Application of Neural Network to Multi-Dimensional Design Window Search in Reactor Core Design

In the reactor core design, many parametric survey calculations should be carried out to decide an optimal set of basic design parameter values. They consume a large amount of computation time and labor in the conventional way. To support directly design work, we investigate a procedure to search efficiently a design window, which is denned as feasible design parameter ranges satisfying design criteria and requirements, in a multi-dimensional space composed of several basic design parameters. The present method is applied to the neutronics and thermal hydraulics fields. The principle of the present method is to construct the multilayer neural network to simulate quickly a response of an analysis code through a training process, and to reduce computation time using the neural network without parametric study using analysis codes. To verify the applicability of the present method to the neutronics and the thermal hydraulics design, we have applied it to high conversion water reactors and examined effects of the structure of the neural network and the number of teaching patterns on the accuracy of the design window estimated by the neural network. From the results of the applications, a guideline to apply the present method is proposed and the present method can predict an appropriate design window in a reasonable computation time by following the guideline.     

偏心针齿摆线行星齿轮传动研究

提出了偏心针齿摆线行星齿轮传动机构.分析研究了该机构的传动原理和传动结构.推导出了传动比计算公式,建立了齿廓方程,给出了齿廓曲率半径计算公式和齿廓出现尖点的条件.偏心针齿摆线行星齿轮传动是一种新型齿轮传动机构,根据这种机构可设计出大传动比的减速器和齿轮减速链轮等其它传动元件.     

转子复冲模结构分析与改进

主要对传统转子复冲模结构存在的问题进行了分析，并分析了改进结构后的转子复冲模。     

Thermal performance analysis and optimum design parameters of heat exchanger having perforated pin fins

This paper reports the heat transfer enhancement and corresponding pressure drop over a flat surface equipped with circular cross section perforated pin fins in a rectangular channel. The channel had a cross section area of 100–250 mm². The experiments covered the following ranges: Reynolds number 13500–42,000, clearance ratio (C/H) 0, 0.33 and 1 and interfin spacing ratio (S_y/D) 1.208, 1.524, 1.944 and 3.417. Correlation equations were developed for the heat transfer, friction factor and enhancement efficiency. The experimental results showed that the use of circular cross section pin fins may lead to heat transfer enhancement. Enhancement efficiencies varied between 1.4 and 2.6 depending on clearance ratio and interfin spacing ratio. Using a Taguchi experimental design method, optimum design parameters and their levels were investigated. Nusselt number and friction factor were considered as performance parameters. An L₉(3³) orthogonal array was selected as an experimental plan. First of all, each goal was optimized separately. Then, all the goals were optimized together, considering the priority of the goals, and the optimum results were found to be Reynolds number of 42,000, fin height of 50 mm and streamwise distance between fins of 51 mm.     

初始位移对销接梁承载力的影响

由于销孔间隙的存在，销接钢结构体系在受荷前就可能沿桌些方向产生位移。给出了初始侧向位移及扭转位移的计算方法，并分析了其对承载力的影响。     

The effect of ZDDP and MoDTC additives in engine oil on the friction properties of DLC‐coated and steel cam followers

Friction tests simulating cam follower sliding conditions were conducted using a pin‐on‐disc test rig. In the case of SAE 5W‐30 class engine oil, the friction coefficient of the combination of steel pins sliding on a steel disc increased from 0.11 to 0.12, while that of steel pins sliding on a diamond‐like carbon (DLC)‐coated disc decreased from 0.12 to 0.10. For 5W‐20 oil containing the friction modifier MoDTC (molybdenum dithio‐carbamates), the friction coefficient of steel pins sliding on a steel disc decreased markedly from 0.12 to 0.04. In contrast, that of steel pins sliding on a DLC‐coated disc decreased more moderately, from 0.11 to 0.08. In both cases, Zn, P, S, and Mo elements derived from ZDDP (zinc dialkyldithiophosphate) and MoDTC additives were not detected on the DLC‐coated disc, while these elements were detected on the steel disc and pins using electron probe microanalysis and X‐ray photo‐electron spectroscopy surface analysis. It appears that a tribochemical reaction film did not form on the DLC material due to its inactive chemical properties. Therefore, an increase in friction due to the formation of the film derived from ZDDP and a decrease in friction due to the formation of the film derived from MoDTC were clearly suppressed in the case of the steel pins sliding on the DLC‐coated disc. It is thought that the tribo‐chemical reaction film was instrumental in reducing friction substantially. The lateral force of the film formed on the steel disc was then measured using an atomic force microscopy lateral force microscopy test. The lateral force of the film resulting from the 5W‐30 oil was much higher than that of the film formed from the 5W‐20 oil with MoDTC. This result coincided well with the results of the friction tests. Judging from these results, it is thought that the high friction coefficient observed for the steel pins on the steel disc for the 5W‐30 oil was caused by the higher shear strength of the film formed from ZDDP. On the other hand, the very low friction coefficient observed for the steel pin‐steel disc combination for the 5W‐20 oil was presumably caused by the formation of a solid MoS₂ lubricant from the MoDTC additive.     

济钢中厚板厂3 200 mm粗轧机主传动系统的改造

本文介绍了济钢中厚板厂3 200 mm四辊粗轧机主传动系统的改造过程,并介绍了交错式万向接轴的应用,这对于提高中厚板轧机主传动轴万向节的承载能力具有重要意义.     

汽车前车门内板检具设计

介绍了汽车前车内板上的部分孔位检测方法及检具设计制造的过程,针对大型零件的检具设计采用了简化方法,降低了成本,提高了检测效率,实现了设计目的。     

中厚板轧机十字轴结构优化

针对济钢中厚板厂3200mm四辊粗轧机万向节十字轴的失效原因,采用有限元的分析方法,对十字轴的结构进行研究和优化,这对于提高中厚板轧机主传动轴万向节的承载能力具有重要意义。     

B311精梳机出条机构加装安全装置的讨论

文章分析了B311直型精梳机出条传动机构的工作原理,结合工厂实践总结出该机构生产使用中存在的问题--无自动安全保险装置,绕毛后极易造成主要传动部件的损坏;生产中坏件率高,维修量大,对生产效率的提高不利.文章从机械角度入手,对该机出条传动机构进行了局部改进,同时对改进机构的加工图纸做了细致标注,在安装细节方面进行了说明.