scholarly journals Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part I: Bolted Joining

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2252
Author(s):  
Anna Galińska
Keyword(s):  
Composite Materials ◽  
Failure Modes ◽  
Bolted Joints ◽  
Weak Point ◽  
Mechanical Joining ◽  
Metal Elements ◽  
Reinforced Polymer ◽  
Reinforced Plastic ◽  
Fibre Reinforced Polymer ◽  
Inspection Techniques

As the fibre reinforced plastic composites gain larger and larger share in industry, the problem of joining them with metal elements becomes significant. The current paper is the first part of the literature review, which gathers and evaluates knowledge about methods suitable for mechanical joining of composite and metal elements. This paper concerns bolted joining, because this method of mechanical joining is widely used for joining composite materials. The paper describes failure modes of bolted joints in composite materials, the influence of the bolt clamping torque, the clearance between the bolt and the hole and aging on the performance of the joint, drilling techniques used in composite materials in order to minimize damages, different fastener types, inspection techniques, and finally, the techniques that have been developed in order to improve the strength of the bolted joints in composites. Since the hole drilled in a composite material in order to perform bolted joining is a weak point of the structure, those techniques: bonded inserts, titanium foil internal inserts, fibre steering, additional reinforcement, and moulded holes, mainly aim to improve the strength of the hole in the composite. The techniques have been discussed in details and compared with each other in the summary section.

scholarly journals Mechanical Joining of Fibre Reinforced Polymer Composites to Metals—A Review. Part II: Riveting, Clinching, Non-Adhesive Form-Locked Joints, Pin and Loop Joining

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1681 ◽  
Author(s):  
Anna Galińska ◽  
Cezary Galiński
Keyword(s):  
Point Of View ◽  
Mechanical Joining ◽  
Fiber Reinforced Plastic ◽  
Metal Elements ◽  
Reinforced Polymer ◽  
Current Review ◽  
Reinforced Plastic ◽  
Weight Penalty ◽  
Fibre Reinforced Polymer ◽  
Commercial Applications

As fiber reinforced plastic composites gain an increasingly larger share in aerospace structures, the problem of joining them with metal elements becomes significant. The current paper is the second part of the literature review, which gathers and evaluates knowledge about methods suitable for the mechanical joining of composite and metal elements. This paper reviews the joining methods other than bolted joining, which are discussed in the first part of the review, namely self-piercing riveting, friction riveting, clinching, non-adhesive form-locked joints, pin joints, and loop joints. Some of those methods are full-fledged and employed in commercial applications, whereas others are merely ideas tested at the level of specimens. The current review describes the ideas and the qualities of the joining methods as well as the experimental work carried out so far. The summary section of this paper contains a comparison of those methods with the reference to their qualities, which is important from the point of view of a composite structure designer: possibility of the joint disassembly, damages induced in composite, complication level, weight penalty, range of possible materials to be joined, and the joint strength.

Durability of coral-reef-sand concrete beams reinforced with basalt fibre-reinforced polymer bars in seawater

2021 ◽  
pp. 136943322098166
Author(s):  
Wang Xin ◽  
Shi Jianzhe ◽  
Ding Lining ◽  
Jin Yundong ◽  
Wu Zhishen
Keyword(s):  
Coral Reef ◽  
Marine Environment ◽  
Failure Modes ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Basalt Fibre ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

A combination of coral reef sand (CRS) concrete and fibre-reinforced polymer (FRP) bars provides an effective solution to the durability deficiency in conventional RC structures. This study experimentally investigates the durability of CRS concrete beams reinforced with basalt FRP (BFRP) bars in a simulated marine environment. Flexural tests are conducted on a total of fourteen CRS concrete beams aged in a cyclic wet-dry saline solution at temperatures of 25, 40 and 55°C. The variables comprise the types of reinforcement (steel and BFRP), the aging duration and the temperature. The failure modes, capacities, deflections and crack development of the beams are analysed and discussed. The results indicate that the ultimate load of the beams exhibits no degradation after aging, whereas the failure mode of the BFRP-CRS concrete beams transition from flexure to shear, which is caused by the degradation in the mechanical properties of the stirrups. The aged BFRP-CRS concrete beams show a substantial increase of over 70% in their initial stiffness compared with the control beams (beams without aging) and a substantial decrease in their crack width after aging due to the prolonged maturation of the concrete. Furthermore, a formula for calculating the shear capacity in the existing code is modified by a partial factor equal to 2, which can predict the capacity of a CRS concrete beam reinforced with BFRP bars in a marine environment.

Tribological behaviour of fibre-reinforced thermoset polymer composites: A review

2020 ◽  
Vol 234 (11) ◽  
pp. 1439-1449
Author(s):  
Santosh Kumar ◽  
KK Singh
Keyword(s):  
Composite Materials ◽  
Polymer Composites ◽  
Matrix Material ◽  
Research Work ◽  
Weight Ratio ◽  
Tribological Behaviour ◽  
Glass Fibres ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Thermoset Polymer

Application of fibre-reinforced polymer composites has increased over the last two decades as compared to conventional materials. This improvement in the application of fibre-reinforced polymer composites is attributed to their unique material properties, such as high strength and stiffness-to-weight ratio, specific modulus and internal vibration damping. However, in most of the industrial applications, composite materials encounter tribological complications. Economic indicators and market dynamics suggested that the market for composite materials is booming and the dominant materials are carbon fibres, glass fibres and thermoset polymer (polyester resin) in resin segments. That is why tribological characteristics are crucial in designing carbon and glass-based fibre-reinforced polymer components. Owing to this importance, the study of tribological behaviour of fibre-reinforced polymer composite materials has expanded significantly. The present study has made an attempt to review the fundamental tribological applications and critical aspects of fibre-reinforced polymers, based on research work, which has been carried out over the past couple of decades. This work has primarily focused on the fibre-reinforced polymer composites, based on carbon and glass fibres with thermosets as the matrix material for probing into tribological behaviours. In the process, the focus has largely been on the most commonly occurring erosive and abrasive mode of wear process.

Fibre Reinforced Polymer Rebar

2015 ◽  
Vol 1124 ◽  
pp. 89-96
Author(s):  
Jan Prokeš
Keyword(s):  
Heat Transfer ◽  
Composite Materials ◽  
Concrete Cover ◽  
Fire Tests ◽  
Corrosion Attack ◽  
Advanced Composite ◽  
Reinforced Polymer ◽  
Advanced Composite Materials ◽  
Fibre Reinforced Polymer

The paper is focused on the use of advanced composite materials in the real application areas of buildings exposed to extreme environmental stress. The paper describe properties of composite rebar, especially with regards to long-term resistance to chemical and corrosion attack, minimization of heat transfer or resistance in construction with reduced concrete cover. The paper also presents behavior of composite rebar and concrete samples with composite reinforcement during loading and fire tests.

Failure Analysis in Hybrid Composite Laminates Using Acoustic Emission and Microscopy

2015 ◽  
Author(s):  
Mostefa Bourchak ◽  
Yousef Dobah ◽  
Abdullah Algarni ◽  
Adnan Khan ◽  
Waleed K. Ahmed
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Failure Analysis ◽  
Hybrid Composite ◽  
Failure Modes ◽  
Glass Fibers ◽  
Frp Composite ◽  
Reinforced Plastic ◽  
Microscopy Techniques ◽  
Damage Type

Fiber Reinforced Plastic (FRP) composite materials are widely used in many applications especially in aircraft manufacturing because they offer outstanding strength to weight ratio compared to other materials such as aluminum alloys. The use of hybrid composite materials is potentially an effective cost saving design while maintaining strength and stiffness requirements. In this work, Woven Carbon Fibers (WCFs) along with Unidirectional Glass Fibers (UDGFs) are added to a an aerospace-rated epoxy matrix system to produce a hybrid carbon and glass fibers reinforced plastic composite plates. The manufacturing method used here is a conventional vacuum bagging technique and the stacking sequence achieved consists of a symmetric and balanced laminate (±451WCF, 03UDGF, ±451WCF) to simulate the layup usually adopted for helicopter composite blades constructions. Then, tensile static tests samples are cut according to ASTM standard using a diamond blade and tested using a servohydraulic test machine. Acoustic Emission (AE) piezoelectric sensors (transducers) are attached to the samples surface using a special adhesive. Stress waves that are released at the moments of various failure modes are then recorded by the transducers in the form of AE hits and events (a burst of hits) after they pass through pre-amplifiers. Tests are incrementally paused at load levels that represent significant AE hits activity which usually corresponds to certain failure modes. The unbroken samples are then thoroughly investigated using a high resolution microscopy. The multi load level test-and-inspect method combined with AE and microscopy techniques is considered here to be an innovation in the area of composite failure analysis and damage characterization as it has not been carried out before. Results are found to show good correlation between AE hits concentration zones and the specimens damage location observed by microscopy. Waveform analysis is also carried out to classify the damage type based on the AE signal strength energy, frequency and amplitude. Most of the AE activity is found to initiate from early matrix cracking that develops into delamination. Whereas little fiber failure activity has been observed at the initial stages of the load curve. The results of this work are expected to clear the conflicting reports reported in the literature regarding the correlation of AE hits characteristics (e.g. amplitude level) with damage type in FRP composite materials. In addition, the use of a hybrid design is qualitatively assessed here using AE and microscopy techniques for potential cost savings purposes without jeopardizing the weight and strength requirements as is the case in a typical aircraft composite structural design.

scholarly journals Strength Characteristics of Concrete Specimen Wrapped with Glass Fiber Reinforced Polymer

2020 ◽  
Vol 8 (5) ◽  
pp. 358-362
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Glass Fibre ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

Glass Fiber Reinforced Polymer (GFRP) is one of a relatively new class of composite material. These materials are manufactured from a combination of fibers and resins. These composite materials have proven to be efficient and economical for the development of new structures and the repair of deteriorating structures in civil engineering. One of the important reasons for the use of GFRP composite materials is because of its superior mechanical properties. These mechanical properties includes impact resistance, strength, stiffness, flexibility and also its enhanced ability to carry loads. In construction industry, in order to meet the advanced infrastructure requirements, new innovative technologies and materials are being introduced. Also any new technology or material has its own limitations but to meet the new requirements, new technologies and materials have to be invented and put to use. With structures becoming old and increasing bar corrosion, old buildings have to be retrofitted with additional materials to increase their durability and life. For strengthening and retrofitting of concrete structures confinement with FRP has various applications. In this project concrete specimens are wrapped with glass fibre reinforced polymers to study the effect of confinement in the strength of specimens. For wrapping bi-directional and uni-directional glass fibre reinforced polymer mats are used. During the uni-directional glass fibre reinforced polymer wrapping, it is wrapped in both horizontal and vertical directions. The fiber used in this paper is bi-directional fibre. To find the effect of wrapping, specimens are wrapped in one rotation and two rotations.

scholarly journals Strengthening of Precast RC Frame to Mitigate Progressive Collapse by Externally Bonded CFRP Sheets Anchored with HFRP Anchors

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jianwu Pan ◽  
Xian Wang ◽  
Fang Wu
Keyword(s):  
Failure Modes ◽  
Progressive Collapse ◽  
Analytical Models ◽  
Strengthening Effect ◽  
Rc Frame ◽  
Concrete Frames ◽  
Catenary Action ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Currently, the robustness of precast reinforced concrete frames is attracting wide attention. However, avoiding “strong beams and weak columns” during strengthening against progressive collapse is a key problem. To discuss this problem, an experimental study on two 1/2-scale precast frame subassemblages under a pushdown loading regime was carried out in this paper. One specimen was strengthened with carbon fibre-reinforced polymer (CFRP) sheets on the beam sides. The middle parts of the CFRP sheets were anchored with hybrid fibre-reinforced polymer (HFRP) anchors. Another specimen was not strengthened. The failure mechanisms, failure modes, and strengthening effect are discussed. The strengthening effect is very obvious in the early catenary action stage. No shearing failure develops on HFRP anchors, which proves that the anchoring method is effective. Based on the experimental results, analytical models and preventive strengthening design and construction measures to mitigate progressive collapse of the precast RC frame are proposed.

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