Research Of Calculation On Seismic Behavior For Nuclear Power Engineering Structures

As a clean energy for nuclear power, its technology is gradually improved, and it hasbecome an important part of the strategy of China’s energy and electricity. The majorearthquake occurred in Japan on March11,2011, however, led to the world’s largest nuclearpower plant in Fukushima nuclear power plant accident. It remind us that the safety of nuclearpower, especially the seismic safety of nuclear power engineering structures still have a lot ofkey issues need to be resolved. Therefore, in the structure design and safety assessment ofnuclear power engineering, a comprehensive earthquake response analysis for the overallstructure is required, and scientific and rational engineering measures are adopted in order toensure the seismic safety of nuclear structure.The structure or building of nuclear power engineering has enormous volume. In order toaccurately analyze the dynamic response of these structures in the earthquake, the finer finiteelement calculation for these structures must be made. However if the general commercialsoftware is used for analysis, there are lower computational efficiency, the secondarydevelopment (boundary conditions, the contact conditions, etc.) and other inadequacies. Forshortening the time of dynamic response analysis of nuclear power engineering structuresearthquake, improving the efficiency of the analysis and taking full advantage of our parallelcomputing hardware (parallel computer), a parallel finite element program which containscontact problems and viscoelastic boundary conditions of earthquake dynamic response of thenuclear power engineering structure is developed based on MPI (Message Passing Interface)in this paper. Some work is made as following:1. The boundary conditions are researched by considering the foundation structureinteraction. The various methods are analyzed. And the superiority that the artificial viscousboundary conditions are applied to the seismic response analysis of engineering structures isindicated.2. The weak integral solutions for dynamic elasticity contact conditions andviscoelasticity of boundary conditions are presented. Its mathematical expressions are unified.And the mathematical essence for dynamic contact conditions and viscoelastic boundaryconditions is also revealed. Simultaneously the procedure realization method of dynamiccontact conditions and viscoelastic boundary is studied. By suing the point-to-point contactmodel, the dynamic contact problems are simulated.3．Based on MPI environment, the earthquake response dynamic finite element parallelcomputation program for nuclear power engineering structure is developed with the contactand viscoelastic boundary conditions. By using six MPI basic library functions, the parallelsource codes are written based on the domain decomposition theory by adopted FORTRANlanguage. And its correctness is verified with the resolve example. The program containssome load conditions required in nuclear power engineering calculations, such as soil pressure, ice load, hydrostatic pressure, hydrodynamic pressure, seepage pressure, contact problems,earthquake load and so on.4．The structural displacement and stress response of an intake structure of nuclearpower plant is analyzed by using our dynamic response parallel finite element program underthe earthquake. And the commercial finite element software (ANSYS) and our software havebeen compared on the computation time and stress precision. It proves the reliability andefficiency of our parallel program. At the same time, the structural internal-force-extractionmethod has been studied and the structural internal-force response has also been analyzed.These efforts could provide the theoretical basis for the structural design and verification.5． The seismic stability of nuclear power slope engineering with dynamic contactcondition is calculated by using strength reduction method and the dynamic response parallelfinite element program. And the calculated result is compared to the result of commercialfinite element software (ANSYS). It further proves the advantages of our parallel program.