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  1. Figure 01 - Spectral Acceleration Sa [m/s²] Versus Natural Frequency f [Hz] of Narrow-Band Response Spectrum According to EN 1998-1 [1]

    ZPA Method in Response Spectrum Analysis

    In a multi-modal response spectrum analysis, it is important to determine a sufficient number of eigenvalues of the structure and to consider their dynamic responses. Regulations such as EN 1998-1 [1] and other international standards require to activate 90 % of the structural mass. This means: to determine as many eigenvalues that the sum of the effective modal mass factor is greater 0.9.

  2. Determination of Pushover Curves in RFEM

    Determination of Pushover Curves

    Pushover analysis is a nonlinear structural calculation for seismic analysis of structures. The load pattern is inferred from dynamic calculation of equivalent loads. These loads are incrementally increased until the global failure of the structure occurs. The nonlinear behavior of a building is usually represented by using plastic hinges.

  3. Signed Results Using the Dominant Mode

    Signed Results Using the Dominant Mode

    In RF-/DYNAM Pro - Equivalent Loads, a signed result option in accordance to the dominant eigenmode is available since version X.06.3039. For the modal combination of results corresponding to the single eigenvalues a quadratic combination rule has to be used, in RFEM and RSTAB the SRSS and the CQC rule are available. It is only allowed to combine results not loads directly. The reason are the mode shapes which are arbitrarily scaled and signed.

  4. Settings of the Time Course Monitor

    Settings of the Time Course Monitor

    The Time Course Monitor displays results of a time history analysis from RF‑/DYNAM Pro - Forced Vibrations. The graphic can be adjusted in the settings. This can be reached via the right click in the context menu. For example you can activate or deactivate the grid in the graphic. Those changes are overtaken into the printout report when you print the graphic.

  5. Complete Quadratic Combination (CQC) Rule in RF-DYNAM Pro - Equivalent Loads

    Quadratic Combination Using CQC Rule

    In RF‑/DYNAM Pro - Equivalent Loads the CQC (Complete Quadratic Combination) rule is available since version X.06.3039.

  6. Complete Quadratic Combination (CQC) Rule in RFEM and RSTAB

    Complete Quadratic Combination (CQC) Rule

    The CQC (Complete Quadratic Combination) rule is available in RFEM and RSTAB since version X.06.3039. In the General Data of the model you can activate the CQC rule and for Load Cases of type “Earthquake” there are two new properties available, the “Angular frequency” and the “Lehr's damping.”

  7. 1 - Reduction of building on cantilever structure. The individual mass points represent storeys. Displacement due to compression normal forces shown in (a) is converted to (b) overturning moments or lateral loads [2].

    Considering Second-Order Theory in Dynamic Analysis

    For the ultimate limit state design, EN 1998‑1 [1], Section 2.2.2 and, require the calculation considering the second‑order theory (P‑Δ effect). This effect need not be taken into account only if the interstorey drift sensitivity coefficient θ is less than 0.1.

  8. Steady-state Solution for Periodically Excited Structures in DYNAM Pro - Forced Vibrations

    Steady-state Solution for Periodically Excited Structures

    With the modal analysis in DYNAM Pro - Forced Vibrations the steady-state solution can be determined for periodically excited structures. Instead of the complete solution of the equation of motion only the special solution is provided.

  9. Neglecting Masses in RF-DYNAM Pro

    Neglecting Masses

    Since version 5.06.1103 masses of nodes, lines, members and surfaces can be neglected in RF‑DYNAM Pro. The setting to activate this feature can be found in the Details dialogue, the neglected masses are valid for all defined mass cases.

  10. Time History Analysis of an Explosion with RF-DYNAM Pro - Forced Vibrations

    Time History Analysis of Explosion

    With RF-DYNAM Pro - Forced Vibrations, you can perform a time history analysis. For example, you can analyze an explosion acting on a nearby building structure. Formulas for the time diagram and the load distribution as well as how this is implemented are shown in the attached figure. In RFEM, the free variable loads are available which enable flexible load distributions.

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