内河连续弯曲航道航行漂角分析

通过概化连续弯道船模试验,研究了千吨级机动驳船在内河航道(Ⅲ级)中的通航条件,结合相关标准和规范,重点研究了水深、流速及弯道中心角对船舶漂角的影响。根据船模试验航行结果表明:船舶下行漂角随着流速、水深及中心角的增大而增大,并提出了漂角同这些参数的相关关系式。     

加筋土挡墙墙背土压力分布规律研究

综合考虑了拉筋垂直层间距与拉筋的抗拉强度的影响,利用微元法提出了加筋土挡墙墙背土压力计算模型,进而得到墙背的土压力强度和合力的理论公式。研究结果表明:文中提出的加筋土挡墙墙背侧向土压力强度公式模型较好地反映了土压力随墙高呈非线性分布的规律;土压力理论值随拉筋竖向间距的增加而增加,随拉筋拉力的增加而减小;主动破裂角随拉筋拉力的增加而增大,随拉筋垂直间距的增加而减小,且加筋后的破裂角比未加筋的大;土压力理论值比变系数法小且大于实测值。     

基于有限差分法的边坡稳定影响因素分析

首先探讨了有限差分法自身的误差,提出了合理的网格密度及边界条件;然后,通过与极限平衡法的比较,研究了剪胀角、抗拉强度、泊松比及弹性模量对边坡安全系数的敏感性以及对边坡变形特征的影响。研究表明:剪胀角、泊松比和弹性模量对边坡破坏时变形的影响较为明显,但弹性模量相对泊松比更为明显,抗拉强度较小时对边坡变形有影响。     

底盘测功机结构参数分析

指出了中国不同行业标准关于底盘测功机结构参数的矛盾,分析了国内外轻、重型车辆底盘测功机安置角和滚筒直径等参数要求的优、缺点;对车辆在底盘测功机上检测进行了受力分析,找到了影响检测安全性的驱动轴重、检测驱动力、安置角等参数之间的关系,建立了轻、重型底盘测功机统一台架结构参数的数学模型;探讨了主、副滚筒同步带的优缺点,建议标定完后拆除同步带进行工况检测。     

应力剪胀对浅埋偏压隧道破坏面形状的影响

采用有限差分软件,对浅埋偏压单线铁路隧道和四车道公路隧道进行数值模拟。研究了围岩的松动土体力学行为,主要考虑应力剪胀对浅埋偏压隧道破坏面形状的影响,并将数值模拟的结果与规范理论解进行了比较。结果表明：剪胀角对浅埋偏压隧道围岩位移和破坏面形状有较大影响。因此,在确定浅埋偏压隧道围岩松动压力时应该考虑剪胀对破坏面形状的影响。     

钢筋混凝土部分质量通病现象及防治方法

经过多年的建设施工经验及研究,针对钢筋混凝土质量通病的现象及防治办法进行了阐述.     

非延迟式点火正时灯检测原理及电路分析

介绍点火正时灯检测原理,主要对非延迟式点火正时灯电路的组成及原理进行分析。     

隧道围岩特性参数反演与开挖方法数值分析

以隧道围岩收敛变形数据,运用系统识别灵敏度分析理论进行隧道围岩特性参数反演。采用反演的隧道围岩特性参数进行隧道施工不同开挖方法的有限元数值仿真分析比较。说明台阶法是较为合理和安全的施工方法。     

Experiment on the secondary flow of a large turn angle turbine stator with a rotating single slanted hotwire

Experiment measurement is adapted to study the secondary flow of turbine. The subsonic stator experiment flow tunnel is set up. Two different inlet velocities and three different stator heights are applied. The method of a rotating slanted hotwire is introduced to measure the stator outlet three-dimensional flow field. The procedure for solving the mean three-dimensional velocity component involving the least-squares technique can be accomplished via the LSQNONLIN optimization function of Matlab. Under different work conditions, the stator outlet secondary flow is more intense at higher inlet flux. Moreover, the shortest stator height will lead to the most intense secondary flow, which gains the largest axial velocity component (w) and radial velocity component (u), but the smallest circumferential velocity component (v).     

Regularization method and immune genetic algorithm for inverse problems of ship maneuvering

Ship maneuverability, in the field of ship engineering, is often predicted by maneuvering motion group MMG) mathematical model. Then it is necessary to determine hydrodynamic coefficients and interaction force coefficients of the model. Based on the data of free running model test, the problem for obtaining these coefficients is called inverse one. For the inverse problem, ill-oposedness is inherent, nonlinearity and great computation happen,and the computation is also insensitive, unstable and time-consuming. In the paper, a regnlarization method is introduced to solve ill-posed problem and genetic algorithm is used for nonlinear motion of ship maneuvering. In addition, the immunity is applied to solve the prematurity, to promote the global searching ability and to increase the converging speed. The combination of regnlarization method and immune genetic algorithm(RIGA) applied in MMG mathematical model, showed rapid converging speed and good stability.