有一个紧固件的半无限板孔周应力有限元分析

用有限元法计算了有一个紧固件孔的半无限平板在紧固件力作用下的孔周应力．在紧固件与孔之间的接触区域的结点间加无长刚杆元．用反复计算的方法确定接触范围；计算出孔周应力等，并与文献［１］的实验结果进行了比较．     

仪器化冲击在评测断口剪切面积比例中的应用

根据示波曲线定量给出的特征载荷点分布关系，结合ESIS给出的评测夏比V型冲击断口剪切面积比例(PSF)经验公式，介绍了仪器化冲击试验在估算PSF数值中的具体应用。估算值与实际测量值所进行的误差离散性与置信区间的分析结果表明，选用合适的经验算法可以在试验过程中实时获得高度可靠的PSF结果。与常规光学手工评测技术相比，该方法不依赖于试验者的主观评测经验、不受特定客观试验条件的限制，具有广阔的应用前景，同时也为材料PSF评测以及动态断裂机理的研究提供了一套方便而有效的试验手段。     

冲击声的固有结构建模及目标识别

将统计数据驱动方法应用于冲击声的固有结构建模,研究了单个冲击信号及冲击声组的时域和频域特征提取方法,并将所提特征用于圆柱壳冲击声和公路空洞检测冲击声分类,获得了良好效果,证实了该方法用于冲击声目标分类的有效程度。     

面向功率冲击平抑的岸电系统储能型电能调控装置容量优化配置策略

针对港口岸电系统负荷侧存在的冲击性功率等电能质量问题,提出一种储能型电能调控装置容量优化配置方法。介绍港口岸电系统及储能型电能调控装置拓扑结构,并分析冲击性负荷运行特征;探讨负荷运行工况与功率因数控制目标之间的关系,根据电池荷电状态与负荷运行工况,提出储能型电能调控装置多类型运行工况自适应容量设计的补偿控制策略;建立储能型电能调控装置技术-经济模型,通过在技术模型中考虑岸电系统电能质量的要求建立容量模型,经济模型提供评估寿命成本和效益的方法。基于某港口岸电负荷实测数据,验证所提方法的有效性。     

Finite‐time attitude‐tracking control for rigid spacecraft with actuator failures and saturation constraints

In this article, the problem of finite‐time attitude‐tracking control for rigid spacecraft is addressed. Uncertainties caused by external disturbances, unknown inertial matrix, actuator failures, and saturation constraints are tackled simultaneously. First, a smooth function that is more qualified to approximate the standard saturation characteristics is presented to deal with the actuator saturation constraints. Second, a fast nonsingular terminal sliding mode (FNTSM) manifold is constructed as a foundation of controllers design. By incorporating the fuzzy logic system into FNTSM technique, a less demanding solution of coping with model uncertainties is provided because the requirement of a prior knowledge of unknown inertial parameters and external disturbances in many existing achievements is removed. To reduce the number of parameters to be estimated, the norm approximation approach is exploited. Subsequently, an antichattering attitude controller is presented such that all the tracking errors converge into arbitrary small domains around the origin in finite time. The result is further extended to obtain a fault‐tolerant controller against completely failed actuators. Finally, numerical simulation is conducted to verify the effectiveness of the proposed control scheme and comparison with relevant literature demonstrates its high performance. Furthermore, an experiment for the large satellite Hubble Space Telescope is carried out to validate the practical feasibility.     

LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connect- ing rod type low speed high torque (LSHT) hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by com- puter simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coef- ficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.     

汽车荷载作用下桥梁冲击系数影响规律研究

以三跨连续箱梁桥为研究对象,建立了桥梁模型和车辆模型从而组成车桥耦合动力模型,并对车辆荷载作用下桥梁结构的冲击系数进行研究分析。研究表明:增加横向车道数可以使桥梁的冲击系数增大,纵向距离越大桥梁冲击系数越小;车辆在制动状态下的桥梁冲击系数明显大于车辆匀速状态时的冲击系数,并且车辆在桥梁中跨前半部分制动时,动力冲击系数要大于后半跨;车辆在跳车冲击作用下,桥梁跨中冲击系数明显增大,且在跨中跳车时,桥梁动力冲击系数为最大。     

清洁生产在环境影响评价中的应用

本文重点针对清洁生产在环境影响评价中的应用进行了详细的分析,以供参考.     

CCSB船用角钢的开发

石横特钢根据CCSB船用角钢对耐蚀、外观以及冲击韧性等综合质量指标要求高的特点,进行合理的工艺设计和严密的生产组织,提高了钢的纯净度、细化了晶粒,角钢-40℃冲击功达到35 J以上,钢材表面质量也达到了较高的水准,总体实物质量达到了CCSB船用角钢的用户要求,成材率96.30%,为企业创造了良好的经济效益。     

P91主蒸汽管道高硬度和低硬度焊缝性能研究

对P91钢的高硬度和低硬度焊缝的冲击功、硬度、断裂韧度和持久强度进行了试验研究,结果表明:硬度高、韧性低的R焊缝具有高的持久强度;硬度低、韧性高的D焊缝具有低的持久强度。材料持久强度的高低与部件的蠕变寿命密切相关。