共查询到10条相似文献,搜索用时 125 毫秒
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超长桁架结构是后续高时空分辨率天基遥感载荷的核心部件,建立其高效动力学模型是实现振动形态高精度控制的关键.为建立高效、精确的动力学模型,首先,根据超长桁架结构的周期性特征和振动变形特性,采用周期单元中心处位移表征整体桁架结构的空间位移,并分别推导了是否考虑桁架结构局部变形特性的两种应变能表达式;然后,根据哈密顿原理以及边界条件,建立了两种不同的等效动力学模型.最后,通过对两种等效模型与超长桁架结构固有特性的对比分析,验证了等效建模的有效性以及考虑局部变形特性提高模型精度的必要性. 相似文献
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采用子结构模态综合(Component Mode Synthesis,CMS)法和频响综合(Frequency response function-Based Substructure,FBS)法分析大型高耸装配结构风力发电高塔系统动力特性.通过子结构模态或频率响应函数(Frequency Response Function,FRF)信息综合成整体的模态或FRF信息,在保证整体分析精度的条件下提高计算效率,同时解决风电塔系统模态和FRF信息不易获得的问题.建立风电塔系统各个子结构的有限元模型和整体模型,分别使用MSC Nastran和LMS Virtual.Lab对各个子结构进行模态综合和频响综合分析,并将综合的结果与整体建模计算的结果进行对比,验证采用子结构CMS法和FBS法分析风力发电高塔系统的可行性和正确性. 相似文献
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该文以空间直立桁架结构的人-机协作装配流程为研究对象,提出一种适用于径向快装桁架模块单元的创新构型,建立了基于状态矩阵和邻接矩阵的桁架结构装配序列、装配模式和装配过程的数学模型。该文还对空间环境下桁架装配的人-机能力约束进行分析,提出基于动素分析的装配任务层级化分解方法,利用比较分配原则制定了适用编程的人-机协作装配任务流程和分配方案。基于所提出方案,通过开展人穿戴模拟宇航服与机械臂协作装配 5 m 长直立桁架结构的地面演示试验,验证了该方案的合理性和组装流程的可行性,为空间大型设施在轨构建提供了技术原理支撑。 相似文献
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An integrated fluid–structure numerical model has been developed to simulate the response of a single degree of freedom (SDOF) structure outfitted with a Tuned Liquid Damper (TLD). The structure is exposed to random external excitations. A non-linear, two-dimensional, flow model has been developed using the finite-difference method. Unlike most existing flow models, the present model does not include any linearization assumptions; it rather solves the entire nonlinear, moving boundary, flow problem under conditions leading to large interfacial deformations. The free surface has been reconstructed using the volume of fluid method and the donor–acceptor algorithm. The Duhamel integral method has been used to determine the response of the structure. The effectiveness and accuracy of the flow model has been validated using a set of benchmark problems and experimental data. The numerical results of this model have been compared with results of an equivalent TMD model. The present fluid–structure model can be used as a valuable tool for performance evaluation and design of more effective tuned liquid dampers. 相似文献
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Beam-like truss structures undergoing large deflections when subjected to static and dynamic loadings are studied by using the matrix method and equivalent continuum models. For the matrix method, an incremental procedure with equilibrium iterations are used. Equivalent continuum beam models are derived based on the properties of a typical substructure of the truss. Solutions obtained by using both methods are compared for a number of examples. 相似文献
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This article presents a three-dimensional analytical model to investigate cross-stream diffusion transport in rectangular microchannels with arbitrary aspect ratios under pressure-driven flow. The Fourier series solution to the three-dimensional convection-diffusion equation is obtained using a double integral transformation method and associated eigensystem calculation. A phase diagram derived from the dimensional analysis is presented to thoroughly interrogate the characteristics in various transport regimes and examine the validity of the model. The analytical model is verified against both experimental and numerical models in terms of the concentration profile, diffusion scaling law, and mixing efficiency with excellent agreement (with <0.5% relative error). Quantitative comparison against other prior analytical models in extensive parameter space is also performed, which demonstrates that the present model accommodates much broader transport regimes with significantly enhanced applicability. 相似文献
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《Advances in Engineering Software》2002,33(7-10):517-526
The extension of an approach, suitable for bolting structures impact computation with a large number of unilateral friction contact surfaces, and with local plasticity of the bolts, is presented. It is a modular approach based on a mixed domain decomposition method and the LATIN method. This iterative resolution process operates over the entire time–space domain. A 3D Finite-Element code is presented and dedicated to applications concerning connection refined models for which the structure components are assumed elastic. Several examples are analysed to show the method's capability of describing shocks throw real three-dimensional assembly. Comparisons between classical dynamic code LS-DYNA3D are presented. 相似文献