Applied Mechanics and Materials Vols. 52-54

Abstract: In CNC lathe servo feed system, many parameters are uncertain, so it is difficult to establish accurate mathematical model of the feed system, and parameters of conventional PID controller can not change the parameters to adjust with the controlled object. Fuzzy PID controller, which has the advantages of conventional PID control and fuzzy control, can solve these problems very well. So we can make it applied in CNC lathe servo feed system. This paper has made a simulation of fuzzy self-turning PID controller in the MATLAB environment. The simulation shows that the fuzzy self-turning PID controller has a better control capability and a higher stability, and it improved the servo feed system dynamic performance.

Abstract: The adaptability to cement pastes and fresh concretes of aminosulphonic acid-based superplasticizer (ASP) and its water reducing ratio and compatibility with Naphthalene based superplasticize (FDN) have been investigated at a given content of ASP. The adaptability to cement pastes was determined by measuring the fluiditiy with time of superplasticized cement pastes, and the adaptability to fresh concretes and compatibility with FDN was evaluated by measuring the fluidity, bleeding, and hardening and mechanical property et.al. of fresh concretes with ASP. The results show that the fluidities at 120 min of cement pastes, with 1.6% of ASP, are over 140 mm, and it increases with the increase of ASP. There is a positive relationship between the water reducing ratios of ASP and its content, and the highest of the water reducing ratio(the highest value is 28%). Moreover, the simultaneous addition of ASP and FDN can effectively decrease the bleeding of concrete.

Abstract: The temperaturel contror of injection molding machine barrel was acted as the research object in this paper, by combining artificial neural network with SPIDNN ,we created the basic structure and algorithm models of neural network on the injection molding machine barrel temperature control. Using of Matlab, control of the neural network on barrel temperature was simulated, the quite satisfactory control effect had obtained. The results show that the control strategy proposed can effectively improve the injection molding machine barrel temperature control accuracy, there is important reference value for temperature control of injection molding machine barrel.

Abstract: Nickel ceramic composite has becoming highly important in mechanical engineering perspective. The paper focused on a newly developed Ni-YSZ composite manufactured by electroless nickel coating. The aims are to ensure good coating with well distributed and high ceramic particle co-deposition. Low metal to ceramic ratio increases nickel ceramic composite resistance to corrosion, wear and thermal. The 2k full factorials design of experiment was used in determining the best EN composite process parameters for high ceramic co-deposition. The composite surface microstructure and characterisation were analysed using scanning electron microscope (SEM) and the Ni composition was measured by SEM coupled with energy dispersive X-ray (EDX).

Abstract: Basically, present enterprise resource planning systems (ERP) do not perform well in an assembly-to-order (ATO) environment due to the lack of effective management of product varieties. To support customized requirements and frequent engineering changes (ECs), we propose a manufacturing-oriented product information model (OMPIM), which consists of item property information and structure information. The proposed model has been applied to an ERP system of an automobile plant.

Abstract: Based on the reference [1], this paper presents an adaptive control law of nonlinear robotic systems. The performance of robot system is testified by a simulation example of 2-dof robots system and doing experiment in SRV-02 equipment which is made in Canada, the results obtained are satisfactory and the tracking error is negligible.

Abstract: In this paper, a forging problem is analyzed by using the overrange collocation method (ORCM), which is a new meshless method. By introducing some collocation points, which are located out of domain of the analyzed body, unsatisfactory issue of the positivity conditions of boundary points in collocation methods can be avoided. Because the overrange points are used only in interpolating calculation, no overconstrain occurs in partial differential equations on the solved problems.

Abstract: The variation of non-metallic inclusions and total oxygen contents in different steel grades were investigated by taking samples in steelmaking process, including gear steel, anchor chain steel, hard wire steel, bearing steel and spring steel. The inclusions mainly were Al2O3, MnS, and their composite inclusions in aluminum killed steel at the beginning of LF refining due to addition of FeAl alloy during the tapping from EAF and feeding of Al wire in LF process, and then Al2O3 inclusion changed to the Al2O3 - CaO composite inclusions after feeding of SiCa wire. The inclusions at the beginning of LF refining mainly were MnS, SiC and their composite inclusions in non-aluminum killed steel due to addition of the composite deoxidation and slagging agents (mainly including CaC2 and SiC) when EAF taping, while the inclusions in tundish mainly were MnS, CaO - SiO2 - Al2O3 composite oxide - sulfide inclusions. It is showed that the inclusions in bearing steel and spring steel samples were mainly globular oxide inclusions and silicate inclusions with higher rated results. Therefore, the refining process should be improved to remove globular oxide inclusions. The inclusions in molten steel were controlled by enhancing the diffusion deoxidation process, adjusting and controlling the basicity and composition of refining slags, respectively, and satisfactory results were obtained. The industrial test shows that the total oxygen content of the aluminum killed steel in the test heat after feeding wire reached the minimum value, which indicates that the optimized slag has a strong ability of absorbing Al2O3 inclusions. For non-aluminum killed steel, the total oxygen content was 0.0027 % to 0.0029 % in rolled products. The inclusions in the end of refining and rolled product were small and dispersed composite inclusions, and the separate Al2O3 inclusions can not be found in the non-aluminum killed steel after optimization of the refining process.

Abstract: A 25kg pressurized induction furnace with maximum nitrogen pressure 6MPa was invented to manufacture high nitrogen stainless steels. The suitable process was explored, and the analysis of radiography and macrosegregation of nitrogen of high nitrogen steel ingot was performed. The mechanical properties and inclusions of the forging ingot were also investigated. The suitable solidification nitrogen pressure can effectively prevent the formation of nitrogen porosity and macrosegregation of nitrogen. It is very important to control the purity of the nitrogen gas to a higher level for avoiding the manganese loss and decreasing oxygen content in the steel during the nitrogen gas pressurized melting process. The sound and compact macrostructure high nitrogen austenitic stainless steel with nitrogen content above 1.0 wt % has been manufactured by the pressurized induction melting method. There are mainly nonmetallic inclusions with the size less than 5μm in the HNS-A ingot. The HNS-A exhibits excellent mechanical properties.

Abstract: Based on topology optimization techniques of structural mechanics, an effective method for solving the structural design problems of heat transfer is presented in this paper. The topology optimization model of heat conduction is then constructed and the corresponding Optimization Criteria based on density approach is inferred to solve the optimal heat conduction equation of temperature field. A Filtering technique is employed in density field to eliminate numerical instabilities in the process of topology optimization. Some numerical examples are presented to demonstrate the accuracy and the applicability of the present method, theory and algorithm. This research provides a new idea and an access to the structural topology optimization design of temperature field, and is of good engineering application value.