Advanced Materials Research Vol. 548

Abstract: Coupling method is developed in recent years to solve numerical problems a new method, meshless - the finite element of a direct coupling method is based on the definition of the generalized unit of coupling of the new method . The core of this method is the use of each unit in the shape function to the assumption that the brain that the whole sub-domain to be seeking to solve the unknown field function. Coupling with other compared with the method is simple to calculate the advantages of a short time.

Abstract: The 35t/h boiler used in the Thermal Power Plant of Tangshan Iron and Steel Co. Ltd. is a chain furnace. Its control system of the conmbustion process is a 2 input-2 output system whose inputs are the quantity of the fuel and desuperheater spray, outputs are the steam pressure and the steam temperature. Due to the nonlinearity, large lag, and coupling impact between the input and output parameters, fuzzy control was introduced. The fuzzy control rule has the adjustable factors and is described by the analytic relationships. The steam pressure is a 2-level control, including the original and final control. In the final control, the effect of the fuel quantity change on the steam temperature is taken into consideration. Thus the correction of the steam temperature for the fuel quantity is introduced. The control rule can be adjusted on-line owing to the regulable factors. For the reason, the control is closer to the actual production, which makes the production more smooth and reliable. Lastly, the modular structural design by means of PLC makes the realization of the fuzzy control algorithm more convenient.

Abstract: Hunchun Mining Co., Ltd. for a 11910 face return air drift mine for the study of the background, using the finite difference software (FLAC) simulated roadway excavation and shoring, anchors through simulation analysis supporting roadway network cable and rock deformation stress distribution, simulation results show that the design of the anchor mesh-supporting design a good change of rock mechanical properties, enhanced adhesion of rock, effectively inhibited the expansion phenomenon, so that the stress distribution roadway more reasonable engineering practice shows that after verification and simulation to determine the support scheme is feasible.

Abstract: The purpose of this study was to investigate injury mechanism and injury biomechanical response of children lumbar segment L4-L5. Firstly, the geometric model of lumbar segment at L4-L5 was extracted from CT scan images of a healthy 6-year-old child for from repairing and refining by reverse engineering software Geomagic to finite element (FE) pre-processing by Hypermesh. The FE model was calculated by LS-Dyna under the conditions given by cadaveric experiments, in which a static load was applied to the center of lumber segment at L4-L5 by a metal plate. The static load was subsequently moved forward and backward 10mm in sagittal plane, respectively. The interfacial force between articular surfaces was the objective to investigate for the comparison between the simulation and the cadaveric experiment as well as the simulation by adult FE model. The simulated results showed that the displacement between L4 and L5 of children was, to some extent, smaller than that of adults. The ratio of calculated force between articular surfaces of L4-L5 of children to the applied force moreover was, to a great extent, smaller than that of adults. Children are much easier to be rendered injury at L4-L5 than adults are, because articular surfaces of children relatively more slightly contribute to distributing the force that nucleus pulposus undergoes than those of adults do. Hence, the current study could be perceived as a theoretical basis for the product design toward vehicle safety.

Abstract: The technique of acidizing stimulation is one of the most critical measures in petroleum industry to enhance production. As acidizing technique being an integrated course which combines science, practice and experience in one, it cannot be explained by mathematical technique precisely. For conventional acidizing, the workload is extremely huge and complicated, since it has built an extensive database with the help of a huge amount of the application samples. The Neural Network has the generalization ability, which not only has the most consistency with training samples, but also is a dependable network for predication of test samples, whose data distribution is similar to the previous ones. Expert system for acidizing based on the BP Neural Networks can predict a favorable acidizing fluids system and suitable dosage reasonably, effectively and accurately with a large pool of initial input parameters. Thereby this expert system can assist field application and realize the systematization and intelligence in oil field.

Abstract: In order to detect and diagnose abnormal conditions of marine diesel engine and ensure its normal functioning, the present study adopts the BP neural network and related algorithms to determine the remote fault diagnosis process. Taking the design of exhaust gas temperature remote monitoring sub-system as an example, MATLAB programming was used for data simulation and verification. The applying of the system on board a real ship shows that it has a high working rate, a reliable and safe storage mode and a self- adaptive process.

Abstract: According to the phenomenon that the piston’s reliability and durability have been significantly weakened due to its high temperature, hard anodizing is used to hinder the heat transfer from the combustion gas to the metal base of the piston. Thermal analyses are performed on pistons with different thicknesses of anodic oxide coatings. The effects of coatings on the thermal behaviors of the pistons are investigated. The numerical results are compared with each other. It has been shown that the maximum surface temperature of the coated pistons with anodic oxide coating which has low thermal conductivity are significantly improved. Also, considering the hard anodizing process, the 100 ~ 150μm thickness of the anodic oxide coating would meet the requirements of the piston’s reliability.

Abstract: In sheet metal forming, springback is defined as an elastic material recovery after unloading of the forming tools. Springback causes variations and inconsistencies of final part dimensions. Therefore prediction of springback is very important for production of precise products used in automobile and aerospace industries. There are various parameters involved in the process of sheet metal forming, including Young’s modulus, coefficient of friction, Poisson’s ratio, blank thickness, blank length, die radius, punch radius and blank holder force. The aim of this paper is to investigate the springback of a U-channel part by finite element analysis (FEA) and to identify the influences of important parameters on the springback of advanced high strength steels (AHSS) using numerical simulation.

Abstract: In the light of growing global competition, organizations around the world today are constantly under pressure to produce high-quality products at an economical price. The integration of design and manufacturing activities into one common engineering effort has been recognized as a key strategy for survival and growth. Design for manufacturability (DFM) requires product designers to simultaneously consider the manufacturing issues of a product along with the geometrical and design aspects. In this paper, part manufacturability was analyzed in detail. An evaluation system of DFM was proposed. Product design can be guided according to feedback information by evaluating the part manufacturability.

Abstract: In recent years, applications have been proven finite-element method (FEM) in metal-cutting operations to be effective process in the study of cutting and chip formation. In this study, the simulation results are useful for both researchers and machine tool manufacturers for improving the design of cutting parameters. Finite-element analysis (FEA) that used in this study of simulation the cutting parameters and tool geometries effects on the force and temperature in turning AISI 1040. The simulation parameters that used in this study are cutting speed (75 - 300 m/min),feed rate (0.2 mm/rev), cut depth (0.75-1.5 mm), and rake angle (0-20 °). The results of cutting forces were (240 – 520 N), the temperature were (300-420 °C), and the heat rate (14202.3-83772.8 W/mm3) on the cutting edge. The simulation process also show that the increase of cutting speed leads to decrease in the cutting forces, while it has increasing in temperature, and heat rate. Also, the results show that the increase of cutting depth associated increase the cutting force only.