某重卡公司自卸车转向横拉杆强度校核

本文分析了某自卸车横拉杆的受力，通过计算横拉杆的临界力以及受到的最大压力，校核其安全系数，进而指出使用环境恶劣是横拉杆弯曲变形的重要原因。     

曲线区段线索张力变化对吊弦计算的影响

通过分析曲线线路上影响承力索张力变化的因素,得出了张力差公式,进而对吊弦计算中承力索张力值进行控制,以提高吊弦计算精确度。     

磁悬浮列车U型悬浮电磁铁电磁力的数值计算与分析

应用电磁场分析软件对常导磁悬浮列车U型悬浮电磁铁的各种电磁力进行数值计算，分析悬浮电磁铁的气隙，水平错位及侧滚角对悬浮力，导向力，侧滚力矩的影响，并将结果与解析计算进行比较，所求得的电磁铁受力结构能为悬浮控制系统和导向控制系统的设计提供准确的设计参数，为磁悬浮转向架抗侧滚梁的优化设计提供可靠的数据。     

INFLUENCE OF SURFACE MORPHOLOGY ON THE MICROHARDNESS OF ELECTROLESS Ni-B DEPOSIT REVEALED BY AFM OBSERVATION

Introduction　　 Electroless Ni- B alloy has many advantagessuch as superior hardness,excellent wear- resis-tance and some special electrical and magneticproperties[1,2 ] . It can be prepared with eitherDimethylamineborane( DMAB) or sodium borohy-dride as reductant[3 ,4] .The deposits with lowerboron contentwhich are mainly applied to electron-ic industry[5] are prepared by DMAB.While sodi-um borohydride can bring about higher boron con-tent deposits which are chiefly used as wear- resis-…     

Prediction method of hydrodynamic forces acting on the hull of a blunt-body ship in the even keel condition

The mathematical modeling group (MMG) model is well known and is widely used in the field of ship maneuverability. However, the MMG model can be applied only after determination of the hydrodynamic coefficients either from comprehensive captive model tests or from general empirical data. Around the cruising speed, when a ship's drift angle is relatively small, several methods have been developed to predict hydrodynamic coefficients from the ship's principal particulars, e.g., Kijima's method. Kijima's method is efficient in predicting the ship's maneuverability at the initial design stage and is even able to assess the effect of changes in stern design. Similarly, for the low speed range when a ship's drift angle is relatively large, several methods for predicting the ship's hydrodynamic coefficients have been proposed, based on captive model tests, such as those by Kose, Kobayashi, and Yumuro. However, most of the methods developed for low speeds cannot be applied to general ship types without additional experiments being performed. In contrast, Karasuno's method uses theoretical and empirical approaches to predict the hydrodynamic forces, even for large drift motions. Although Karasuno's model utilizes the ship's principal particulars and is applicable to a general vessel, it has not been widely used. This is because the form of Karasuno's model is relatively complicated and its accuracy around the cruising speed is less than that for other methods that have been specifically developed for the cruising speed range. A practical method for predicting hydrodynamic forces for the entire operating speed range of blunt-body ships is proposed in this article. It is based on the MMG model and predicts hydrodynamic coefficients based on a ship's principal particulars. A regression model for the proposed method has also been proposed by analyzing 21 different blunt-body ships. Finally, simulations of a very large 4-m crude carrier (VLCC) model using the proposed method were carried out and the results compared with free-running experiments (both at the cruising speed and at low speeds) to validate the efficacy of the model.     

动力分散型交流传动电动车组设备布置及装饰

25kV动力分散型交流传动电动车组车体设计采用了许多新技术和新工艺,文章从车体结构、平面布置、电气设备布置、车内设备布置及车内装饰结构等方面对其作了整体介绍。     

考虑水荷载作用的铁路隧道衬砌结构设计

采用室内模型试验方法,通过改变围岩注浆圈模拟介质的渗透系数,进行10组铁路隧道衬砌结构的水荷载折减系数测试试验,研究水荷载折减系数与注浆圈综合渗透系数的关系。试验结果表明,当围岩注浆圈渗透系数小于10-5cm.s-1时,水荷载折减系数取0~0.3为宜;反之,取值为0.3~1。按考虑水荷载和不考虑水荷载两种受力模式对隧道衬砌结构进行计算分析结果表明,存在较大水荷载作用的隧道衬砌结构设计不宜套用标准图,建议采用钢筋混凝土圆形衬砌结构。     

波浪作用下单体网格式浮架受力的数值模拟

模型试验表明重力式网箱在波浪作用下，单纯浮架的受力贡献比例较大。本文运用波浪理论，通过建立浮架、锚绳及浮子的运动方程，采用五阶龙格-库塔进行数值求解，得到了单体网格式锚碇单纯浮架的数值计算模式。将计算模型简化为四点锚碇，并将计算结果与实验结果进行了比较，二者符合程度较好。在此基础上，比较了单体网格式锚碇与四点锚碇单纯浮架的受力，结果表明网格式锚碇方式浮架受力较小。     

一种新型大容量水雷内记仪

介绍了一种基于USB主控制器和移动U盘的新型大容量水雷内记仪及其设计方案,并给出了微处理器与USB主控制器SL11HS构成的USB硬件接口和USB接口软件设计实例,总结了新型大容量水雷内记仪的优点及应用前景。