Approximate Analysis for Statically Indeterminate Structures

What is the purpose of creating a simpler, statically determinate model during the design process?

• To eliminate the need for further analysis

• To ensure the structure is stable

• To estimate member sizes for a more precise analysis

• To analyze the structure's load behavior

Which method assumes that long, slender diagonals cannot resist compression?

• Portal Method

• Cantilever Method

• Equal Diagonal Forces

• Diagonal Tension Only

What is a common assumption made for building frames with rigid connections?

• The columns are not connected to the girders

• There is a moment in the girder

• The girder supports an axial force

• There is zero moment in the girder, 0.1L from the left support

What is the role of portal frames in structures?

• To provide lateral support only

• To transfer horizontal forces to the foundation

• To eliminate the need for columns

• To increase the weight of the structure

In fixed-supported structures, where do points of zero moment typically occur?

• At the center of each girder

• At the top of the frame

• At the midpoint of all three members

• At the base of each column

What assumption is made in the cantilever method for fixed-supported frames?

• A hinge is placed at the top of each column

• The axial stress in a column is proportional to its distance from the centroid

• The shear at the exterior column hinges is greater than at the interior hinges

• There is no moment in the girder

What is the primary function of trusses in portal frames?

• To replace the vertical columns

• To provide lateral stability only

• To reduce the overall weight of the structure

• To support heavy loads and span significant distances

Which method assumes that each diagonal carries half the panel shear?

• Cantilever Method

• Equal Diagonal Forces

• Static Equilibrium Method

• Diagonal Tension Only

What is a key characteristic of pin-supported structures?

• They allow both rotation and translation

• They prevent any movement at the supports

• They allow rotation but prevent translation

• They are always statically determinate

In the context of lateral loads on building frames, what does the portal method assume?

• The frame is not considered a superposition of portals

• The shear at the interior column hinges is less than at the exterior hinges

• A hinge is placed at the center of each girder

• The columns are fixed at the base