纤维金属混杂层合板拉伸强度分析

基于经典层合板理论的分析方法,对纤维金属混杂层合板的理论解进行扩展,并利用有限元对纤维金属混杂对称铺设层合板进行数值分析,与单向拉伸条件下的试验值比较,认为有限元计算能满足工程计算的要求;同时着重讨论了铺层方式、金属层厚度以及金属层材料属性对拉伸强度的影响,为大型复杂结构的有限元分析提供有益的参考.     

发射动力系统内弹道优化设计计算

建立了燃气-蒸汽发射动力系统内弹道优化设计的基本关系式,并对某型导弹的弹射内弹道进行了设计计算.计算结果与试验结果相吻合,对弹射内弹道的工程设计具有一定的参考价值.     

非理想条件下三轴磁通门传感器误差修正方法

三轴磁通门传感器应用较为广泛,但非正交误差和非水平误差影响了三轴磁通门传感器的磁场测量精度.根据三轴磁通门传感器测量原理,分析了非理想条件下与理想条件下磁场转化矩阵关系.为消除三轴磁通门传感器中非正交误差和非水平误差的影响,建立了以磁场转化矩阵参数为自变量的优化模型.采用全局优化能力强、寻优效率高的微分进化算法求解该优化模型,求得磁场转化矩阵参数即可实现非正交误差和非水平误差的同时修正.三轴磁通门传感器误差修正实验表明,该方法在一定程度上可有效消除三轴磁通门传感器中非正交误差和非水平误差的影响,对提高三轴磁通门传感器磁场测量精度具有重要意义.     

潜艇水压平衡式发射装置内弹道仿真建模

通过对潜艇水压平衡式发射装置工作原理的分析,基于发射装置各部分之间的联立关系,建立了发射装置发射气瓶及发射阀部分、活塞组件部分、发射管武器部分等各子系统的数学模型。应用Simulink对潜艇水压平衡式发射装置武器发射内弹道的全过程进行仿真研究,Simulink仿真结果与武器发射的实际情况相符合,表明数学模型的可行性和正确性。所建仿真模型可用于潜艇水压平衡式发射装置内弹道的动态分析及相关问题研究。     

轻质夹层结构复合材料的制备及性能

为减轻以往夹层结构复合材料的密度,采用高强玻璃钢材料作为表层、多种空心玻璃微珠填充聚氨酯改性环氧树脂合成的轻质吸声材料作为芯材,制备了一种新型的轻质夹层结构复合材料,对夹层复合材料的制备工艺进行设计,并研究其水声性能和力学性能。结果证明,以南京玻纤院的S2高强织物采用真空成型合成的玻璃钢作为表层材料和轻质聚氨酯改性环氧树脂材料作为芯材来制作的夹层结构复合材料具有重量轻、水声性能和力学性能优良的特点,在降低夹层结构复合材料重量的同时,具有良好的声隐身性能和承载性能,更有利于工程应用。     

水面舰艇规避线导鱼雷策略

对潜射线导鱼雷的防御是水面舰艇面临的最大难题之一.本文首先指出现有防御策略研究中存在的认识误区,归纳出线导鱼雷的制导规律;其次分别针对线导导引状态和自导追踪状态的鱼雷防御进行了系统分析,得到了水面舰艇应将鱼雷置于舰尾180°舷角高速脱离的规避机动策略;最后分析了规避策略的可行性和最优性,并指出了在具体实施过程中应该注意的一些问题.研究结果对于提高水面舰艇的生存能力具有重要意义.     

弹性安装设备等效总激励力的计算方法研究

针对弹性安装条件下多机脚设备总激励力估算繁琐的问题,提出一种设备等效激励力的计算方法。该方法将弹性安装的多机脚设备等效为只有一个机脚支撑的设备,将原有的多个隔振器简化为一个具有有效总阻抗的隔振器,利用原机脚隔振器上下端的响应与隔振器的有效总阻抗估算出的激励力,即可等效为该设备的总激励力。为验证该方法的准确性,利用该方法对某船用设备振动激励力进行估算。实验数据分析表明,在临界频率以内,可以忽略隔振器之间的耦合,估算值与实际测量值之间的误差小于5 dB,满足工程要求。     

溢油漂移轨迹回推技术在海事调查中的应用

海上油污染事故调查是海事监管的重要职责。近年来,屡有不明来源油污事件发生,溢油时间不明,调查难度大。基于大气、水动力模型和溢油模型的溢油漂移轨迹回推技术能够实现对不明来源油污的回推溯源,通过回推结果指导海事调查的方向,缩小排查范围,在实际应用中取得了良好的效果。     

Simulating the impacts of household travel on greenhouse gas emissions,urban air quality,and population exposure

This paper establishes a link between an activity-based model for the Greater Toronto Area (GTA), dynamic traffic assignment, emission modelling, and air quality simulation. This provides agent-based output that allows vehicle emissions to be tracked back to individuals and households who are producing them. In addition, roadway emissions are dispersed and the resulting ambient air concentrations are linked with individual time-activity patterns in order to assess population exposure to air pollution. This framework is applied to evaluate the effects of a range of policy interventions and 2031 scenarios on the generation of vehicle emissions and greenhouse gases in the GTA. Results show that the predicted increase of approximately 2.6 million people and 1.3 million jobs in the region by 2031 compared to 2001 levels poses a major challenge in achieving meaningful reductions in GHGs and air pollution.     

Real time queue length estimation for signalized intersections using travel times from mobile sensors

We study how to estimate real time queue lengths at signalized intersections using intersection travel times collected from mobile traffic sensors. The estimation is based on the observation that critical pattern changes of intersection travel times or delays, such as the discontinuities (i.e., sudden and dramatic increases in travel times) and non-smoothness (i.e., changes of slopes of travel times), indicate signal timing or queue length changes. By detecting these critical points in intersection travel times or delays, the real time queue length can be re-constructed. We first introduce the concept of Queue Rear No-delay Arrival Time which is related to the non-smoothness of queuing delay patterns and queue length changes. We then show how measured intersection travel times from mobile sensors can be processed to generate sample vehicle queuing delays. Under the uniform arrival assumption, the queuing delays reduce linearly within a cycle. The delay pattern can be estimated by a linear fitting method using sample queuing delays. Queue Rear No-delay Arrival Time can then be obtained from the delay pattern, and be used to estimate the maximum and minimum queue lengths of a cycle, based on which the real-time queue length curve can also be constructed. The model and algorithm are tested in a field experiment and in simulation.