Spektrum
Language: Matlab
Purpose:Dynamic response calculations
Calculating eigenvalues of dynamic matrix is certainly not a problem for present-day computing. However, after finding vibration mode periods of the structure, engineers often continue calculation with substantial assumptions regarding building response. Current seismic building design standards offer quite simple, but very inaccurate methods for bypassing response calculations.
Spektrum is designed for dynamics analysts to have better insight in structures behavior during earthquakes. Algorithm is based on Newmark’s method of integration of Duhamel’s integral. Input data must contain valid earthquake accelerogram records in tubular form. By using Sprektrum, engineer can make his design process more specific. He can observe structure behavior in relation to specific or generic accerelograms without using response envelope that standards promote.
Calculations are performed in two modes. In “Spektrum response” mode user imports accelerogram data of one earthquake and chooses response type (movements, accelerations, normalized accelerations, quasivelosities etc.). Results are shown as series of graphs. Engineer can examine what will be the response of the structure by reading appropriate coordinates.
In “Spektrum envelope” mode, user can consequently import numerous accelerogram data. Idea is to provide the analyst the opportunity to combine both existing and generic accelerograms. In that way engineer can apply accelerograms of the nearby earthquakes that have already happened, complemented with generic ones. Calculation results with an envelope of specific responses. After finding the appropriate structure response, engineer can adjust structures rigidity in order to decrease effects of the seismic load.