The Stability of Quaternion Metrices and Their Judging Criteria

Some conceptions of stable quaternion matrices and some judging criteria are given.The Robrach theorem,Taussky theorem,Ostrowski Schneider theorem and Gerschgorin theorem are generalized to quaternion field.The conclusion about two quaternion matrices,i.e.,inferior positive matrices are unstable,interior negative matrices are stable and some other results are pointed out.     

Fire resistance performance on restrained high strength Q460 steel beams

为了研究约束高强度Q460钢梁的抗火性能,在已有约束钢梁分析理论的基础上,引入残余应力,提出了约束钢梁的抗火性能分析方法,并采用普通强度约束钢梁试验数据对分析方法进行了验证。考虑高强度Q460钢材高温下力学性能参数,利用所提出的方法分析了约束高强度Q460钢梁的抗火性能,并与普通强度Q345钢梁进行了对比。对影响约束高强度Q460钢梁的抗火性能参数进行了分析,包括荷载比、残余应力、轴向约束刚度、转动约束刚度和受火方式等。研究表明：所提出的分析方法准确可靠,高强度Q460钢梁抗火性能与普通强度钢梁具有较大的区别,高强度Q460约束钢梁的抗火性能明显优于普通强度约束钢梁。荷载比、轴向约束刚度、转动约束刚度、受火方式对高强度Q460约束钢梁有较大影响。     

Behavior and Design of High-strength Bolt in Tensile Connection

The tensile strength of high strength bolt is affected by many factors, including prying force. The prying force can result in the increment of bolt force, for which the connection failed ahead of time. Several methods are presented for calculating the prying force. In the China's "Code for Design of Steel Structure" (GB50017), there is no formula for calculation of prying force and a factor of 0.8 is considered in formula for tensile strength of bolt for taking the prying force into account. It is proposed that the design value of tensile resistance for high strength bolt should be increased.     

Effect of Stitching on the In-plane Tensile Strength of Stitched Composite Laminates

Some additional effects of stitching on the in-plane mechanical properties of composite laminate is introduced while it was used to improve the interlaminar of plane mechanical properties of the composite laminate. The paper investigates the effect of stitching on in-plane tensile strength of composite laminates. The results show that the effect of stitching is dependent on the stitching parameters. The in-plane tensile strength of laminates is degraded with the decreasing of stitching space and step and increasing diameter of stitching thread. It is found that the initial damage of laminate increased with increasing of stitching parameters such as stitching density. This causes the decrease in the in-plane strength of composite laminate.     

切线泵流动特征的整流场数值模拟

对单级切线泵在设计工况进行了定常流动数值模拟，分析了叶轮流道及蜗壳内的液体流动情况。结果表明，切线泵内流场非常复杂，叶轮进口有明显冲击，叶轮各流道的速度、压力差异很大，环形蜗壳内流动呈现旋涡推进特征，上、下游流动有强烈的相互作用，整机流场不具有对称性；环形蜗壳的几何结构以及流场上、下游的相互作用是导致整机流场非对称特性的主要原因。计算结果为进一步改进结构、提高性能、减小水力损失提供了理论依据。     

喷雾机器人远程控制系统的设计与试验研究

结合喷雾机器人作业环境的要求,开发出基于客户端/服务器模式的远程控制平台.该平台实现了通过无线网络实时传输各类数据和控制命令,客户端再现了机器人的工作环境和状态.在此基础上进行了系统性能测试和轨迹测试.试验结果表明:为了保证良好的操控性,机器人所处区域信号强度必须大于30%,操作者根据反馈信息判断机器人是否偏离预定路径,并在偏离时给予有效的纠正,为解决喷雾机器人重喷、漏喷的问题提供了一种方法.