碾压混凝土单轴抗压强度的数值模拟

碾压混凝土的强度关系到碾压混凝土结构的安全.采用随机骨料模型模拟碾压混凝土的细观结构,利用有限元方法数值模拟碾压混凝土试件单轴抗压的细观损伤断裂,并对其单轴抗压破坏过程进行了研究.     

自增强外压球壳应力强度计算与分析

基于弹塑性变形理论,对厚壁外压球壳弹塑性变形进行了分析,研究结果为自增强技术在外压球壳上的应用提供了计算方法与数值依据。利用Abaqus对7000m载人潜器上一单开孔球壳进行了自增强模拟计算,计算结果表明,自增强处理后球壳上及穿舱件盘处结构应力下降明显,结构应力分布趋于均匀统一,有助于提高球壳体疲劳寿命。     

低速船用柴油机整机吊具可靠性的有限元分析

船用低速柴油机的吊具受力复杂且不规则,传统设计通过简化模型计算其理论强度,与实际工况误差较大。文中利用有限元软件ANSYS分析,以6S42MC整机吊具为研究对象,采用三维软件PROE建立该吊具模型并对其进行有限元分析,根据分析所得的应力分布和形变情况,判断吊具的可靠性;通过改变吊具的结构尺寸,对减少吊具应力的方法进行探究;对吊具进行拓扑优化。分析结果表明,文中方法可以检验吊具的安全性,提高经济效益,同时为吊具的理论设计提供了依据。     

深水起重铺管船横摇运动性能分析(英文)

For a large floating vessel in waves,radiation damping is not an accurate prediction of the degree of roll unlike other degrees of freedom motion.Therefore,to get the knowledge of roll motion performance of deepwater pipelay crane vessels and to keep the vessel working safety,the paper presents the relationship between a series of dimensionless roll damping coefficients and the roll response amplitude operator(RAO).By using two kinds of empirical data,the roll damping is estimated in the calculation flow.After getting the roll damping coefficient from the model test,a prediction of roll motion in regular waves is evaluated.According to the wave condition in the working region,short term statistics of roll motion are presented under different wave parameters.Moreover,the relationship between the maximal roll response level to peak spectral wave period and the roll damping coefficient is investigated.Results may provide some reference to design and improve this kind of vessel.     

Energy efficiency optimization analysis of fuel cell/lithium battery hybrid ship based on whale optimization algorithm北大核心CSCD

[目的]为提升船舶的能源利用率,对多因素影响下的燃料电池/锂电池混合动力船舶能效优化方法进行分析。[方法]基于Matlab/Simulink仿真建模软件,建立对象船舶的能效仿真模型,研究通航环境要素对船舶能效的影响。考虑动力源特性和船舶功率需求,提出基于模糊逻辑的功率分配策略,以优化系统能量流动。然后在此基础上,以系统总能耗最低为优化目标,建立考虑多因素的船舶航速非线性优化模型,采用鲸鱼优化算法开展优化模型动态寻优,并进行不同航行方法和航行时间约束下的能效优化分析。[结果]结果显示,在总航行时间不变的情况下,采用所提的考虑多因素的船舶能效优化方法可以降低船舶5.04%的总能耗和13.16%的燃料电池氢气总消耗。[结论]所述方法对船舶节能减排具有积极的作用,同时对提高船舶续航力和经济性具有重要意义。     

石油修井机操控室人机分析

本文针对因人机工程模块中缺乏中国大陆成年人数字模型而导致CATIA软件在车辆人性化设计适用性差的现象,以GB10000-1988和石油修井机操控室结构设计参数需求为依据,建立了中国大陆成年男子P95、P50和P5人体数字模型和石油修井机数字化样机,完成了视野域、可操作域和坐姿舒适性人机工程分析,为提升国产汽车操作方便性、可靠性与安全性提供了理论依据。     

输油管清蜡车操作人员作业姿态分析

本文针对输油管清蜡车操作人员传统的作业姿态,应用CAITA选取合适的人体模型并调整为正常作业姿态,完成舒适度评估、上肢评价与视野分析,并结合分析结果提出改进方案,为其后进行输油管清蜡车操作空间设计提供了客观的理论指导依据。     

轨道吊远程操作方案

轨道吊远程操作系统作为全自动码头的基础技术之一,对港口发展有着重要意义。在对大连港现有设备介绍的基础上,详细介绍远程操作方案的功能和具体实施方案。该方案取得良好的经济效益。     

An approach for Baltic Dry Index analysis based on empirical mode decomposition

The bulk shipping market is seasonal, cyclical and highly volatile. Due to the nonstationary and nonlinear nature of price series and the complexity of influencing factors, it is difficult to analyse the fluctuations in the bulk shipping market. In this study, a method based on empirical mode decomposition (EMD) is proposed to investigate the volatility of the Baltic Dry Index (BDI). In this method, the original freight price series is decomposed into several independent intrinsic modes, using EMD first. Then, the intrinsic modes are composed into three components: short-term fluctuations caused by normal market activities, the effect of extreme events and a long-term trend. Numerical experiments indicate that the proposed method can effectively reveal the characteristics of bulk freight price series with different economic meanings and decrease error accumulation. Meanwhile, by decomposition of intrinsic modes, the complexity of the model formulation can be controlled and the operability of the model can be improved.     

基于CST的金属腔体电磁环境仿真分析

本文将CST电磁仿真软件应用于金属腔体电磁兼容问题的研究中,利用该软件构建物理模型,并对金属腔体内的电磁环境进行仿真计算。仿真结果与理论计算、实测数据吻合较好,为金属腔体电磁环境的预测和评估提供了有效的依据,可以作为相关工程应用参考。