Comparisons of the use of twist, pilot-hole and step-drill on influence of carbon fiber-reinforced polymer drilling hole quality

2017 ◽  
Vol 52 (11) ◽  
pp. 1465-1480 ◽  
Author(s):  
Gong-Dong Wang ◽  
Melly S Kirwa
Keyword(s):  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Hole Quality ◽  
Pilot Hole ◽  
Reinforced Polymer ◽  
Thrust Forces ◽  
Step Drill ◽  
Delamination Damage

Understanding the drilling-induced damage to carbon fiber-reinforced polymer composites remains the most active research being undertaken in the composite materials world of today. Despite the vast amounts of literature available, the relationship between drilling and damage to the composites has not been fully understood. In this research, a comparative study of different drilling methods including the use of a twist drill, the use of a pilot hole/pre-drilled hole and the use of a step drill on the influence of the hole quality has been accomplished. In order to achieve this comparison, thrust forces have been monitored during drilling experiments where four different feed rates and one spindle speed have been considered. A finite element model has also been included to study delamination damage on the laminates and validate the experimental results. Results show that thrust forces increase with increasing feed rates and that drilling by step drill is the most appropriate method as it records low forces hence minimal delamination damage.

Restoring Initially Cracked Reinforced Concrete Beams utilizing Carbon Fiber Reinforced Polymer Strips

2019 ◽  
Vol 7 (1) ◽  
pp. 30-34
Author(s):  
A. Ajwad ◽  
U. Ilyas ◽  
N. Khadim ◽  
Abdullah ◽  
M.U. Rashid ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Loading Test ◽  
Control Beam ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced polymer (CFRP) strips are widely used all over the globe as a repair and strengthening material for concrete elements. This paper looks at comparison of numerous methods to rehabilitate concrete beams with the use of CFRP sheet strips. This research work consists of 4 under-reinforced, properly cured RCC beams under two point loading test. One beam was loaded till failure, which was considered the control beam for comparison. Other 3 beams were load till the appearance of initial crack, which normally occurred at third-quarters of failure load and then repaired with different ratios and design of CFRP sheet strips. Afterwards, the repaired beams were loaded again till failure and the results were compared with control beam. Deflections and ultimate load were noted for all concrete beams. It was found out the use of CFRP sheet strips did increase the maximum load bearing capacity of cracked beams, although their behavior was more brittle as compared with control beam.

High thermal conductivity carbon fiber reinforced polymer based on a carbon fiber from pitch and dispersed-filled ENPB matrix

2018 ◽  
pp. 130-137
Author(s):  
E. A. Nikolaeva ◽  
A. N. Timofeev ◽  
K. V. Mikhaylovskiy
Keyword(s):  
Thermal Conductivity ◽  
Carbon Fiber ◽  
High Thermal Conductivity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Carbon Powder ◽  
Fiber Reinforced ◽  
Thermophysical Characteristics ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

This article describes the results of the development of a high thermal conductivity carbon fiber reinforced polymer based on carbon fiber from pitch and an ENPB matrix modified with a carbon powder of high thermal conductivity. Data of the technological scheme of production and the results of determining the physicomechanical and thermophysical characteristics of carbon fiber reinforced polymer are presented. 

scholarly journals Thermal Shock Behavior of Twill Woven Carbon Fiber Reinforced Polymer Composites

2021 ◽  
Vol 5 (1) ◽  
pp. 33
Author(s):  
Farzin Azimpour-Shishevan ◽  
Hamit Akbulut ◽  
M.A. Mohtadi-Bonab
Keyword(s):  
Thermal Properties ◽  
Carbon Fiber ◽  
Thermal Cycling ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Mechanical And Thermal Properties ◽  
Fiber Reinforced ◽  
Cycling Process ◽  
Reinforced Polymer ◽  
Thermal Cycling Process

In the current research, the effect of cyclic temperature variation on the mechanical and thermal properties of woven carbon-fiber-reinforced polymer (CFRP) composites was investigated. To this, carbon fiber textiles in twill 2/2 pattern were used as reinforced phase in epoxy, and CFRPs were fabricated by vacuum-assisted resin-infusion molding (VARIM) method. Thermal cycling process was carried out between −40 and +120 °C for 20, 40, 60 and 80 cycles, in order to evaluate the effect of thermal cycling on mechanical and thermal properties of CFRP specimens. In this regard, tensile, bending and short beam shear (SBS) experiments were carried out, to obtain modulus of elasticity, tensile strength, flexural modulus, flexural strength and inter-laminar shear strength (ILSS) at room temperature (RT), and then thermal treated composites were compared. A dynamic mechanical analysis (DMA) test was carried out to obtain thermal properties, and viscoelastic properties, such as storage modulus (E’), loss modulus (E”) and loss factors (tan δ), were evaluated. It was observed that the characteristics of composites were affected by thermal cycling due to post-curing at a high temperature. This process worked to crosslink and improve the composite behavior or degrade it due to the different coefficients of thermal expansion (CTEs) of composite components. The response of composites to the thermal cycling process was determined by the interaction of these phenomena. Based on SEM observations, the delamination, fiber pull-out and bundle breakage were the dominant fracture modes in tensile-tested specimens.

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