共查询到19条相似文献，搜索用时 218 毫秒
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基于测量结构水下光纤应变获取冰力的方法首次应用于渤海JZ20-2NW加锥导管架平台,该方法方便进行零点标定,可获取结构总冰力的绝对信息(包括均值和波动值)。首先介绍了JZ20-2NW平台的现场监测系统,主要包括结构水下应变响应记录冰力信息,甲板上部视频记录同步冰情(冰厚、冰速和来冰方向)信息和拾振器记录结构冰振响应;重点分析了由测点应变向结构总冰力的转化方法,并对总冰力进行了初步分析。将无量纲化实测冰力与5种典型冰力计算模型进行了比较,分析结果表明,锥体宽度与海冰厚度比值(简称"宽厚比")对冰力大小及变化起决定作用。 相似文献
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应用ANSYS软件建立了平台和冰相互作用的有限元模型,构建了自升式平台的冰激振动模型,并计算基于2种冰力模型的自升式平台的动力响应。此动力分析方法具有建模方便和计算精度高的特点。以某自升式平台为例,计算了冰和平台结构相互作用的耦合效应,为自升式平台冰激振动安全评估提供了参考依据。 相似文献
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海洋平台结构的冰力作用模型 总被引：10，自引：0，他引：10
首先分析了工程中静冰力计算中普遍应用的Korzhavin -Afanasev公式和Schawz公式 ,提出了统一的静冰力模型 ,给出了挤压破坏、屈曲破坏和弯曲破坏冰力系数函数CI(t)。应用该冰力模型分析了自激振动产生的条件 ,指出冰屈曲破坏和弯曲破坏动冰力可以作为强迫振动模型 ,冰挤压破坏动冰力则需要考虑CI(t)与冰阻尼的耦合效应。最后应用冰力一般模型计算单自由度结构的响应 相似文献
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基于黏聚单元法的抗冰海洋平台与层冰相互作用数值模拟 总被引：1，自引：1，他引：0
通过商业有限元软件LS-DYNA采用黏聚单元法模拟层冰的断裂问题,在IIHR冰池模型试验相同缩尺比参数下对KULLUK抗冰平台受到的冰力进行数值计算,探究冰厚与冰速等冰况参数对平台冰力的影响。计算结果表明,在极地作业平台主要遭遇北极海域冰况范围下,相同冰厚情况时冰速变化对倒锥形结构平台的横向冰力影响不大,而同冰速时冰力随着冰厚的增加接近线性增加。同时将计算所得结果与同条件下IIHR冰池模型试验数据、ARCTEC、ACL非冻结模型冰试验数据、实船数据和通过ISO19906规范中提供的针对大锥面结构受到层冰冰力的经验公式计算所得数据等进行了对比,验证了选用冰参数的可靠性以及该数值模型在模拟大尺度宽锥形平台遭受层冰作用问题中的适用性。 相似文献
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根据水文气象资料求出了辽东湾四个测站的平整冰厚、平整冰抗压强度,进而在选用合理冰力计算公式的基础上,计算了辽东湾海区孤立桩柱上的年极值冰力,并确定了冰力的概率分布模式:年极值冰力不拒绝威布尔、正态、对数正态和极值Ⅰ型分布.又根据冰力模型试验资料得到了孤立桩柱上冰力的短期分布规律:不拒绝极值Ⅰ型分布. 相似文献
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作用于平台桩腿的海冰屈曲破坏冰压力随机过程模型及其参数确定 总被引：2，自引：1，他引：2
冰对结构的作用过程是典型的随机过程。本文在冰压力过程为平稳过程的假设下，从渤海海冰对平台桩腿作用的大量实测冰压力数据中，选取了２１条冰屈曲破坏时的冰压力时程曲线，对它们进行谱分析后，得到了单点冰屈曲破坏的压力随机过程的谱密度，并确定了谱参数及其跟环境要素的关系，依据文献［１］中冰压力沿圆柱面的空间分布，建立了绕桩腿的冰压力随机场模型，并得到了作用于桩腿的总冰力随机过程及其谱密度。本文的研究成果为平台结构冰激随机振动和疲劳累积损伤分析提供了荷载基础 相似文献
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冰激振动及冰荷载动力特性的试验研究 总被引：2，自引：0，他引：2
回顾了解决海冰引起结构振动分析方法的要求，通过室内冰力模型试验得出了冰激振动的重要参数－冰力频率，幅值的特性。研究表明，在低冰速时，冰力频率与冰速对冰厚之比呈线性关系；高冰速时，冰力步与冰速对冰厚之比呈现恒定性，文章还根据试验数据以及统计分析，推荐了冰力幅值计算公式和取值范围。 相似文献
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The effect of the cone spacing of a conieal structure on the ice force is studied by model experiments. The ice force reduction coefficient presented in this paper expresses the relationship between the ice force and the arrangement of cones. The experiments prove that the mode of the ice failure before the boundary of upward-downward bending cone (UDBC) is crushing. A conclusion can also be drawn from the experiments that the ice force on the boundary of UDBC is by far less than that on a vertical pile with the same diameter. Moreover, the ice force frequencies on upright and inve-rted cones are obtained under the field condition of the platform JZ20-2, respectively. The results show that the alterna-tion of the ice force on UDBC can hardly induce resonance of platform JZ20-2. 相似文献
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The shielding effect of the front pile-row on the ice force acting on the hack pile-row is studied by ice force model tests. In the tests, the front pile-row is designed to model jacket legs and the hack pile-row to model the water resisting pipe-phalanx within the jacket. The shielding factor for ice force corresponding to different conditions are given in this paper. The research indicates that there are many factors, including the longitudinal and lateral spacing between the front and hack pile-row, ice attacking angle and the ratio of pile diameter to ice thickness, that influence the shielding effect on ice force. 相似文献
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Some problems concerning the ice forces and ice response spectra are studied from both theoretical and practical points of view. On the basis of structural analysis,the analysis method of ice response spectra is proposed, since it plays an important role in the prediction of maximum structural response in cold regions. And it is illustrated that it is easy to study the structural response to ice using the ice response spectra. 相似文献
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冰对锥体结构作用力的预测模型分析 总被引：4，自引：0，他引：4
通过对作用在锥体结构上的各种静冰力预测模型的介绍,根据大量实验室模拟测试数据,运用直方图对比、无量纲效应分析及统计分析等手段,对有关静冰力计算公式进行了全面分析与确认.所采用的分析方法为我国渤海辽东湾JZ20-2平台原型冰荷载测试数据与预测模型的比较,为利用原型观测数据建立适合于我国渤海环境条件下冰对锥体结构作用力预测模型,提供了有效的技术手段,同时也为有冰海域结构物的可靠性分析提供了各统计量有价值的参考数据. 相似文献
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Shi Qingzeng Chen Xing
Professor Dept. of Ocean Eng. Naval Arch Tianjin Univ. Tianjin
Lecturer Dept. of Ocean Eng. Naval Arch. Tianjin Univ. Tianjin 《中国海洋工程》1995,(2)
Spectrum and self-excite characters are the two significant characters of the dynamics of sea ice. The spectrum character of sea ice is mainly shown by the spectrum of ice force. The spectrum character of the sea ice is its intrinsic attributes. When the spectrum of ice force from the dynamic response of ice and structure interaction are evaluated, the effect of dynamic character of the structure must be eliminated. In this paper, the ice force spectrum at Bohai Bay and Liaodong Bay is evaluated from the displacement and strain responses of a single degree and a multi-degree freedom structure. The evaluated ice force spectrum can be used to define the spectrum character of ice in the analysis of ice induced vibration. 相似文献
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A New Model for Ice Forces on A Conical Structure 总被引：1，自引：0，他引：1
The ice force is an important factor to be taken into account for offshore structures in cold regions, and the calculation method of the ice force is meaningful for the offshore structure design. The cone is now used as an optimal ice-resistant structure because it can cause bending failure of the ice sheet. The interaction between an ice sheet and a conical structure is studied in this paper and Croasdale‘s model is modified based on field observations. The newly built model separates the ice sheet into the emersed part and the floating part, and the equilibrium analyses are canied out respectively. The bending moment distribution of the ice sheet is analyzed for the determination of the position of bending failure, which serves as a supplementary restraint. The analytic solution of the ice foree on a conical structure is obtained it is verified with the experimental data of previous researches. 相似文献