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Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

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China Ocean Engineering 2024年第2期38卷 255-270页

作者： ZHANG Long ZHAO tian-feng College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing 102249China

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating *** harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue *** structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue ***,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural ***,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into *** research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

关键词： SCR girth weld random vibration self(cross)power spectrum structural stress method biaxial fatigue damage

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“偷师”大自然:仿生海洋防污技术

科学通报 2022年第1期67卷 8-10页

作者：靳会超田丽梅赵杰任露泉吉林大学工程仿生教育部重点实验室长春130022 吉林大学威海仿生研究院威海264207

海洋生物污损指的是海洋中的细菌、藻类、藤壶等在水下表面附着和生长的一种现象[1].生物污损会增加船体阻力、加速表面腐蚀、破坏螺旋桨,导致额外的油耗和过高的维护成本.额外的油耗加剧了CO2、SO2等气体的过量排放,影响各国政府对"碳... 详细信息

海洋生物污损指的是海洋中的细菌、藻类、藤壶等在水下表面附着和生长的一种现象[1].生物污损会增加船体阻力、加速表面腐蚀、破坏螺旋桨,导致额外的油耗和过高的维护成本.额外的油耗加剧了CO2、SO2等气体的过量排放,影响各国政府对"碳中和"目标的实现.海洋生物污损还对跨海大桥、钻井平台、养殖网箱、海底管道等多种水下设施具有负面影响[2].据统计,海洋生物污损每年给全球海洋工业造成的损失超过150亿美元[3].传统的防污涂层一般通过释放有毒物质(例如氧化铜、三丁基锡等)杀死污损生物来达到防污效果.

关键词：海洋生物污损跨海大桥防污效果有毒物质海洋防污全球海洋污损生物表面腐蚀

Frost heaving and crack initiation characteristics of tunnel rock mass in cold regions under low-temperature degradation

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Journal of Mountain Science 2024年第8期21卷 2844-2854页

作者： CHEN Wenhua XIANG tian School of Civil Engineering Beijing Jiaotong UniversityBeijing 202303China

Water freezing in rock fractures causes volumetric expansion and fracture development through frost *** study introduces a novel analytical model to investigate how uneven freezing force and surrounding rock pressure influence fracture initiation,based on mass conservation,elasticity,and water-ice phase transition principles.A model for rock fracture initiation considering freezing temperature,uneven freezing expansion,in-situ stress,and lateral pressure was proposed based on fracture *** for stress intensity factors were developed and validated using the phase field *** effects of rock elastic modulus anisotropy and critical fracture energy density on fracture initiation were also *** results show that the values of KI and KII exhibit an upward trend as the freezing temperature,uneven expansion,in-situ stress,and lateral pressure *** uneven freezing expansion has the most significant influence on KI and KII values among these *** the uneven freezing expansion coefficient increases to 0.5,the fracture initiation mode shifts from tensile fracture to shear *** the lateral pressure coefficient increases to 1,the fracture initiation mode shifts from tensile fracture to shear *** elastic modulus anisotropy causes fractures to propagate in a clockwise direction,forming a'butterfly'*** fracture energy density an isotropy causes counterclockwise deviation in propagation direction,resulting in branching paths and an'H'-shaped pattern.

关键词： Rock fractures Fracture water Uneven freezing expansion Phase field method Initiation angle Anisotropy

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水利工程档案管理的常规问题和对策探讨

河南水利与南水北调 2019年第8期48卷 95-96页

作者：田利梅河南省白沙水库管理局

水利工程是促进我国社会经济发展的重要因素,对区域生态环境稳定发展起到了重要意义。在水利工程中,水利工程档案作为保证工程质量的核心因素,更是工程关键所在。文章首先对加强水利工程档案管理的意义进行阐述,从管理意识问题、管理体... 详细信息

水利工程是促进我国社会经济发展的重要因素,对区域生态环境稳定发展起到了重要意义。在水利工程中,水利工程档案作为保证工程质量的核心因素,更是工程关键所在。文章首先对加强水利工程档案管理的意义进行阐述,从管理意识问题、管理体系问题、管理职责问题三个方面,对水利工程档案管理的常规问题进行解析,并以此为依据,提出水利工程档案管理常规问题的处理对策。

关键词：水利工程档案管理常规问题对策

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松软地面机器系统研究进展

农业机械学报 2015年第5期46卷 306-320页

作者：李建桥黄晗王颖田丽梅任露泉吉林大学工程仿生教育部重点实验室长春130022 装甲兵技术学院基础部长春130117

松软地面机器系统的理论研究,对农业、林业、矿业和军事等领域作业机械的发展具有重要的科学意义和工程应用价值。本文总结了松软地面机器系统基础理论,以及松软干沙地面轮壤关系最新研究进展;从土壤动物形态、结构和柔性方面阐述仿生... 详细信息

松软地面机器系统的理论研究,对农业、林业、矿业和军事等领域作业机械的发展具有重要的科学意义和工程应用价值。本文总结了松软地面机器系统基础理论,以及松软干沙地面轮壤关系最新研究进展;从土壤动物形态、结构和柔性方面阐述仿生脱附减阻机理,综述了地面机械触土部件的仿生理论基础;概括了用于地面力学特性测试的技术方法和地面机器系统研究的土槽测试系统;分析归纳了数值模拟方法在地面机器系统研究中的进展;进而对松软地面机器系统理论方法在触土部件和车辆行走机构中的应用研究进行了展望。

关键词：松软地面地面机器系统土槽数值模拟仿生

某国道水泥混凝土路面病害分析及加铺方案比选研究

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公路工程 2019年第3期44卷 138-142页

作者：朱孝笑田莉梅北京交通职业技术学院北京102200 廊坊师范学院建筑工程学院河北廊坊065000

结合某国道水泥混凝土路面现状,分析了水泥混凝土路面常见的几种病害,并对目前常用的3种加铺方案做了比选研究。研究认为,分离式加铺方案优于复合式加铺方案和直接式加铺方案,但在实际的工程中,加铺方案的选用还需根据具体情况来确定。

关键词：混凝土路面病害加铺方案

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某露天铁矿采场边坡优化设计可靠度分析

金属矿山 2016年第4期45卷 132-135页

作者：田莉梅张兆财廊坊师范学院建筑工程学院河北廊坊065000 北京科技大学土木与环境工程学院北京100083

根据某露天铁矿采场地质条件和开采形成的边坡形态,共选择4个典型剖面,设计了6个边坡角优化方案。采用Morgenstern-Price法计算边坡安全系数,所得安全系数均大于1.0,但极限平衡法未考虑岩土体参数的空间变异性,无法全面反应边坡的安全... 详细信息

根据某露天铁矿采场地质条件和开采形成的边坡形态,共选择4个典型剖面,设计了6个边坡角优化方案。采用Morgenstern-Price法计算边坡安全系数,所得安全系数均大于1.0,但极限平衡法未考虑岩土体参数的空间变异性,无法全面反应边坡的安全性。鉴于可靠性分析方法的优越性,采用蒙特卡洛模拟法进行随机模拟试验,分析各边坡设计方案所得平均安全系数与上述极限平衡法求得的安全系数相接近,但破坏概率均在可接受的破坏概率阈值之下,可靠性指标均大于可接受的可靠性指标最小值,满足工程稳定性要求。

关键词：边坡可靠度蒙特卡洛模拟法设计优化

Numerical investigation on characteristics of interfacial wave of liquid film in gas-liquid two-phase flow using OpenFOAM

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Chinese Journal of Aeronautics 2024年第2期37卷 233-248页

作者： Xiaoqi MA Yueshe WANG Jiaming tian State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Liquid film cooling as an advanced cooling technology is widely used in space *** operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket *** stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right *** to improve the stability of thin film has become a hot *** view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical *** effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied *** can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this ***,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of ***’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this ***,the maximum height and maximum slope angle of wave will level off as the gas velocity ***,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.

关键词： Interfacial wave Gas-liquid Two-phase flow VOF model OpenFOAM

Prediction of ball-on-plate friction and wear by ANN with data-driven optimization

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Friction 2024年第6期12卷 1235-1249页

作者： Alexander KOVALEV Yu tian Yonggang MENG State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

For training artificial neural network(ANN),big data either generated by machine or measured from experiments are used as input to"learn"the unspecified functions defining the *** experimental data are fed directly into the optimizer allowing training to be performed according to a predefined loss *** predict sliding friction and wear at mixed lubrication conditions,in this study a specific ANN structure was so designed that deep learning algorithms and data-driven optimization models can be *** ball-on-plate friction and wear data were analyzed using the specific training procedure to optimize the weights and biases incorporated into the neural layers of the ANN,and only two independent experimental data sets were used during the ANN optimization *** the training procedure,the ANN is capable to predict the contact and hydrodynamic pressure by adapting the output data according to the tribological condition implemented in the optimization algorithm.

关键词： machine learning deep learning artificial neural network mixed lubrication