Advanced Materials Research Vols. 228-229

Abstract: The general function library and hydraulic control library of EASY5 software were used to establish the dynamic model of hydraulic system of a sudden load, which could assimilate impulsion based on accumulator. The system was simulated with different diameters of the oil supply hole of accumulator. The simulation results were compared and analyzed to research the influence of oil damping to the effect of assimilating impulsion based on accumulator. From the simulation results, a hydraulic circuit consists of a throttle valve controlled by pressure and an accumulator was put forward to improve the capacity of accumulator to assimilate impulsion by changing the oil damping of accumulator through throttle valve, which had certain of meaning in project.

Abstract: In order to make better use of excavator in foundation pit, a new excavator with telescopic arm is designed in this paper. The innovations mainly manifests in four aspects. First, the use of telescopic arm decreases the height for the excavation in foundation pit. Secondly, the design of truss-guide and trolley brings a high speed to excavator’s lateral move in large scale, easy for dirt shoveling in the wide foundation pit. Thirdly, the travelling system with two pails of dual-pedrail makes it possible for excavator free walking, flexible steering, and obstacle avoiding. The last but not the least, the wireless remote control technology can keep operators distant from danger and other unpleasant working conditions.

Abstract: In this research X65 steel is chosen as the test material, and tension test and three-point bending test of X65 are made, then we got the load - displacement curve and the resistance curve. Using the finite element method to derive load - displacement curves of tension test based on the micro-plastic damage model, and the parameters controlling ductile crack growth are gotten by compared with the test results. We obtained the resistance curve of numerical calculation by WARP3D based on the parameters, which in good agreement with the experimental results. The results indicate that the three-point bending fracture toughness can be predicted by tension test based on micro-plastic damage mechanism.

Abstract: The purpose of this paper is to discuss the application of oxygen-enriched combustion in metallurgic furnaces. Based on the knowledge of combustion and air separation, some advantages of oxygen-enriched combustion are carried on. In this work, the relation between energy efficiency and oxygen enrichment is presented, the result showed that furnaces can reach more than 10% energy saving by properly applying oxygen-enriched combustion technology. A system which combines the oxygen-enriched combustion technology and the CO2 capture with membrane separation technology is evaluated. In this system, the energy cost for CO2 capture can reach 0.9GJ/(t CO2). Finally, some problems that still need further study are also discussed.

Abstract: The surface heat treatment can lead to the residual stress and inhomogenous effects in coating-substrate system. Based on the well-known Hall-Petch relationship between the coating yield strength and its grain size, the inhomogenous effect can be extended to the grain size gradient effect. In this work, a mechanical model of a coating-substrate specimen is developed to quantify the residual stress and grain size gradient effects on the energy release rate of the coating on its substrate. Using a Micro-Composite-Double-Cantilever Beam Model (MCDCBM), the analytic solutions can be derived, and they can be used to characterize the fracture toughness of the inhomogenous coatings on substrates in terms of the critical energy release rate. Finally, a numerical example is presented to show how the critical energy release rate is obtained.

Abstract: According to MR fluid properties and MR damper structure, a multi-body dynamic model of semi-active landing gear was built by using virtual prototype in ADMAS/Aircraft. Fuzzy control system for the semi-active landing gear with MR damper was designed under the MATLAB/Simulink environment. Co-Simulation of ADAMS/Aircraft and MATLAB/Simulink were carried out. The simulation results show that semi-active landing gear with MR damper based on fuzzy control strategy can reduce the aircraft’s vibration and improve the ride comfort characteristics. Co-simulation method provides one simple feasible method for the process of landing gear design, development and manufacture. It also offers a new way to advance designing quality for complex dynamic system and control strategy simulation.

Abstract: Nowadays there is little ergonomics consideration in the oil engineering machines and the improvement of comfort levels in the high intensity work of oil workers should be noted. Taking the case of the interface design of operation domain of the workover machines, this paper studied the design method of man-machine interface of oil workover machines basing on its development trend, from the view point of improving operation efficiency and operating reliability. In the paper two kinds of software, SolidWorks and CATIA, were used to build 3D virtual human body models and conduct the man-machine interface design of the workspace. Ultimately, a new thinking of man-machine interface optimization design of oil machinery was obtained by making a comparison of the two design processes.

Abstract: A scheme of mould opening degree auto-detecting device is proposed. The inner-wall dimension of mould working segment can be measured and the opening degree can be calculated by using the auto-detecting device. Due to the mechanical structure design the off-line measurement in mould opening degree is realized. The paper analyzed the factors which causing error and calculated the error corresponding to these factors, so the total error is obtained. The hardware and software system is designed based on VC++ GDI. The measurement result is displayed in screen using curve mode.

Abstract: The electrical–magnetic transport properties of (La0.7Ca0.3MnO3)(1-x)/(BN)x composites has been investigated systemically by conventional solid-state reaction method. The results of X-ray diffraction (XRD) and scanning electronic microscopy (SEM) show that BN and LCMO coexist in the composites and BN mainly goes into the grain boundary region without any chemical reaction with La0.7Ca0.3MnO3, which are in accordance with the results of the magnetic measurements. It is very interesting that with increasing of BN content level (x < 0.25), the metal–insulator transition temperature (TP) remains constant (nearly at 275K), and the resistivity increases very slowly. But when x > 0.25, TP shifts to lower temperature and the resistivity increases dramatically. The resistivity threshold of the composites occurred at x = 0.25, and specially the magnetoresistance (MR) reaches a maximum value (about 26.32 %) at 100K in an applied magnetic field of 3kOe. The results also indicate that the doped BN has an important effect on the low field MR (LFMR), which results from spin-polarized tunneling.

Abstract: Due to the complicated structure of the cast-steel joints of Sunny Valley at Shanghai World Expo Axis, its mass production method faces many problems. In order to manufacture the qualified joints with low cost, high efficiency and high quality, a robot-based manufacturing technology with lost foam process is proposed. With this technology, all joints can be decomposed to standard units. After being cut and assembled by robots, these units can form a complete lost foam joint model used in the lost foam casting process. The cast-steel joints manufactured are measured by three-coordinates measuring machine. Results show that this technology is effective.