本课题基于随机振动理论、振型分解反应谱法、非线性有限元法及数值计算技术,针对大跨度空间结构的动力特性,研究其振型特征及其分布以及对不同参与系数及其累积效率的影响规律,提出大跨度空间结构振型分类方法及评定不同类型振型对其动力响应贡献的计算方法及界定准则;根据大跨度空间结构振型特征及频率分布规律,研究其动力计算模型的构成特点,提出大跨度空间结构动力计算模型简化的原则与方法;根据简化动力计算模型,改进适用于大跨度空间结构的静力弹塑性分析方法即Push-down法;根据大跨度空间结构振型响应和输入激励的相关性、振型响应贡献界定准则以及不同参与系数的意义及作用,提出大跨度空间结构地震反应分析遴选主振型的方法与准则;针对不同参与系数,提出相应的振型累积迭加改进算法以及适用于大跨度空间结构地震反应分析的修正的振型迭加算法。基于现有软件平台进行二次开发,编制相应大跨度空间结构地震反应分析数值计算模块。

Based on the random vibration theory, the modal analysis response spectral method, the nonlinear finite element method and the numerical computation technique, the characteristics of effect of vibration mode types and their distribution on the participation factors and their accumulation will be explored. A classification method of vibration modes and the contribution cumputation techniques and the evaluation criterion of contribution of different types of vibration modes to dynamic responses of a structure will be proposed. According to distinguishing features of vibration modes and regular distribution patterns of corresponding frequencies, composition of the danymic model of the spatial structure is investuigated and the simplification method of the danymic model is proposed. Based on the simplified danymic model, the push-down method, an elastic-plastic static analysis method, is improved. Based on the correlation between model responses of the structure and input excitations, the evaluation criterion of model response contribution and the purpose of different participation factors, a selection method and an evaluation criterion of dominant vibration modes in dynamic analysis of long span structure will be proposed. For different participation factors, the suitable accumulation techniques of vibration modes will be put forward and a new updated mode superposition method will be proposed. Based on current commercial analysis softwares, a numerical computation program module for seismic analysis of long span spatial structures will be developed.