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在土木、水利工程中有许多不连续介质工程结构问题 ,对这类结构进行可靠度分析 ,需要考虑不连续界面的模拟、非线性方程组的求解以及非线性极限状态方程的求解问题等。对于大型复杂结构 ,采用随机有限元法在计算时间、空间和提高精度等方面都存在一定困难。本文另劈蹊径 ,提出用界面元模型统一模拟连续与非连续介质 ,用修正的 Newton-Raphson法求解非线性方程组 ,用响应面法计算结构可靠度的新方法 ,并结合大型工程结构的可靠度计算问题 ,实例验证了该方法的优点和适用性。论文的主要研究工作有 :(1)在系统全面地研究结构可靠度分析响应面法的基础上 ,首次提出了变 f二次序列响应面法 ,并给出了收敛控制准则。(2 )建立了基于界面元模型的二次序列响应面法计算结构可靠度列式 ,研制了电算程序。(3)建立了非线性动力问题结构可靠度计算的时程分析法 ,针对某重力坝绘出了可靠指标的时程曲线。(4 )用刚体模型、变形体连续介质模型和变形体非连续介质模型分别计算分析了某高拱坝坝肩动力稳定可靠度 ,得出了有参考价值的研究成果。
In civil engineering and hydraulic engineering, there are many discontinuous medium engineering structural problems. To analyze the reliability of such structures, we need to consider the simulation of discontinuous interfaces, the solution of nonlinear equations and the solution of nonlinear limit state equations. For large and complex structures, the use of stochastic finite element method in the calculation of time and space and improve accuracy and so there are some difficulties. In addition, this paper proposes a new method to solve the nonlinear equations by using the modified Newton-Raphson method and the new method to calculate the structural reliability by using the interface element model. In addition, a new method of calculating the structural reliability by the response surface method is proposed, Degree calculation problem, the examples verify the advantages and applicability of the method. The main contributions of this dissertation are as follows: (1) Based on a systematic and comprehensive study of structural reliability analysis response surface method, the response surface method based on f-order sequence is proposed for the first time. The convergence control criterion is also given. (2) Based on the second-order response surface method of interface element model, the structural reliability formula is established and the computer program is developed. (3) The time history analysis method of structural reliability calculation of nonlinear dynamic problem is established, and the time history curve of reliable index is plotted for a gravity dam. (4) The dynamic stability and reliability of the dam abutment of a high arch dam are calculated and analyzed separately with the rigid body model, the continuous medium model of the deformed body and the discontinuous medium model of the deformed body, and the research results with reference value are obtained.