2×1200t双臂架变幅式起重机索力测试研究

2×1 200 t双臂架变幅式起重机是为起重船配套的1种非自行式起重机,主要用于海上风力发电设备的起吊和安装。本研究根据振动频率法,采用振动测试分析系统,对不同工况下起重机钢索的索力进行测试分析,并与设计值进行对比,为在正常工作状态和超载状态下合理、安全地使用起重机提供依据。     

干密度对黄土邓肯-张模型参数的影响

为研究黄土的工程力学特性,对土样进行不同初始条件的室内三轴试验。将试验结果用邓肯-张模型进行拟合分析,获得了太原地区黄土的邓肯-张模型参数及其随干密度变化的规律。结果表明,随着干密度增大,黄土的抗剪强度、黏聚力和内部摩擦角都有增大趋势,切线弹性模量和体积变形模量迅速增加,初始干密度大的试样表现出剪胀和应变软化现象。试验所得参数可供黄土地区工程设计参考。     

关于船员考试改革问题探究

文章对现行的船员考试制度中存在的问题进行汇总,并对问题进行了系统性地分析,依据当前接受培训的学员及船员的素质提出相应的解决方案和建议,对现行的船员考试改革问题具有一定的指导意义,以对提高船员的素质起到积极的作用。     

高速公路拼接路基的冲击压实施工技术研究

为提高拼接路基的压实质量,宁沪高速公路扩建工程采用了冲击压实工艺。通过现场试验段的冲击压实试验,取得了不同填料、不同压实遍数与压实度、沉陷量的相关数据,通过数据分析,并结合现场施工工艺,提出了高速公路拼接路基冲击压实施工的若干建议。     

Investigation on the formation mechanism of ordered carbide (FeMn)<Subscript>3</Subscript>AlC in the Al added twinning-induced plasticity steels

The spinodal composition zone in Al added Fe-Mn-Al-C twinning-induced plasticity（TWIP） steels can be determined by contents of Al and C and aging temperature together, based on the thermodynamic analysis. Precipitation of ordered（FeMn）₃AlC carbide by the mechanism of spinodal decomposition occurs in the C-rich and Al-rich zone with low aging temperature. Increase of aging temperature shrinks spinodal composition zone to the high Al and C contents. As a result, the precipitation of（FeMn）₃AlC carbide alters from spinodal decomposition to classical nucleation-growth manner gradually. Further calculation indicates that the diffusion of Al can play a key role in determining the growth rate of（FeMn）₃AlC carbide at high aging temperature.     

Dynamic modeling and active control of a strap-on launch vehicle

Dynamic modeling and active control of a strap-on launch vehicle are studied in this paper. In the dynamic modeling, the double-compatible free-interface modal synthesis method is used to establish dynamic model of the system, and its model precision is compared with those of finite element method(FEM), fixedinterface modal synthesis method and free-interface modal synthesis method. In the active control, the swing angle of rocket motor is used as design variable, and the control law design based on the model of mass center motion is adopted to validate the system. Simulation results indicate that the double-compatible model synthesis method can properly approximate the FEM which is used as the benchmark solution, and the model precision of the double-compatible modal synthesis method is obviously higher than those of the fixed-interface and freeinterface modal synthesis methods. Based on the control law design, the deflection of mass center of the launch vehicle is very small.     

Deliberative collision avoidance for unmanned surface vehicle based on the directional weight

The purpose of this study is to realize the intelligent deliberative obstacle avoidance for unmanned surface vehicle (USV), based on the International Regulations for Preventing Collisions at Sea called COLREGS. Firstly, a three-level system architecture is designed for the ship intelligent collision avoidance system. Secondly, an intelligent collision avoidance algorithm is presented based on the calculation of motion parameters and the rules of COLREGS. Thirdly, according to COLREGS, the marine environment is modeled from the electronic chart data and radar information, and a deliberative collision avoidance algorithm is written. Finally, the deliberative collision avoidance simulation is carried out for the USV. The feasibility and reliability of intelligent collision avoidance algorithm are verified by the vivid simulation results.     

地铁隧道通风系统中组合阀安全性问题的探讨

就地铁隧道通风系统中组合阀安全性问题进行初步探讨,针对国内外对组合阀不同的安全性要求进行分析和比较,指出设立组合阀耐火极限、高温正常工作时间、泄漏量和疲劳强度四个主要指标的必要性。     

可调螺距桨的模糊智能系统理论及仿真研究

PID控制是过程控制中应用比较广泛的一种控制器,具有简单、鲁棒性好和可靠性高等特点,但仅对于线性定常系统的控制非常有效,对于非线性、时变的复杂控制系统如可调桨系统不能达到理想的控制效果.其超调值较大、响应时间较长、系统的动态品质较差.为了弥补常规PID的不足、改善控制效果,满足复杂控制系统的设计要求,我们采用模糊控制理论对可调桨进行智能控制.仿真研究表明模糊控制比常规的PID控制具有更为突出的特色和优点.     

常温施工式填缝料低温性能评价体系的研究

结合东北地区的气候特点．分析了规范中关于常温施工式填缝料低温性能评价方法的不足．补充了用于评定填缝料与水泥混凝土粘结性能的低温拉伸试验．并结合-10℃的弹性试验,通过对7种常温施工式填缝料的室内研究,建立了常温施工式填缝料的低温性能评价体系．提出了相应的指标要求。采用此评价体系和指标对7种填缝料进行了综合评定和分级．结果与实际工程的使用效果一致。