Study And Application On The Generation Algorithm Of The Floor Response Spectrum

With the development of economy, it is inevitable to build an important building in high intensity earthquake prone area. To get ground motion's acceleration time history information of some specific engineering characteristics through artificial seismic dynamic fitting is an important research topic in structural earthquake field. Compared to the hydraulic structure and civil engineering seismic design, seismic design of nuclear power plant due to serious harm occurred after the accident and the complexity of their structure, the requirement of artificial wave fitting technology is more strict, the performance is that precision's requirements in the artificial ground motion's time history fitting is higher. At the same time, nuclear power seismic design response spectrum, especially as a secondary input data of nuclear power plant floor spectrum, whose morphology is more complex, has a few more of its peak, and the difference between peak and valley is big. The above characteristics have led to the work requirements that improve the response spectrum fitting. Under the existing technical conditions, the single damping ratio response spectrum's fitting which is regular has been able to achieve high precision. In engineering, in view of the difference between the artificial wave and the real seismic record in the intensity and frequency, the engineers have a skeptical attitude to the reliability of the artificial wave's shape and expression.For the above problems, this paper mainly carried out the following work:(1) Firstly, this paper introduces the development of the artificial wave fitting technique and the related knowledge. Based on the traditional frequency domain iterative method, the initial screening strategy and the correction algorithm are presented, solved the problem that the long period segment floor response spectrum of the nuclear power plant floor spectrum due to the uncertainty of artificial treatment is higher, which leads to the technical problem that the calculated response spectrum value can not meet the requirements of the target response spectrum., thus, the efficiency of response spectrum fitting is improved on the whole.(2) An artificial wave fitting method based on the waveform analysis of the target waveform is proposed, and by means of the wavelet transform, this method is proved to be more close to the true ground motion in the frequency and intensity than the artificial wave generated by the traditional method.(3) Aiming at the floor spectrum whose peak and valley is deep and precision control point is density, A special technique is proposed, which comprehensively use the method that adjust the frequency domain response spectrum and time history correction in time domains, the detailed discussion and the specific algorithm are given.(4) In the field of multi damping ratio response spectrum fitting, based on the theory of the narrow band's superposition of the time history, a method is presented for the simultaneous superposition of the initial wave and the time history of the narrow band with different coefficients.