The Simulation Of Artificial Seismic Wave For Multi-support Excitation And The Application In Long-span Structure

The seismic wave which is inputted in larg span structure is different because of wave travelling effect and local field effect.IF we input the uniform seismic wave,the structural responses will be differennt from actual situation. So the analysis of multi-support excitation is necessary .The limited seismic array record can not meet the amount of multi-support excitation design and the condition of complicated and changeable field.The technology of artificial seismic wave for multi-support excitation and the input method based on artificial seismic wave for single-support excitation considering the space and time variation has increasingly become the concern of the engineering sector hot spot.Research has shown that the data of strong motion record is a unstable process, not only in the amplitude of intensity distribution of the harmonic component,but also in the corresponding phase of the harmonic component of unstable distribution.The current traditional way of generating artificial seismic wave,biased in favour of attention to the unstable intensity for the purpose of fitting objective response spectrum,while the phase of the harmonic component only briefly conferred with each other independent of the [0,2Ï€] within the uniform random distribution volume,making the unstable characteristics of the phase has greatly weakened. Osaki Shun-yin put forward the phase difference concept in the analysis of the demographic characteristics of phase.The research also discovered that taking the actual earthquake response spectrum record and the phase difference as the control quantity, comparing the traditional uniform distribution of the phase,can generate more similar to the actual seismic wave record. The unstable distribution characteristic of harmonic intensity and phase is also more clearly.Accordingly, this article mainly has studied on the following contents:(1) This article has introduced the artificial seismic wave for single-support excitation technology.Facing the project application,introduced the statistical parameters of phase difference in various field,analyzed the controlled variable selection and the technology of fitting target response spectrum fitting.(2) Discussed how to expand to artificial seismic waves for multi-support excitation based on artificial seismic wave for single-support excitation,embodied the spectrum amplitude attenuation and traveling wave effect guaranting the two near-point earthquake displacement curve nearly identical. (3) Discussed the multi-support excitation input mode in the long-span structures seismic analysis,mainly introduced the application question of the displacement input method, the acceleration input method and the large mass method.(4) Used the large-scale finite element common software ANSYS10.0,used the different artificial wave input combination and the multi-support excitation input mode separately carry on the computation and the analysis for the long-span bridge model,obtained the displacement and the endogenic force response under the multi-support excitation.