移动式装卸臂在液体粮油码头装卸系统中的应用

根据天津临港工业区某粮油码头工程实例,着重分析在粮油码头上应用移动式装卸臂的可行性,结合粮油码头装卸工艺系统的总体布置情况．介绍移动式装卸臂的主要技术参数和移动式装卸臂的配置情况,并通过与软管装卸方式的对比论述采用移动式装卸臂的优势．可供同类码头工程参考。     

汽车悬架控制臂的多目标拓扑优化

以多工况下的柔度(静态)和振动固有频率(动态)为目标函数,对汽车悬架控制臂进行多目标拓扑优化。基于SIMP变密度的拓扑优化方法,将多级容差序列规划与折衷规划法相结合,首先进行自由振动工况下的频率优化,然后以此为基础进行静态工况下的柔度优化,最终得到了同时满足静态柔度最小和振动低阶频率最高要求的控制臂拓扑结构。     

19500吨干货船多块折叠式舱口盖举臂结构有限元分析

通过运用UG、MSC.Patran/Nastran以及MSC.Adams软件,对19500 t干货船多块折叠式舱口盖的举臂结构进行了有限元分析.计算所得结果与试验结果相当吻合,表明研究分析方法正确,计算模型合理.本文的分析结果可为举臂结构设计提供理论依据.     

高速滚动汽车轮胎稳态温度场分布的数值研究

建立了滚动轮胎热平衡状态下的简化传热数学模型。应用自行开发的传热和热弹性力学分析有限元软件对中型载货车用9．OO一20(12P．R)尼龙斜交胎进行了稳态温度场仿真计算，获得了胎体内部的稳态温度场分布。分析了轮眙的速度、几何结构参数及材料特性参数对轮胎最高温升的影响，通过回归分析建立了该轮胎速度与最高温升的经验计算公式。     

客车空气悬架前导向臂的设计改进

简要介绍空气悬架导向臂的设计改进过程,并对改进前后的导向臂和主销后倾角进行简要分析。     

Experimental investigations on hydrodynamic interactions between the cylinder and nets of a typical offshore aquacultural structure in steady current

A series of physical experiments were performed in steady current to investigate the hydrodynamic interactions between the cylinder and nets which constitute a main part of offshore aquacultural platforms. The hydrodynamic characteristics of only the cylinder, only nets and combined cylinder-net structures are measured and analyzed systematically under different current velocities, inflow angles and solidity ratios of nets. Based on experimental data, fitted formulas for hydrodynamic coefficients of a single resin net are proposed and compared to previously published empirical formulas. It is observed that the existence of the cylinder brings an increment up to 9.2% to drag coefficient of net panels whose solidity ratios are higher than 0.347, whereas this effect is negligible for nets with lower solidity ratios and perpendicular to the inflow. For nets inclined with 45°, the increment of the drag coefficient of net panels due to the existence of the cylinder is more significant (up to 22.9%) than that for perpendicularly placed nets. Furthermore, the existence of nets also leads to a noticeable increase in the drag coefficient of the cylinder, up to 40.18% for a relatively large net solidity ratio of 0.458, representative of biofouling condition. The increment increases with the rise of the solidity ratio of nets and it is larger for nets placed perpendicularly to the inflow than inclined. Effects of the cylinder and nets on lift coefficients of each other are a bit complicated, leading to an increase or reduction of lift coefficients depending on the inflow velocity, inflow angle and net solidity ratios. Finally, it is worth noting that the hydrodynamic interaction between the cylinder and nets deserves to be considered in current practice of hybrid methods by combining potential flow theory, Morison and screen models for aquacultural structures, especially for biofouling conditions.