Reliability Analysis Of Hydraulic Engineering Based On Finite Element Method

In hydraulic engineering there are many uncertain things. The limit state functionis the highly nonlinear implicit function of the basic design variable, especially for thecomplex large-scale structures in structural reliability analysis and structure analysis isalso an intricacy. At present we can realize structure analysis in virtue of powerfulgeneral structural FEM analysis software, but these software have more or lessshortcomings in structural reliability analysis. So it is necessary to enhance thecapability of structural reliability analysis based on the existing software. on account ofthis motivation using the theory of reliability design a program of structural reliabilityanalysis ,which is on the basis of general FEM software ANSYS.In the present article the theory of structure reliability analysis is simply introducedsuch as First-Order Reliability Method (FORM), Response Surface Approach and TwoPoint Approximation Method, and the second development approach of ANSYS is alsointroduced. An Approach for complex structural system reliability is proposed, namelyconsider the system effect and make the limit state function as one or some or all of theresponse to the action on the structure by random variables exceed allowed such asstress, bending moment, shearing force and displacement so on. This approach can omitthe failure mode of inner of the structure and have the virtue of simplifying thereliability analysis of structure. Find out the reliability indexes of all limit statefunctions and then get the system reliability index using reliability bounds estimationmethod.Applying the above theories and methods and using program language ofFORTRAN 95 under the compiler of Compaq Visual Fortran 6.5 successfully realizethe probability finite element method program based on ANSYS and the numericalresults show that the program is feasible and accuracy.