Journal of Mechatronics and Artificial Intelligence in Engineering
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Structural simulation analysis of high pressure common rail pipe
Get PDFAs one of the key components of the common rail system, the accuracy of pressure field and velocity field analysis of the common rail pipe is related to the service reliability. In order to obtain the velocity and pressure distribution that difficult to be measured in the experiment, this paper considers using three-dimensional modeling and establishing the three-dimensional model of oil flow in the common rail pipe based on the fluid simulation software, and then obtains the velocity field and pressure field distribution of the common rail pipe through numerical simulation. The cone angle at the nozzle structure of common rail pipe is compared and analyzed. Meanwhile the most appropriate cone angle’s processing angle among the commonly used processing cone angles is obtained, which improves the rationality of common rail pipe structure processing. It is great significance to the subsequent rail pressure stabilization analysis of common rail pipe
Correlations between basal metabolic rate in humans with different age, gender, BMI and local earth magnetic field activity
Get PDFDaily energy expenditure includes resting metabolism (RMR), endogenous thermogenesis (or thermal effects of food), and energy expenditure associated with exercise. RMR depends on body weight, age, gender, genetic factors, medications used and health status. Every living organism is affected by external factors. Fluctuations in magnetic fields can affect almost every biological system more or less, depending on the characteristics of the particular biological system and magnetic fluctuations. Environmental energy phenomena affect psychophysical processes that can affect people in a variety of ways, depending on their sensitivity, health status, and ability to self-regulate. The aim of this study: to investigate the correlations between basal metabolic rate in humans with different age, gender, BMI and local Earth magnetic field activity. Information on gas metabolism during respiration was obtained by indirect calorimetry where the gas flow was continuously analysed. O2 consumption and CO2 emissions were continuously analysed. The best quality 5 min section was selected from the 15 min recording (automatically selected by the computer). The results were analysed and mean resting metabolic rate (M_RMR) was calculated. Investigations of metabolic rate were performed in Lithuanian, Druskininkai, Medical SPA Center ,,UPA”. Power of spectral density of Local Geo Magnetic field (LGMF) was calculated in 0.32 to 36 Hz frequency range from the Lithuanian (GCI003) magnetometer for East – West direction (E-W). 395 persons were investigated: 116 men and 279 women. All participants were divided into two groups according gender. Women and men groups were divided again into two groups according mean age, the mean was 46 years. Was analysed correlations in women younger (≤ 46 years) and older (> 46 years) groups and the same for men younger (≤ 46 years) and older (> 46 years) groups. On the next step all women and all men, then younger women group, older women group, younger men group and older men group was divided according BMI mean (29), with less than ≤ 29 BMI and with more than > 29 BMI. On the basis of obtained results, we can conclude, that correlations between LGMF and basal metabolic rate features are negative. More expressed negative correlations are seen in persons with smaller BMI. With age negative correlations with LGMF decrease in men group and increase in women group. Sensitivity of persons of different gender to LGMF – differ
Experimental analysis of cutting force during machining difficult to cut materials under dry, mineral oil, and TiO2 nano-lubricant
Get PDFDifficult-to-machine materials, e.g., Titanium alloys, are highly applicable in diverse industries that yield strength and wear resistance. However, they prove difficult to machine due to high vibration, leading to high cutting forces during the machining process. This vibration occurs from chip discontinuity and thereby leads to high friction between the cutting tool and workpiece. In order to minimize these challenges, lubricants are employed in machining operations to reduce frictional and other unnecessary cutting forces and improve surface finish. This research focuses on studying the nano-lubricant effects in reducing cutting forces in the machining of TI-6AL-4V-ELI alloy. Also, carry out a comparative study of dry, mineral oil, and TiO2 nano-lubricant during face-milling machining for optimal performance. Additionally, the study develops a predictive mathematical model for cutting force using a Taguchi L9 orthogonal array. A two-step approach was employed to develop the nano-lubricant before the machining process. The dynamometer is used to collect the cutting force data at the end of each sample. The Results show that the lubrication conditions play a significant role in the reduction of cutting forces. The mineral oil-based-TiO2 nano-lubricant reduces the cutting force by 19 % compared with the mineral oil during the machining of TI-6AL-4V-ELI alloy. Furthermore, the optimal parameters to reduce cutting forces during face milling of TI-6AL-4V-ELI alloy are cutting speed at 3000 rpm, 200 mm/min feed rate, 0.3 mm depth of cut to obtain the minimum cutting force 30 (N). This study concludes that the application of TiO2 nanoparticles in mineral oil significantly improves the thermal and mechanical properties, which leads to a reduction of cutting force
Identification of shallow cracks in rotating systems by utilizing convolutional neural networks and persistence spectrum under constant speed condition
Get PDFThe positive benefits of early faults detection in rotating systems have led scientists to develop automated methods. Although unbalancing is the most prevalent defect in rotor systems, this fault normally is accompanied by other defects such as crack. In this article, an effective self-acting procedure is addressed in identifying shallow cracks in rotor systems throughout the steady-state operation. To classify rotor systems suffering cracks with three various depths, firstly, healthy and cracked systems are modeled by employing the finite element method (FEM). In the following, systems' vibration signals are calculated in different situations numerically; for pre-processing stage, the persistence spectrum is implemented. Finally, by using a supervised convolutional neural network (CNN), rotor systems are classified by regarding the crack depths. The result of the testing step revealed that this hybrid method has rational capacity in distinguishing shallow cracks in steady-state operation where many other methods are somehow powerless
Failure analysis of gas pipeline in a gas collecting station
Get PDFThe gas collecting line of a gas collecting station failed and had obvious corrosion pits. The failure reasons of the pipeline in this section are studied by means of macroscopic morphology analysis, mechanical property analysis, hardness analysis and microstructure analysis. The results show that the main reason is the mechanical damage caused in the construction process for the damage of the anticorrosive coating on the outer surface of the pipe section. The main reason for the failure of “corrosion pit” inside the pipe section is that the wet gas transported contains CO2, which dissolves in water to generate H2CO3, and the pipe section is corroded in H2CO3 solution by electrochemical corrosion, which gradually develops into a more serious corrosion pit. In order to prevent the occurrence of such failure, 13Cr (martensite) material can be used to meet the corrosion resistance requirements, but also can appropriately increase the gas temperature in the tube to reduce the solubility of CO2 in water to prevent corrosion
Erratum: Feature-based performance of SVM and KNN classifiers for diagnosis of rolling element bearing faults
Get PDFManufacturing of complex geometric structure metal matrix structures used for special purposes
Get PDFThree-dimensional (3D) production systems are making rapid progress and their needs are met in every field from the construction sector to the food sector. This technology is based on a hardware called the 3D printer which performs layered production. These printers are used in producing both prototypes and machine parts and mold tools. 3D prints can be produced using 3D printers with that are based on different technologies. These production systems have some disadvantages as well as the advantages they provide. Filament supported productions have a common problem if the fluid gets stuck in the flow line. In this study, screw extruder design and product development will be provided as a new generation production technology to be used in additive production as an innovative approach in additive manufacturing technology
Hydromount elastic shell dynamic stiffness calculation using finite difference method
Get PDFA preliminary approach to calculate hydromount elastic shell dynamic stiffness using finite difference method is presented in the article. This approach is necessary to calculate and assess maximum shear deformations of hydromount rubber shell needed to further determine the hydromount stiffness and damping coefficients at resonance frequencies. For this reason, finite difference method is applied when assessing maximum shear deformations of hydromount rubber shell, caused by variable loads. It was found that using reduced length and reduced arc dimensions of cut-out hydromount shell segment the equivalent stiffness can be determined. The novelty of the proposed method lies in the possibility of a quick and fairly accurate numerical calculation of the rubber shell stiffness using the values of the rubber modulus of elasticity, its permissible shear stress, and the nominal load (weight). This approach can be used to determine and optimize the geometric dimensions of the mounts shells with a given stiffness