Manipulation of robots is carried out by the operators through a sequence of commands. However, the accuracy of the manipulation is still hindered due to parameter uncertainty. This results in less... Show More

Manipulation of robots is carried out by the operators through a sequence of commands. However, the accuracy of the manipulation is still hindered due to parameter uncertainty. This results in less accurate robotic operations and hence affects the job performance. Due to measurement errors and sensor faults, the operation of robots malfunctions. Generally, errors are reduced with the use of high precision sensors and correcting hardware faults. However, corrections can also be made on a software platform to handle the correction process. Presently, the Denavit–Hartenberg (DH) parameters of a robotic manipulator are optimized for forward kinematics problems. The optimization is carried out using the JAYA approach. The 6R MTAB Aristo XT robot is selected as a case study for the experimental validation of the proposed approach. Experimental results reveal that the optimization of DH parameters improves accuracy for forward kinematic estimation problems. The proposed JAYA approach can further be extended to other robotic manipulators for parameter optimization problems.

This paper aims to assess the dimensional deviation of Fused Deposition Modeling (FDM) processed ABS and ULTRAT parts using a new geometrical model which can evaluate three types of dimensional... Show More

This paper aims to assess the dimensional deviation of Fused Deposition Modeling (FDM) processed ABS and ULTRAT parts using a new geometrical model which can evaluate three types of dimensional deviation: along the z-axis, along external and internal dimensions, and through diameters. The methodology involves a step-by-step procedure wherein after establishing the experimental plan and manufacturing the specimens, the measurements taken are analyzed via Grey Relational Analysis (GRA) to find out the optimal combination of parameters leading to the minimum deviation in all dimensions of parts for both materials. Statistical techniques such as Analysis of Variance (ANOVA) and Signal to Noise (S/N) ratio were also used. Subsequently, a confirmation test was carried out to validate the results obtained. The findings of the ANOVA and the S/N ratio were in good concordance with those of GRA.

Finite element simulation using ANSYS software, to analyze the effect of coating layers of different materials on piston compression ring. Similar material properties to that in the actual... Show More

Finite element simulation using ANSYS software, to analyze the effect of coating layers of different materials on piston compression ring. Similar material properties to that in the actual structural piston-compression-ring were considered on the simulated model. Three different coating materials, MgZrO3, La2Zr2O6, 3YSZ, and NiCrAl as bond coat materials of 1.6 mm thickness, were chosen to investigate the deformation, von Misses stress-strain, temperature distribution, heat flux of the core and coating layers. The results showed that the total elastic deformation was maximum for coating type MgZrO6, which was equal to 1.767 µm, and was higher by 0.46 times than uncoated ring. While, maximum von Misses stress was observed for coating type La2Zr2O6, which was higher by 1.69 times than that of the uncoated ring. Moreover, the maximum elastic strain was for type MgZrO6, which was equal to 0.003576, higher by 12.33 times comparing with the uncoated ring. Also, temperature rise and heat flux were maximum in the case of the uncoated ring.

This research develops a procedure for DEA window analysis and MPI evaluation of a manufacturing process with fuzzy inputs and outputs. A real case study was provided to illustrate relative... Show More

This research develops a procedure for DEA window analysis and MPI evaluation of a manufacturing process with fuzzy inputs and outputs. A real case study was provided to illustrate relative efficiency and MPI assessment of a blowing machine over a period of one a year. The proposed approach was implemented to measure the technical, pure technical, and scale efficiency scores for decision making unit. The results showed that the blowing process was technically inefficient due to scale inefficiency. Therefore, management should optimize the size of operations and better utilize resources. Then, the lower and upper MPI values and their corresponding technology change and efficiency change were calculated. The MPI results revealed the reasons behind MPI progress or regress in current period measured with respect to next period. This procedure provides great assistance to process engineering in obtaining reliable feedback on process performance and guide them to take proper actions.

The forming of low and high strength tailor welded steel sheets into preferred three-dimensional shapes by a homogeneous distribution of plastic strain is highly difficult. In this work, the... Show More

The forming of low and high strength tailor welded steel sheets into preferred three-dimensional shapes by a homogeneous distribution of plastic strain is highly difficult. In this work, the formability of tailor-welded blanks prepared using laser welding of low (IS 513 CR2, IS 513 CR3) and high tensile strength (AISI 304) steel sheets were analyzed and the formation of the edge profile and weld line movement was also examined. The results showed a decrease in formability characteristics owing to the increase in Strength Ratio. Scanning Electron Microscope analysis of the fracture locations within unsuccessfully formed tailor welded blanks showed the presence of tempered martensite in the soft zone was found to be the most predominant factor affecting its failure. The formability characteristics of investigated tailored blanks were predicted using finite element simulation and compared with experimented results for validation.

This work investigates the tensile testing of glass fibre-reinforced polymer (GFRP) composite material and its most influencing parameter. The GFRP constitutes bi-axial glass-fibre and epoxy-matrix.... Show More

This work investigates the tensile testing of glass fibre-reinforced polymer (GFRP) composite material and its most influencing parameter. The GFRP constitutes bi-axial glass-fibre and epoxy-matrix. The three parameters considered for the tensile test are the load, elongation, thickness, and the experiment's factorial design is L9 orthogonal array. The percentage contribution of load, extension, and thickness for stress and strain is calculated using variance (ANOVA) analysis. Optimizating parameters made using response surface method (RSM). Since the solutions arrived at by this optimization process are promising, the optimized outcomes are high load, low elongation, and high thickness. Such works are beneficial for replacing concrete slabs constructed on the roads for rainwater harvesting. In such applications, non-crimp GFR panels with openings at regular intervals may replace concrete slab structures. A mathematical response surface model for the stress and strain parameters has been formulated. The model validation is done using the Pearson product-moment coefficient.

Duplex and super duplex materials possess the properties of both Austenite and Martensitic steels. Properties like hardness and toughness are very high for duplex grades and are... Show More

Duplex and super duplex materials possess the properties of both Austenite and Martensitic steels. Properties like hardness and toughness are very high for duplex grades and are difficult-to-machine. In this study, machining performance of Duplex Stainless Steel (DSS 2205) and Super Duplex Stainless Steel (SDSS 2507) was estimated during CNC dry milling operation. Cutting parameters namely feed rate, spindle speed and depth of cut were considered for this investigation and were optimized by considering surface roughness, cutting force and cutting temperature during CNC milling using Taguchi technique. Results revealed that depth of cut has more effect on cutting force than spindle speed and feed rate. Surface roughness was highly influenced by feed rate than spindle speed and least influenced by depth of cut for both the materials. Results also showed that, cutting temperature is mainly influenced by spindle speed. Optimum value for all the responses was obtained at spindle speed of 4200 rpm, feed rate of 50 mm/min and depth of cut of 0.35 mm for both DSS 2205 and SDSS 2507.

Islands-Matrix-Dual-phase (I-M-DP) steel is received a great deal attention for better concern with the emissivity, fuel consumption and passengers safety. A number of deformation plasticity issues... Show More

Islands-Matrix-Dual-phase (I-M-DP) steel is received a great deal attention for better concern with the emissivity, fuel consumption and passengers safety. A number of deformation plasticity issues are yet to be fully understood. Complex deformation stages for various stain is predicted as the natural outfall of the plastic strain localization caused by the ill-assorted deformation between the martensite-island phase and the ferritic-matrix phase. Modeling is carried out both in macro level by bending under tension (BUT) for different roller radius/sheet thickness ratios to acquire strain and stress state deformation and micro scale by Representative Volume Element (RVE) according to element position. It can relate both the 2D, 3D micro and macro scale finite element based BUT model’s result of flow behavior. Systematically strain based severe deformation pattern arises from outfall of plastic strain localization and von Mises stress distribution in island-matrix steels are investigated on the microstructure by finite element method for ill-assorted deformation between phases.

The degradation of metallic industrial assets, equipment, and components costs governments, industries, and citizens billions of dollars a year. Also, the degradation of industrial assets and... Show More

The degradation of metallic industrial assets, equipment, and components costs governments, industries, and citizens billions of dollars a year. Also, the degradation of industrial assets and infrastructure proliferates a myriad of safety problems. AssessLIFE software addresses this strategic deficiency by focusing on forecasting strategies rather than on mitigation strategies in the active battle against industrial asset degradation. By employing tested and proven scientific analytical computations, forecasting, prediction, and analytics, the AssessLIFE software plans to significantly reduce the billions of dollars expended via inspection, treatment, and repair of degradation-prone assets and infrastructure. The AssessLIFE software leverages many scientific studies and research in many fields of engineering. The AssessLIFE software also emphasizes the computerization or automation of the processes of metallic (alloys and welds) degradation mechanisms and parameters using digital techniques.

In the present work, an attempt was made to use vegetable oil as a cutting fluid during minimal fluid application to make the process more environmentally friendly. Coconut oil was selected as the... Show More

In the present work, an attempt was made to use vegetable oil as a cutting fluid during minimal fluid application to make the process more environmentally friendly. Coconut oil was selected as the vegetable oil in this study considering its availability, physical properties, and lubricating ability. The effect of newly formulated coconut oil-based emulsified cutting fluid on cutting performance during turning of hardened AISI 4340 steel with the minimal fluid application was investigated. It was observed that the coconut oil-based cutting fluid offered better cutting performance in terms of tool wear, surface roughness, cutting force, cutting temperature, and tool chip contact length when compared to mineral oil-based cutting fluid and raw coconut oil. It was also observed that the percentage of concentrate in the cutting fluid was to be maintained as 30% to achieve better cutting performance. The use of coconut oil-based cutting fluid holds promise as an environment friendly alternative for mineral oil-based cutting fluid.

Additive manufacturing is a popular emerging technology of producing parts directly from digital models. This technology has presented benefits such as freedom of design, the ability to customise... Show More

Additive manufacturing is a popular emerging technology of producing parts directly from digital models. This technology has presented benefits such as freedom of design, the ability to customise, and shortened process chains. Presently, there are different Additive Manufacturing (AM) processes that are available in the market. Often, transport equipment manufacturing companies are faced with challenges while selecting the AM processes that are suited to their needs. Decision-makers need to consider all the underlining factors before a conclusion is reached. This paper proposes an approach that can be used by companies in the rail sector to select AM technologies that are suited to their applications. The approach involves identifying suitable parts, comparing applicable AM technologies and selecting the most suitable technology. The next stage involves re-designing the parts based on the selected technology. The approach is applied to benchmark parts from the industry. The study provides enlightenment on how AM can be applied in the rail industry.

Ag has the lowest stacking fault energy of all metals, which allows twin formation to occur more easily. The (111)-preferred orientation Ag nanotwinned films is fabricated by either sputtering or... Show More

Ag has the lowest stacking fault energy of all metals, which allows twin formation to occur more easily. The (111)-preferred orientation Ag nanotwinned films is fabricated by either sputtering or evaporation method exhibit columnar Ag grains grown vertically on Si substrates. Ag nanotwinned films have a (111)-preferred orientation with a density about 98% and diffusivity that is 2 to 5 orders of magnitude higher than those of (100) and (110) surfaces. Low temperature direct bonding with (111)-oriented Ag nanotwins films is proposed to fulfil the requirements for wafer-on-wafer (WoW), chip-on-wafer (CoW), and chip-on-wafer-on-substrate (CoWoS) advanced 3D-IC packaging, with the process temperature drastically reduced to 100°C. Such an innovative bonding method also provides a promising solution for die attachment of Si chips with DBC-ceramic substrates for power module packaging.

The reliability of critical aircraft components continues to shift towards onboard monitoring to optimize maintenance scheduling, economy efficiency and safety. Therefore, the present study... Show More

The reliability of critical aircraft components continues to shift towards onboard monitoring to optimize maintenance scheduling, economy efficiency and safety. Therefore, the present study investigates changes in dynamic behavior of turbine blades for the detection of defects, with focus on substrate cracks and TBC spallation as they relate to vibration modes 1 to 6. Two‐dimensional and three-dimensional finite element simulation is used. The results indicate that TBC spallation reduces natural frequencies due to the ensuing hot spot and overall increase in temperature, leading to drops in blade stiffness and strength. Cracks cause even larger frequency shifts due to local plastic deformation at the crack that changes the energy dissipation behavior. Mode 1 vibration shows the largest shifts in natural frequencies that best correlate to the size of defects and their position. As such, it may be most appropriate for the early assessment of the severity and location of defects.

Effects of chemical treatments with benzoyl chloride, acetone and alkali on the physical and mechanical properties of Orange Peel Particulate (OPP) reinforced epoxy composite materials have been... Show More

Effects of chemical treatments with benzoyl chloride, acetone and alkali on the physical and mechanical properties of Orange Peel Particulate (OPP) reinforced epoxy composite materials have been studied. Hand lay-up technique was applied to manufacture the composites. The experimental results illustrate that chemical treatment with benzoyl chloride has a considerable impact. The properties of OPP reinforced composite material have been enhanced by 15% (for tensile test) and 30% (in case of flexural test) due to benzoyl chloride treatment as compared to raw OPP composites. It is evident from Fourier Transform Infrared Spectroscopy (FTIR) that non cellulosic content was removed from the surface of the fiber due to benzoyl chloride treatment. After chemical treatment there was good interfacial bonding between matrix and filler material as observed in SEM micrographs. From the experimental observations, it can be seen that among all fabricated composites, set of composites with 30% filler loading yields excellent mechanical properties.

This study evaluates CNC milling parameters (spindle speed, depth of cut, and feed rate) on medical-grade PMMA. A single objective analysis conducted showed that the optimal material removal rate... Show More

This study evaluates CNC milling parameters (spindle speed, depth of cut, and feed rate) on medical-grade PMMA. A single objective analysis conducted showed that the optimal material removal rate (MRR) occurs at a spindle speed of 1250 rpm, a depth of cut of 1.2 mm, and a feed rate of 350 mm/min. The ANOVA showed that feed rate is the most significant factor towards the MRR, and spindle speed (11.83%) is the least contributing. The optimal surface roughness (Ra) occurred at spindle speed of 500 rpm, depth of cut of 1.2 mm, and feed rate of 200 mm/min. The milling factors were insignificant. A regression analysis for prediction was also conducted. Further, a multi-objective optimization was conducted using the Grey Relational Analysis. It showed that the best trade-off between the MRR and the Ra could be obtained from a combination of 1250 rpm (spindle speed), 1.2 mm (depth of cut), and 350 mm/min (feed rate). The depth of cut was the largest contributor towards the grey relational grade (54.48%), followed by the feed rate (10.36%), and finally, the spindle speed (4.28%).

Finite Element (FE) simulation of sheet/tube forming precision depends mainly on the accuracy of the constitutive modeling. The present paper aim is to compare the constitutive models to fit the... Show More

Finite Element (FE) simulation of sheet/tube forming precision depends mainly on the accuracy of the constitutive modeling. The present paper aim is to compare the constitutive models to fit the stress-strain curves. The accurate deformation behavior of the SS 304 tubes depends on the constitutive modeling of hardening behavior. Deformation data of the tensile specimens cut from tubular sample were collected by conducting Uniaxial tensile tests (UTT) at three different rolling directions. Five constitutive relationships were then recognized by fitting the true stress and strain data with the constitutive models of Hollomon, Power, Krupowsky, Voce and Ghosh, and the fitting accuracy were analyzed and compared. Effects of hardening models on Forming Limit Curves (FLC), pressure loading and bulge height of the hydroformed tube were then studied. The obtained FLC from the simulations were compared with experimental FLC to predict the accuracy of the hardening models.

This paper presents test results for silica and corundum base metals casting sands. Standardized tests were carried out to understand physical and mechanical properties of the metal casting sands... Show More

This paper presents test results for silica and corundum base metals casting sands. Standardized tests were carried out to understand physical and mechanical properties of the metal casting sands and molding mixtures prepared with these refractory bases. Grain distribution, grain size, grain shape classification, moisture content, pH, LOI, Weibull distribution tensile test, permeability and roughness are the properties that have been evaluated. Tensile, permeability and roughness tests are carried out with different molding mixtures changing base sand and Phenolic-isocyanate and Furanic binders. The results of the tensile test were adjusted to a Weibull distribution. Weibull modulus of each molding mixture and the strength at a probability of failure of 63% is obtained. The permeability and roughness results were subjected to ANOVA and T-Test. Regular grains contributes to increase strength of molding mixture while permeability is not affected by time and amount of binder.

Single point incremental sheet metal forming has passed through a period of ample improvement with developing responsiveness from research societies and industries globally. The process has... Show More

Single point incremental sheet metal forming has passed through a period of ample improvement with developing responsiveness from research societies and industries globally. The process has expressively spared the practice of using costly dies, which makes it an appropriate process for manufacturing prototypes and small batch production. It also discovers easiness in fabricating components of timeworn equipment. Additionally, in recent years, aluminum alloys become the most commonly used materials in the automotive, aeronautics, and transportation industries for their structural and other applications. The effect of various process parameters on the formability of Single Point Incremental Forming of aluminum alloys has been critically surveyed. Ultimately, this article also debated the dares associated with the Single Point Incremental Forming process and recommended some correlated research regions which probably charm significant research considerations in the future.