【作者】 张亚辉；

【导师】 林家浩； 邓可顺；

【作者基本信息】 大连理工大学 ， 计算力学， 1999， 博士

【摘要】 本文的研究工作分为两大部分。第一部分结合自然科学基金委员会和航天工业总公司联合资助项目“复杂结构动力学”子课题—“开口加肋壳热/屈曲/振动耦合分析”,研究了复杂壳体结构在机械/温度荷载作用下的屈曲分析、几何非线性分析、热/屈曲/振动耦合分析、动力响应分析及随机响应分析等问题。开发了工程结构弹性静力分析、屈曲分析、动力分析程序DDJTJQ97。在论文中,着重对如下问题进行了研究(1)采用了增量加载法(引入0.618法及二分法混合搜索),研究了考虑材料因素(杨氏模量、泊桑比及线膨胀系数)随温度变化的热屈曲分析问题。(2)将切线刚度阵的增量加载法与修正的Newton-Raphson迭代法相结合,进行了极值点型的几何非线性(后屈曲)分析和分歧点型的近似后屈曲分析。(3)对有初始膜(轴)内力的结构,考虑几何刚度阵对结构原刚度阵的影响,进行了分歧屈曲分析和自由振动分析。(4)用高效精确的精细逐步积分方法研究了航天结构的瞬态动力响应问题。(5)应用并发展了虚拟激励法,对航天结构平稳、非平稳随机响应问题进行了研究。第二部分结合自然科学基金资助课题“非平稳多源激励随机响应”,对复杂结构多点随机地震响应问题进行了系统的研究。首先研究了复杂场地条件下的多点输入平稳随机响应问题。地面运动的空间变化考虑了行波效应、部分相干效应和局部效应的影响。其次推导了考虑行波效应、部分相干效应和局部效应的多点非平稳随机地震响应的虚拟激励算法公式。使之能精确地处理Priestley模型所表达的非均匀调制演变随机激励,并对复杂大跨度工程结构的多点激励效应作了计算比较。针对以往虚拟激励法在地面支座很多时计算量比较大的不足,提出了提高效率的有力措施。最后基于均匀平稳随机地震响应将随机法与我国抗震规范反应谱方法作了比较,为将随机振动方法应用于工程抗震设计作了探索。更多还原

【Abstract】 This paper consists of two parts. The first one is about the dynamic behavior of stiffened shells under mechanical and thermal loading which is a part of the project “Dynamics of Complex Structures”jointly supported by the Natural Science Foundation of China (NSFC) and China Aerospace Corporation. The second one is about the multiple input random seismic response of complex structures, which is also supported by NSFC. Five aspects are studied in the first part, i.e., 1) Elastic bifurcation thermal buckling analysis of stiffened shells, in which material properties (Young’s modulus, Poisson’s ratio and thermal expansion coefficient) are changeable due to the thermal loading. For such nonlinear problems, the increment-based iterative strategy is used. 2) Investigation of geometrically nonlinear analysis and post buckling analysis, which are on the basis of the increment-based iterative strategy and the modified Newton-Raphson method. 3) The bifurcation buckling analysis and coupled vibration analysis of structures with the influence of initial stresses taken into account. 4) Transient dynamical response analysis of astronautical structures. The precise integration method is applied and developed to solve this problem. 5) Stationary and non-stationary random analyses of astronautical structures, which are investigated by using and improving the pseudo excitation method (PEM). In the second part, the stationary and non-stationary random response analyses of structures subjected to multiple seismic excitations are investigated. Spatial variations of the ground motion due to the wave passage effect, the partial coherency effect and the local effect are all included. The PEM formulae for multiple input stationary/non-stationary random response problems are derived. Not only the above three effects due to the spatial variations of ground motion are involved, but also the non-uniformly modulated evolutionary random excitations proposed by Priestley are precisely dealt with. When there are too many ground supports, the pseudo excitation method is further improved for both stationary and non-stationary random seismic analyses. Based on uniform seismic excitations, comparisons are made between the random vibration scheme and the response spectrum method stipulated by the Chinese code. This is a valuable exploration for applying the random vibration method to engineering designs.更多还原