Unit 2 Review part 2 Flashcards
Why is all framework of a truss a two-force member?”
It is either in compression or tension
The webbing of a truss resists ________ forces, while the top and bottom chords resist ________.
shear, bending
True or false: The vertical webbing pieces in a truss are zero force members.
True
What are 4 ways to brace a frame:
- Lateral bracing
- Knee bracing
- Rigid infill panels
- Fix the ends to the ground
How do we know whether or not a frame is determinate or indeterminate?
A frame is determinate if it has 1) three or fewer reaction components, so it can be solved with the 2) three equations of equilibrium.
It is indeterminate if there are 3) more than three reactions.
What are three names for very large columns?
- Masts
- Pylons
- Piers
Who discovered that a column’s failure is due to bucking, not material failure?
- Leonard Euler
How many layers are most common for post and beam construction?
- One, two, and three. Any number can be used though
What 4 materials are most common for non-load bearing walls?
- Wood
- Steel stud
- Brick
- Concrete block
What 4 materials are most common for load-bearing walls?
- Wood
- Cold-rolled steel sections
- Concrete block
- Concrete (precast and cast-in-place)
What are the three categories for post and beam frames?
- Braced
- Knee braced
- Rigid frame
True or false: A simple joint transfers moments between the connected members.
False
What three elements are common for cross bracing?
- Cable
- Steel rod
- Structural steel
What is the most effective angle for frame angle bracing?
45 degrees
What’s the difference between a rigid frame pinned at the base, versus one that is fixed at the base?
- Frames that are pinned at the base do not have resisting moments (are not firmly set in place). The columns will rotate a bit at the connections on the ground.
- Frames that are fixed at the base aren’t going to move at all.
What materials are most commonly used for parallel chord trusses?
- Wood
- Steel
- Wood and steel
How do we know if a truss is top or bottom chord bearing?
- It is top chord bearing if the top chord bears the weight of the rest of the truss
- It is bottom chord bearing if the bottom chord bears the weight of the rest of the truss
True or false: Folded plates don’t require anything to prevent them from flattening.
False. They require stiffeners. Stiffeners can be:
- Ties
- Diaphragms thick edges
What are the three materials that folded plates can be made of?
- Wood
- Steel
- Concrete
What are the benefits of precast concrete as opposed to cast-in-place? (4)
- Enables better control over dimensions
- Better control in the curing process
- Better control of strength, permeability, and endurance
- Is shipped to the site when needed
What is the most common thickness for a hollow core precast slab?
200mm (can be 150 - 300mm)
What is the most common width for a precast slab?
1200mm
How are hollow core plates prestressed?
They use cables in the bottom where tension occurs
What load does an external non-loadbearing wall need to withstand?
Wind load
What materials can a non-loadbearing partition wall be made of?
- Wood
- Steel stud
- Concrete block (in certain circumstances, such as when a high fire rating is required)
When is a concrete block considered “hollow core”?
It is considered hollow core if 25 percent or more of the cross-section area of the block is empty.
What are two names for smaller columns?
- Posts
- Struts
When does axial loading happen?
- When the load is applied to the exact center of the column cross-section, and
- there are no lateral forces present
True or false: it is possible to achieve axial loading
False
What is the opposite of eccentric loading called?
Eccentric (non-axial) loading
What is the distance between the column center and the column load called?
Eccentricity
