基于聚类分析理论确定广梧高速公路高液限土改良方案

针对广梧高速公路高液限土的不良特性,进行了一系列室内试验,测试土样的物理力学指标;借助聚类分析理论,对样本土样进行分类,并确定各类的属性特征值和改良方案;根据土样与属性特征值的相关距离确定各类土样的改良试验项目。以新土料改良方案确定过程为例,介绍了研究结论的使用过程。     

气液增压技术在工程领域中的应用

通过对液压站,气液增压系统的分析,详细的介绍了二者之间的优缺点。经过对单向阀一钢球压装机床方案的讨论,压装力的计算,证明了气液增压技术在机床上应用的可行性,从根本上解决了液压站占地面积大,噪音大等缺点。为气液增压系统在工程领域中大量使用提供了依据。     

粘性流体晃荡与弹性结构的相互耦合作用

提出了处理粘性流体晃荡与弹性结构相互耦合作用的理论及相应数值计算方法.流体运动采用N-S方程描述,控制方程采用有限差分法离散,并由超松弛迭代法求解.液体自由表面通过流体体积法进行重构.为了考虑液舱结构变形对液体晃荡的影响,应用了FAVOR技术.由此建立了描述液体晃荡与结构相互耦合作用的水弹性理论,并由相应的计算方法进行了系列运算,以考察二维液舱不同结构刚度对液体晃荡的影响.计算结果有助于进一步理解此类问题的物理现象.     

雷达液位测量技术在海洋工程中的应用

文章旨在探讨海洋平台和FPSO等海洋工程设计中一些舱内液位测量设备新兴的应用技术,着重讲述两种不同形式的雷达液(物)位计在不同舱内液位测量中的应用.     

液态粉煤灰填筑桥头路堤的应用研究

桥头与台背填料间的不均匀沉降引起的桥头跳车和填料对台背的水平推力引起的桥台倾覆问题,一直是公路工程中的难点。以唐津高速公路在天津地区的试验段为例,采用液态粉煤灰填筑桥头台背路堤。研究结果表明:轻质型材料液态粉煤灰具有强度大、质量轻、不需要机械压实等优点,且对桥头台背的压力小,与台背间的不均匀沉降也小,是较好的桥头路堤填筑材料。     

Experimental research on friction-reduction with super-hydrophobic surfaces

Many recent studies have confirmed the existence of liquid slip over particular types of solid surfaces, and these so-called super-hydrophobic surfaces have been shown to generate effective liquid slip because of the air trapped between the surface structures. In this paper, based on boundary layer theory, the microscopic structure of the super-hydrophobic surface is analyzed. The liquid slip effect on friction-reduction over super-hydrophobic surfaces under various flow conditions is investigated by experiments with a flume and water tunnel. The experimental results show that the greatest amount of drag-reduction that can be achieved is 8.76% at a low Re.     

化学品船不锈钢液货舱酸洗钝化试验研究

阐述了化学品船不锈钢液货舱产生腐蚀的原因、钝化膜的形成机理及对不锈钢液货舱进行整体酸洗钝化的工艺,提出了化学品船不锈钢液货舱酸洗钝化的方案选择。     

机车操纵台液晶显示器参数调节对视觉功效的影响

从视觉功效学的角度出发,在0～500lx照度下,对车载液晶显示器(LCD)显示调控指标和环境照明对亮度对比度的影响进行了研究,以判读兰道环的绩效指数和主观评价为指标,对LCD在不同照度和亮度对比度条件下的视觉功效进行了实验,确定了在不同照明条件下LCD的最佳调节值,为LCD的科学化和智能化调节提供了理论依据和数据。     

Experimental and numerical study on tuned liquid dampers for controlling earthquake response of jacket offshore platform

Earthquake loading has to be considered when the offshore platform is constructed in active fault zone. Tuned liquid dampers (TLD) have been proposed to control the dynamic response of structures. Liquid sloshing experiments on cylinder tank show the sloshing happens more seriously when the frequency of external excitation is close to the fundamental sloshing frequency of liquid. Lumped mass method is employed to numerically analyze the controlling earthquake effect on TLD. Based on TLDs the feasibility to control earthquake response of jacket platform is studied and applied to CB32A oil tank platform. Using extra TLDs in CB32A to control the seismic response of the platform is researched by the model test and numerical simulation. Lumped mass method can simulate the behavior of TLD during earthquake very well and gives close numerical results compared with those from model experiments. It has been found that the ratio of the fundamental sloshing frequency of liquid to the natural frequency of platform is the key factor to control earthquake response. The larger ratio of water-mass to platform-mass is also useful to reduce vibration as well.     

外壳板采用纵骨加强的双层加肋圆柱壳水下声辐射分析

建立了外壳板加纵骨的双层加肋圆柱壳水下声辐射计算方法，计算模型采用Donnell壳体理论，考虑了环肋、舱壁和实肋板对内外圆柱壳的径向、切向、纵向反作用力以及纵向反弯矩，利用傅氏变换和模态展开在波数域建立了计算模型的声弹耦合控制方程。推导了所有结构部件以及水介质的速度阻抗表达式，采用数值计算方法在波数域求解出径向振动速度，利用稳相法得到远场辐射声压。研究表明，如果纵骨沿圆周均匀排列，则纵骨的存在不导致圆柱壳周向模态耦合，纵骨加强的双层圆柱壳水下声辐射计算可以大大筒化。采用文中方法研究了环频率以下外壳板加纵骨的双层加肋圆柱壳水下声辐射特性，计算表时：在较低的频率段，外壳板采用纵骨加强使双层加肋圆柱壳水下辐射声压增大；增大纵骨刚废，结构辐射声压也相应增大；纵骨间距对双层加肋圆柱壳水下声辐射影响比较复杂，辐射声压谱随纵骨间距变化较大，而总声级变化不明显。