Applied Mechanics and Materials Vols. 66-68

Abstract: The purpose of this study is to explore the effecting principle in the drying process. The factors such as hot air temperature, hot air flow, drying time on the grain moisture content have been all investigated. Using UD to establish the optimization mathematics model which making the grain dryer moisture content as the goal of the design, making the factors of hot air flow, drying time, air temperature as parameters, with the help of UD to analysis the effecting principle of the drying process parameters on the grain moisture content, some references have been provided to the tower dryer.

Abstract: For the motor current noise signal, vibration signal, the phase current signal, a motor dynamic system model is established. A motor energy detection equation is introduced and constituted by an innovation series of these signal tested in the dynamic system, then the main factor analysis of the motor abnormal elements is presented by orthogonal decomposition, and the main factor distribution chart is described by decomposing the main failure elements to tow-dimensional observation vector. The motor fault can be detected on-line by using the main factor analysis, and then the failure factors can be identified with fault Mode.

Abstract: In order to effectively achieve MH-Ni battery state of charge estimation, grey system neural network model is put forward to predict battery state of charge by using the parameters of battery pulse current response signal as input for grey system neural network. The state of charge is as the network output and the response parameters of the battery pulse current as the input. The results show that its prediction accuracy of the state of charge can be achieved to requirements of the electric vehicles in applications by this method to predict the state of charge.

Abstract: In this paper, an optimization study of partially covered beam with a constrained viscoelastic layer is presented. An energy approach and Lagrange’s method are used to establish the governing equation of motion of a CLD covered beam, and the assumed modes method is employed in solving the equation to obtain the modal loss factors which are used as the objective of optimal layout. A genetic algorithm of big mutation is employed to search for the optimum of the patch’s location, the thicknesses of both the constraining layer (CL) and the viscoelastic layer (VL) and the shear modulus of the viscoelastic material with the restriction of added volume of the total CLD treatment. Numerical results show that the optima of the design variables are highly relevant to each other. The thinner constraining layer requires a softer viscoelastic material for an optimal damping treatment. The variation of the CL thickness decreases slowly and that of the VL thickness increases with the increase of the thickness of the CLD treatment. One end of optimal damping treatment locates closely one end of base beam.

Abstract: A probabilistic neural network was developed to classify corrosion damage depth ranges based on the aluminum alloy failure mode. The results obtained indicate that corrosion damage depth for aluminum alloy can be classified into three groups. Statistical study on classified corrosion damage was carried out. The results show that pitting corrosion depth for aluminum alloy is in conforms to Gumbel distribution. The normal distribution fits well with intergranular corrosion depth and the exfoliation corrosion depth is consistent with Weibull distribution law. It may be necessary to use several distribution functions rather than a single distribution to represent corrosion damage characteristics due to the large distribution of corrosion depth in aircraft materials. According to corrosion damage depth distribution, corrosion depth was simulated by Monte Carlo method and used as the starting crack size. Fatigue lives were estimated by using a life prediction program AFGROW and the results are in good agreement with the experimental data. A probabilistic analysis shows that the distribution of fatigue lives is strongly correlated to the distribution of corrosion damage depth and should be classified into several groups to study.

Abstract: In this study, different oil extraction processes, such as extrusion pretreatment, ultrasound-ethanol assisted demulsification and traditional hexane extraction of oil, were employed to extract oil from soybean in order to compare their different effects on oil quality, fatty acid distribution and V_E content of oil. The result shows that the quality of oil from extrusion pretreatment aqueous enzyme extraction (EAEP) of oil and ultrasound-ethanol assisted demulsification aqueous enzyme extraction of oil were same. The raw oil quality from the above two processes was better than the hexane extraction of oil. The fatty acid contents of oil were similar in different oil extraction processes. The V_E content of oil from ultrasound-ethanol assisted demulsification process was decreased, while the extrusion pretreatment aqueous enzyme extraction of oil had no influence on V_E concentration.

Abstract: Cylinder head and fuel injecting vibration consist of rich information about the working state of the locomotive engine, which shows important potential on the engine fault online diagnosis and regular maintenance. Through acquiring the cylinder head and fuel injecting vibration signals, comparing with the standard signals, fault diagnosis strategy is researched. By analyzing the cylinder head vibration curve with the method of vibration comparison value, the working states of all the cylinders are obtained. With the vibration curve of the fuel injecting, the problem of the injectors is found which helps to locate the fault. The strategy is applied to the No.0015 locomotive of the Rizhao Seaport Transportation Company. The matching between the analysis result and practical locomotive state shows the validity of the strategy which can dramatically improve the maintaining efficiency as well as decrease the degree of over maintenance and lack of maintenance.

Abstract: Surface degradation and cracking of dense hydroxyapatite were evaluated through Vickers micro indentation using indentation loads ranged from 25 gf to 2000 gf. Crack lengths, imprint diameters and the number of lateral cracks and chips were measured using SEM. The crack length-indentation load data were analyzed with regard to the specific relations of Palmqvist and fully developed radial cracks. Crack type transition load from Palmqvist to median crack was experimentally assessed through serial sectioning technique. The analytical estimated transition load, based on the theoretical relation of the indentation load and crack lengths showed a good agreement with one obtained from experimental itinerary. Palmqvist and median cracks were identified in low and medium indentation loads, respectively. High indentation load could also lead to the formation of lateral cracks and chips. The tendency for lateral cracking was evaluated taking into account the number of lateral cracks and chips. The chips were found to be appeared just after test in higher indentation load, whereas in medium loads they could be detectable only after several weeks.

Abstract: Proprioception provides feedback that is vitally important for motor control. A deficiency in joint proprioception is thought to be associated with various upper limb rheumatological disorders. Currently, there is a lack of a portable device that could be used for measuring functional proprioception at the fingertips in the field. Therefore, a novel portable device for measuring pinch movement discrimination between index finger and thumb of either hand was constructed. This device is manually operated and requires the subject to make an absolute judgment of a joint position, choosing which one of five pre-experienced positions is being presented to them, with trials given in a random order. The 5 physical differences used were between 1.22 and 2.42cms. Reliability analysis was performed over a 7-day interval, with 8 healthy young adult volunteers. The discrimination scores, measured as the Area Under the Curve (AUC), for the group showed a mean (SD) of 0.794 (0.544) and 0.794 (0.549) on days 1 and 8, respectively. The day 1 and 8 reliability assessed with the interclass correlation coefficient ICC(3,1) was 0.85. Nondominant hands showed better pinch discrimination on the two days, with AUC values of 0.800 and 0.810 compared with 0.788 and 0.778, but these differences were not statistically significant (p>0.05). No difference in pinch movement discrimination was found between sexes. The ease of use and portability of the novel device for measuring functional proprioception at the fingertips described in this note make it ideal for measuring hand functional proprioception as part of clinical and epidemiological studies. The mid-range AUC discrimination scores found with healthy young adults mean that factors thought to diminish (eg. hand injury) or improve (eg. having expert finger skills) discrimination could be detected with the device.

Abstract: The support vector interval regression model is an effective method to estimate imprecise data. Parameters of this model is very important in order to obtain the excellent regression result. The flexible polyhedron search algorithm is a fast optimization algorithm. Based on the flexible polyhedron search algorithm, this paper proposes an automatic parameters selection method for the support vector interval regression model. Experiments illustrate the validity and applicability of the support vector interval regression model based on the flexible polyhedron search algorithm.