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Highlights Wind turbines are subjected to extreme weather and load conditions; hence, high strength and impact resistance are required. Furthermore, wind turbine blades can be subjected to impact loads such as bird strikes, resulting in the formation of microcracks. Self‐healing capsules can be used to mend turbine blades for microscale damage. The incorporation of self‐healing capsules may cause a decrease in the mechanical characteristics of the composites prior to impact resistance, which can be compensated for with efficient fillers such as silicon carbide whiskers (SiCw). Thus, a novel hybrid composite structure is examined with the advantage of using a self‐healing mechanism and SiCw reinforcement. Tensile, tribological, and Charpy impact tests were performed to characterize the mechanical and tribological properties, which were supported with microscopic observations. Multiple experimental characterizations were performed to investigate the impact, and the ultimate tensile strength (UTS) and energy absorption capacity of the structure were shown to increase by 32% and 45%, respectively, with the addition of SiCw. The presence of self‐healing agents provides a 5% rise in UTS after enough time for healing following the collision. The structure's tribological performance is improved by 10% in wear resistance and 20% in friction coefficient. Hybrid laminated composite structure with silicon carbide whisker and self‐healing capsules. Tensile and Charpy impact tests conducted with microscopic observations Increased ultimate tensile strength and energy absorption capacity by 32% and 45%. Tribological improvement by 10% in wear resistance and 20% in friction coefficient. [ABSTRACT FROM AUTHOR]

The importance of recycling engineering components and thus obtaining low‐cost production solutions has become prominent in today's world. In this study, the mechanical and dynamic behaviors of three‐dimensional‐printed recycled polyethylene terephthalate glycol (RePET‐G) beams were investigated numerically and experimentally for the first time in the literature. Initially, the governing equations of the beams were determined according to the Bernoulli–Euler beam theory, and these equations were numerically solved using the differential quadrature method and ANSYS program. Subsequently, to validate the accuracy of the numerical models, the obtained natural frequencies were compared with experimental results. It was observed that the numerical results showed good agreement with the experimental results. Finally, the effects of beam length, infill rate, and building direction on the natural frequencies of RePET‐G beams were investigated. The outcomes showed that as the beam length changed, natural frequencies were significantly affected. Increasing the infill rate, especially for beams with vertical building direction, from 20% to 100% led to a slight decrease in the natural frequency values of the structure. Moreover, it was found that for beams with an infill rate of 100%, the natural frequency values obtained in the horizontal building direction were higher than those obtained in the vertical building direction. Highlights: Printable recycled filaments have great potential for vibration applications.Sample length affects the first natural frequency value of RePETG parts.Differential quadrature and ANSYS methods can be utilized for the vibration.For the 3D‐printed samples, rising infill rate causes a natural frequency drop. [ABSTRACT FROM AUTHOR]

Real service requirements of the assembly performance and joining properties of design components are critical for composite usage in the aerospace industry. This experimental study offers a novel and comprehensive analysis of dry drilling optimization for glass-reinforced, high-performance epoxy matrix composites used in aerospace structures, focusing on thrust force and delamination. The study presents a first-time investigation into the combined effects of spindle speed (1000, 2250, 4000 and 5750 rpm), feed rate (0.2, 0.4, 0.6 and 0.8 mm/rev) and tool diameter (3 and 5 mm) using a custom-designed drill tool specifically developed for this application, filling a gap in the current literature. By employing the Taguchi design of experiments, the study identified that medium spindle speeds (2250–4000 rpm), lower feed rates (0.2 mm/rev) and smaller tool diameters (3 mm) provided optimal conditions for minimizing thrust force and delamination. These results present actionable insights into improving the structural integrity and performance of drilled aerospace-grade composite components, offering innovative advancements in both the aerospace and defense industries. [ABSTRACT FROM AUTHOR]

Highlights Rapid prototyping, also known as additive manufacturing, is a nascent technology that is gaining traction in the context of environmental concerns and waste reduction, as well as the growing trend towards customized design. The additive manufacturing method, which has applications in diverse fields such as aviation, architecture, biomedical and automotive engineering, has also begun to be utilized in the construction of yachts and yacht hulls within the maritime industry. In this experimental study, the influences of sea water on polylactic acid (PLA) and carbon fiber reinforced polylactic acid (PLA/CF) parts manufactured at different infill rates (20%, 60% and 100%) were investigated. The parts were exposed to sea water for three different periods (1, 5, and 10 days) and subsequently subjected to wear tests. The dimensional accuracy, surface roughness, hardness, water absorption, volume loss, and friction coefficient of parts were measured and calculated. Additionally, the worn surfaces of the parts were investigated using field emission scanning electron microscope (FESEM) images. The findings indicate that PLA and PLA/CF parts can be produced with high dimensional accuracy. Furthermore, it can be reported that the water absorption of PLA/CF parts increased, particularly with an increase in the infill rate, while the volume loss decreased. Obtained results indicate the necessity of optimizing the 3D printing parameters and the relationship between the ambient conditions and the wear performance of the 3D printed parts. 3D printing is a highly promising method for the production of polymer composites. A pioneering study into the effect of infill rate and water absorption on the wear performance. Coefficient of friction values of PLA and PLA/CF parts ranged between 0.37 and 0.75. PLA/CF mostly exhibited higher volume loss than PLA with water absorption. Volume loss declines with a raise in the infill rate from 20% to 100%. [ABSTRACT FROM AUTHOR]

In recent years, the number of studies focusing on the additive manufacturing has increased seriously to elucidate the critical points such as physical, chemical, and mechanical properties. Contrary to common trends and for the first time in the literature, this experimental endeavor aims to comprehend the combined impact of reinforcement type and heat treatment on the wear features of additively manufactured polyamide 6 (PA6) composites. As reinforcement materials, glass, and carbon fibers were utilized and all samples were created through the fused filament fabrication. Half of the samples were subjected to annealing treatment after the main production, and characterization works were performed using a fused emission scanning electron microscope, differential scanning calorimetry, and dynamic mechanic analysis. From the outcomes, it is seen that heat treatment has a positive effect on the hardness, and wear resistance of the composites. Besides, glass fiber‐reinforced samples display lower friction coefficient and lower volume loss results than other samples. For all samples, secondary annealing causes a positive impact on wear endurance in most cases. On the other side, the wear mechanism of the tested samples changes with the test force level and reinforcement type. At lower test forces, abrasive wear‐induced debris parts are detected on the deformed surfaces of PA6 and carbon‐added samples, but this case is opposite for the highest force of 40 N. Highlights: Additive manufacturing was underlined as a promising way to create polymer composites with high dimensional accuracy.The combined effect of secondary annealing and reinforcement type on the wear resistance of 3D‐printed PA6 composites was examined for the first time in the literature.Carbon and glass fibers were compared to explore their effect on friction coefficient and wear behavior of polymer composite samples produced via FFF technology.Hardness and surface roughness measurements were used to comprehend the dry sliding wear results.Depending on the increasing test force levels and reinforcement type, deformation, and abrasion mechanisms were analyzed. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to elucidate the machining properties of low-cost expanded clay-reinforced syntactic foams by using different neural network models for the first time in the literature. The main goal of this endeavor is to create a casting machining-neural network modeling flow-line for real-time foam manufacturing in the industry. Design/methodology/approach: Samples were manufactured via an industry-based die-casting technology. For the slot milling tests performed with different cutting speeds, depth of cut and lubrication conditions, a 3-axis computer numerical control (CNC) machine was used and the force data were collected through a digital dynamometer. These signals were used as input parameters in neural network modelings. Findings: Among the algorithms, the scaled-conjugated-gradient (SCG) methodology was the weakest average results, whereas the Levenberg–Marquard (LM) approach was highly successful in foreseeing the cutting forces. As for the input variables, an increase in the depth of cut entailed the cutting forces, and this circumstance was more obvious at the higher cutting speeds. Research limitations/implications: The effect of milling parameters on the cutting forces of low-cost clay-filled metallic syntactics was examined, and the correct detection of these impacts is considerably prominent in this paper. On the other side, tool life and wear analyses can be studied in future investigations. Practical implications: It was indicated that the milling forces of the clay-added AA7075 syntactic foams, depending on the cutting parameters, can be anticipated through artificial neural network modeling. Social implications: It is hoped that analyzing the influence of the cutting parameters using neural network models on the slot milling forces of metallic syntactic foams (MSFs) will be notably useful for research and development (R&D) researchers and design engineers. Originality/value: This work is the first investigation that focuses on the estimation of slot milling forces of the expanded clay-added AA7075 syntactic foams by using different artificial neural network modeling approaches. [ABSTRACT FROM AUTHOR]

In this study, the effects of multiple printing parameters on the screw pull out force of PLA samples produced with a 3D printer were investigated statistically. Based on the Taguchi L27 orthogonal array, tests were carried out at different levels of printing speed, printing temperature, infill density, build plate temperature and infill pattern factors. Experiment results were assessed at the 95 % confidence level with analysis of variance, main effects and interaction graphs. Thus, the effects of factors and some two-way interactions on the screw pull out force and the levels that give the optimum response are determined. Accordingly, it is obtained that only the printing temperature, infill rate, infill pattern and printing temperature-fill rate factors and interactions are significant; It is also found that the infill density has the highest effect on the holding force with 55.08 %, followed by the printing temperature (18.62 %), printing temperature-infill density (12.19 %) and infill pattern (4.03 %). Finally optimum pull out force is predicted at the second level of printing speed (A2= 50 mm/s), third level of printing temperature (B3= 230 ° C), third level of infill density (C3=100 %), third level of build plate temperature (D3=80 ° C) and the first level of infill pattern (E1= Grid) as 1885.89 N. In 3 confirmation experiments performed at these levels, an average pull out force of 1993.33 N is obtained and it is determined that the result was within the specified confidence interval. Thus, the optimization made is of sufficient accuracy. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced plastics (CFRPs) have been specially developed to enhance the performance of commercial and military aircraft because of their strength, high stiffness-to-density ratios, and superior physical properties. On the other hand, fasteners and joints of CFRP materials may be weak due to occurring surface roughness and delamination problems during drilling operations. This study's aim is to investigate the drilling characterization of CFRPs with different drilling parameters and cutting tools. Drilling tests were performed with the Taguchi orthogonal array design (L18: 2^1 3^3). Tests were conducted with three levels of cutting speed (15, 30, 45 m/min), three levels of feed rate (0.05, 0.1, 0.2 mm/rev), two levels of drill diameter (3 and 5 mm), and three different types of drills (two twist drills with a point angle of 138° and 120° and one brad drill). Thrust forces were recorded during drilling tests, and afterwards surface roughness and hole delamination were measured. Obtained results were analyzed with Taguchi and two-way ANOVA. The general tendency was that low cutting speed, high feed rate, and small diameter drill caused an increase in thrust force. Surface roughness decreases with increasing tool diameter, decreasing feed, and cutting speed. Delamination factors of the samples dropped depending on decreasing thrust force levels. Remarkably, it is possible to control the delamination factor values via better surface quality. The brad drill and larger point angle have a negative effect on the drilling quality of CFRPs. According to all results, the cutting speed of 45 m/min and feed rate of 0.05 mm/rev using a type II drill having a 120° point angle and 5 mm diameter (12th trial) and the cutting speed of 30 m/min and feed rate of 0.05 mm/rev using a type II drill having a 120° point angle and 3 mm diameter (2nd trial) were determined as optimum drilling conditions. [ABSTRACT FROM AUTHOR]

Selective laser melting (SLM) is a three-dimensional (3D) printing process that can manufacture functional parts with complex geometries as an alternative to using traditional processes, such as machining wrought metal. If precision and a high surface finish are required, particularly for creating miniature channels or geometries smaller than 1 mm, the fabricated parts can be further machined. Therefore, micro milling plays a significant role in the production of such miniscule geometries. This experimental study compares the micro machinability of Ti-6Al-4V (Ti64) parts produced via SLM compared with wrought Ti64. The aim is to investigate the effect of micro milling parameters on the resulting cutting forces (Fx, Fy, and Fz), surface roughness (Ra and Rz), and burr width. In the study, a wide range of feed rates was considered to determine the minimum chip thickness. Additionally, the effects of the depth of cut and spindle speed were observed by taking into account four different parameters. The manufacturing method for the Ti64 alloy does not affect the minimum chip thickness (MCT) and the MCT for both the SLM and wrought is 1 μm/tooth. SLM parts exhibit acicular α martensitic grains, which result in higher hardness and tensile strength. This phenomenon prolongs the transition zone of micro-milling for the formation of minimum chip thickness. Additionally, the average cutting force values for SLM and wrought Ti64 fluctuated between 0.072 N and 1.96 N, depending on the micro milling parameters used. Finally, it is worth noting that micro-milled SLM workpieces exhibit lower areal surface roughness than wrought ones. [ABSTRACT FROM AUTHOR]

In the last century, polymer materials such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate glycol (PET-G) are widely used in many industrial fields due to being light, cheap, sustainable, and providing enough strength for engineering applications. Although plastic materials are mostly manufactured by the extrusion method, the 3D printing method is also taking the attention of researchers in the last decade because of its advantages over traditional methods. When the literature efforts about 3D printed polymers are examined, it can be seen that they are mostly focused on mechanical performance-determining processes such as tensile, compression, and threepoint bending. In this performance, the effect on layer height on the drop-weight impact behavior of 3D printed PET-G samples with fused deposition modelling (FDM) was examined at the various ambient temperature of 20°C, 40°C, and 60°C besides determining the hardness and tensile strength of the specimens. The results show that a maximum average hardness value of 69,4 Shore D was obtained at the specimen with layer height of 0,4 mm. It was determined that as the layer height value increased, the hardness values of the structures increased and the tensile strength values decreased. Besides, it can be stated that the layer height plays a more important role in the energy absorption amounts of the parts than the test temperature. Lastly, according to macroscopic and microscopic detections, no cracks were observed in the samples with a layer height of 0.4 mm, while it was determined that cracks were formed extending from the center to the corners in the samples with a layer height of 0.1 mm and 0.2 mm. [ABSTRACT FROM AUTHOR]

Among the various renewable energy sources, wind energy offers an effective solution to the energy providers. Onshore wind turbines are generally designed for sites with low wind resources, while offshore wind turbines can be more efficient in producing energy thanks to their longer blades that provide more than 10 MW of rated power. Offshore wind turbine blades are subjected to significantly higher stresses and harsh environmental conditions. Therefore, hybrid composites composed of carbon and glass fibers can offer cost‐effective and long‐lasting solutions for wind turbine blade manufacturers. Turbine blades are connected with main spars through bolted connections and high interlaminar stresses occurring during the drilling process can cause to delamination in the composites. To prevent catastrophic failure related to defective machining, the drilling process must be performed meticulously and all machining‐related results must be analyzed step by step. In this paper, dry drilling properties of hybrid glass‐carbon fiber laminate epoxy matrix composites were examined experimentally in order to contribute to the wind energy sector. The results showed that the delamination factor could be decreased with higher cutting speeds or lower feed rates. Besides, higher feed levels caused higher thrust forces on the tool body. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to experimentally compare the mechanical properties of the traditional honeycomb structure, which is one of the cellular structures with its own specific area of use with its features such as lightness and load absorption, and the new generation re-entrant, chiral and hybrid structure (re-entrant + honeycomb) with negative Poisson behavior. In this context, standard test samples with honeycomb, reentrant, chiral and hybrid structures were produced with fused deposition modelling (FDM) under optimum conditions by using PLA material and different geometric parameters. Tensile and compression tests, hardness tests and surface roughness measurements were carried out with the specimens that were additively manufactured. According to the results, it was determined that the direction of the unit cells in the cellular structure and the rib thickness affect the energy absorption properties of the cellular structures. While the tensile and compressive strengths of the cellular structures increased with increasing rib thickness, the average Ra value and hardness value were measured as 14 μm and 75 Shore D respectively. Although negative Poisson ratio was observed depending on the amount of deformation in re-entrant, chiral and hybrid structures, positive Poisson behavior was observed in honeycomb structures. [ABSTRACT FROM AUTHOR]

It is known that products made of polymer materials or especially polymer materials with glass fiber and carbon fiber are used in many different areas such as automotive, aerospace, and defense. At this point, studies in the literature have gained momentum due to the combination of fiber-reinforced polymer materials emerging as a result of technological developments and industrial demands, and the fused deposition modeling (FDM) method providing the production of parts in desired sizes and complexity. Residual stresses and distortions occurring in polymer-based composite parts produced with FDM are among the problems that should be minimized. In this study, the influences of fiber ratio (%10, %15, and %20), infill rate (%20, %50, and %80), and infill pattern (line, honeycomb, and triangle) on the residual stresses and warpages generating in impact test specimens produced from glass fiber reinforced ABS filaments by fused deposition modeling were tried to be determined with the Digimat 2021 program. As a result of the findings, it was determined that the distortion values decreased and the thermal residual stress values went up with the increase in fiber ratio and infill rate. In addition, it can be reported that the distortions that bring out as a result of the separation of the produced parts from the production platform are caused by the high deformations condensing at the lower corner points of the parts. [ABSTRACT FROM AUTHOR]

In recent years, the interest in light metals has increased due to the increasing demand for components with high specific strength and long service life in the industry. In this context, titanium alloys have become very common and popular owing to their high strength/weight properties and superior refractory characteristics. In this study, the effect of boundary condition and tapered angle on the natural frequency and vibration behavior of the beam was investigated in Ti-6Al-4V beams coated with three different ceramic materials; Al2O3, AlN, and TiB2. Tapered angle values are considered as 0°, 0.2°, 0.4°, 0.6° and 0.8°. Besides, boundary conditions were evaluated in two conditions including left side fixed or both sides fixed. All analyzes were performed in the finite element-based Ansys APDL 19 program. According to the results obtained from the analyses, it was observed that there was a change in the natural frequency values according to the type of coating material, but no difference was found in terms of increase/decrease tendency. In addition, the resultant displacement values were determined for all samples. The results indicated that the resultant displacement values were severely affected by the tapered angle. A decreasing resultant displacement trend was observed in all samples with increasing tapered angle. [ABSTRACT FROM AUTHOR]

On the road to real applications, although there are lots of efforts focusing on mechanical and physical features in the literature, their machining abilities were examined in a very limited manner. In this study, machining properties of pumice reinforced AA7075 syntactic foams manufactured via the newly offered sandwich infiltration technique were investigated by performing face turning. Physical and microstructural (optical and SEM works) analyses were conducted on fabricated foams to carry out sample characterization. All machining forces were measured for different cutting speeds (25, 50, and 100 m/min) and feed rates (0.05, 0.10, and 0.15 mm/rev). After the turning operation, areal surface roughness values were measured using a 3D surface profilometer and material removal rate (MRR) values were calculated. Besides, chip mixtures including pumice and metal fragments were collected to probe chip morphology in detail. The results showed that machining forces were affected by the operation parameters differently, and the lowest surface roughness was detected at the cutting speed of 100 m/min and 0.05 mm/rev feed rate. Furthermore, the shape of the metal chips changed from long/continuous characteristic to saw-tooth morphology depending on increasing cutting speed levels while pumice particles exhibited breakaway tendency as the feed rates went up. [ABSTRACT FROM AUTHOR]

Inconel 718 and Ti6Al4V which are the most widely used alloys in metal additive manufacturing, are preferred in applications in many fields such as automotive, aerospace and biomedical. As it is known, functional lightweight parts attract the attention of researchers due to their high specific strength despite their light weight. As a result of the increasing interest, the idea of producing lightweight parts with superior properties such as homogeneous distribution of the load and good absorption with additive manufacturing (AM) technology has come to the fore. Although AM methods such as selective laser melting (SLE) have many advantages over traditional manufacturing methods, residual stresses and distortions occur in the part during production, and their measurements in cellular structures are experimentally very difficult and time consuming. In this study, cellular structures used as scaffold and implant core structure in the biomedical field were designed with 100%, 73.4% and 42.6% infill rates. The residual stresses (σx, σy, and σz), distortions, plastic strains and maximum temperature values that occur during the production of these cellular structures from Inconel 718 and Ti6Al4V materials by SLM method were determined by the Amphyon 2021 AM simulation program. According to the obtained results, plastic strains, which provide a prediction of crack formation, were localized in the corner regions between the support structure and the main part. In addition, after a critical manufacturing height, higher maximum temperature values were observed in the cellular structures than the full structure. [ABSTRACT FROM AUTHOR]

Pipes are mainly used in waste, drain and vent systems as well as transporting various liquids that might be corrosive, flammable, explosives, volatile, reactive, or sometimes hazardous to human health. Though pipes are used at the underground or above ground, all of them are exposed to vibration because of external factors. In this study, we focused on topology optimization of steel and PVC (Polyvinyl Chloride) pipes to get lighter ones which will lead to using less material during manufacturing, less CO2 emission while transporting them to usage areas by vehicles and easier assembling process. Firstly, new lightweight pipe designs were modeled, and then these novel pipe designs with lattice wall thickness were analyzed by using Ansys finite element program in clamped-free, hinged-hinged, and clamped-clamped boundary conditions to obtain the natural frequencies, mode shapes, and displacement values. Moreover, obtained finite element results for steel and PVC pipes were compared with analytical results calculated by using the equation to check and compare with the finite element results. Finite element results were found similar to analytical results at an acceptable level. The results show that lightweight pipes have similar natural frequency values to the commonly used pipe which has fully solid wall thickness and some significant results about displacement values were attained. Lastly, the effect of pipe material on vibration behaviors of pipes was investigated in depth. [ABSTRACT FROM AUTHOR]

It is known that three-dimensional (3D) printing technology which enables to transform an imagination into 3D real product, has started to take place in many different areas from the space-aviation sector to the health sector and its usage is gradually increasing. With the unstoppable development of technology, the emergence of new materials and manufacturing methods or the necessity of developing existing ones has become an inevitable fact. Four-dimensional (4D) printing technology which also includes 3D printing technology as one of the steps of 4D printing and this 4D printing technology allows the 3D printed products from smart materials to change their shape over time when these 3D printed products are stimulated by external stimulus such as heat, water, light or etc. In this study, 4D printing technology and components have been examined and some useful information has been tried to be presented to our country's researchers and engineers about the development process and potential application areas of this technology. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, coating applications of hard engineering ceramics on metallic alloys have become notably widespread in order to expand the service life of the critical design components working in though conditions like corrosive/oxidative or erosive/abrasive media. Even though scientific efforts on coating processes and their effects on wear and corrosion performance have been studied for years, there is a lack of investigation about mechanical properties, especially thermo-mechanical features of hard ceramic coated metals. In this paper, on the purpose of determination of the thermal stress distribution, effects of coating materials (Al2O3, AlN and TiB2) and coating thickness (400 µm, 600 µm, and 800 µm) on Von-Mises stress, shear stress and resultant displacement for single and full surface coating models designed on Ti-6Al-4V base material are investigated at 373 K, 573 K and 873 K. The results show that modulus of elasticity and thermal expansion coefficient of coating ceramic materials and base metallic material affect the elongation and stress values observed on designed models significantly. Besides, coating thickness and ambient temperature are also effective on thermal properties. Lastly, it can be pointed out that resultant displacement values on a singlesurface coating model are higher than full surface coating model. However, Von-Mises and shear stress values calculated with finite element analysis on single surface coating model is lower than the values read for fullsurface coating model. [ABSTRACT FROM AUTHOR]

Tool steel is a widely used material in forming and manufacturing of injection molds / equipments. Injection and forming dies are subjected to repetitive high pressure and heat during operation, which leads to unexpected formation of cracks in the die. In case of continuation of continuous and repeated loads, starting crack causes the die lose its function or stopping injection process. In this study, a series of finite element analyzes and optical investigations have been carried out to determine the cause of the damage of 1.2367 hot work tool steel injection gate brush which has lost its function as a result of repetitive mechanical and thermal loading, and the design of the injection gate brush has been changed to prevent this damage. As a result of new designing of injection gate brush, a decrease in stresses of gate brush under working was observed. Hereby, the strength of injection gate brush was improved. [ABSTRACT FROM AUTHOR]

Cutting with abrasive water jet is an effective method for many engineering materials. Owing to its ability providing close tolerances and dimensional accuracy as well as cutting of extremely hard materials, total using rate of abrasive water jet cutting (AWJC) in the industry rises day by day. In addition to cutting, turning of the many industrial materials can be turned into the practice with abrasive waterjet turning (AWJT) technology. In recent years, AWJC and AWJT become considerably popular cases in the machining of hybrid composite materials which consist of at least two unlike reinforcements and researches about this subject increase rapidly in order to elucidate process details and influences of input parameters. Water pressure, traverse speed, abrasive flow rate, standoff distance and abrasive particle mesh size are the most prominent parameters of the process. In this paper, abrasive waterjet cutting/turning applicability of hybrid composites was reviewed and an initiative was done to rake together the newest surveys published in the technical literature. Our purpose is to achieve detailed overview for AWJC/AWJT of hybrid composites and to emphasize feasibility of the AWJC/AWJT for them and to discuss future real application possibilities of the method. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The using areas of composite materials in mainly aerospace sector and other industry have been increased due to their more light, high fatigue strength, impact strength and specific strength properties than metals. The critical factor in fiber reinforced laminate composites from composite materials is to crack formation on interface matrix structure and fibers carrying loads and distributing forces to matrix structure. Also, the cracks on interface matrix structure and fibers cause decreasing the composite structure strength with crack propagations under loads. In this study, the effect of location and angle of the crack in the laminate hybrid composite material reinforced with glass-epoxy, boron-epoxy, carbon-epoxy, glass-boron-carbon-epoxy fibers at different angles on mechanical behaviors is determined with finite element analyses. In analyses, the different located crack and crack angles (0° and 30°) inside the laminate composite structure with different fiber materials reinforced at different angles (0°, 15°, 30°, 45°, 60°, 75° and 90°) with 1.5 mm of total composite thickness were formed and applied tensile forces. Afterwards, stress and displacement values were obtained in the cracked fiber reinforced structures. According to results, Decrease in stress at top and bottom aluminium plate was observed in case of parallel fiber orientation to the applied forces. Beside, shear stresses increase with increasing the crack angle. [ABSTRACT FROM AUTHOR]

Today's manufacturing sector has introduced to a manufacturing method depending on developments in materials, engineering software and laser technologies which are combined to manufacture as a useful engineering part of 3-D digital design by layer upon layer from polymer, metal, ceramic materials. This method has entered into the literature as "Additive Manufacturing" and today it has been used in mainly medical, automotive, space-airplane, computer and home appliances sectors and also prototypes of parts with specific and complex geometries and / or make it possible to produce a useful engineering part. In this study, the studies conducted in the area of modern manufacturing science were evaluated and the point reached in 3-B additive manufacturing, additive manufacturing methods and application areas were investigated and it was tried to give information that could be projected to our manufacturing sectors. [ABSTRACT FROM AUTHOR]