Among the modal calculation methods, the Mode Combining Method or the Mode Addition Method in the Time History Area is under the control of the user.
Earthquake calculation is made automatically according to the selected Modal calculation method.
Modal Calculation Methods; It consists of 2 methods: Mode Merging and Mode Addition. Earthquake calculations of all buildings covered in Chapter 4 can be made with Calculation Methods . The reason is that Modal Calculation Methods are developed in a way that takes every mode into account.
In the Mode Combination Method, mode shapes are taken as basis in the distribution of the total earthquake force. This method is to evaluate the equations that give the behavior of multi-degree of freedom systems separately for each mode shape. Unlike the equivalent earthquake load method, in determining the total earthquake strength, the number of vibration modes depends on the mass participation ratio and many modes affect the behavior.
Both calculation methods can be selected from the Analysis settings - general settings tab.