平台运动下悬链线立管涡激振动响应特性分析

悬链线立管会在半潜平台运动带动下出现涡激振动现象,对立管疲劳寿命造成影响.借助海工结构物动力分析软件Orcaflex建立立管模型,使用Iwan-Blevins尾流振子模型进行数值模拟.通过与试验结果对比验证了该方法的可行性.同时建立实尺度悬链线立管模型,并考虑背景海流的影响,分析平台垂荡、纵荡运动下的立管涡激振动响应和疲劳损伤.研究表明,平台运动产生的非定常流场将引起悬链线立管发生涡激振动现象,并在背景洋流激励的基础上增大疲劳损伤,在立管结构实际工程设计时应予以关注.     

Validation of a dynamic mooring model coupled with a RANS solver

Standard design procedures and simulation tools for marine structures are aimed primarily for use by the offshore oil and gas. Mooring system restoring forces acting on floating offshore structures are obtained from a quasi-static mooring model alone or from a coupled analysis based on potential flow solvers that do not always consider nonlinear mooring-induced restoring forces, fluid structure interactions, and associated hydrodynamic damping effects. This paper presents the validation of a dynamic mooring system analysis technique that couples the dynamic mooring model with a Reynolds-averaged Navier-Stokes (RANS) equations solver. We coupled a dynamic mooring model with a RANS equations solver, and analyzed a moored floating buoy in calm water, regular and irregular waves and validated our motion and mooring force predictions against experimental measurements. The mooring system consisted of three catenary chains. The analyzed response comprised decaying oscillating buoy motions, linear and quadratic damping characteristics, and tensile forces in mooring lines. The generally favorable comparison of predicted buoy motions and mooring forces to experimental data confirmed the reliability of our implemented coupling technique to predict system response. Additional comparative results from a potential flow solver demonstrated the benefits of the coupled dynamic mooring model with RANS equations. The successful validated tool of coupling the dynamic mooring model with the RANS solver is available as open source, and it shows the potential of the coupled methodology to be used for analyzing the moored offshore structures.     

Theoretical and numerical analysis of bending behavior of unbonded flexible risers

This paper presents theoretical and numerical study on bending properties of unbonded flexible risers. To capture nonlinearities in layer's sliding, the stress component due to slip-stick behavior is considered and energy conservation principle considering sliding-caused heat consumption is employed in the analytical model. Besides, a finite element model estimating mechanics of unbonded flexible risers' bending is proposed. In the finite element model, couplings between bending moment–curvature and axial stress as well as contact interaction among layers and tendons have been considered. The theoretical and numerical results were validated against the corresponding experimental data in literature and mutually compared in analyzing nonlinear bending behavior of flexible risers. Moreover, the impacts of axisymmetric loads on riser's bending behavior have been further investigated.     

柔性基层在襄十高速公路上的应用

用沥青稳定粒料作基层在我国高等级公路施工中为数不多，无论从配合比设计到工程的实体施工都没有成功的经验可以借鉴，我公司联合武汉理工大学土木工程系。借鉴于国外牛津试验路级配并结合我国石料加工实际情况，在襄十高速公路上对柔性基层作了尝试。本文从柔性基层的配合比设计到施工技术都作了较为详细的阐述。     

从六沾铁路接触网验收对施工介入的思考

总结六沾铁路接触网验收工作中发现的具有代表性的施工质量问题,从接触网设计和工程开工准备阶段、施工阶段、调试阶段及接触网器材验收检验等方面,提出施工介入的重点工作,为接触网设备接管后的运行安全、方便管理、节省维护成本创造条件。     

弓网动态接触压力测量方法研究

在电气化铁路中,弓网接触压力对机车供电可靠性及质量起着重要作用。通过总结分析国内外测量方法,对影响弓网接触压力的因素及受电弓受力情况进行分析,设计一种检测弓网动态接触压力及机车运行方向摩擦力的装置,并对误差进行分析。     

对高速铁路动车组停在接触网分相区内救援办法的探讨

高速铁路电分相采用锚段关节式电分相后,由于中性段长度较器件式增长,动车组停在分相区的概率大大增加,给动车组停在电分相无电区时的救援工作带来新的问题。根据我国已开通运营的京津、武广、郑西高速铁路关节式电分相结构,探讨动车组停在分相无电区后利用接触网开关救援办法,并对完善我国高速电气化铁路电分相设计提出建议。     

关于接触网动态检测缺陷处理程序的探讨

针对接触网动态检测缺陷处理程序和方法进行了分析和探讨,提出动态缺陷的处理程序包括数据分析、缺陷点查找、缺陷处理、效果观察、总结反馈5个基本程序,对于每个程序给出了处理方法和注意事项。     

柔性隔振系统功率流传递特性研究

由于基础和隔振器存在着动力耦合,经典隔振理论的局限性日益突出,从而出现了将基础简化为欧拉梁、柔性板、圆柱壳等。本文将基础简化为两端固支弹性梁,运用四端参数法推导了单层柔性隔振系统传递功率流,并运用电力类比法对推导结果进行了验证。通过数值仿真,分析了偏心激励对功率流传递特性的影响,并将功率流与振级落差频谱曲线进行了比较。结果表明：偏心激励会激发系统的高阶模态,基础的刚性会影响振级落差对功率流的估计。     

Evaluating Flexible Transport Solutions

Abstract

Flexible transport services (FTS) have been of increasing interest in developing countries as a bridge between the use of personal car travel and fixed route transit services. This paper reports on findings from a recent study in Queensland Australia, which identified lessons from an international review and implications for Australia. Potential strategic directions, including a vision, mission, key result areas, strategies, and identified means of measuring performance are described. Evaluation criteria for assessing flexible transport proposals were developed, and approaches to identifying and assessing needs and demands outlined. The use of emerging technologies is also a key element of successful flexible transport services.