UBET-based numerical modeling of bulk deformation processes

The paper summarizes the development of numerical procedures for modeling bulk deformation process and preform designing techniques based on the upper bound elemental technique (UBET). UBET has a unique place where an approximate, but faster solution is needed for decision making. In designing and optimizing multistage forging and profile ring-rolling processes, an approximate solution can be used to identify the most influential process parameters. Once an optimum combination of process conditions are determined, computationally intensive, but more accurate finite element analysis can be used to verify and refine results. In this paper, UBET procedures for closed-die forging and profile ring rolling are high-lighted. Experimental investigations are used to validate the model predictions. Also, the UBET-based preform design tool is presented as a process and die design tool for multistage forging processes. Application of these techniques is presented with evidence of effective material usage and extended overall die-life.     

60Mn环件断裂分析

60Mn环件在装配150h后发生崩裂.利用断口分析、化学成分分析、显微组织检验以及有限元计算对断裂件进行了分析.结果表明,环件中存在白点,白点在装配应力和内部氢压的作用下发生滞后扩展,当白点裂纹扩展到临界尺寸时,裂纹尖端的应力强度因子超过零件材料的断裂韧度,从而发生崩裂.     

铸轧辊的改进设计

对铸轧辊辊芯的表层处理、辊芯的结构、铸轧辊的装配进行了改进设计 ,提高了铸轧辊的性能 ,延长了使用寿命     

快速判断工艺尺寸链中的封闭环

在尺寸链图中以加工工序为依据，利用封闭环的自然形成特性（间接保证特性）快速确定封闭环。     

高速线材轧机锥套故障分析与改进

高速线材生产线精轧机、预精轧机使用的锥套，在材质、结构、处理工艺及生产操作上存在诸多不当之处，为此进行了多项改进，使锥套故障彻底排除，使用寿命达3～5月，而价格仅为进口件的1／3。     

环件开式辗扩力和力矩计算

用上限法分析了环件开式辗扩变形，导出了辗扩力和力矩计算公式，阐述了辗扩力和力矩与辗扩进给速度的关系。根据环件辗扩实验结果，对文中的辗扩力和力矩计算公式进行了验证。     

扁锭结晶器的故障诊断及排除方法

从国外引进的低液位组合结晶器，内置水套，石墨环镶嵌在结晶器四周内壁上，分上下两级水道。在铸造中，由于水质原因会造成喷水水眼堵塞，人为因素也会造成石墨环损坏，结晶器缺陷会造成铸造缺陷，严重时会生产不合格产品。从生产实践出发，对结晶器故障诊断、排除及日常维护技术进行了研究。     

Anti-periodic solutions in a ring of four neurons with multiple delays

This paper is concerned with the existence and exponential stability of anti-periodic solutions of bidirectional associative memory (BAM) neural networks with multiple delays. Applying inequality techniques and Lyapunov method, Sufficient conditions which ensure the existence and exponential stability of anti-periodic solutions of the BAM neural networks are presented. Our results are new and supplement some previously known ones.     

飞腾平台中硬件数据压缩的驱动设计与实现

数据压缩是有效处理大数据的关键技术,在飞腾处理器平台上基于zlib库的数据压缩通常采用软件的方式实现,在数据处理量大而且实时性要求较高的情况下,已经难以满足需求。针对这个问题,通过研究zlib编程函数库,结合飞腾处理器的特性,完成了飞腾平台中硬件数据压缩的驱动设计与实现,其中提出了双向DMA传输技术和基于一致性内存的命令环机制,从而进一步提高了基于硬件的数据压缩的效率。通过实验证实了飞腾平台中采用硬件数据压缩改进的有效性。     

Annular ring slot antenna design with reconfigurable polarization

A microstrip‐fed conventional annular ring slot (ARS) antenna with linear polarization (LP) is initially studied. To generate two orthogonal degenerate modes for circular polarization (CP) radiations, two identical meandering perturbation slots (MPS) are symmetrically loaded into the ARS. By further incorporating a PIN diode switch across each MPS, the proposed antenna can switch between left‐hand CP (LHCP), right‐hand CP (RHCP), and LP. All three polarizations have shown good impedance bandwidth and broad CP bandwidth that can satisfy the wireless local area network (WLAN) 2.4‐GHz operating band (2400–2480 MHz). Furthermore, desirable gains of 1.8–2.0 dBi and 2.40–2.84 dBic are also exhibited at LP and LHCP/RHCP, respectively. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:110–120, 2016.