塑料造粒模板使用寿命降低的探析

介绍了造粒模板的结构及其工作流程，提出了制作造粒模板的要求，分析了模板使用寿命降低与模板选材、切粒刀、熔融物料、加热介质、钎焊工艺及其操作程序等因素有关，并提出了解决办法。     

Finite element solutions for optimal square plates

Using intuitive arguments analytical calculations of the moments in subdomains of uniformly loaded plates are carried out. Summing the moment volumes for these ‘analytic elements’ the results are identical to those obtained by optimization arguments. A general finite element procedure is then used to obtain useful approximations of these optimal solutions.     

Effective Hybrid/Mixed Finite Elements for Folded-Plate Structures

A new formulation in which the assumed stress field is divided into membrane and bending stress fields is developed. A family of effective shell elements of hybrid/mixed finite element method that accounts for transverse shear deformations is proposed based on a modified Hellinger–Reissner variational principle. In this paper, the present shell elements possess different three-field assumptions, which are described by compatible displacement, incompatible displacement, and stress fields. Several benchmark problems are conducted to test both the accuracy and reliability of the proposed shell elements. Numerical analyses show that the present shell elements pass all the patch tests, do not contain any spurious zero energy modes, and have no lock phenomena even for very thin plate and shell. Further insight into the performance of the present shell elements is gained to demonstrate the high accuracy of the elements by several folded-plate structure problems. The numerical results demonstrate the validity, reliability, and applicability of the present elements. The present elements are valid for thick as well as thin shell structures.     

Reissner厚板的一般解析解答及其应用

本文基于原始的 Reissner 板模型,根据文献中的控制方程,给出了 Reissner 厚板弯曲问题的一般解析解答形式。在此基础上,详细地讨论了均布荷载下四边固支矩形 Reissner 厚板的弯曲问题,并在 VAX-8200机上编制了相应的 FORTRAN 程序。本文提出的厚板解析方法,无论从力学意义上,还是数学运算上,都比习惯的迭加法简明的多。算例表明:结果可靠、方法可行。     

多孔钢板在双轴受压与边缘剪力荷载共同作用下的极限强度

作为作者系列研究成果[Paik J K．Ultimate strength of perforated steel plates under edge shear loading．Thin-Walled Structures，2007，45：301-6，Paik J K．Ultimate strength of perforated steel plates under axial compressive loading along short edges．Ships Offshore Struct，2007，2（3）：（inpress）]的终结篇，与前期论文在边缘剪力或单轴压力荷载方面进行了对比，目的是研究双轴受压和边缘剪力作用下多孔钢板的极限强度特点，这是船舶和船舶型海洋结构在货物和水压作用下的一个典型受力模式。板的约束考虑为四边简支，中心区域为圆形孔。一系列ANSYS非线性有限元分析中考虑了不同的板尺寸（厚度）。在有限元分析基础上，推导出组合荷载下多孔板的极限强度交互关系公式，可用于可靠性分析或规范中极限强度的预测。     

中小功率CO2激光的厚板切割技术

分析了激光厚板切割技术的能量平衡和技术难点,具体介绍了几种厚板切割新技术,包括预热法、散焦法、激光锯切法、双聚焦法.并从工艺角度分析了几种切割技术的优缺点.     

废MO-Cu合金回收金属钼和铜的工艺研究

研究了用硝酸处理Mo-Cu合金板材废料，回收金属钼、铜盐的方法并对反应产生的氮氧化合物进行处理，防止环境的污染。实验表明，用硝酸处理钼铜合金板材废料时，硝酸的浓度应控制在30％-40％，回收的金属钼粉纯度很高，钾、铁、镍等含量很低。该方法工艺简单、投资少、污染小，钼的回收可并入钼酸铵的生产系统。     

Experimental study on productivity enhancement of an improvised inclined solar still

Experimental studies are carried out on the inclined solar still with baffle plates for enhancing its performance. The baffles placed in the inclined solar still act as a solar collector which helps in increasing the contact time with solar radiation thereby raising the saline water temperature. Experiments are carried out during winter and early summer climate of Chennai, India. Experimental parameters, such as ambient temperature, solar radiation, glass temperature, water temperature and distillate output are recorded. Hourly productivity is found to be higher during sunny days. The estimated production of fresh water through analytical study is 3.50?kg/m² per day for a minimum mass flow rate of 0.0833?kg/min. The actual experimental yield is 2.793?kg/m² per day. Also, the inlet saline water temperature affects the yield and the latter is found to be highest at 48.5°C.     

费托反应器SA387 Gr11 Cl2特厚板筒体立焊施工技术

全面分析了费托反应器SA387 Gr11 Cl2筒体特厚板的焊接性,针对立焊过程中易产生的冷裂纹、再热裂纹及不易成型等问题,制定了详细的焊接工艺并施焊,通过对产品焊接试件化学成分、力学性能等的检测、分析,对焊接工艺的适用性进行了评判。结果表明,采用PHOENIX CHROMO 1焊条,双U形坡口,焊前预热,小电流、短弧多层多道施焊,焊后立即消氢和消应力热处理等多种工艺措施,可以有效避免冷裂纹、再热裂纹的产生,得到高质量的焊接接头,满足费托反应器的制造质量要求。     

水韧温度对衬板用轻质奥氏体钢组织和性能的影响

开发出衬板用新型轻质Fe-Mn(23.8%)-Al(7.1%)-C(1.02%)钢,测试不同水韧温度处理后实验钢的力学性能。利用X射线衍射分析、显微组织及断口形貌观察、析出物能谱分析,研究不同的水韧温度对新型钢种的组织、力学性能、断裂机理的影响。结果表明:实验用钢的密度6.84 g/cm3,与普通高锰钢相比,密度下降约12.3%;在1050℃保温1 h水韧处理后综合性能最佳,其冲击韧性值(V型缺口)ak达到231.3 J/cm2,硬度为205 HB,抗拉强度为809.6 MPa,屈服强度410.9 MPa,断后伸长率为59.6%。断口形貌呈等轴韧窝状,断裂机理为典型微孔聚集型断裂。