平台支撑的潜艇平面舱壁的极限强度分析

借助国际通用的大型非线性有限元分析软件,对潜艇内部以加强平台取代水平横桁的平面舱壁结构的极限强度进行了非线性的有限元分析.阐述了单元及网格尺度的选择和求解控制策略;求得了结构的应力、应变分布规律;以及探讨了结构极限承载能力、破坏模式、塑性破坏机理.模型试验结果表明,试验值与有限元分析计算值吻合良好.     

基于作战需求的数据链平台定位报告周期分析

文章以指控平台指挥战机打击敌机为例，在分析杀伤目标对平台定位报告周期要求的基础上，提出了一种基于作战需求的平台定位报告周期计算方法。所得结果与实际应用的数值基本吻合。     

高等院校数学教学改革与数学实验的思考

本文阐述了对高职院校开设数学实验课的必要性,以及对数学实验课的开设方式以及数学教学改革的一些思考。     

多跨连续梁在移动荷载序列作用下的动力响应

连续梁桥是公路桥梁工程中常用的一种桥型。利用达朗贝尔原理,建立移动荷载序列作用下的连续梁偏微分运动方程。通过振型叠加法和伽辽金积分,将偏微分方程转化为常微分方程。利用ANSYS软件的模态分析功能,计算出连续梁的固有频率及振型数据,利用拟合振型的方法拟合出振型函数,结合推到方程,利用MATLAB编程求解。讨论了荷载移动速度、荷载间距对动力响应影响的变化规律。其结果对于多跨连续桥梁的动态设计、动力性能评估以及振动的控制具有一定的实际意义。     

肇兴大桥承台大体积砼施工温度控制

文章依托肇兴大桥工程施工实例,对大体积砼裂缝产生的机理进行了分析,介绍了大体积砼温度计算与监测方法,并提出了有效的现场温控措施,为大体积砼施工提供方法借鉴。     

Research and application of non-clay low damage temporary bridging drilling/ completion fluids system

Following the basic theory of protecting gas-reservoirs from damage with the temporary bridging technology, inert calcium carbonate (CaCO3) particles, whose diameter is consistent with the size of pores or apertures in the reservoir, were selected as the bridging agent, and modified resolvable starch was selected as filtration loss reducing particles to form the non-clay low damage temporary bridging drilling/completion fluids system (NLTDFS). Under the simulated condition of the well bottom during real drilling, NLTDFS was used to conduct dynamic and static damage experiments of cores for 48 hours, respectively, and then the experimented cores were permeated with pure nitrogen from the undamaged end to the damaged one to measure their recovery of permeability. The results showed that the permeability recovery rate of the core reached 90% or so, and the damaged depth was less than 1 cm, which demonstrates that NL TDFS has higher temporary bridging effectiveness and lower damage to the gas-reservoir than other drilling fluids system. NLTDFS has been used to drill many horizontal wells, and four of them have obtained high yield of natural gas. The yield of natural gas of LPl well reached 85 X 104 m3/day after completion with the rump pipe. The formation of the stable well wall and smooth drilling led to an API loss less than 4 mL and an HTHP loss less than 15 mL.     

TBM操作异常情况及其处理

对实际工作中遇到的TBM操作异常情况及相应处理措施进行了介绍，以期对同类工程有所参考。     

湘江长沙综合枢纽平面布置研究

在通航河流上修建枢纽综合利用工程,由于受到河段河势、地形、地质等条件的制约,且这类工程因需同时满足电站、船闸等水工建筑物对水流、泥沙条件的要求,因此在进行总体布置时往往会遇到枢纽中各建筑物布置合理与否问题,需要妥善处理,以便充分发挥各建筑物的功能,取得枢纽的综合效益。湘江长沙综合枢纽在进行平面布置时作了多方案的比较,提出了较合理的枢纽总体布置方案。文章根据湘江长沙综合枢纽平面布置研究成果,介绍枢纽布置方案的优劣,供同类工程参考。     

A Secure Multi-Routing Platform for Ad Hoc Network

In an ad hoc network, it is usually difficult to optimize the assignment of network routing resources using a single type of routing protocol due to the differences in network scale, node moving mode and node distribution. Therefore, it is desirable to have nodes run multiple routing protocols simultaneously so that more than one protocols can be chosen to work jointly. For this purpose,a multiple routing platform for Ad hoc networks is proposed on a higher level of current routing protocols. In order to ensure the security of the platform, a security mechanism and its formal analysis by BAN logic is given. The simulation results of the network performance demonstrate that the proposed multi-routing platform is practicable in some complex applications.     

泡沫轻质混凝土单轴循环加卸载试验研究

为研究循环加卸载对泡沫轻质混凝土力学性能的影响,采用微机控制电子万能试验机对湿密度为700 kg/m~3的泡沫轻质混凝土试样开展3组方案的循环加卸载试验,重点研究循环加卸载对其应力-应变曲线、峰值强度、弹性模量的影响。研究结果表明:随着循环加卸载的进行,应力-应变曲线出现不断迁移的现象,且对于3种试验方案,第一次循环加卸载引起的迁移值最大,而后,采用加卸载方案1、方案2,迁移值随着加卸载次数增加而减小,采用加卸载方案3,迁移值随着加卸载次数的增加先减小后增加;对于3种加卸载方案,峰值强度随着加载幅值的增加而增大,且随着循环加卸载次数的增加而增大;对于3种加卸载方案,第1次加卸载对弹性模量影响最大,而后,对于试验方案1、方案2,弹性模量随着循环加卸载次数的增加而增加,而对于试验方案3,弹性模量随着循环加卸载次数的增加而减小。