基于AIS船站的港口海事监测信息系统研究

本文简单介绍了一种利用AIS船站作为岸基设备组成海事监测信息系统的设计方案.利用分布式数据库技术将原始信息存储在各安装点并将数据送往中心数据库,对数据进行处理后再存储到中心数据库,从而实现对水上目标的监测.     

饱和粘土循环动力分析边界面模型的积分算法

基于运动硬化准则的新型边界面塑性模型,能够预测循环载荷作用下饱和粘土的动力响应,该模型的数值积分格式是合理评估海洋环境下大圆筒结构等近海工程结构承载性能和动力响应的保证.采用基于SMP准则的变换应力法,建立能考虑土体拉伸特性的边界面模型,根据广义梯形法则提出该模型的积分算法,模拟饱和粘土的三轴拉伸试验和动三轴试验,数值结果与土工试验数据吻合较好.     

钢筋混凝土T梁桥病害处理措施与加固设计

钢筋混凝土T梁桥由于造价低、施工方便等特点,在低等级公路上普遍使用。然而,随着经济发展和交通量的增加,该桥型挠度大、裂缝多等病害也大量出现。根据太湖长河东门新桥在使用时期出现的病害,作出了详细的分析,提出了针对性的处理措施与加固设计方案,解决了桥梁运营的安全问题。该文就钢筋混凝土T梁加固改造问题做了较为深入的探讨和分析,对今后同类桥梁有指导意义。     

连续梁预应力部分施工中的关键工序研究

连续梁桥是中等跨径桥梁中常用的一种桥梁结构,预应力混凝土连续梁桥是其主要结构形式,它具有接缝少、刚度好、行车平顺舒适等优点,其中,预应力是连续梁施工的重点和难点。以新建太中银铁路跨石中高速公路特大桥连续梁施工为例,对影响预应力部分施工的关键要素进行简要阐述。     

液舱晃荡与浮体非线性耦合运动分析(英文)

Nonlinear interactions among incident wave, tank-sloshing and floating body coupling motion are investigated. The fully nonlinear sloshing and body-surface nonlinear free surface hydrodynamics is simulated using a Non-Uniform Rational B-Spline (NURBS) higher-order panel method in time domain based on the potential theory. A robust and stable improved iterative procedure (Yan and Ma, 2007) for floating bodies is used for calculating the time derivative of velocity potential and floating body motion. An energy dissipation condition based on linear theory adopted by Huang (2011) is developed to consider flow viscosity effects of sloshing flow in nonlinear model. A two-dimensional tank model test was performed to identify its validity. The present nonlinear coupling sway motion results are subsequently compared with the corresponding Rognebakke and Faltinsen (2003)’s experimental results, showing fair agreement. Thus, the numerical approach presented in this paper is expected to be very efficient and realistic in evaluating the coupling effects of nonlinear sloshing and body motion.     

粘流方法的螺旋桨尾流场数值分析(英文)

The computational fluid dynamics(CFD) method is used to numerically simulate a propeller wake flow field in open water.A sub-domain hybrid mesh method was adopted in this paper.The computation domain was separated into two sub-domains,in which tetrahedral elements were used in the inner domain to match the complicated geometry of the propeller,while hexahedral elements were used in the outer domain.The mesh was locally refined on the propeller surface and near the wake flow field,and a size function was used to control the growth rate of the grid.Sections at different axial location were used to study the spatial evolution of the propeller wake in the region ranging from the disc to one propeller diameter(D) downstream.The numerical results show that the axial velocity fluctuates along the wake flow;radial velocity,which is closely related to vortices,attenuates strongly.The trailing vortices interact with the tip vortex at the blades’ trailing edge and then separate.The strength of the vortex shrinks rapidly,and the radius decreases 20% at one diameter downstream.     

撞角球鼻艏形式和参数变化对阻力影响的研究

通过数值计算及模型试验确定了撞角球鼻艏形式和参数对阻力的影响。针对3个形式各异的球鼻艏方案,开展了CFD计算和模型试验,结果显示:当傅汝德数为0.28时,撞角球鼻艏的剩余阻力系数比无球鼻艏的剩余阻力系数约小20%。以8个主要参数各异的撞角球鼻艏方案为对象,采用CFD技术分析了撞角球鼻艏的参数变化对兴波阻力的影响,并确定了撞角球鼻艏的宽度比和纵向长度比对兴波阻力系数的影响。     

An Experimental Study on the Dynamic Response Characteristics of Variable Valve Timing Mechanism

为一台可变气门正时(VVT)发动机的配气相位调节器开发了一套可变气门正时机构的测试系统,完成了机油控制阀(OCV)工质流量特性的测试.分析了VVT动态响应特性的测试原理.借助该测试系统,测得不同的OCV、转速、温度和压力时相位器的动态响应曲线.最后进行了相位器泄漏量的测试.     

The Effects of Gear Shaft Deformation on Gear Contact State in Transmission

建立了变速器齿轮与齿轮轴系统的有限元模型,并对其进行有限元分析,以计算齿轮轴变形和轮齿接触应力,分析变速器齿轮轴变形对齿面接触状态的影响.通过与经典方法计算结果的比较,表明所建立的齿轮与齿轮轴系统有限元模型,不但可准确计算齿轮轴变形和齿面接触应力,且能综合分析齿轮轴变形对齿面接触区域的载荷分布、轮齿间载荷分配和齿面接触应力的影响,为更全面、精确分析变速器齿轮的齿面接触状态和载荷分布,预测齿轮疲劳寿命提供依据.     

A Study on the Safety Design of Crash Structure in a Fuel Cell Car

探讨某款燃料电池轿车碰撞结构安全设计的思路,阐述其具体设计,并借助有限元法对该车模型进行了碰撞模拟,根据模拟结果进行了改进设计,并验证改进设计的有效性.结果表明改进后的碰撞结构安全设计可行、有效.