scholarly journals Sulfate and Calcium Chloride Resistance of Steel/Glass Fiber-Reinforced Polymer Hybrid Panel for Improved Movable Weir Application

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
S.-K. Lee ◽  
S.-Y. Yoo ◽  
C.-G. Park

This study evaluated the performance of a hybrid panel that can overcome the current problem of corrosion of the steel panels of improved movable weirs when they are exposed to a sulfate and calcium chloride environment such as sea water. A hybrid panel with glass fiber-reinforced polymer (GFRP) layers on both sides of a steel panel means that the central panel is not exposed to the external elements, which can avoid corrosion problems. In this study, to maximize the hybrid panel’s strength and durability, the moisture absorption characteristics and the durability in an accelerated environment were evaluated. The test results were considered to indicate no durability issues as the final absorption ratio was approximately 2.0% or less in all environments. Also, from the accelerated deterioration test results when the steel panel processed by sand blasting was applied in all accelerated deterioration environments, it satisfied the residual strength level of 65% or more. However, in the case without surface processing, upon exposure to MgSO4 solution, it did not satisfy the standard residual strength level of 65%. These results show that sand blasting on the surface of a steel panel is adequate for hybrid panels for improved movable weirs.

2017 ◽  
Vol 747 ◽  
pp. 220-225
Author(s):  
Alberto Pedro Busnelli ◽  
Ruben Edgardo López ◽  
Jorge Carlos Adue

This is the presentation of the research carried out by the Faculty of Engineering at Universidad Nacional de Rosario on the use of pultruded Glass Fiber Reinforced Polymer (GFRP) plates to increase the flexural strength of reinforced concrete beams.Pultruded plates are the type of elements made of composite materials which are most widely used for this kind of strengthening. Although around the world the material used for these plates is carbon fibers, its high cost prevents its widespread use in our country.One of the aims of our research program is, precisely, to verify whether it is possible to substitute such plates for significantly cheaper glass fiber elements manufactured in Argentina. The test results have proved that this alternative is feasible.What's more, the greater thickness of the glass fiber plates allows the use of additional anchor bolts. These bolts provide the system with post-critical resistance and ductility-characteristics which are absolutely necessary, for example, in structures in seismic areas.


2021 ◽  
Vol 9 (1) ◽  
pp. 72-78
Author(s):  
Osama Daoud ◽  
Ahmed Fadul

The behavior and shear strength of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars was investigated. Total of six reinforced concrete beams without stirrups were constructed and tested up to failure. The beams measured 1400 mm long, 150 mm wide and 300 mm deep and were tested in two-points bending with constant shear span 350 mm in all tested beams, and shear span to depth ratio a/d 1.37. The test variable was the reinforcement ratio. The test beams included three beams designed as tension control (T.C) with GFRP bars, three beams designed as compression control (C.C) with GFRP bars. The test results were compared with predictions provided by ACI 440.1R-15 design guideline and proposed equations in the literature. The test results indicated that the relatively low modulus of elasticity of FRP bars resulted in reducing shear strength. In addition, shear strength provided by ACI 440.1R-15 guideline underestimate shear strength capacity in which proposed equations in the literature had given better prediction than ACI 440.1R-15. The failure mode in T.C beams is diagonal tension by bond failure not by rupture of FRP and C.C beams is shear compression by crushing of the web in extreme fiber.  


Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Gabriel Mansour ◽  
Panagiotis Kyratsis ◽  
Apostolos Korlos ◽  
Dimitrios Tzetzis

There are numerous engineering applications where Glass Fiber Reinforced Polymer (GFRP) composite tubes are utilized, such as desalination plants, power transmission systems, and paper mill, as well as marine, industries. Some type of machining is required for those various applications either for joining or fitting procedures. Machining of GFRP has certain difficulties that may damage the tube itself because of fiber delamination and pull out, as well as matrix deboning. Additionally, short machining tool life may be encountered while the formation of powder like chips maybe relatively hazardous. The present paper investigates the effect of process parameters for surface roughness of glass fiber-reinforced polymer composite pipes manufactured using the filament winding process. Experiments were conducted based on the high-speed turning Computer Numerical Control (CNC) machine using Poly-Crystalline Diamond (PCD) tool. The process parameters considered were cutting speed, feed, and depth of cut. Mathematical models for the surface roughness were developed based on the experimental results, and Analysis of Variance (ANOVA) has been performed with a confidence level of 95% for validation of the models.


Author(s):  
Priyadarsini Morampudi ◽  
Kiran Kumar Namala ◽  
Yeshwanth Kumar Gajjela ◽  
Majjiga Barath ◽  
Ganaparthy Prudhvi

Lubricants ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 22
Author(s):  
Emadelddin Hassan ◽  
Iasonas Zekos ◽  
Philip Jansson ◽  
Toa Pecur ◽  
Christophe Floreani ◽  
...  

Erosion of tidal turbine blades in the marine environment is a major material challenge due to the high thrust and torsional loading at the rotating surfaces, which limits the ability to harness energy from tidal sources. Polymer–matrix composites can exhibit leading-blade edge erosion due to marine flows containing salt and solid particles of sand. Anti-erosion coatings can be used for more ductility at the blade surface, but the discontinuity between the coating and the stiffer composite can be a site of failure. Therefore, it is desirable to have a polymer matrix with a gradient of toughness, with a tougher, more ductile polymer matrix at the blade surface, transitioning gradually to the high stiffness matrix needed to provide high composite mechanical properties. In this study, multiple powder epoxy systems were investigated, and two were selected to manufacture unidirectional glass-fiber-reinforced polymer (UD-GFRP) plates with different epoxy ratios at the surface and interior plies, leading to a toughening gradient within the plate. The gradient plates were then mechanically compared to their standard counterparts. Solid particle erosion testing was carried out at various test conditions and parameters on UD-GFRP specimens in a slurry environment. The experiments performed were based on a model of the UK marine environment for a typical tidal energy farm with respect to the concentration of saltwater and the size of solid particle erodent. The morphologies of the surfaces were examined by SEM. Erosion maps were generated based on the result showing significant differences for materials of different stiffness in such conditions.


Author(s):  
Iurii Burda ◽  
Michel Barbezat ◽  
Andreas J Brunner

Glass-fiber reinforced polymer (GFRP) composite rods with epoxy matrix filled with electrically nonconducting particles find widespread use in high-voltage electrical insulator applications. The service loads require a range of different, minimum material property values, e.g. toughness, tensile, or compressive strength, but also component-specific performance, e.g. pull-out friction of surface crimped metal fittings or electric breakdown strength. The contribution discusses selected examples of the effects of different particle filler types on the properties of filled epoxy resin as well as on the behavior of GFRP rods with such a matrix. In all investigated systems CaCO3 was used as micron-sized filler, complemented by different amounts of either nanosilica or core-shell rubber (binary filler), or by both, nanosilica and core-shell rubber (ternary filler). With ternary filler combinations at a content of 36 wt%, fracture toughness GIC was improved in nanocomposite epoxy plates and in GFRP rods by 60% and 100%, respectively compared to a matrix with 20 wt% CaCO3 (used as reference system). The glass transition temperature Tg for some ternary systems dropped from 160 °C (for neat epoxy), to approximately 140 °C, the maximum allowed drop in Tg in view of requirements from further processing steps of the electrically insulating components. The ternary fillers yield transfer of the improvements of fracture properties from epoxy nanocomposite plates into the GFRP rods beyond that of the system with CaCO3 filler only. Compressive strength of the GFRP rods was improved by about 20% only for the binary nanosilica and CaCO3 filler, and was not significantly enhanced with the ternary systems. That combination, however, did not yield improvements in toughness beyond the CaCO3-filled nanocomposite plates and rods. With the range of filler types and contents investigated here, it was hence not possible to simultaneously optimize both, fracture toughness and compressive strength of the GFRP insulator rods.


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