scholarly journals Experimental Investigation of Fatigue Debonding Growth in FRP–Concrete Interface

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1459 ◽  
Author(s):  
Xinzhe Min ◽  
Jiwen Zhang ◽  
Chao Wang ◽  
Shoutan Song ◽  
Dong Yang
Keyword(s):  
Growth Rate ◽  
Weight Ratio ◽  
High Strength ◽  
Load Level ◽  
Experimental Results ◽  
Fatigue Load ◽  
Load Range ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Externally Bonded

An externally bonded fiber reinforced polymer (FRP) plate (or sheet) is now widely used in strengthening bending members due to its outstanding properties, such as a high strength to weight ratio, easy operating, corrosion and fatigue resistance. However, the concrete member strengthened by this technology may have a problem with the adhesion between FRP and concrete. This kind of debonding failure can be broadly classified into two modes: (a) plate end debonding at or near the plate end, and (b) intermediate crack-induced debonding (intermediate crack-induced (IC) debonding) near the loading point. The IC debonding, unlike the plate end debonding, still needs a large amount of investigation work, especially for the interface under fatigue load. In this paper, ten single shear pull-out tests were carried out under a static or fatigue load. Different load ranges and load levels were considered, and the debonding growth process was carefully recorded. The experimental results indicate that the load range is one of the main parameters, which determines the debonding growth rate. Moreover, the load level can also play an important role when loaded with the same load range. Finally, a new prediction model of the fatigue debonding growth rate was proposed, and has an excellent agreement with the experimental results.

scholarly journals Numerical Modeling of GFRP Reinforced Concrete Slabs

2017 ◽  
Vol 1 (4) ◽  
Author(s):  
Omer R EL Zaroug, John P Forth, Jianqiao YE
Keyword(s):  
Finite Element ◽  
Mechanical Load ◽  
Weight Ratio ◽  
High Strength ◽  
Load Range ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Element Program ◽  
Fibre Reinforced Polymer

The use of non-metallic fibre reinforced polymer reinforcement as an alternative to steel reinforcement in concrete is gaining acceptance mainly due to its high corrosion resistance. High strength-to-weight ratio, high stiffness-to-weight ratio and ease of handling and fabrication are added advantages. Other benefits are that they do not influence to magnetic fields and radio frequencies and they are thermally non-conductive. However, the stress-strain relationship for Glass fibre reinforced polymer reinforcement (GFRP) is linear up to rupture when the ultimate strength is reached. Unlike steel reinforcing bars, GFRP rebars do not undergo yield deformation or strain hardening before rupture. Also, GFRP reinforcement possesses a relatively low elastic modulus of elasticity compared with that of steel. As a consequence, for GFRP reinforced sections, larger deflections and crack widths are expected than the ones obtained from equivalent steel reinforced sections for the same load. This investigation provides details of the numerical analysis of GFRP reinforced slabs loaded mechanically using the commercial finite element program (DIANA). To prove the validity of the proposed finite element approach, a comparison is made with experimental test results obtained from full-size slabs. The comparisons are made on the basis of first cracking load, load-deflection response at midspan, cracking patterns, mode of failure and loads at failure. Using the DIANA software for the analysis of GFRP reinforced slabs under mechanical load is possible and can produce acceptable predictions throughout the load range in terms of final load and crack patterns. However, DIANA overestimated the first cracking load and tended to over predict the experimental deflections.  

scholarly journals Flexural Behavior of Artificially Degraded Steel I Section Externally Bonded With GFRP, BFRP&CFRP

2019 ◽  
Vol 8 (2) ◽  
pp. 2478-2484
Keyword(s):  
Weight Ratio ◽  
Steel Structure ◽  
Steel Structures ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Structure Result ◽  
Strengthening Method

Due to the distinctive advantages such as high strength to weight ratio, high resistance to corrosion and chemical attacks, fiber reinforced polymer (FRP) sheets are widely used for strengthening and repairing of existing steel structures. In last two decades, study has been carried out over the use of FRP for strengthening and repairing of concrete structures. More recently, the use of FRP to strengthen existing steel structures has received much attention. Strengthening and retrofitting is necessary for steel structure after some time because durability and capacity of steel structure get reduced over the time .Conventional strengthening method such as welding of additional steel plate to existing structure result in increase in dead load , also it will undergo corrosion if strengthen structure is placed in corrosive environment. Use of FRP for strengthening and retrofitting of steel structure will be the excellent solution for these disadvantages. The main aim of this paper is to study the flexural behavior of artificially degraded steel I section externally bonded with GFRP, BFRP, and CFRP

On-Site Pull-Out Tests of Steel Anchor Spikes Applied to Brickwork Masonry

2014 ◽  
Vol 624 ◽  
pp. 266-274 ◽  
Author(s):  
Matteo Panizza ◽  
Paolo Girardello ◽  
Enrico Garbin ◽  
Maria Rosa Valluzzi ◽  
Giuliana Cardani ◽  
...  
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Point Of View ◽  
Clay Brick ◽  
Bond Behaviour ◽  
Reinforced Polymers ◽  
Pull Out ◽  
Externally Bonded ◽  
Steel Cords ◽  
Steel Cord

Externally Bonded (EB) composite materials are becoming a widespread solution for strengthening interventions on masonry buildings, even Cultural Heritage structures, due to several positive aspects mainly related to their high strength-to-weight ratio. In recent years, beside common epoxy-based Fibre-Reinforced Polymers (FRP), steel-based composites have been proposed: they are composed by unidirectional high-strength steel cords that can be coupled to either organic (Steel Reinforced Polymers, SRP) or inorganic (Steel Reinforced Grouts, SRG) matrices, in relation to their optimized spacing. The bond behaviour of all these EB composites has a strong influence over the effectiveness of interventions, since the detachment of reinforcements from the substrate generally represents the weaker failure mechanism. In order to improve this aspect, several anchorage devices have been proposed, being spikes, among them, one of the most suitable for masonry supports. Spikes are made of a bundle of fibres partly in the form of a bar, to be inserted and glued into a hole drilled in the substrate, and partly loose, to be spread and connected to reinforcement strips. Despite their importance also from a design point of view and considering the variety of shapes and materials, there are still few investigations in this field, being clear that both the spike-to-reinforcement and the spike-to-masonry connections need to be studied. Focused on the spike-to-masonry connection, this paper is aimed at investigating the performance of steel cord spikes applied to existing clay brick masonry, by means of overall 39 pull-out tests carried out taking into account the bonded length (equal to the hole depth), the type of embedding material and the number of steel cords forming the anchorage. The main results of this experimentation are herein presented and discussed.

scholarly journals Sequential Laser–Mechanical Drilling of Thick Carbon Fibre Reinforced Polymer Composites (CFRP) for Industrial Applications

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2136
Author(s):  
Sharizal Ahmad Sobri ◽  
Robert Heinemann ◽  
David Whitehead
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Weight Ratio ◽  
High Strength ◽  
Industrial Applications ◽  
Fibre Laser ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Thrust And Torque

Carbon fibre reinforced polymer composites (CFRPs) can be costly to manufacture, but they are typically used anywhere a high strength-to-weight ratio and a high steadiness (rigidity) are needed in many industrial applications, particularly in aerospace. Drilling composites with a laser tends to be a feasible method since one of the composite phases is often in the form of a polymer, and polymers in general have a very high absorption coefficient for infrared radiation. The feasibility of sequential laser–mechanical drilling for a thick CFRP is discussed in this article. A 1 kW fibre laser was chosen as a pre-drilling instrument (or initial stage), and mechanical drilling was the final step. The sequential drilling method dropped the overall thrust and torque by an average of 61%, which greatly increased the productivity and reduced the mechanical stress on the cutting tool while also increasing the lifespan of the bit. The sequential drilling (i.e., laser 8 mm and mechanical 8 mm) for both drill bits (i.e., 2- and 3-flute uncoated tungsten carbide) and the laser pre-drilling techniques has demonstrated the highest delamination factor (SFDSR) ratios. A new laser–mechanical sequence drilling technique is thus established, assessed, and tested when thick CFRP composites are drilled.

Stretch Formability Behaviour of Glass Fibre Reinforced Nanoclay on Fiber Metal Laminated Composites

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
K. Logesh ◽  
V.K Bupesh Raja ◽  
C. Krishnaraj
Keyword(s):  
Ductile Fracture ◽  
Epoxy Resin ◽  
Glass Fibre ◽  
Weight Ratio ◽  
High Strength ◽  
Core Material ◽  
Fibre Metal Laminates ◽  
Sem Image ◽  
Pull Out ◽  
Fibre Metal

Innovations and research in material processing have brought forward new and improvised materials that are applied in body panels of automobiles, aircraft cabins and railway wagons. These materials are used widely is because of their good mechanical properties and their high strength to weight ratio. In this paper Fibre Metal Laminates (FMLs) were added with organo modified montmorillonite (MMT) commonly known as nanoclay along with epoxy resin. The homogeneous dispersion of nanoclay in epoxy resin is accomplished by a hand stirrer dispersion method in ethanol. The FML material was processed by hand layup method. In this study the aluminium alloy 5052-H32 was used as a skin material and glass fibre (woven roving) used as core material which is bounded by epoxy with 5 wt.% nano clay (closet 30B). The fabricated sandwich material was cut by using water jet machine as per IS standards for testing. The fabricated material subjected to erichsen cupping test and was observed under Scanning Electron Microscope (SEM). The results from SEM image analysis indicated that the FML had fibre pull out and surface cracks were obtained in the skin material. Progressive loading resulted in ductile fracture which is absorbed in the specimen. Fibres came across brittle failure and the skin through ductile fracture. Non-uniform distribution of reinforcement is observed in the material, SEM micrographs revealed fibre cracks which were oriented in line to the direction of crack growth on the skin material. This study shows that these fibre metal laminates can be safely applied in automotive field.

scholarly journals Pull-out Behaviour of Extended Hollobolts for Hollow Beam-Column Connections

2018 ◽  
Author(s):  
Mohd Fazaulnizam Bin Shamsudin ◽  
Walid Tizani
Keyword(s):  
Concrete Strength ◽  
Weight Ratio ◽  
High Strength ◽  
Element Model ◽  
Embedment Depth ◽  
Gusset Plates ◽  
Hollow Section ◽  
Hollow Beam ◽  
Pull Out ◽  
Joint Behaviour

The use of structural hollow sections (SHS) as columns in single-storey and multi-storey results in better compression strength, low surface area, architectural attractiveness and high strength to weight ratio. One major constraint when connecting to hollow sections is in accessing and tightening the bolt from the inside of the hollow section. To resolve this issue, full welding is usually applied. But this may suffer from high labour cost, and the potential of low quality welding due to workmanship and varied environmental conditions. Connecting using additional components, such as gusset plates and brackets, helps to ease this problem but lowers aesthetic appeal. To avoid the need to access to the inner face of the column section, new type of fasteners known as blind bolts were introduced. In this paper, experimental and numerical studies were conducted using a new anchored blind bolt known as the Extended HolloBolt (EHB), with the objective of using the component method for predicting joint behaviour within the tensile region. The behaviour of EHB in a group with different connection topologies and configurations was investigated using a total of 36 tests with one row of M16 Grade 8.8 and 10.9 bolts subjected to pull-out loading in tension. The experimental work covers a range of parameters such as bolt gauge, concrete strength, concrete type, bolt embedment depth and bolt class. A finite element model was implemented with good agreement between experimental and simulated load-deflection results, which have a maximum difference of 2.5%, shows that the model is suitable to be used for parametric studies or analytical work in further research on the EHB.

scholarly journals The electrical and mechanical properties of Cadmium chloride reinforced PVA:PVP blend films

2020 ◽  
Vol 12 ◽  
pp. 120006
Author(s):  
Rana S. Mahmood ◽  
Sabah A. Salman ◽  
Nabeel Ali Bakr
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Polymer Blend ◽  
Weight Ratio ◽  
Experimental Results ◽  
Casting Method ◽  
Ac Electrical Conductivity ◽  
Elongation At Break ◽  
Blend Films ◽  
Reinforced Polymer

In this study, pure polymer blend (PVA:PVP) film and salt (CdCl2·H2O) reinforced polymer blend films were prepared at different weight ratios (10 wt%, 20 wt%, 40 wt%) using the casting method. The effect of the salt weight ratio on the dielectric properties of the polymer blend films reinforced by CdCl2·H2O salt were investigated, and the experimental results showed that the dielectric constant and the dielectric loss factor decreased as the frequency increased for all polymer blend films. Moreover, the above-mentioned properties increased with increasing salt weight ratios at the same frequency. The experimental results also showed an increase in AC electrical conductivity with increasing frequency, for all polymer blend films, and the AC electrical conductivity also increased with an increase in the weight ratio of the salt at the same frequency. The effect of the salt weight ratio on the mechanical properties of the salt-reinforced PVA:PVP polymer blend films was also studied. The experimental results obtained from the tensile test of the salt-reinforced polymer blend films show significant change in the values of tensile strength, elongation at break, and Young’s modulus with increasing salt weight ratios; the hardness value first increases then decreases with increasing salt weight ratios, and the fracture energy value increases with increasing salt weight ratios, thus they could be good candidates for hard adhesives with low flexibility.

OPTIMIZATION OF MECHANICAL PROPERTIES OF E-GLASS WOVEN FABRIC COMPOSITE

2017 ◽  
Vol 41 (3) ◽  
pp. 375-386 ◽  
Author(s):  
N. Azhaguvel ◽  
S. Charles ◽  
M. Senthilkumar
Keyword(s):  
Mechanical Properties ◽  
Weight Ratio ◽  
High Strength ◽  
Influential Factor ◽  
Woven Fabric ◽  
Reinforced Polymer ◽  
Fabric Composite ◽  
Gfrp Composite ◽  
Material Orientation ◽  
Grey Relational

Manufacturing of composite material has been an extensive area of research as they have high strength-to-weight ratio that are equivalent or superior to many metallic materials. This paper describes the preparation of E-Glass (woven fabric) Fiber Reinforced Polymer Composite (GFRP) with different fiber mat material, orientation and resin. The purpose of this paper is to investigate the influence of the process parameters on the mechanical properties of GFRP composite using Taguchi experimental design in combination with Grey Relational Analysis (GRA). The conclusion revealed that fiber orientation and resin were the most influential factor on the mechanical properties, respectively. It is observed that the optimum properties were obtained at 400 fabric mat, polyester resin, 45°/–45°orientation.

Surface Roughness Study of Milled Carbon Fiber Reinforced Polymer (CFRP) Composite Using 4 mm 2-Flute Titanium Aluminum Nitride (TiAlN) Coated Carbide End Mills

2014 ◽  
Vol 887-888 ◽  
pp. 1101-1106 ◽  
Author(s):  
Mohamed Konneh ◽  
Sudin Izman ◽  
Mirza Emmil Dzahi Padil ◽  
Rosniza Roszat
Keyword(s):  
Surface Roughness ◽  
Weight Ratio ◽  
High Strength ◽  
Milling Process ◽  
Machining Parameters ◽  
Inherent Anisotropy ◽  
Pull Out ◽  
Cfrp Composite ◽  
End Mills ◽  
Coated Carbide

As the goal for aircraft weight reduction and low fuel consumption becomes a dire concern in aerospace industries, there is driving desire for the increasing use of advanced exotic materials such as composites, titanium and Inconels in the aerospace industry because of their high strength to weight ratio. Nevertheless the inherent anisotropy, inhomogeneous properties of CFRP and low bonding strength within the laminates make machining of these composite materials results in several undesirable effects such as delamination, micro-cracking, burr, fiber pull out and breakage. This paper discusses an experimental investigation into the influence of machining parameters on surface roughness when milling CFRP using 4 mm-diameter 2-fluted carbide end-mill coated with Titanium Aluminium Nitride (TiAlN). Relationship between the machining variables and the output variables is established and a mathematical model is predicted for the surface roughness produced during the milling process for the machining conditions investigated.

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