考虑裂纹扩展的周向裂纹损伤圆柱壳的极限强度

为了正确评价和预测大型海洋平台结构在疲劳裂纹损伤条件下的承载能力,须要全面、系统地研究圆柱壳这类基本构件在考虑裂纹扩展条件下的极限强度。针对含周向壁穿裂纹损伤的圆柱壳,利用已有的关于弹塑性裂纹及裂纹扩展的理论解析解,通过系列计算,探讨了裂纹初始长度、圆柱壳直径板厚比、材料的临界CTOD、临界CTOA、屈服应力及杨氏模量等参数对极限强度的影响,并就其对各参数的敏感度作了相应的分析。提出极限强度损失系数κ、强度冗余系数λ及裂纹剩余扩展长度ξ等无因次参数,并以此定量地评价由裂纹扩展所引起的结构承载能力的变化。这项研究为进一步合理地评估含裂纹损伤的结构系统整体的极限强度完成了一项基础性工作。     

G2在作战指挥控制流程建模仿真中的应用研究

作战指挥控制流程是影响军队作战效能的重要因素。从作战指挥控制流程的特点出发,描述了一个应用G2软件建立指挥控制流程仿真模型的方法,对比介绍了几种现有的流程建模方法。利用G2/ReThink对描述的指挥控制流程进行建模和仿真,并简要开发了一个防空指挥控制流程仿真模型。通过对作战指挥控制流程的仿真,为流程的优化和改进提供了决策支持。     

基于排队论的战略预警指挥手段效能评估研究

针对信息化条件下战略预警指挥中信息流动的特点,运用排队论的原理,定义了战略预警指挥手段效能的指标,构建了效能评估模型,为评估信息化条件下作战指挥体系效能,优化体系结构提出了一种新的方法。     

海上单体高速客船结构规范设计系统开发

以海上单体高速客船为研究对象,分析海上单体高速客船结构规范设计系统开发的目的、系统的构成和功能,介绍主要模块程序开发思想和方法。使用所开发的程序系统实现计算机辅助海上单体高速客船结构设计,可提高结构规范设计的效率。     

Experimental and numerical procedures of a sonar platform with a sound absorption wedge

Experiments involving a sonar platform with a sound absorption wedge were carried out for the purpose of obtaining the low frequency acoustic characteristics. Acoustic characteristics of a sonar platform model with a sound absorption wedge were measured, and the effects of different wedge laid areas on platform acoustic characteristic were tested. Vibration acceleration and self-noise caused by model vibration were measured in four conditions: 0%, 36%, 60%, and 100% of wedge laid area when the sonar platform was under a single frequency excitation force. An experiment was performed to validate a corresponding numerical calculation. The numerical vibration characteristics of platform area were calculated by the finite element method, and self-noise caused by the vibration in it was predicted by an experiential formula. The conclusions prove that the numerical calculation method can partially replace the experimental process for obtaining vibration and sound characteristics.     

阻振质量参数对动力舱段隔振性能影响规律研究

Rigid blocking masses are located in the typical base structure of a power cabin based on the impedance mismatch principle.By combining the acoustic-structural coupling method and statistical energy analysis,the full-band vibration and sound radiation reduction effect of vibration isolation masses located in a base structure was researched.The influence of the blocking mass’ cross-section size and shape parameters and the layout location of the base isolation performance was discussed.Furthermore,the effectiveness of rigid vibration isolation design of the base structure was validated.The results show that the medium and high frequency vibration and sound radiation of a power cabin are effectively reduced by a blocking mass.Concerning weight increment and section requirement,suitably increasing the blocking mass size and section height and reducing section width can result in an efficiency-cost ratio.     

海事系统重点建设项目社会稳定风险评估

文中结合海事系统重点建设项目的特点,对其潜藏社会稳定风险的评估内容、评估程序以及处置对策进行探讨。     

被撞船舷侧典型结构单元的吸能机理分析

为了研究高腹板梁在碰撞过程中的剪切破坏机理.提高对船舶结构碰撞吸能的认识.文章从某油轮舷侧截取典型结构单元--带板梁作为研究对象.基于极限平衡理论和LS-DYNA软件对其碰撞破坏过程进行分析.研究带板梁极限载荷、最大挠度和最大吸能影响因素和计算方法,同时分析弯曲应变能和膜应变能占总吸能的比重.结果表明:单元尺寸和材料极...     

舰船刚性阻振质量基座中频振动特性研究

有限元与统计能量混合法(FE-SEA)将计算低频响应的有限元法(FEM)与计算高频响应的统计能量法(SEA)结合起来,有效解决了FEM计算量大而SEA计算不准的中频域问题。提出在舰船弹性基座中引入刚性减振器,即在舰船基座与船体结构连接部位布设刚性阻振质量,并采用基于FE-SEA混合法的VA One软件对舰船刚性阻振质量基座的中频振动特性进行了研究。结果表明,刚性阻振质量对中高频结构噪声可起到明显的隔振作用,而对低频结构噪声的减振效果则不明显,甚至没有减振效果,这对刚性阻振技术在实艇基座减振降噪设计中的应用具有一定的实际工程价值。     

深圳九围河截污工程中电气设备自动化控制的特点及改进建议

根据该工程污水泵、启闭机等电气设备的运行特点和联锁保护要求,介绍了该工程电气设备自动化控制的特点、存在的问题及改进建议等。论证了泵站自动化控制系统工程的成功应用不仅可方便操作,降低操作人员的劳动强度,而且对泵站的安全、稳定、高效运行,减少设备故障,降低运行维护成本起着非常重要的作用,同时也提升了泵站运行管理工作的水平。