System Reliability Analysis Of Reinforced Concrete Frame Based On Accurate Stochastic Finite Element Model

Because uncertainty exists in all aspects of structures, stochastic finite element method becomes popular to solve practical engineering problems in the field of structural design and analysis. It can be considered as a very valuable method for structure reliability analysis by using the results of finite element analysis and considering the randomness of structure. This paper will estabilish accurate finite element model of reinforced concrete frames based on earthquake simulation software platform OpenSees to analyze system reliability by using first order reliability method based upon stochastic finite element method. On the basis of above, a general optimized selection method of different failure modes can be proposed. The main content includes:(1) A fiber element model of reinforced concrete frame is established on the platform OpenSees, and system reliability and sensitivity analysis is performed. Reliability index and failure probability under two different limit states as bearing capacity and inter-story drift is calculated and system reliability index can be achieved by considering the correlations between different limit states. At last, a method of system reliability analysis with key random variables is proposed after the sensitivity of each random variable is analyzed.(2) An optimized selection method of different failure modes is analyzed based on system reliability for reinforced concrete frame structure. Three-dimensional accurate finite element models of four frame structures of different level are established. Different structural forms of two failure modes are considered and the system reliability of the two failure modes is calculated. The conclusion that which kind of failure mode is more reasonable is drawn through analyzing the results and at last, the optimization method of different failure modes is proposed.(3) One disadvantage known as low visualization of OpenSees is obvious according to the above analysis. As a result, OpenSees is visualized in this paper by visualizing processing software GiD, object-oriented visual language TCL and the graphical interface program package TK. A powerful tool to solve complex engineering problems is provided by OpenSees with visual modeling and structural analysis.