圆柱体货物超限位置及超限程度确定方法的研究

经由铁路运输的超限货物必须准确确定其超限等级，以确保货物及行车安全，圆柱体货物超限计算点的选取至今缺乏相应的理论依据。本文通过实例说明上前在判断货物超限程度上存在的问题，并且在对圆柱体货物外形与各限界之间的关系的进一步分析的基础上，给出了圆柱体货物超限程度及其位置的判定原则及实现方法。     

水泥土试件尺寸及边界约束对其强度影响的理论分析

应用双剪屈服准则推导了不同尺寸和边界约束条件下，水泥土圆柱体试件抗压强度的理论计算公式，理论分析表明水泥土抗压强度与圆柱体高度和直径比有关，而且与表面是否抹油有关，理论分析结论得到了试验结果的验证。根据理论分析与实测结果，对工程中水泥粉喷桩钻芯试件尺寸提出了建议。     

不同直径圆柱体芯样劈裂抗拉强度问题的探讨

圆柱体芯样劈裂抗拉强度换算成小梁抗折强度是以直径１５０ｍｍ芯样为基础的。笔者通过实践认为，对于其他直径芯样，应首先对其劈裂抗拉强度进行尺寸换算，然后才能进一步换算为小梁抗折强度。并提出一换算系数。     

基于圆柱体试件的车辙试验方法研究

依据汉堡试验机的试模,提出更为合理的评价沥青混合料试验方法,运用60℃时弹性模量为500MPa的环氧树脂柔性试模代替汉堡试验机的有机玻璃试模,并在标准车辙试验机上进行试验,最后和车辙板车辙试验作比较,发现圆柱体试件的车辙试验方法远优于车辙板车辙试验,试验结果可靠性更高。进一步提出车辙总变形相对其他指标更能有效地反映沥青混合料的高温性能。     

The bending vibration response and approximate calculation of elastic cylindrical shell

Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects, so it is important to conduct vibration research on the shells and find it＇s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell＇s bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation. The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.     

涡激振动影响下细长海洋结构物的阻力特性

利用柔性圆柱体涡激振动水池模型试验对细长海洋结构物发生涡激振动时的阻力特性进行研究。利用试验测得的圆柱体模型顺流向平均弯曲应变,结合梁复杂弯曲理论,计算出模型各截面处的平均阻力,获得沿模型轴向分布的阻力系数,分析涡激振动影响下细长海洋结构物阻力系数的变化特性。研究结论表明:均匀流下细长海洋结构物的阻力为非均布载荷,涡激振动对阻力系数具有放大效应,导致阻力系数在1.4~2.5之间变化。     

Exciting forces for a wave energy device consisting of a pair of coaxial cylinders in water of finite depth

Two coaxial vertical cylinders-one is a riding hollow cylinder and the other a solid cylinder of greater radius at some distance above an impermeable horizontal bottom,were considered.This problem of diffraction by these two cylinders,which were considered as idealization of a buoy and a circular plate,can be considered as a wave energy device.The wave energy that is created and transferred by this device can be appropriately used in many applications in lieu of conventional energy.Method of separation of variables was used to obtain the analytical expressions for the diffracted potentials in four clearly identified regions.By applying the appropriate matching conditions along the three virtual boundaries between the regions,a system of linear equations was obtained,which was solved for the unknown coefficients.The potentials allowed us to obtain the exciting forces acting on both cylinders.Sets of exciting forces were obtained for different radii of the cylinders and for different gaps between the cylinders.It was observed that changes in radius and the gap had significant effect on the forces.It was found that mostly the exciting forces were significant only at lower frequencies.The exciting forces almost vanished at higher frequencies.The problem was also investigated for the base case of no plate arrangement,i.e.,the case having only the floating cylinder tethered to the sea-bed.Comparison of forces for both arrangements was carried out.In order to take care of the radiation of the cylinders due to surge motion,the corresponding added mass and the damping coefficients for both cylinders were also computed.All the results were depicted graphically and compared with available results.     

气泡减阻实验研究

为研究气泡对航行体侧壁的减阻效果，设计一套试验装置。利用该装置，采用壁面通气法研究不同通气量、不同来流速度和不同通气角度对气泡减阻效果的影响。实验结果表明：在通气量和通气角度不变的条件下，减阻率随来流速度增加而增加；在来流速度和通气角度不变的条件下，随通气量增加，减阻率先增加然后变小；在来流速度和通气量不变的条件下，减阻率随通气角度的增大而减少；在一定的条件下，取得了20．34％的减阻率。     

基于VOF法的半球-圆柱体液舱晃荡数值模拟

利用三维建模软件建立了纵荡激励下半球-圆柱体液舱内粘性液体晃荡的数值模型,利用计算流体动力学软件对不同工况下的液体晃荡进行了数值模拟,得到了液体对各监测点的作用力和液舱模型的一阶固有振动周期,分析了不同装载率、不同激励幅值、不同激励频率对液舱内液体晃荡的影响。     

两圆柱体在波浪载荷作用下的运动响应分析

基于势流理论和波浪辐射/绕射理论,利用水动力分析软件(AQWA)研究两圆柱体在波浪作用下的运动响应特性,给出不同入射角与不同频率规则波作用下,小圆柱体单独运动时的六自由度响应幅值算子(RAOs)及运动响应,并与两个并排圆柱体六自由度响应幅值算子(RAOs)及运动响应作比较。结果表明:大圆柱体的干扰将使小圆柱体的纵摇、横摇、横荡、垂荡运动加剧,对小圆柱体漂移力也有较大影响,但对小圆柱体的纵荡与首摇运动影响不大。计算结果与传统方法计算值相近,证明此软件合理,可为两船在波浪中的干扰模拟计算提供参考。