The Analysis Of Finite Element On Dynamic Characteristics Anti-seismic Of Steel Bracket Of The Boiler

The paper introduces the developing status quo, characteristics and meaning of steel structure, as well as making a conclusion on design philosophy and method of steel structure. With application of finite element method, structure dynamics theory and large finite element analytic software ANSYS, analyze the steel bracket of the boiler of some power plant in Henan Province under all different combination of loads such as net bearing capacity, dynamic performance and earthquake-resistant behavior. According to the requirements of the architectural anti-seismic specification base shear method only holds for the structure that does not exceed the height of 40m, and whose the quality and inflexibility distribution are in equality along the height with sheared deformation, which is irregular structure. An actual earthquake wave with representativity is elected in the paper to conduct the relevant spectral analysis and time interval analysis.At calculation of statical analysis on steel bracket, according to the technique qualification, under the different combination modes, such as static load, working load, wind load and level earthquake load, analyze importantly distortion and internal force of the key position of the structure under worst combination operating condition. And the result can meet the requirement of the design.On dynamic analysis of the boiler bracket, make use of model analysis function of ANSYS dynamic analysis to work out whole ten-step frequency and the relevant vibration mode by subspace method, according to the vibration mode analysis to make sure the front three-step frequency evident, existing the serious twisting phenomena.On the spectral analysis of the structure, make use of frequency value of modal analysis, as well as design reacting spectral curve of anti-seismic specification, to work out seismic acceleration valve under every step frequency, which is used to reactthe frequency of the spectrum--acceleration valve, to calculate the reaction of thebracket under seismic reacting spectrum. From the result, the earthquake reacts evidently.On time interval analysis of the boiler bracket, adopt acceleration-time earthquake wave input provided by some Earthquake Bureau. Due to ground shock existing hyperdimension ponderance, and excentric structure can produce torsion influence at earthquake happen, therefore, besides unilateralism earthquake input at analysis, stress analysis of bimodality earthquake on the structure should beconsidered. Work out stress of relevant structure position and the relevant time travel curve. This result shows that the earthquake is in evident response to the different intensity structure. But all analytic results can meet the anti-seismic conditions. Earthquake-resistant behavior of the structure is in good condition. This result also validates the conclusion that the steel structure has a good earthquake-resistant behavior.On the said analysis, we can get acquainted with stress circs of anomalistic bracket structure all side. I hope the paper can give reference for the project design practice.