For analysis, which is more accurate. Portal method or Cantilever method? Which one is necessary to use in a three-story structure?

The cantilever method is more accurate and is necessary to use in a three-story structure. 

Step-by-step explanation

Structural analysis is the process of identifying the fundamental elements of a structure and analyzing how they are connected. There are two main methods used in structural analysis: the cantilever method and the portal method. The cantilever method relies on a beam or column to support loads, while the portal method uses openings in a structure to allow loads to be applied. The two methods have different advantages and disadvantages, which will depend on the specific situation.

The cantilever method uses a beam to extend from the foundation up to the structure. The portal method uses a hole in the foundation that is large enough for the structure to fit through. The advantage of using the cantilever method is that it allows for more flexibility in design. The disadvantage is that it can be more difficult to build.

The cantilever method is often used when a beam or column is supported at only one end. The other end is free to move, allowing the analyst to determine how much stress is being applied at each point on the structure. This method can be helpful in determining whether a load is concentrated at one point or spread out over a larger area. The portal method uses beams or columns that have holes in them. The analyst determines how much stress is being applied to each hole.

The cantilever method is better than the portal method when it comes to transferring energy. It is more expensive, but it is more stable because there is less risk of wind or rain damage.

"In the cantilever method, analysis is based on the frame behavior like a bending cantilevered beam, so it is more accurate for taller structures (such as a three-story structure). On the other hand, the portal method is recommended to use on shorter or squat structures, since it analyzes shear critical frames."