Applied Mechanics and Materials Vols. 236-237

Abstract: Laboratory experiments and numerical simulations, using Particle Flow Code (PFC2D ), were performed to study the behavior of marble under tri-axial loading and pre-existing fissure uniaxial compression. The laboratory tri-axial compression results of marble was analyzed, and the calibration of the micro-properties of BMP (Bonded particle model ) in PFC2D with the test data was carried out successfully. The pre-existing fissure was simulated by smooth joint contact, and the cracking propagation mode of pre-existing fissure was carried out with the calibrated BMP properties and single smooth joint contact. The simulation show that the tensile crack firstly initiated along the vertical direction to pre-existing fissure, and then gradually departs towards the direction of axial stress, and finally develops along the direction of axial during compression. The numerical simulation coincide with our understanding of fracture mechanics.

Abstract: The uniformity of plating copper layer thickness and film clip rate is one of the important indicator of PCB’s quality, which will affect depply by electroplating. This papar think about it from the uniformity of electric field distribution, and try to make the PCB have copper coating uniformity higher than 90% and rang less than 12 m through optimization the process parameters of the core equipment in the process of copper - Tong Gang, thereby reducing the positive film clip rate, and improving the quality of PCB. The main process parameters needed to optimize in this article is the anode placement, anode length and so on

Abstract: The method of smelting High nitrogen steels by blowing nitrogen from the device bottom is a promising way of increasing nitrogen with gas. Introduced the device and technical development of smelting High nitrogen steels in domestic and foreign countries, expounded the method and character of dissolving nitrogen into liquid steel at high temperature and high pressure, and analyzed the advantage of increasing nitrogen by bottom-blowing nitrogen. The domestic research is at the developing period of experimental research. The High nitrogen steels which content is more than 1.0% was produced with bottom-blowing nitrogen method at high pressure. The velocity of dissolving nitrogen with bottom-blowing was increased and the smelting time was shortened. The technical effect was very good.

Abstract: Remanufacturing is a growing branch of the traditional manufacturing industry. In this study, a discrete harmony search (DHS) algorithm is proposed for thedisassembly scheduling of products in the remanufacturing engineering.Firstly, the disassembly scheduling of products is regarded as flexible job shop scheduling problem. Then, the harmony search algorithm is discretized for the disassembly scheduling problem.Finally, simulation experiments are carried out to test the proposed discrete harmony search algorithm. The results and comparisons show the effectiveness of the proposed DHS algorithm in solving the disassemblyscheduling problem in remanufacturing engineering.

Abstract: Besides the performances of handling, stability, ride comfort, power and fuel economy, the sound pressure levels in the automobile passenger compartments heavily influence the customer’s purchasing decision. The interior acoustics of automobile passenger compartment was analyzed in this paper. The frequency response analysis was performed on the vehicle body due to road roughness. The frequency response of vehicle body’s output spectrum, nodes’ velocity is used as the boundary condition of the acoustic cavity. With boundary element method and acoustic transfer vector method, the panel acoustic contribution was analyzed. By modifying the stiffness, damping or mass of the corresponding panel, the acoustic pressure levels at the driver’s and passenger’s ear were decreased.

Abstract: Mechanical manufacturing enterprises face numerous choices about information. In order to take full advantage of the information, the technologies and methods of implementing information integration should be carefully studied. Firstly, the developments of its standard protocols are analyzed. Secondly, the information integration of mechanical manufacturing enterprises is discussed. At last, an example is provided to illustrate the method of information integration.

Abstract: According to the user’s high technical requirement in papermaking process, advanced control system has been supplied to satisfy the performances. Meanwhile, energy consumption and cost are considered. The computer integrated process system (CIPS) of process industry which could effectively integrate enterprise resource planning, management execution system and process control system information is necessary and suitable for papermaking process. Here based on the analysis of pulp and paper process, we put forward the papermaking process computer integrated process system and try to obtain the optimal control project and execution system. And a novel optimized application project based on SIMATIC PCS7 distributed control system proves the excellence of computer integrated process system.

Abstract: Prognostic health-management of aero-engine’s fleet have features with multi-source and asynchronous. Cruise engine gas temperature (EGT) and Take-off EGT have always been the focus of evaluating gas performance and predicting the remaining life. The calculation method of EGT Margin was showed based on the introduction of the definition and classification of the EGT. It analyses not only the relationships between Cruise EGT and Take-off EGT but also each other’s main functions. Meanwhile, an instance was used to explain the disadvantages of using Cruise EGT to calculate life prognostics.

Abstract: Effective utilization and expansion of production capacity has crucial cost implications, and arguably drives the profitability of the operation in the hydrogen fuel cell vehicles (HFCVs) industry. We develop a production capacity model for a HFCVs manufacturer decision, which is expressed by the market and the assumptions of information usage. From three factors of equipment construction, the rapid advancement of the HFCV technology and the inconsistent between the manufacturing capacity and the effective capacity, we expressed the basic mathematic descriptions of question. Then the computing model is programmed in the EXCEL interface. After the operation of the simulation, the different scenarios show that demand and capacity variability has clear impaction on the decision. The observation provides perception on the production capacity decision in HFCVs industry as capacity expansion and the cell technologies arise. Both result in different cost type and the cost of the transition. It also implicates that not the computer simulation but the information technology application are important to improve the industry decisions.

Abstract: This paper primarily makes an analysis and study on existing production processes adopted in production lines of mechanical processing industry, and adopts methods of process analysis and work analysis, principles of “ECRS”, 5W1H questioning and improvement analysis sheets and relevant techniques to perform detailed analysis on the existing production processes in respect of complicated process settings, unreasonable processes and other problems in processes of production. According to field observations and data collected, measures are proposed to solve such problems like low efficiency in material flows, waiting of parts, long hauling distance etc. and process improvement plans are made on basis of facilitating reasonable material flows and benefits maximization. The results of analyses and appraisals on new plans show the efficiency of production processes has been improved effectively, which will make it possible that enterprises reduce costs and enhance their competitiveness further.