Search for: fiber-reinforced-plastics
Total 62 records
M.Sc. Thesis Sharif University of Technology ; Akbari, Javad
Nowadays, processes with the ability to machine advanced materials are very much needed by industries. Therefore, compare of a rotary ultrasonic-assisted machining process with a conventional machining process is carried out in this study. In order to evaluate this process, the milling and drilling processes are conducted on the carbon fiber-reinforced polymer composite and titanium materials where cutting forces, surface roughness, and fiber pull-out are selected as critical factors for analysis. As a result, it is seen that rotary ultrasonic-assisted machining has a good performance in the milling and drilling of advanced materials. In particular, it is shown that fiber pull-out is...
Fracture Modeling of Strengthened Arc Concrete Structures with FRP by Concrete Damage Plasticity and XFEM, M.Sc. Thesis Sharif University of Technology ; Khoei, Amir Reza
Usage of FRP material is developed in recent year, because advantages of this material researcher studied the effect of this strengthening method on beam column and masonry structures, but few research’s related to RC arches that strengthen with FRP. This studies showed performance of structure properties but many parameters influence. In this research, a model developed that can model RC arch with FRP till complete failure, after verifying model with experimental result parametric study done. This parameter are effect of strengthening scheme, influence of shape of arch and geometry of arches. Concrete damage plasticity used for modeling behavior of concrete, also for modeling interface...
M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi
In recent years, the development of the plate bonding repair technique has been shown to be applicable to many existing strengthening problems in the building industry. This technique may be defined as one in which composite sheets or plates of relatively small thickness are bonded with an epoxy adhesive to, in most cases, a concrete structure to improve its structural behaviour and strength. The sheets or plates do not require much space and give a composite action between the adherents. The old structure and the new bonded-on material create a new structural element that has a higher strength and stiffness than original one. According to the available methods of analysis and design for...
Investigation of Dynamic Behavior of Concrete Slabs Reinforced with GFRP Bars and Prestressed Concrete Slabs under Impact Loading, Ph.D. Dissertation Sharif University of Technology ; Khaloo, Alireza
Prestressed and reinforced concrete slabs are common structural elements that could be exposed to impact loading. Although, use of reinforced concrete slabs and utilization of Fiber Reinforced Polymer (FRP) as alternative to traditional steel reinforcement slabs are growing, but the influence of various parameters on their response under impact loads is not properly evaluated. In addition, studies on steel reinforced concrete slabs have been found in literature, but investigation of prestressed slabs and GFRP reinforced concrete slabs under impact load is limited. This study investigated the effect of rebar’s material, amount and arrangement of reinforcements, concrete strength and slab...
M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza
FRP rebars due to various properties such as high resistance to weight ratio, high corrosion resistance, high tensile strength, low weight, resistance to electrical and magnetic conductivity, and other desirable properties, have always been an interesting topic for researchers as an alternative to steel rebars in special conditions.In this research, a two-dimensional sway intermediate concrete frame with three stories and two bays reinforced with GFRP bars was designed and studied. Unlike previous researches and design codes, the compressive strength of the bars was considered in the design process. With computer coding in Matlab software, column interaction diagrams and a special contour...
A Study on the Effect of Different Lubrication Methods on Surface Integrity and Tool Wear during Ultrasonic-Assisted Milling of CFRP, M.Sc. Thesis Sharif University of Technology ; Akbari, Javad
The aim of this study was to compare the effect of different cooling conditions (dry, flood, mql) on machined surface parameters (smoothness and protrusion of fibers) and tool erosion in carbon fiber reinforced plastic composite materials (CFRP) in the presence of ultrasonic vibrations or without it. Is. Today, carbon fiber reinforced plastic composite materials or CFRP have become one of the most widely used materials in industry due to their strength and light properties. For example, these materials have been used in the manufacture of products from commercial aircraft to shoes, tennis rackets, golf clubs, fishing rods, etc. The combination of carbon fibers woven with resin in alternating...
Fabrication and Investigation of Structure and Mechanical Properties of Bagasse Fibers Reinforced PP: Role of Alkalization and Calcium Carbonate Filler, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza
The consumption of plastics in the world is increasing and this is accompanied by the challenges of production from oil products and carbon footprint, waste production and environmental issues. The solutions to these challenges are material recycling and the production of biocompatible plastics. Polypropylene is a widely used polymer that is commonly used in conjunction with reinforcements such as fiberglass. Natural fibers can be substituted to increase the biocompatibility of the composite, which, despite its many advantages, presents challenges. The most important challenge is the poor adhesion of the fibers and the matrix due to the hydrophilicity of natural fibers and hydrophobicity of...
Article Journal of Reinforced Plastics and Composites ; Volume 27, Issue 15 , 2008 , Pages 1635-1647 ; 07316844 (ISSN) ; Moslemian, R ; Afshin, M ; Nazemi, M. H ; Sharif University of Technology
This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed. These solid laminates include a number of glass plies with total thickness equal to core thickness. The effect of solid laminate size and interface angle of foam-solid laminate in the bonding zone on the bearing strength, failure loads and type of modes are investigated. The numerical study is performed using 3D FEM in ANSYS commercial code. Tsai-Wu failure criterion is used in the failure analysis. The...
Article Surface and Coatings Technology ; Volume 344 , 25 June , 2018 , Pages 729-741 ; 02578972 (ISSN) ; Toufigh, V ; Mofid, M ; Sharif University of Technology
Elsevier B.V 2018
This research investigated the long-term environmental effects on the bond at the interface between fiber-reinforced polymer (FRP) and a masonry brick. Seven types of FRP fabrics were used and placed on the masonry brick using the wet lay-up technique. Unidirectional and bidirectional fibers made of aramid, carbon, and glass and also combination of these fabrics were used. A total of 525 specimens were exposed to five chemical solutions with pH values of 2.5, 7, 10, 12.5 and substitution sea water for 1, 3, 6, 9 and 12 months. A chamber was also used to simulate the ultraviolent (UV) radiation on the specimens. A series of single-lap shear tests were performed on these specimens to determine...
Article European Journal of Wood and Wood Products ; Volume 76, Issue 1 , 2018 , Pages 163-174 ; 00183768 (ISSN) ; Toufigh, V ; Mofid, M ; Sharif University of Technology
Springer Verlag 2018
The advantages of fiber reinforced polymer (FRP), such as high specific strength, resistance against corrosion and formability, have made it a more acceptable alternative to conventional materials regarding repairing and retrofitting of structures. Although investigations in recent years have proved the concern of civil engineers about the environmental effects on the bond between FRP and concrete or masonry (especially moisture and temperature), only few researches have been reported on FRP-wood interfaces. This research investigated the effect of five different environments on the bond at the interface between FRP and wood. A series of pull-out tests were performed on 375 wood specimens...
Investigation of the equivalent material properties and failure stress of the re-entrant composite lattice structures using an analytical model, Article Composite Structures ; 2020 ; Farrokhabadi, A ; Sharif University of Technology
Elsevier Ltd 2020
In the present study, a novel theoretical model is developed, based on classical laminate theory, to predict the equivalent mechanical properties of the re-entrant lattice structures, which composed of continuous fiber reinforced composite struts. Three main mechanism of stretching, flexing and hinging are considered and a general closed-form formulation is derived to estimate the auxetic honeycomb's elastic and shear modulus as well as Poisson's ratios. In spite of previous studies in which the response of honeycomb structures is modeled using beam theory, here, each strut of unit cell is expressed as a composite laminate with orthotropic mechanical properties and classical laminate theory...
Article Construction and Building Materials ; Volume 169 , 2018 , Pages 578-590 ; 09500618 (ISSN) ; Jafari, A ; Bazli, M ; Ghahri, R ; Sharif University of Technology
Elsevier Ltd 2018
This paper presents the results of diagonal compression tests conducted on a series of un-reinforced and reinforced masonry specimens. Reinforced specimens were strengthened by using three types of mortar coating (with and without inner reinforcement), mesh reinforcement, and PP-band reinforcement. In particular, four different reinforcement methods with mortar coating (bare mortar coating, coating with steel mesh, coating with polymer reinforcement, and coating with GFRP mesh reinforcement), three different mesh-only reinforcement (steel mesh, polymer mesh with larger grids, and polymer mesh with smaller grids), and 2 different arrangements of PP-bands (4 × 4 and 6 × 6) were tested. Also,...
Article Mechanics of Advanced Materials and Structures ; 2017 , Pages 1-8 ; 15376494 (ISSN) ; Toufigh, V ; Saadatmanesh, H ; Ahmari, S ; Kabiri, E ; Sharif University of Technology
This research investigates the flexural behavior of a polymer concrete beam/pile encased with carbon fiber sleeve. The mechanical properties of carbon fiber sleeves in tension and cement and polymer concrete in compression were determined. Polymer concrete beams were tested in flexure to determine the bending moment capacity. Then, the test results were compared to the theoretical model results. Finally, a parametric study was conducted to determine the influence of beam/pile parameters on the capacity of the element. Based on the investigation, carbon fiber sleeve filled with polymer concrete exhibits outstanding structural performance including ductility and bending capacity. © 2017 Taylor...
Article Journal of Reinforced Plastics and Composites ; Volume 36, Issue 18 , 2017 , Pages 1355-1368 ; 07316844 (ISSN) ; Yarigarravesh, M ; Mofid, M ; Sharif University of Technology
This study examined the bond at the interface of masonry bricks and fiber-reinforced polymer when exposed to five environments. Three fabrics (aramid, carbon, and glass) and one type of epoxy resin were used. A total of 375 brick-fiber-reinforced polymer specimens were made using wet lay-up technic and exposed to chemical solutions at four pH values (2.5, 7, 10, and 12.5) and substitute seawater. The effect of dry heat on the bond at the interface was also investigated. Single-lap shear tests were then carried out on the samples after 2, 4, 6, 8, 10, and 13 weeks of exposure. The experimental results indicated that freshwater and seawater had a considerable effect on the bond strength of...
Article European Journal of Wood and Wood Products ; Volume 76, Issue 6 , 2018 , Pages 1623-1636 ; 00183768 (ISSN) ; Yarigarravesh, M ; Mofid, M ; Sharif University of Technology
This research investigated the long-term environmental effects on bond strength at the interface between fiber- reinforced polymers (FRPs) and timber. A total of 581 timber specimens were bonded with seven types of FRP sheets (unidirectional and bidirectional glass, carbon, aramid, and hybrids) using a wet lay-up technique. The specimens were exposed to acidic, alkaline, fresh water, and sea water solutions with pH of 2.5, 7, 7.25, 10, and 12.5 for 1, 3, 6, 9, and 12 months. A chamber was also used to simulate ultraviolet radiation after 6 months. A series of single-lap shear tests were then conducted to determine the interfacial bond strength reduction. The results showed that bidirectional...
Article Mechanics of Advanced Materials and Structures ; Volume 26, Issue 4 , 2019 , Pages 333-340 ; 15376494 (ISSN) ; Toufigh, V ; Saadatmanesh, H ; Ahmari, S ; Kabiri, E ; Sharif University of Technology
Taylor and Francis Inc 2019
This research investigates the flexural behavior of a polymer concrete beam/pile encased with carbon fiber sleeve. The mechanical properties of carbon fiber sleeves in tension and cement and polymer concrete in compression were determined. Polymer concrete beams were tested in flexure to determine the bending moment capacity. Then, the test results were compared to the theoretical model results. Finally, a parametric study was conducted to determine the influence of beam/pile parameters on the capacity of the element. Based on the investigation, carbon fiber sleeve filled with polymer concrete exhibits outstanding structural performance including ductility and bending capacity
Article International Journal of Solids and Structures ; Volume 42, Issue 9-10 , 2005 , Pages 2741-2754 ; 00207683 (ISSN) ; Nosier, A ; Zebarjad, S. M ; Sharif University of Technology
A semi-analytical method is developed for the analysis of deformation and three-dimensional stress field in rotating annular disks made of cylindrically orthotropic nested rings. The method is based on a layerwise theory and the Hamilton principle. The proposed method is applied to calculate in-plane and out-of-plane stresses in a rotating disk made up of two nested rings that is rigidly fixed (or free) at the inner boundary and is free at the outer boundary. The computed results are compared with those obtained from the finite element method. It is found that because of discontinuity of material properties, the stress field is three-dimensional at the interface of two rings. © 2004 Elsevier...
The effects of elevated temperatures on the performance of concrete-filled pultruded GFRP tubular columns, Article Thin-Walled Structures ; Volume 169 , 2021 ; 02638231 (ISSN) ; Khaloo, A ; Azizmohammadi, M ; Sharif University of Technology
Elsevier Ltd 2021
Usage of concrete-filled pultruded glass fiber-reinforced polymer (GFRP) tubes (CFPGT) as columns can increase the service life of structures. However, marine structures such as oil platforms are always prone to fire because of the low resistance to the elevated temperatures. The purpose of this investigation is to evaluate the effects of concrete core strength (30 and 60 MPa), and exposure temperature (25, 100, 200, 300, and 400 °C) and time (60 and 120 min) on the compressive and bond behavior of CFPGTs. The properties of unexposed and exposed concrete core, pultruded GFRP hollow tubes, and CFPGTs were determined via compressive and disk-split tests. Also, the push-out test was used to...
Article Journal of Nanomaterials ; Volume 2016 , 2016 ; 16874110 (ISSN) ; Haji Gholami, I ; Masajedian, S ; Mertiny, P ; Sameoto, D ; Taheri, F ; Sharif University of Technology
Hindawi Publishing Corporation 2016
Crashworthiness, energy absorption capacity, and safety are important factors in the design of lightweight vehicles made of fiber-reinforced polymer composite (FRP) components. The relatively recent emergence of the nanotechnology industry has presented a novel means to augment the mechanical properties of various materials. As a result, recent attempts have contemplated the use of nanoparticles to further improve the resiliency of resins, especially when resins are used for mating FRP components. Therefore, a comprehensive understanding of the response of nanoreinforced polymer composites, subjected to various rates of loading, is of paramount importance for developing reliable structures....
Dynamic performance enhancement of RC slabs by steel fibers vs. externally bonded GFRP sheets under impact loading, Article Engineering Structures ; Volume 213 , 2020 ; Khaloo, A ; Sadraie, H ; Sharif University of Technology
Elsevier Ltd 2020
Recently, to improve the dynamic behavior of Reinforced Concrete (RC) slabs under impact load, the methods of externally bonding Glass Fiber Reinforced Polymer (GFRP) sheets to slab and internally reinforcing concrete by steel fibers have been proposed. Nevertheless, it is required to investigate the comparison between these two methods on response of RC slabs under impact loads. In this study, the influence of volume fraction of steel fibers, the number of GFRP sheet layers (one or two) and the arrangement of GFRP sheets (covering the whole or parts of surface), are examined. Performance of fourteen 1000 × 1000 × 75 mm concrete slabs including one plain slab, one steel RC slab, three steel...