individualism, social theory has aimed for a non-reductionist outlook and an equal treatment of agency and structure. Numerous theories of this sort have been put forward, in different terminology and with different arguments but agreeing on the pitfalls of individualistic or structural reductionism (prominent examples are Bourdieu, 1977; Bhaskar, 1979; Giddens, 1984; Archer, 1995; Mouzelis, 1995). For present purposes, the requirement is to add structural layers to the theory and let them interact with the individual layer. One way to do so is to identify structural and social capacities to act, putting them alongside individual capacities (Jackson, 2005). The theoretical underpinning of the capability approach can then draw upon three layers, two of which have a social and structural nature.
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Introduction to Mobile Cloud Computing and Battery Optimization in Mobile Devices

Introduction to Mobile Cloud Computing and Battery Optimization in Mobile Devices

architecture, Layered architecture, Open Mobster architecture and many more. But in this paper we focus on the Layered and Open Mobster architecture of mobile cloud comp[r]

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Effect of Nitriding on Wear Behavior of Graphite Reinforced Aluminum Alloy Composites

Effect of Nitriding on Wear Behavior of Graphite Reinforced Aluminum Alloy Composites

Aluminum 6061 alloy with the chemical composition given in Table 1 was used as the matrix material. The optical emission spectrometer was used determine the chemical composition of the alloy. The reinforcement material used was graphite which is a solid lubricant with adequate resistance to wear. The composites were fabri- cated by liquid metallurgy technique, the details of which are available elsewhere [6]. Graphite particles (0%, 3%, 5% and 7% by weight) were heated separately to a no- minal temperature to remove moisture content if any, and introduced into the vortex of the effectively degassed Al 6061 molten alloy. The molten alloy was stirred rigo- rously using a stirrer having a ceramic coated steel im- peller.
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Conventional and Advanced Composites in Aerospace Industry: Technologies Revisited

Conventional and Advanced Composites in Aerospace Industry: Technologies Revisited

PMCs use organic polymer as the matrix, which is primarily responsible for shape, rigidity, transference of load uniformity through the bonding of reinforcement and matrix, and protects both composites and reinforcements from chemical and corrosion attacks [7, 10]. In commercial PMCs, the matrix phase can be classified as either thermoset or thermoplastic. Thermoset plastics cannot be heat-softened, melted and reshaped again once molded. Some examples of thermosetting plastic are polyesters, vinyl esters, epoxies, bismaleimides, and polyamides. 3D crosslinked structure originating from the curing possesses provides high dimensional and chemical stability, high-temperature strength, good resistance to cracking and durability compared to thermoplastics [7]. Thermosetting polyesters and vinyl esters are primarily used in fiber-reinforced plastics due to their low cost. Epoxies are
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