桥梁抗震分析方法

介绍了现行桥梁抗震计算分析的几个方法．确定性方法中的弹性静力法，静力弹塑性分析，反应谱法，时程分析法；概率性抗震分析方法中的随机振动虚拟激励法．并对各个方法的优缺点加以说明，着重介绍了随机振动虚拟激励的基本原理和特点．最后提出了有待进一步研究的几个问题．     

Time-dependent fuzzy random location-scheduling programming for hazardous materials transportation

The tremendous use of hazardous materials has promoted the economic development, which also brings about a growing risk causing a widespread concern. In this work, we consider a location-scheduling problem on hazardous materials transportation under the assumption that transportation risks are time-dependent fuzzy random variables. First, we formulate a scheduling optimization model and design a fuzzy random simulation based genetic algorithm to optimize the departure time and dwell times for each depot–customer pair. Then we establish an expected value model and design a modified particle swarm optimization algorithm to minimize the en route risks and site risks. Finally, numerical examples are given to illustrate the effectiveness of the proposed models and algorithms.     

船舶在规则纵浪中的混沌运动

Parametric resonance can lead to dangerously large rolling motions, endangering the ship, cargo and crew. The QR-factorization method for calculating (LCEs) Lyapunov Characteristic Exponents was introduced; parametric resonance stability of ships in longitudinal waves was then analyzed using LCEs. Then the safe and unsafe regions of target ships were then identified. The results showed that this method can be used to analyze ship stability and to accurately identify safe and unsafe operating conditions for a ship in longitudinal waves.     

桁架式Spar平台在波浪中的运动预报与实验测量

基于细长体水动力公式和刚体全非线性运动方程,以及桁架式Spar平台主体与其锚泊系统相互耦合的力和位移边界条件,建立了桁架式Spar平台在波浪中的运动响应预报模型,对其在波浪中的运动和锚泊力进行了预报。通过运动光学测量系统和拉力传感器在哈尔滨工程大学水池对Spar平台模型在波浪中的运动和锚泊力进行了测量。数值预报结果和实验测量进行了比较,结果表明二者符合得很好。     

基于数值模拟的盾构隧道地表变形的可靠度分析

在分析盾构法隧道引起地表变形原因的基础上 ,指出隧道围岩参数及盾构掘进对岩土体的扰动都具有很大的随机性 ,因而导致地表变形具有不确定性。利用ANSYS有限元程序进行数值模拟试验取得地表变形数据 ,在此基础上设定主要影响因素为随机输入变量 ,地表变形为随机输出变量 ,采用蒙特卡洛方法模拟出地表变形的统计值 ,并计算了失效概率及可靠度 ,为隧道施工地表变形的可靠性分析提供了一条新的途径     

考虑相干性的四轮随机路面输入模型的研究

借鉴DieterAmmon的路面相干函数模型,通过实测的路面信号验证该相干函数模型的可行性,应用遗传算法求解左右轮输人间的传递函数,建立四轮随机路面输入模型。最后对生成路面功率谱密度进行验证,结果表明所构建的路面文件满足相关要求。     

出口箱随机入港下的集装箱码头泊位调度

针对港口竞争环境下产生的出口箱随机入港分散堆放策略,综合考虑出口箱堆场堆存位置分布以及泊位分配与集卡路径之间的相互影响,提出了出口箱随机入港下的集装箱码头泊位调度问题,并以船舶停靠泊位为决策变量,以所有集卡行驶总路径最短为目标函数,建立了泊位调度优化模型。采用基于遗传算法的启发式算法,对遗传算子进行了改进设计。最后,应用算例对模型和算法进行仿真实验,并将优化后结果与传统的先到先服务泊位调度模式进行比较分析。结果表明:以集卡行驶总路径为考量的泊位调度优化可使集卡行驶总路径缩短11.51%,可明显降低港口的运营成本,同时获得合理的泊位分配计划,模型和算法可行有效。     

基于离散元法细观分析的隧道掘进对砾石地层扰动的初步研究

砾石土地层是一种较为特殊的地质环境,其复杂的物质结构及力学性质在隧道工程中引起了广泛的关注。利用一种随机多边形生成法建立砾石土地层;横断面开挖采用删除隧道周围部分颗粒模拟地层损失的方法;纵断面开挖采用设置支护墙体并后退的方法,以此开展横断面不同含石量和不同隧道埋深条件下地层位移、颗粒微观转动及受力分析;纵断面不同含石量条件下地层位移、开挖面支护压力的研究。结果表明:1)开挖造成的砾石颗粒位移显示地层受扰动的范围随着碎石土地层含石量增高而逐渐缩小;2)支护压力的变化趋势随着模拟开挖面支护墙体后退先大幅下降后趋于稳定,且含石量越低,支护压力越大;3)随着隧道埋深的增加,地表最大沉降值减少,且二者之间呈线性关系。     

Data-driven train set crash dynamics simulation

Traditional finite element (FE) methods are arguably expensive in computation/simulation of the train crash. High computational cost limits their direct applications in investigating dynamic behaviours of an entire train set for crashworthiness design and structural optimisation. On the contrary, multi-body modelling is widely used because of its low computational cost with the trade-off in accuracy. In this study, a data-driven train crash modelling method is proposed to improve the performance of a multi-body dynamics simulation of train set crash without increasing the computational burden. This is achieved by the parallel random forest algorithm, which is a machine learning approach that extracts useful patterns of force–displacement curves and predicts a force–displacement relation in a given collision condition from a collection of offline FE simulation data on various collision conditions, namely different crash velocities in our analysis. Using the FE simulation results as a benchmark, we compared our method with traditional multi-body modelling methods and the result shows that our data-driven method improves the accuracy over traditional multi-body models in train crash simulation and runs at the same level of efficiency.     

大型桥梁施工预测控制系统研究

为了保证实际施工中结构各节段在构形和受力状态两方面逼近施工节段合理状态,避免事故发生,确保工程高效、安全、优质,基于归一化映射规则,研究灰因和白果,提出了适应任意灰序列的灰预测模型NGM(1,1);研究遗传算法的随机摄动法,提高向前滚动优化效率;研究强度、稳定性的同步分析技术,保证施工过程强度、稳定性安全。在此基础上,论述了大型桥梁施工控制系统的理论特色,以实例说明了其应用,论证了其正确性。