15 research outputs found
An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability
© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe
Elastic-plastic stress analysis in a thermoplastic composite cantilever beam loaded by bending moment
In this study, an elastic-plastic stress analysis is carried out in a thermoplastic composite cantilever beam loaded by a bending moment at the free end. The composite beam is reinforced unidirectionally by steel fibers at 0, 30, 45, 60, and 90 orientation angles. An analytical solution is performed for satisfying both the governing differential equation in the plane stress case and boundary conditions for small plastic deformations. The solution is carried out under the assumption of the Bernoulli-Navier hypotheses. It is found that the intensity of the residual stress component of sigma(x) is maximum at the upper and lower surfaces or at the boundary of the elastic and plastic regions. The composite material is assumed to be as hardening linearly. The Tsai-Hill theory is used as a yield criterion
Test to Graph
This Excel Spreadsheet contains some macros. It is developed to automize the whole kinematic calculations for the LVI impact test.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Test to Graph
This Excel Spreadsheet contains some macros. It is developed to automize the whole kinematic calculations for the LVI impact test.
İmportant Notes:
1. These codes were generated for PCB M202B Quartz Force Ring sensor. If anyone uses any other force sensor, he/she must change the conversion factor in the codes.
2. The LVI rig has 15.5 kg mass of a impactor. If anyone uses different from the existing one, he/she must change the mass of the impactor. The password of the "Template" sheet is "a"
Elastic-plastic stress analysis of composite beams loaded by bending moment
An elastic-plastic stress analysis is carried out in a thermoplastic composite cantilever beam loaded by a bending moment at the free end. The orientation angle is chosen as 0degrees, 15degrees, 30degrees and 45degrees. An analytical solution is performed for satisfying both the governing differential equation in the plane stress case and boundary conditions for small plastic deformations. The solution is carried out under the assumption of the Bernoulli-Navier hypotheses. It is found that the intensity of the residual stress component sigma(x) is maximum at the upper and lower surfaces. The beam material is assumed to be strain-hardening. The Tsai-Hill theory is used as a yield criterion. The displacement components are found in the elastic region
Thermal-cycling behavior of conicraly bonds coated with thermal barrier coatings (TBCs) produced with atmospheric plasma spraying (APS)
Thermal barrier coatings (TBCs) are commonly applied as a thermal insulation in order to protect against environmental influences in the components of high-temperature gas turbines and jet engines. Gas-turbine components are affected by aggressive conditions of the environment during the service, being subjected to failures such as corrosion, thermal shock and oxidation. Plasma-spray technology is used to produce metallic bonds and ceramic top coats as a cost-effective method to prolong the lifetime of TBCs. In the present research, CoNiCrAlY bond-coat and YSZ top-coat powders included in the TBCs were deposited onto Inconel 718 superalloy substrates using atmospheric plasma spraying (APS). The TBCs were exposed to a furnace cycling test at 1150 °C and one-hour cycles. The presence of porosity and cracks facilitating the diffusion of oxygen in the top-coating structure led to the formation of thermally grown oxides (TGOs) at the interface. In addition, the most effective factors of failures were the formation and growth of mixed oxides at the bond/top-coat interface and the presence of imperfections. According to the test results, an increasing number of thermal cycles resulted in a decrease in the lifetime of the TBCs related to the sintering of the top coating due to the effect of high temperature
Mechanical Properties and Melt Quality Relationship of Sr-modified Al-12Si Alloy
The formation of oxide film on the surface of aluminium melts, i.e. bifilms, are known to be detrimental when they are incorporated into the cast part. These defects causes premature fractures under stress, or aid porosity formation. In this work, Al-12 Si alloy was used to cast a step mould under two conditions: as-received and degassed. In addition, 10 ppi filters were used in the mould in order to prevent bifilm intrusion into the cast part. Reduced pressure test samples were collected for bifilm index measurements. Samples were machined into standard bars for tensile testing. It was found that there was a good agreement with the bifilm index and mechanical properties
Correlation Between Machinability and Chip Morphology of Austempered Ductile Iron
In this work, macrostructure, microstructure, and work hardening of as-cast and austempered ductile iron chips produced by different cutting speeds were investigated. Cutting forces, surface roughness, and tool wear were also studied. After austenitizing at 900 degrees C for 90 min, samples were austempered in a salt bath at 360 degrees C for 90 min. Machinability tests were conducted with uncoated cemented carbide tools on a CNC lathe. The tests were carried out without using any lubricant. In these tests, the cutting speed was varied in the range 50-200 m/min, while the feed rate (0.12 mm/rev) and depth of cut (2 mm) were kept constant. The tangential, feed, and radial cutting force components acting on the tool holder were measured with a three-component dynamometer. The chips obtained during machining were polished by embedding into epoxy resin, examined with optical microscope and micrographs were taken. The microhardness values were measured on each chip sample. As the cutting speed was increased, deformation strengthening of the microstructure was increased, which decreased the tool life. It was also detected that during the machining, with the effect of cutting forces and stress, spheroidal graphites were broken off in the chip and lost their sphericity, so the chip became fragile and unstable and the graphite displayed a lubricant feature. At low cutting speed, a built-up edge was observed. However, as the cutting speed was increased because of heating, built-up edges were unstable