Earthquake force analysis method Dynamical method
In contrast with the static loading, dynamical analysis method is discussed. In this method, structure reflections at any point of time during the earthquake are determined by impressing accelerations due to ground motion (map acceleration) in structural basic level and performing related dynamical calculations. This method can be used in elastic linear or nonlinear analysis of the structures.
Dynamical analysis method has been suggested along with other methods in Japan and USA at the present time. In this method, structure dynamical behavior has been analyzed under earthquake mapping acceleration, and forces, anchors, tensions, and displacements are obtained. Dynamical analysis could be materialized in elastic and rigid domains. Some of the factors that make dynamical analysis method essential are:
- Important structures that by importing into the elastic domain and their profit extension will be thrown or is dangerous such as nuclear power plants.
- Structures which their dynamical characteristics has a significant difference with simple model similar to multi-class frame with identical stiffness and mass. Such structures must be designed on the spur of the case for determining force distribution based on regulation suggestion by one of the Pseudo-dynamical or dynamical method.
- Cases that period of two or more modes are as much as close that mode affiliation occurs and other Pseudo-dynamical method is not sufficiently accurate. For example, in buildings that period of transitional and torsional modes are equal, mode affiliation will be appeared.
- Interaction of foundation and structure for heavy loads