A spherical balloon membrane is filled with gas with atmospheric pressure and defined volume (these values are used for FE model definition only). Determine the overpressure inside the balloon due to the given isotropic membrane prestress. The add-on module RF-FORM-FINDING is used for this purpose. Elastic deformations are neglected both in RF-FORM-FINDING and in the analytical solution; self-weight is also neglected in this example.
Balloon – Prestressed Membrane
There is a known complexity in calculating footfall response on irregular floors or staircases of any type. Footfall Analysis uses the RFEM model and the modal analysis results of RF-DYNAM Pro - Natural Vibrations to predict the vibration levels at all locations on a floor. A rigorous analysis method is essential to enable an accurate investigation of the dynamic behavior of the floor.
The software incorporates the most up-to-date analysis procedures, allowing the user to select between the two most often used calculation methods available, namely the Concrete Centre Method (CCIP-016) and the Steel Construction Institute Method (P354).
- Footfall Analysis links with RFEM, using the model geometry from there, thus the user is not required to create a second model specifically for footfall analysis
- Allows the user to analyze any type of structure for footfall analysis, irrespective of the shape, material, or use
- Quick and accurate predictions of resonant and impulsive (transient) responses
- Cumulative measurement of vibration levels – VDV analysis
- Intuitive output enabling the engineer to advise improvements of critical areas in a cost-effective way
- Pass/fail limit check in accordance with BS 6472 and ISO 10137
- Selection of excitation forces: CCIP-016, SCI P354, AISC DG11 for floors and stairs
- Frequency weighting curves (BS 6841)
- Quick investigation for full model or specific areas
- Vibration Dose Analysis (VDV)
- Adjusting the minimum and maximum walking frequencies as well as the walker’s weight
- User input damping values
- Varying the number of footfalls for resonant response, user input or software calculated
- Environmental response limit based on BS 6472 and ISO 10137
- Overall maximum response factors and critical nodes
- Resonant analysis (maximum response factor, RMS acceleration, critical node, critical frequency)
- Impulsive (transient) analysis (maximum response factor, peak acceleration/velocity, RMS acceleration/velocity, critical node, critical frequency)
- Vibration dose values for both resonant and impulsive analyses
Charts
- Response factor vs walking frequency
- Mass participation vs eigenmodes
- Velocity time history
With the activated option 'Topology on Form-Finding Form' in Project Navigator - Display, the model display is optimized based on the form-finding geometry. For example, the loads are displayed in relation to the deformed system.