PDD 01 Flashcards
(195 cards)
What are four material characteristics that should be considered when selecting exterior finishes for a building?
- Making sure the material is appropriately used.
- Material can withstand the elements (sun, wind, rain, etc.)
- How often does the material require maintenance.
- How well does the material perform for its intended use and longevity.
How should the performance of materials be considered during the design phase?
- Materials should be tested to assure they will perform as expected and designed.
- The life span of the material should be evaluated to make sure it will withstand normal wear and tear.
How does building orientation
effect natural daylighting?
Windows facing north will not get any
direct sunlight, whereas windows facing
south will receive a fair amount of sunlight
year round.
Describe the treatments for a
North-facing window vs. an
East-facing window.
North-facing windows: will not get any
direct light but will provide an even glow
from reflected light all day. In hot places
they have almost no heat gain. In cold
climates, a north window will be cold and
grey.
East-facing windows: will receive sunlight
in the morning and are opportunities to
start warming up the building at the
beginning of the day.
Describe the treatments for a South-facing window vs. a West-facing window.
- South-facing windows: receive sunlight nearly all day. In hot climates, use overhangs above the windows to block the summer sun from coming in. A 2 foot overhang will shade the summer sun but allow the winter sun to come in.
- West-facing windows: receive hot afternoon sun until sunset. The western sun is much lower in the sky, so overhangs will not prevent the heat from entering the building. Using louvers will help control the amount of sun that enters the building.
What is a free body diagram?
- An FBD is a representation of a
body and all forces and moments acting on it. - It does not include internal forces.
What structural connection can resist either x or y forces, but not moment?
Pinned connections
This type of structural connection only resists forces in the y direction.
Roller connections
Within any structural member in bending, _____ is quantified as the maximum translation measured perpendicular to its central axis.
Deflection
- In a beam, deflection is the vertical distance that the beam sags at midspan.
- It’s usually expressed as a fraction of the span.
- Often noted as the Greek letter delta (Δ).
The formula for deflection of a beam with a uniformly distributed load is:
Δ = 5 wl4 / 384 EI
The fibers within a beam develop an internal moment to resist the moment caused by deflection. This resisting moment is called:
Bending moment
The centroid of an area is conceptually defined as:
- The center of gravity of a mass
- For simple geometric shapes, like circles and rectangles, determining the centroid is easy and simply corresponds to the geometrical center.
- For many common asymmetrical shapes, the centroid is calculated.
A factor relating the shape of a structural section and the distribution of its material relative to a chosen axis is called:
- A section’s moment of inertia, usually denoted “I”.
- The units are in4 or inches to the fourth power.
The ratio of a section’s Moment of Inertia and the distance between the neutral surface and the outermost edge of the section, “c” is referred to as:
The section modulus
The formula for Section Modulus is: S = I / c
The two reasons that column buckling occurs are:
If an applied load is eccentric, or doesn’t occur exactly at a column’s centroid, it will impart some degree of moment, causing bending.
No material is truly uniform in its internal composition. Any slight variation of the material will tend to allow buckling in a column.
Finding this value quantifies a cross section’s ability to resist buckling under an axial compressive load by relating its moment of inertia and area.
Radius of gyration
The radius of gyration is a convenient parameter, providing a
measure of the resistance of a cross section to lateral buckling.
A load imposed on a structural member at some point other than the centroid of the section is called:
Eccentric Load
Bending stress is a function
of the section modulus and
the:
bending moment
Define slenderness ratio:
The ratio of a wall or columns
unsupported height/length to its thickness
and measures its ability to resist buckling
when a compressive load is applied.
Vertical steel reinforcing
within reinforced concrete
columns essentially are very
slender ______ when
compressive stress is applied.
columns
A special kind of made up
beam that uses members
efficiently by placing them in
pure compression or tension,
when loaded properly, to carry
loads over a span is called a:
truss
The two methods for manually
analyzing trusses are:
the method of joints and the method of
sections
In this type of truss analysis, a
cut is made passing through
no more than three members,
and the three equations of
equilibrium are applied:
method of sections
Forces acting toward a joint
indicate a truss member is in:
tension