排序方式: 共有73条查询结果,搜索用时 31 毫秒
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This paper presents a practical procedure for creating finite element (FE) model for vibration analysis of cruise ships. The most preferable FE modelling approaches are studied and discussed through case studies of common ship structures, which cover the range from low to high frequencies. The application of homogenized equivalent single layer (ESL) theory based equivalent element for stiffened panel is extended to local forced vibration analysis, where inertia induced interaction between plate and stiffener occurs. Modal method is used with an energy-based correction for accounting the plate-stiffener interaction into modal properties. Case study results reveal that mesh density of one 4-node element per web frame spacing is suitable for global FE-model when vibration analysis is limited to global hull girder modes. For such modes it is sufficient to only include the membrane stiffness of stiffened panels. For investigating the response at higher frequencies, bending properties of stiffened panel should be included and mesh density should be at least two elements per web frame spacing. Then forced vibration analysis can be performed with an excellent accuracy up to frequencies about one third of the local plate natural frequencies between the stiffeners. Beyond that, the influence of the local plate vibration becomes more significant in panel vibration, making the ESL-theory based element limited. With the applied correction method, the validity of the ESL-model can be extended to approximately two thirds of the local plate natural frequency. 相似文献
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To optimize offshore wind turbine (OWT) design, an engineering tool has been developed allowing for a detailed investigation of the effects of nonlinear soil stiffness and damping on foundation dynamics. We have studied the response of a vertically oscillating offshore wind monopile foundation in a realistic soil profile subjected to loads between 1 and 200 MN in the frequency range 0–10 Hz with pseudo-static and equivalent linear dynamic model. The non-linear soil behaviour is modelled with an equivalent linear method with shear modulus reduction and damping curves as input. The tool is verified and validated by comparison with elasto-dynamic model and experiments. With increasing load amplitudes foundation stiffness increases and damping decreases. For large load amplitudes the lower part of the pile foundation contributes more to foundation damping. The results indicate the nonlinear foundation stiffness and damping can be modelled rationally by combining stiffness and hysteretic damping from nonlinear static tools with apparent mass and radiation damping from elasto-dynamic analysis. The tool can be used to compute soil springs and dampers based on laboratory-based soil stiffness and damping. 相似文献
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并列双幅桥面斜拉桥属于空间体系结构,理应应用三维空间有限元程序来完成其静力分析。作者采用了等效双悬臂梁的机构进行平面等效模拟以,使塔、墩、梁、索四者处于共平面工作,从而可以应用常用的平面杆系专用程序,使计算大为简化,且具有较满意的精度。 相似文献
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黄宝瀛 《铁道劳动安全卫生与环保》1995,22(2):119-122
等半径双回转式通风管道是一种新型活动管道设计方案。该设计两次运用回转接头,解决了局部排风系统中罩口的机动功能,已被广泛地应用于现场排尘排毒工程中,使用方便,效果良好。 相似文献
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南京长江第二大桥南汊主桥流线形薄壁扁平钢箱梁分析的新方法 总被引:8,自引:0,他引:8
本文介绍南京长江第二大桥南汊主桥流线形扁平薄壁钢箱梁横隔板的空间节段模型和采用梯形纵向加劲肋钢桥面计算的等效格子梁法,分析了正交异性板的第二体系的应力,和传统的Peklian Esslinger法相比较,采用空间节段模型和等效格子梁法得到的结果更加全面、准确。 相似文献
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货车车架的等效载荷简化 总被引:23,自引:2,他引:23
为了探讨货车的货箱和车架荷的简化问题,设计和制作箱-车架模拟试验装置,通过试验证明了货箱和车架之间的相互作用力是以集中力形式传递的,并且货箱的结构形式对车架的受力有显著影响,为了进一步验证模拟试验的结论,等效载荷的简化模型是可行的,实际车架结构的应力计算也进一步支持了货箱-车架模拟试验的结论。 相似文献
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王黎宏 《筑路机械与施工机械化》1993,(6)
采用多目标优化方法,解决自行式桥梁检测车伸缩臂油缸—连杆举升机构的优化设计问题,取得了较好的设计效果。文中对如何建立数学模型,权系数对优化结果的影响等问题进行了说明。 相似文献