基于模态振型的预应力混凝土梁损伤检测

以预应力简支梁为例,通过Ansys有限元模型,分析模态振型在预应力混凝土结构损伤检测中的技术可行性。结果表明:模态振型不仅可以明确地确定结构损伤的存在,而且可以较准确地确定结构损伤的位置。所得结果对于预应力钢筋混凝土梁的健康状况检测具有一定的参考价值。     

基于微观遗传算法的结构形状优化设计

在形状优化中,传统的优化方法对目标函数和约束条件形态的要求严格,难以获得全局最优解。为解决这个问题,将微观遗传算法应用于结构形状优化中。既消除了对目标函数和约束条件形态的限制,提高了全局寻优能力;又减少了结构分析次数,节省了计算时间,为结构的形状优化提供了一种实用方法。通过算例,验证了该方法的正确性。     

基于ASM和FNN的人脸识别

将主动形状模型ASM(Active Shape Model)与模糊神经网络FNN(Fuzzy Neural Networks)相结合并用于人脸识别。针对经典ASM对初始化位置敏感、收缩速度慢的现象和传统模糊神经网络难以解决高维模式分类的问题进行了分析和改进。ORL人脸库上的试验表明了该算法的有效性。     

Estimation of the hydrodynamic coefficients of the complex-shaped autonomous underwater vehicle TUNA-SAND

Hydrodynamic coefficients strongly affect the dynamic performance of autonomous underwater vehicles (AUVs). Thus it is important to have the true values of the coefficients in order to simulate the AUV’s dynamic performance accurately. Although these coefficients can be predicted by many methods, most are only applicable for AUVs with streamlined shapes. Computational fluid dynamics (CFD) can be applied to estimate the hydrodynamic coefficients of AUVs with complex shapes. In this study, CFD was applied to estimate the hydrodynamic coefficients of the AUV TUNA-SAND (which stands for terrain-based underwater navigable AUV for seafloor and natural resources development), which has a complex block-like structure. First, the validity of the CFD simulation was verified by comparison with experimental results. Second, the relationships between hydrodynamic loads and motions for all six degrees of freedom were analyzed using the simulated results. Third, the importance of each hydrodynamic coefficient was investigated based on these relationships. There are 16 key damping coefficients that relate to viscosity and 12 key inertial coefficients that relate to the potential flow around TUNA-SAND. Finally, the values of all the key coefficients were obtained and verified by comparing the solutions of the simulated dynamics with the experimental results.     

内河航道衡重式护岸的优化研究

采用复形优化方法,结合《港口及航道护岸工程设计与施工规范》中推荐的抗滑、抗倾稳定的分项系数计算方法,考虑内河航道船形波等荷载作用效应,对衡重式护岸进行优化设计研究,并对工程实例进行了计算分析。     

哑铃形钢管拱缀板加固方案研究

分析了液态混凝土压强对钢管结构的作用,指出了哑铃形钢管拱先圆管后腹腔灌注顺序的合理性,提出了缀板采用对拉杆加固的方案,并分析了对拉杆间距、直径、材质等对缀板位移和应力的影响。     

关于土拱效应的几个问题

提出了岩土工程领域土拱理论中几个值得探讨的问题，如拱脚的存在形式、拱形、拱体几何参数及微观特性等．根据土拱的不同形成机制，指出拱脚的存在形式有直接拱脚、摩擦拱脚、土体拱脚及二异拱脚4种．在此基础上，通过工程实例对拱形及拱体几何参数提出了初步见解，以期对土拱理论的发展和完善起到积极作用．     

节段预制、悬臂拼装工艺在工程中的综合运用

上海长江隧桥B6标段60 m跨连续箱梁采用节段梁短线法预制、悬臂拼装新型施工技术.节段梁采用全液压模板、短线法高精度预制技术制作,采用水上运输、垂直提升、桥面水平运输等多环节运输,设计可全方位调整节段模块的上行式架桥机进行悬臂拼装,施工全过程运用计算机技术进行计算和监控,确保施工线形质量.对节段预制拼装技术、临时固结技术、合龙段施工技术等进行阐述.     

Piecewise Linear Analysis for Pseudo-elasticity of Shape Memory Alloy （SMA）

Based on the Brinson constitutive model of SMA, a piecewise linear model for the hysteresis loop of pseudo-elasticity is proposed and applied in the analysis of responses of an SMA-spring-mass system under initial velocity activation. The histories of displacement and velocity of the mass, and the response of stress of SMA are calculated with Brinson‘s model and the piecewise linear model. The difference of results of the two models is not significant. The calculation with piecewise-linear model needs no iteration and is highly efficient.     

南京江北新区青奥片区城南河人行桥（水月桥）设计

*南京江北新区水月桥设计考虑桥梁与周边环境的协调,采用新月的造型,通过平纵弧线变化形成韵律感,体态轻盈。结构上采用不同半径的主辅式钢梁,将结构美观、受力合理很好的结合在一起。主梁截面采用单箱单室钢箱梁截面,梁下设置V型桥墩,辅梁铺设在主梁伸出的挑梁上,产生通透轻盈的视觉效果,达到功能、美学、文化与技术的和谐统一。该桥的景观创意及结构设计可以对类似工程有借鉴作用。*