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服役中后期导管架海洋平台结构可靠性评估 总被引:2,自引:0,他引:2
为使海洋平台在服役中后期内安全服役,有必要对现役平台进行安全评估.以埕岛海域某服役中后期导管架式海洋平台为例,研究其可靠性变化问题.首先,根据平台状况资料,考虑平台结构的腐蚀、冲刷等损伤随年限增加而变化的情况,建立了反映结构实际动力特性的有限元模型;然后,考虑结构非线性,沿平台的不同方向逐级施加载荷,得到平台的桩顶位移与横向载荷的关系曲线,根据该曲线得出平台不同时间的极限承载力;最后,考虑冰荷载的不确定性,利用Monte-Carlo法研究平台每年的失效概率及可靠度指标,得到可靠度指标随服役年限变化的曲线,进而预测平台结构在未来服役期内的可靠度. 相似文献
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以保障海洋平台结构整体安全度,延长海洋平台使用寿命为目的,提出基于机器学习算法的海洋平台结构整体安全度评估方法。基于层次全息建模理论,从环境、技术状态、功能模块等6个角度出发,共选取22个评估指标构建海洋平台结构整体安全度评估指标体系;采集评估指标数据,利用数据清洗与转换等处理方法预处理指标数据。将海洋平台结构整体安全度划分为5个等级。利用机器学习算法中的卷积神经网络构建评估模型,将评估指标数据作为输入,指标数据特征提取与数据降维等过程输出海洋平台结构整体安全度评估等级。实验结果显示该方法指标数据利用率较高,可准确评估海洋平台结构整体安全度,提升海洋平台使用的安全性。 相似文献
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研究海洋钻井平台结构安全性评估程序集成技术,介绍集成系统的实现流程和功能模块。该系统是以Orient平台为基础开发的一套集成化仿真软件,实现包括前后处理的水动力性能预报和结构安全性分析过程。具有方便的使用界面、合理的输入输出接口、优良的计算结果实时显示和后处理功能,提供标准规范化的接口,使设计过程规范化和自动化,在设计阶段即可把握设计方案的综合性能,提高工作效率。 相似文献
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定期对在役固定平台进行状态评估,对于平台的安全运行至关重要。描述了对在役平台进行状态评定的基本步骤以及须要考虑的环境条件,并从结构评估的角度,重点阐述了平台结构模拟的一般要求及细节考虑,对平台的静力、地震响应、疲劳以及基础强度的评价等,给出了分析评价的基本考虑和要求。 相似文献
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基于结构疲劳、断裂控制原理,平台结构疲劳裂纹产生、扩展规律以及修复更新可靠性评估技术,对平台结构进行安全寿命评估及维修决策方法进行了初步研究,给出了中后期服役海洋平台的安全寿命评估与维修决策基本思路和方法;提出了平台安全寿命评估及维修决策方法的基本框架,并依靠剩余强度和裂纹扩展计算来对已有损伤的结构进行安全寿命评定,给出科学的检维修方案,以保证结构安全、经济、可靠地运行。 相似文献
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抗冰海洋平台的全寿命优化设计I-理论与模型 总被引:1,自引:1,他引:0
文章基于投资—效益准则,建立了抗冰平台全寿命总费用最小的优化设计模型;考虑了多种类型的性能要求(结构、设备、人员),并建立了相关判据;提出了包括结构的初始费用、维修费用和期望损失费用的冰区海洋平台全寿命总费用评估模型;提出了平台结构主要功能的确定及描述方法、相应的功能失效损失值估计模型。 相似文献
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文章主要介绍了海洋平台常用流量计的原理和特点,结合海洋平台的特点叙述了流量计选型时的注意事项,并给出了海洋平台常用流量计的选型原则和计算方法,为海洋平台选出最合适的流量计提供了一种方案。 相似文献
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通过对海上石油平台防污染管理的相关国际公约、国内法规的梳理,分析了国际公约和国内法规的异同点,并结合管理现状提出了建议。 相似文献
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ZHANG Zhao-de CHEN Shuai 《船舶与海洋工程学报》2007,6(3):1-5
Structural cracks can change the frequency response function (FRF) of an offshore platform. Thus, FRF shifts can be used to detect cracks. When a crack at a specific location and magnitude occurs in an offshore structure, changes in the FRF can be measured. In this way, shifts in FRF can be used to detect cracks. An experimental model was constructed to verify the FRF method. The relationship between FRF and cracks was found to be non-linear. The effect of multiple cracks on FRF was analyzed, and the shift due to multiple cracks was found to be much more than the summation of FRF shifts due to each of the cracks. Then the effects of noise and changes in the mass of the jacket on FRF were evaluated. The results show that significant damage to a beam can be detected by dramatic changes in the FRF, even when 10% random noise exists. FRF can also be used to approximately locate the breakage, but it can neither be efficiently used to predict the location of breakage nor the existence of small hairline cracks. The FRF shift caused by a 7% mass change is much less than the FRF shift caused by the breakage of any beam, but is larger than that caused by any early cracks. 相似文献
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随着海洋石油产业的蓬勃发展,海洋采油平台组块结构向大型化发展已成为必然趋势。然而中国现有的多数平台组块建造场地设计等级较低,已不能满足大吨位海洋平台组块的建造需要,多数场地的超负荷使用给安全生产带来巨大隐患。以采用滑块压柱式滑道装船为例,介绍高桩承台滑道在平台组块滑移装船过程中受力分析及安全评价的方法。 相似文献
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Second-order estimates to measure platform reliability are generated and used to provide an additional space to select safety
margins appropriate to the owner's perception or for risk-averse managers. The aleatory and epistemic uncertainties in the
parameters of an offshore platform are explicitly considered in the reliability analysis and the platform structural reliability
becomes a random variable, assessing then the beneficial effects of a reduction on these uncertainties. One of these benefits
is for risk-aversive managers who often demand additional room to make conservative decisions regarding reliability estimations.
Proposed here is a procedure to generate the frequency diagram of platform reliability with the use of confidence bounds to
support reliability and cost decisions based on percentiles instead of mean values. The concepts are illustrated through a
typical offshore platform in Mexico. The frequency diagram of the platform reliability index is built for several alternative
designs and three levels of epistemic uncertainty. The results may be applied for decision making on new designs and also
on the assessment and optimal inspection, retrofit, and decommissioning of existing platforms. 相似文献
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William G.McDougal 《水道港口》2010,31(5):319-319
A-Jacks are concrete armor units that are used in both open channel and coastal applications.In open channel applications,they are used for bank and toe protection,flow and grade control,bridge pier scour protection,energy dissipation,and habitat.These small units may be fabricated in standard block machines.In coastal applications,A-Jacks are used in breakwaters,jetties,revetments,and habitat development.Coastal units are generally much larger and more robust than the small open channel units.This paper focuses on coastal applications and in particular,combines results on three topics:(1)recent hydraulic model studies,(2)alternative fabrication methods,and(3)bundle placement construction methods.Hydraulic models studies were conducted that examined the standard random and uniform placement methods,and also the bundle placement method.In bundle placement,3~20 A-Jacks are banded together,lifted with a spreader bar,and placed as a single crane pick.This significantly decreases installation time during construction.It also provides a more hydraulically stable placement technique.The hydraulic model tests examined the bundle stability in random waves for cases where the binding remains in tack and is removed.The geometry of A-Jacks enables a variety of fabrication techniques.One option is to fabricate the A-Jacks as two pieces using flat forms and then grout the two pieces together.Flat forms may be used in conventional block machines for A-Jacks sizes up to 1.3 m.Larger sizes may be wet cast in flat forms or gang forms.The A-Jacks geometry has been recently modified to increase grouting efficient and strength.Large A- Jacks may also be cast in a single piece using "clam shell" type forms. 相似文献