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Nickel–titanium shape memory alloys (SMAs) are popular due to their usefulness and functional characteristics. The binary NiTi SMA was alloyed with vanadium to improve memory retention properties. In this study, the abrasive aqua jet machining method was adopted to machine the Ni50Ti48V2 ternary SMA to minimize the kerf taper angle (KTA), surface roughness (Ra) of machined Ni50Ti48V2 surface, and enhance the material removal rate (MRR). RSM-BBD optimization using the input variables such as abrasive flow rate (AFR), water jet pressure (PWJ), nozzle traverse speed (VTS), and standoff distance (SFD) predicted that PWJ and SFD highly contributed to MRR, Ra, and KTA responses. Small variation in variation after optimized AWJM conditions, and XRD analysis confirmed no phase changes after AWJM. [ABSTRACT FROM AUTHOR]

In this study, the duplex stainless steel is machined using a wire-cut electrical discharge machining process to overcome the issues of poor finishing, lower dimensional accuracy, and rapid wear of cutting tools in conventional machining processes. The higher rate of material removal and superior finish on the machine surface is dependent on kerf loss, which is expressed as the mean kerf width assessed at certain locations. Nevertheless, this approach is typically not effective in explicating the intricacies of true kerf loss due to the random selection of distinctive points. This work proposes an area-based measuring approach to quantify the kerf loss by taking into account any imperfections on the kerf wall. At the pulse on time of 20 μs and current of 3 A, the machining appears not stable. The pulse on time, current, and voltage of 12 µs, 1 A, and 80 V proved suitable for obtaining excellent dimensional precision. [ABSTRACT FROM AUTHOR]

Laminated metal-composite structures or fiber metal laminates (FMLs) are advanced engineering materials currently being utilized in several distinct applications, especially in aircraft and automobile manufacturing industries where an improved impact and fatigue resistance are required. Machining of FMLs is an important task in obtaining near-net shapes for joining and assembly of the components. However, the delamination occurs during conventional machining making FMLs as difficult-to-machine materials. Therefore, the present study will look into the abrasive water jet cutting (AWJC) of novel fiber intermetallic laminates (FILs) made of with alternatively stacked carbon/aramid fiber adhesively bonded with r-GO filled epoxy resin matrix and Nitinol shape memory alloy sheet embedded laminates. The AWJC experiments were performed on fabricated FILs to investigate the cut quality features including kerf taper (Kt), surface roughness (Ra) and kerf deviation (KD) by varying addition of r-GO from 0-2 wt% in the laminates, traverse speed (400-600 mm/min), waterjet pressure (200-300MPa) and nozzle height (2-4 mm), respectively. Statistical results obtained through ANOVA reveals that the traverse speed and nozzle height are the utmost significant variables which influencing the cut quality characteristics followed by waterjet pressure. Surface morphology analysis shows the wear and erosion mechanism of FILs at varying AWJC conditions. For an improved cut quality, the optimal AWJC parameters are achieved through a metaheuristic-based Barnacles Mating Optimization Algorithm (BMOA). [ABSTRACT FROM AUTHOR]

Laser machining is a cutting-edge thermal energy-based industrial methodology that can be employed to replace the traditional mechanical machining practices in micro-domain applications. In this work, complex hexagonal shape profiles were cut on the surfaces of Nickel-based superalloy (Alloy 276) by fiber optics laser cutting system. Response surface methodology – Central Composite Design approaches were attempted for optimizing laser machining factors to obtain the better output responses. ANOVA was used to identify the significant machining factors which affect the cut quality characteristics. The desirability approach in multi-response optimization was deployed to achieve the minimal kerf width, low surface roughness, minimum heat affected zone while simultaneously increasing the material removal rate. To validate the predicted results obtained from the desirability index analysis, confirmation test was conducted based on a higher desirability index value. The result reveals that the error percentage is less than 5 for all the responses. The results of the confirmation test show that the proposed procedures are effective in improving laser machining parameters for obtaining the better responses. [ABSTRACT FROM AUTHOR]

The kerf taper angle is one of the most significant parameters for AWJ cutting. Choosing the best cutting parameters is critical to reducing the kerf taper. Therefore, the aim of this work is to demonstrate on to implement RSM in conjunction with the Rat swarm optimizer algorithm to optimize the kerf taper angle of a Titanium alloy. Thirty-two number of experiments were conducted according to CCD considering five process parameters namely jet traverse rate, water jet pressure, abrasive flow rate, stand-off distance and diameter of focusing nozzle to achieve kerf taper angle. A second-order full quadratic model is used for mathematical modeling. The result demonstrates that the model is sufficiently adequate and acceptable. A recent Rat Swarm Optimization (RSO) algorithm is considered for finding out the global optimal solution. It is observed that after optimizing the process that the jet traverse rate of 1.952 mm/sec, water jet pressure of 250.548 MPa, abrasive flow rate of 0.554 kg/min, stand-off distance of 3.75 mm and diameter of focusing nozzle of 2.0 mm gives minimized with 0.754 degree of kerf taper angle. A series of verification tests are carried out to ensure that the optimization technique is accurate in determining the best levels of process. [ABSTRACT FROM AUTHOR]

Bismaleimide-based hybrid fiber composites (BMI) with their expanded thermomechanical properties have been broadly utilized in Aircraft primary applications. The supplanting of carbon fiber with other fiber (kevlar/glass/basalt) is redone to the requirements of the business. To maintain the surface quality, the hybrid composites can be machined with unconventional methods like Abrasive Water jet Machining. In this work, the exploratory examination of interaction boundaries, such as Water pressure (Wp), Transverse speed (Ts), Standoff distance (SOD), Abrasive mass flow rate (ma) of AWJM on hybrid BMI composites was done. Experiments were conducted based on Design of Experiments created from Response surface strategy utilizing Central Composite Design (CCD) and the impact of interaction boundaries on kerf taper and surface roughness were analyzed. The experimental outcomes showed that for the minimum kerf angle, the significant parameters were transverse speed, water pressure, and abrasive flow rate and for minimum surface roughness, transverse speed was the significant parameter. The microstructure analysis revealed that plowing deformation of fiber and abrasive particle embedment at high speed and mass flow rate led to delamination of fiber, which was limited by optimal parameters essentially diminishing kerf taper and surface roughness. [ABSTRACT FROM AUTHOR]

Inconel-625 is a tough-to-cutting material used in ultra-supercritical power plants for flanges, offshore oil sectors, and turbine blades, among other high-temperature components. The objective of this article is to determine the link between four key process independent variables: traverse speed (TSP), abrasive mass flow rate (AMFR), abrasive aqua jet pressure (AAJP), and gap distance (Gd) to the surface roughness (SRa), kerf angle (KEA), and erosion rate (MRR). The response surface methodology-Central composite design (RSM-CCD) was used to perform the experimental interpretations. The influence of individual abrasive aqua jet cutting (AAJC) factors was determined using analysis of variance technique (ANOVA). It was found that AAJP is the dominant factor in the responses. When the AAJP reached its maximum value of 300 MPa, the SRa and KEA reduced by 27.19% and 13.83%, respectively, the MRR improved by 23.71%. The Desirability analysis is handled to optimize the AAJC parameters of Inconel-625. The optimal values of parameters obtained were 300 MPa AAJP, 75 mm/min TSP, 2.4 mm Gd, and 0.55 kg/min AMFR to minimize SRa, KEA, & maximize the MRR. The scanning electron microscope is used to examine the surface morphology and erosion mechanisms. [ABSTRACT FROM AUTHOR]

This study investigates the influence of the stand-off distance (SoD), laser speed (LS) and laser power (LP) on kerf geometry (upper width Wu, down width Wd and kerf angle KA) and mean surface roughness (Ra) during CO2 laser cutting of 3D-Printed Polyethylene-Terephthalate-Glycol (PET-G) thin plates. A full factorial design is implemented, having two levels for SoD and three levels for LS and four levels for LP, resulting in twenty-four (24) cuts. The specimens were manufactured with the Fused Filament Fabrication (FFF) process and had a thickness of 4 mm. First, the Wu, Wd, and KA parameters were measured. Then, the specimens were cut into 24 smaller parts, and the Ra of the processed surfaces was measured. After analyzing the results using descriptive statistical analysis and contour plots corresponding to the two objectives of KA and Ra, a feed-forward and backpropagation neural network (FFBP-NN) was applied. After a series of subsequent training, it was found that the 3-10-2 NN architecture was quite efficient in explaining the variation in terms of the responses, thus having merit in practical applications related to laser cutting. The LC surfaces showed much better Ra (7.2-12 μm) than those in the literature for FFF parts surfaces without post-processing (10.3-30 μm). [ABSTRACT FROM AUTHOR]

With steadily rising expanse of the engineering sector, demand for composite materials has been growing progressively over the years. Particularly, glass fiber reinforced polymer (GFRP) composites are being increasingly applied in various industries in the aerospace, automobile, and construction sectors due to their lightweight and superior performances. The present investigation examines the effect of traverse rate, jet pressure, standoff distance, and multi-walled carbon nanotubes (MWCNT), mixed with epoxy/glass fabric nanocomposites, on abrasive water jet machining (AWJM) responses, such as kerf taper (KT), surface roughness (Ra), material removal rate (MRR), entrance and exit delamination factor (DF) by using the Taguchi approach. The study has established that the addition of MWCNT in the GFRP laminates optimizes the machining responses. The investigation, using analysis of variance approach, revealed the most dominant parameter, which influences the machining performance of the composites. A significant enhancement in AWJM responses could be attained with optimal parameters. And also validates using surface examinations. [ABSTRACT FROM AUTHOR]

A hybrid approach through combining genetic algorithm (GA) and adaptive neuro-fuzzy inference system (ANFIS) for modeling the correlation of laser beam cutting (LBC) parameters and enhancing the quality performance characteristics of machined Hastelloy C276 is emphasized. The LBC experiments are performed by considering gas pressure (GP), cutting speed (CS), pulse energy (PE) and stand-off distance (SOD) as input parameters. The output responses are material removal rate (MRR), kerf taper (KT) and surface roughness (Ra) for the present investigation. The optimal ANFIS training variables are obtained through GA. The training, testing errors, and statistical validation parameter results exposed that the ANFIS learned by GA is outperformed in forecasting LBC responses. In addition, to obtain the optimal combinations of LBC parameters, the multi-response optimization based on maximizing MRR and minimizing KT and Ra was performed using a trained ANFIS network coupled with a whale optimization algorithm (WOA). The responses such as MRR of 236.98 mg/min, KT of 1.135° and Ra of 1.109 µm are forecasted for the optimum cutting conditions: GP of 3 bar, CS of 319.8 mm/min, PE of 5.93 J and SOD of 2.97 mm, respectively. Furthermore, the WOA predicted results are validated by conducting confirmatory experiments. [ABSTRACT FROM AUTHOR]

A hybrid approach through combining genetic algorithm (GA) and adaptive neuro-fuzzy inference system (ANFIS) for modeling the correlation of laser beam cutting (LBC) parameters and enhancing the quality performance characteristics of machined Hastelloy C276 is emphasized. The LBC experiments are performed by considering gas pressure (GP), cutting speed (CS), pulse energy (PE) and stand-off distance (SOD) as input parameters. The output responses are material removal rate (MRR), kerf taper (KT) and surface roughness (Ra) for the present investigation. The optimal ANFIS training variables are obtained through GA. The training, testing errors, and statistical validation parameter results exposed that the ANFIS learned by GA is outperformed in forecasting LBC responses. In addition, to obtain the optimal combinations of LBC parameters, the multi-response optimization based on maximizing MRR and minimizing KT and Ra was performed using a trained ANFIS network coupled with a whale optimization algorithm (WOA). The responses such as MRR of 236.98 mg/min, KT of 1.135° and Ra of 1.109 µm are forecasted for the optimum cutting conditions: GP of 3 bar, CS of 319.8 mm/min, PE of 5.93 J and SOD of 2.97 mm, respectively. Furthermore, the WOA predicted results are validated by conducting confirmatory experiments. [ABSTRACT FROM AUTHOR]

In this work, two typical surface characteristics, i.e., mean surface roughness and angle of the kerf during laser processing of 3D-printed Polylactic Acid (PLA) plates with 4.00 mm in thickness, are investigated. A carbon dioxide laser was utilized to separate 27 work pieces of rectangular shape. The governing laser parameters, speed of cutting and laser power, were varied according to full factorial experimental methodology. An orthogonal array (OA) having nine combinations was implemented, and nine specimens were cut with the same set-up and the same parameters three times (27 replicates in total). The experimental results were analyzed using descriptive statistical analysis, i.e., histograms, box plots, interaction charts and optimized using analysis of means (ANOM) plots as well as ANOVA analysis. The data analysis indicated that laser speed is the dominant parameter for the kerf angle, whilst both the laser velocity and power are important for mean surface roughness of the cut surface for PLA 3D-printed parts. The spread of the data is smaller in Y direction, which indicates that the weaving phenomenon affects the laser cut performance. [ABSTRACT FROM AUTHOR]

Abrasive water jet (AWJ), which is a non-traditional machining method, is more widely used today. Various materials such as metals, ceramics, polymers, and composites can be easily machined with AWJ. In this study, cutting of St37 steel plates in stacked form with AWJ was investigated. The experiments were carried out according to the general full factorial design. Experimental parameters were inter-stack distance, traverse speed, and abrasive mass flow rate also each of these parameters was chosen at three levels. Surface roughness and kerf widths were examined to determine the cutting performance. Analysis of variance (ANOVA) of all outputs was provided and thus the effects of experimental parameters and their levels on cutting performance were found. The most effective parameters for surface roughness and kerf width in almost all conditions were abrasive mass flow rate and inter-stack distance, respectively. In addition, a concept for multi-simultaneous cutting was developed with mathematical differences of surface roughness and kerf taper angle. Thus, optimum levels of experimental parameters were found for minimum mathematical differences. [ABSTRACT FROM AUTHOR]

Machining of high strength and shock-absorbent Metal Fiber Laminate (MFL) becomes inevitable to attain the geometric shape and size, as to validate the functionality in various impact protection environments. A class of titanium metal laminate alternatively interleaved with high strength basalt and shock absorbing flax fibers have been machined with an abrasive water jet method. Machining experiment trials with WJP-water jet pressure, TS-traverse speed, SOD-stand-off distance, and AMFR-abrasive flow rate and parametric optimization on quality factors of surface roughness (Ra) and kerf ratio (KR) were done using a Central Composite Design (CCD)-Response Surface Methodology (RSM). Experimental investigation reveals that the surface roughness and kerf ratio significantly decreased by 27.59% and 9.16% as water jet pressure was increased to peak value. Similarly, abrasive mass flow rate raised to its higher value, the Ra and KR slightly decreased by a margin of 6.5% and 2.5%. However, a reverse effect on surface roughness and kerf ratio was observed as an increase of SOD and TS. Surface topology analysis reveals that the material removal mechanism of the Ti sheet is shear plastic deformation with plowing marks, that of basalt fiber is brittle fracture with micro-chipping, and that of flax fiber is bulk machining. [ABSTRACT FROM AUTHOR]

Geometrical machining errors in terms of overcut and/or undercut are the inherent problems associated with wire-cut electric discharge machining (EDM) process. Such errors are ultimately transformed into compromised dimensional accuracy of the machined part. The magnitude of the said errors is presumed the same in both the cutting orientation of work part. However, practically there exists variations along both the cutting orientations, i.e. axial and lateral. Moreover, not only the lateral and axial dimensions are different from the designed dimensions but also a noticeable difference in errors magnitude is observed along both the cutting directions. Variation in kerf along different edges of the machined profile also plays a pivotal role in error amplification. Such difference in geometrical dimensions seriously matters in high-precision applications. Therefore, the present research examines the impact of seven control parameters for minimizing the magnitude of kerf width, axial and lateral dimensional errors. Al-alloy 6061 is taken as a substrate because of its wide use in precision-oriented applications. Parametric effects are thoroughly analyzed through statistical tests and SEM-based analysis. Results revealed that the use of optimal settings yields a reduction of 13.5%, 49%, and 27% in the magnitudes of kerf width, axial, and lateral dimensional errors, respectively. [ABSTRACT FROM AUTHOR]

The use of cladded bimaterial composites has grown in the recent past as they offer a combination of properties at low cost. But the heterogeneity which is the inherent attribute of these composites makes it challenging to accurately cut via conventional means. Therefore, thermal cutting is commonly employed for their cutting which not only produce poor cut quality and deeper heat affected zones but also demand subsequent finishing operations. Wire electric discharge cutting (WEDM) is a proficient alternate but low material removal (MRR) and widen kerf slot (KW) due to sideways sparking limit its application. Moreover, both layers of material have different thermoelectric properties and are subjected to simultaneous cutting by a single moving wire electrode which lead to produce different spark strength against both layers. In this regard, the present study aims to investigate the cutting potential of WEDM for cladded bimaterial with a prior focus on both the aforesaid issues, i.e. MRR and KW. Considering the thermoelectric nature of the WEDM, workpiece-related parameters like orientation of work surface and layer thickness of each layer are taken as control variables in addition to the WEDM process parameters. Experimental results are thoroughly analyzed using statistical and SEM analysis. [ABSTRACT FROM AUTHOR]

Gas/plasma cutting of cladded materials provides inferior cut quality that demands subsequent finishing processes. Abrasive waterjet cutting could be a proficient alternate in terms of cut quality. However, the inherent problem of kerf taper and low material removal rate in comparison to the said thermal cutting processes limit its application. Therefore, potential of aforesaid machining process for cutting of stainless-clad steel is investigated with a prior focus on maximizing the material removal rate with minimum kerf taper. Abrasive mass flow, traverse speed, water pressure, and stand-off distance have been selected as input parameters. ANOVA analysis revealed that traverse rate as well as abrasive mass flow are the major contributing factors for both the responses. Optimal settings of parameters developed by S/N ratio analysis results in an improvement of 18.6% in material removal rate and 39% in the kerf taper. Moreover, regression models are developed and validated through various statistical tests. [ABSTRACT FROM AUTHOR]

Plasma cutting is an effective way to cut hard metals. In this process, three output parameters cutting width (kerf), surface roughness (Ra) and heat-affected zone (HAZ) are critical factors which affect the quality and efficiency of the cutting. In this paper, an experimental study was conducted to investigate the cutting quality in terms of kerf, Ra, and HAZ for the 309 stainless steel plasma cutting. First, the research tested the effect of input parameters including current, gas pressure, and cutting speed on the process outputs. Then, the results were used to develop three predictive models by intelligent systems based on genetic algorithm (GA) and artificial neural network (ANN). Finally, a hybrid technique of genetically optimized neural network systems (GONNs) was designed and employed to simultaneously optimize the process outputs. The results show that the implemented strategy is an effective method for optimizing the output parameters in the plasma cutting process. [ABSTRACT FROM AUTHOR]

Nickel-based superalloys are predominantly used to manufacture marine, automotive, and aerospace parts due to its excellent corrosion resistance in acidic environments and high-strength characteristics. Machining of these alloys are extremely difficult through conventional process because of their tendency to quickly work harden and poor thermal conductivity. Plasma arc cutting (PAC) is a disruptive metal-cutting process to perform cutting of difficult to cut materials even for intricate profiles. The present work examines the effect of PAC process variables such as arc current, gas pressure, cutting speed, and stand-off distance on evaluating the surface roughness, kerf width, and micro hardness of Monel 400™ superalloy. Experiments are designed and conducted using Box-Behnken design (BBD) of response surface methodology. The quadratic models are developed and assessed for its performance using analysis of variance (ANOVA). Optimal machining process conditions, cutting speed of 2427.08 mm/min, gas pressure of 3.83 bar, arc current of 45 A, and stand-off distance of 2.14 mm are obtained through multiobjective desirability approach. From the confirmation experiments, the relative error is found to be 2.68% for surface roughness, 4.45% for kerf width, and 4.36% for micro hardness which confirms the feasibility and efficiency of proposed methodology. [ABSTRACT FROM AUTHOR]

Aluminum metal matrix composites (AMMCs) explicitly show better physical and mechanical properties as compared to aluminum alloys and results in a more preferred material for a wide range of applications. The addition of reinforcements embargo AMMCs employment to industry requirements by increasing order of machining complexity. However, it can be machined with a high order of surface integrity by nonconventional approaches like abrasive water jet machining. Hybrid aluminum alloy composites were reinforced by B4C (5-15 vol%) and solid lubricant hBN (15 vol%) particles and fabricated using a liquid metallurgy route. This research article deals with the experimental investigation on the effect of process parameters such as mesh size, abrasive flow rate, water pressure and work traverse speed of abrasive water jet machining on hybrid AA6061-B4C-hBN composites. Water jet pressure and traverse speed have been proved to be the most significant parameters which influenced the responses like kerf taper angle and surface roughness. Increase in reinforcement particles affects both the kerf taper angle and surface roughness. SEM images of the machined surface show that cutting wear mechanism was largely operating in material removal. [ABSTRACT FROM AUTHOR]

Magnetic induction-free abrasive wire sawing is a hybrid process that applies a homogeneous magnetic field to transport more abrasives into the sawing channel. This causes the performance of wire sawing significantly improved. Magnetic field strength is a key factor in determining the magnetic force acting on the magnetic abrasives, then affecting the quantity of abrasives adsorbed on the saw wire surface. However, the background magnetic induction strength produced by two permanent magnets is limited in this process. To further investigate the influence of magnetic field strength on the wire sawing performance, a magnetic system, which is based on the magnetic circuit design principle and the structure of single-wire sawing machine, is designed and fabricated. The magnetic field characteristics of the designed magnetic system are investigated both by numerical simulations and experiments. An experimental setup that installs the fabricated magnetic system on the single-wire sawing machine is built to conduct the magnetic induction-wire sawing experiments. The results show that the optimal magnetic induction strength is aboutB0 = 135 mT. In this case, the kerf loss is decreased by 10% compared to the free abrasive wire sawing technology without a magnetic field. [ABSTRACT FROM PUBLISHER]

This work focuses on the effect of chemical treatment of coconut sheath/unsaturated polyester (CS/UPR) composite on the performance of abrasive waterjet machining (AWJM). Two different chemical treatments, namely alkali (NaOH) and trichlorovinylsilane, were imposed on the CS fiber. Further, the induced compressive strength arising as a result of AWJM was studied along the radial and depth directions of the composite. Experimental results revealed significantly lower induced stress at all points compared to the ultimate stress of CS/UPR composites except the free-edge loading condition. The chemically treated composites also exhibited inconsistent results in the machining characteristics such as kerf taper angle (Ta) and surface roughness (Ra) under varying cutting conditions. However, no direct correlation was seen between interfacial adhesion andTaandRaof the cutting zone. The maximum decrease of 12% ofTaand 22% ofRawas found for silane-treated composites compared to the untreated ones. In addition, the composite failure mechanisms such as fiber pullout, fiber breakage, interfacial debonding, matrix failure, and voids were identified in the cutting surfaces through scanning electron microscopy analysis. [ABSTRACT FROM PUBLISHER]

Polymer matrix composite materials have been increasingly used in aerospace, defense, automotive and marine industries. In these fields, nontraditional machining method of abrasive water jet (AWJ) has been used significantly in order to form polymer matrix components. In this study, glass fiber reinforced vinyl ester composite plates have been investigated under various AWJ cutting parameters by using the Taguchi experimental design in detail. For Taguchi experimental design, experimental parameters of standoff distance, abrasive mass flow rate, traverse speed, pressure and material thickness were determined at three levels. Top kerf width and the surface roughness were investigated in order to understand the cutting performance. Finally, linear regression models were conducted and all performance parameters were examined using analysis of variance (ANOVA) and main effects plots. According to the overall test results, standoff distance was determined as the most effective one. The optimal parameter levels were obtained by the ‘main effects plots’, and finally, the predictive modeling was validated by performing the optimal combination of parameter levels. [ABSTRACT FROM PUBLISHER]

For machining of composites, abrasive water jet machining is widely employed. For assembly of the machine tool structure, production of slots is essential. In this paper, abrasive water jet machining of composite laminates was experimentally investigated for various cutting parameters in terms of average surface roughness (Ra) and kerf taper (Kt). By generating a response surface model, the experimental values obtained for quality characteristics (Ra and Kt) were empirically related to cutting parameters. The effects of cutting parameters on quality characteristics were analyzed by utilizing empirical models and also optimized within the tested range based on desirability approach. The optimum parameter levels were also validated by confirmation test. From this investigation, it is evident that for obtaining a minimum kerf taper, traverse speed, water pressure, and abrasive mass flow rate are significant parameters and for obtaining less surface roughness traverse speed is the significant parameter. [ABSTRACT FROM AUTHOR]

In laser beam machining, the main concern is the machining quality as kerf width of the end product. It is essential for industrial applications to cut the workpiece with minimum kerf width. However, it is difficult to develop a precise functional relationship between input and output variables in laser machining. Therefore, an effort has been conducted to build up an intelligent fuzzy expert system (FES) model to predict the kerf width in CO2laser cutting. The employed input parameters were assisting gas pressure, laser power, cutting speed, and standoff distance. The fuzzy logic was performed on fuzzy toolbox in MATLAB R2009b by employing Mamdani technique. In total, 81 experiments were carried out and experimental results were used for training and testing of the developed fuzzy model. Relative error and goodness of fit were used to investigate the accuracy of the prediction ability and the values of 3.852% and 0.994, respectively, were found to be satisfactory. This paper will extend knowledge about the prediction of kerf width by using FES model. [ABSTRACT FROM PUBLISHER]

The surface growth stress in logs can be determined by slitting the log axially and measuring the outward deflection of the two halves. The saw kerf removes stressed material which generates a compressive strain in the remaining material and thereby reduces the surface growth stress. The purpose of the work is to establish the magnitude of this error. The analysis assumes a uniform compressive stress in the core of the log and a logarithmic distribution in the outer region. The total axial force in the kerf before removal is calculated and, from this, the stress change in the material remaining after kerf removal is derived. Data are presented for a range of kerf widths and for three different growth stress distributions. Direct measurement of the kerf removal error was made by direct measurement of the contraction of the log and by strain gauges to measure the strain. The measured values were close to the calculated values for three growth stress distributions. The analysis yields acceptable values for the kerf removal error. The investigation concludes that for kerf widths not greater than one-tenth of the log diameter, the error in the measured tensile surface growth stress is less than 10%. [ABSTRACT FROM PUBLISHER]