Structures 2

Front 1

flange

Back 1

Horizontal elements of wide flange beam

Front 2

Modulus of Elasticity

Back 2

slope of stress/strain curve=E

Front 3

z-arm

Back 3

distance between two opposite forces in bending and shear
2/3 d (where D = depth)

Front 4

web

Back 4

vertical element of wide flange beam

Front 5

wide-flange section (W)

Back 5

cross section of efficient beam-reduces area (I) while maintaining strength

Front 6

plate girder

Back 6

Built up steel section; beacause it is so big

Front 7

chord-top and bottom

Back 7

flanges in a truss

Front 8

T-beam

Back 8

cross section used in concrete-material in compression

Front 9

composite material

Back 9

material or structure made up of more than one element

reinforced concrete

Front 10

Glulam

Back 10

method for wood construction
layers of glue and smaller members to create a stronger structural element

Front 11

moment capacity envelope

Back 11

diagram showing rectangular elevation with moment curve and extra material, used to create more efficient beams

Front 12

bond stress

Back 12

stress of rebar on concrete which prevents sliping

Front 13

shear key

Back 13

keys on rebar to keep it from slipping out of concrete

Front 14

development length

Back 14

length of rebar needed to develop total tension capacity in concrete (not in steel because no tension in steel)

Front 15

hook

Back 15

in short beams where capacity is reached before development length

Front 16

compression reinforcing

Back 16

reinforcing for negative moment (on compression side)

Front 17

compression flange buckling

Back 17

lateral buckling in unsupported compression flange

Front 18

braced compression flange

Back 18

mechanical connections-floors on top of beams, spot weld-connections that keep top flange from moving, buckling

Front 19

unbraced compression flange

Back 19

susceptible to compression flange buckling

Front 20

lateral buckling

Back 20

buckling due to lateral load

Front 21

lateral moment of inertia

Back 21

stiffness of cross section with lateral load (y-axis) in normal cross section Ix>Iy

Front 22

lateral rigidity

Back 22

resistance to lateral load

Front 23

open section

Back 23

T section or W section

Front 24

closed section

Back 24

box beam

Front 25

spandrel beam

Back 25

beams on ends of structure, load on one side only-
section has rotational force applied along its axis-
box beam better for spandrel

Front 26

deflection

Back 26

PL/EI

Front 27

hinge, pin, shear connections

Back 27

not fixed connections-don't develop moment

Front 28

shear tab

Back 28

steel plate that connects beam in shear, pin, hinge connections

Front 29

cantilever

Back 29

beam supported on one side only
acts as lever
beam acts shorter (less deflection)

Front 30

balanced section

Back 30

smallest cross section you can use in a beam
positive moment=negative moment
1/3 original span on either side
1/5 of total length
50% more span without decreasing cross section

Front 31

Draw the elevation fo a simply-supported, uniformly-loaded rectangular beam whose section varies with respect to its bending stresses. What are the shear stress implications of such a profile

Back 31

▬
▼

Front 32

Why is a simply-supported constant cross section beam said to be "inefficient?" Show 2 possible methods to achieve a moe efficient member in each material: steel, wood, concrete

Back 32

sheer increased-make sure you have capacity for shear

Front 33

Draw the moment capacity diagram for the reinforced concrete beam shown on the board:

Back 33

------
/ \
-- --
/ \

Front 34

What two methods are used to anchor steel rebar in a concrete beam?

Back 34

epoxy & shear key

Front 35

List Six Factors that effect a beam' deflection:

Back 35

PL/EI
1.)load
2.)length
3.)modulus of Elasticity
4.)moment of intertia
5.)types of connection
6.)post/pretenstion

Front 36

Does the addition of an overhang decrease or increase the efficiency of a simply supported beam? why?

Back 36

increase it's a cantilever it enables you to span more distance without changing the cross section

Front 37

The roof of a building is 50' wide by 200' long. If the beams are 50' long and running parallel with the 50' (transverse) direction at a 25' spacing, what column spacing will require the smallest beam section if only two columns are used to suppor each beam?

Back 37

30'

Front 38

Show two methods of constructing a cantilever in steel and two ways in wood.

Back 38

butt joint, continuous floor,triangular, clamped beam and clamped column (needs to be continuous

Front 39

what architectural design advantage does cantilevering the floor at the exterior offer in a multistory highrise building? what is the corresponding interior planning ramification of this technique?

Back 39

increase length-1/3 more floor area, decrease section

Front 40

Can draped pre-stressing tendons be pre-tensioned? Why?

Back 40

No. Cause they are draped.they would then have to be pre-tension before

Front 41

What is the difference between bonded and un-bonded post-tensioning?

Back 41

epoxy and no epoxy

Front 42

Draw where the strands should be located for maximum efficiency in a simple-span beam that is pre-tensioned; post-tensioned:

Back 42

in pretensioned_at the bottom of the beam pulled taut.

in post-tensioned draped along moment curve and then pulled taught to creat a camber.

Front 43

why are the top surfaces of precast concrete floor elements typically finished with a rough surface?

Back 43

to enable another pour of concrete for bonding

Front 44

what purpose does a bearing pad under a precast concrete floor plank serve?

Back 44

column doesn't crush by tension of beam.

Front 45

In detailing the connection between an interior poured concrete bearing wall and the precast concrete hollow core floor planks bearing on it from both sides, what two items are critical to remember to specify

Back 45

bearing pad, chamfer

protects column from being crushed from the deflection of the beam.

Front 46

Briefly explain two reasons why the architectural design and structural/ construction concept of the Montreal 1976 Olympic Stadium (not the tower) were not complimentary:

Back 46

No tension ring --► cantilever. slope different

Front 47

Why are fixed connections very hard to achieve in a wood structure?

Back 47

can't weld-no butt joints

Front 48

What is necessary in the detailng of a fixed connection between:

a.) 2 steel WF sections
b.) a cold joint between two pours of a reinforced concrete member

Back 48

a.)2 webstiffners...le box
b.)running rebar

Front 49

Draw the bending stress diagrams for a steel rectangular section at the following loading stages: design limit, elastic limit, half plastic moment, full plastic moment.

Back 49

safety
/

yield limit

+/

half-plastic moment
_/
elastic moment
_|

Front 50

Where is it necessary to check for the need of lateral bracing along the length of the fixed end beam shown on the board? why?

Back 50

compression flange buckling

Front 51

What two additional costs are incurred when a building's structure is exposed to the exterior elements if it has a fixed connections?

Back 51

thermal expansion, thermal transfer, thickened floors

Front 52

prestressing

Back 52

prestressing introducing stress before the beam is loaded

Front 53

pretension

Back 53

a type of prestressing. tensioning rebar before concrete is poured

Front 54

post-tension

Back 54

a type of prestressing. tensioning rebar after concrete has set

Front 55

prestressing strand
post-tensioning strand

Back 55

cable rod

Front 56

precast concrete

Back 56

concrete that is poured and then put into place

Front 57

precast floor plank (solid, hollow)

Back 57

concrete cast before put into place with tongue and groove joint to join in construction. and gives more of a connection

Front 58

casting bed

Back 58

mold

Front 59

steam curing

Back 59

strip formwork early

Front 60

camber

Back 60

curve concrete slab forms after post-tensioning

Front 61

bearing pad

Back 61

pad that is placed beam and coulmn to prevent crushing from deflection of beam

Front 62

single tee

Back 62

concrete section with rebar

Front 63

double tee

Back 63

concrete section with rebar

Front 64

bonded (unbonded) tendons

Back 64

bonded=epoxy unbonded=nothing

Front 65

draped tendons

Back 65

rebar & cable laid out for post-tensioning

Front 66

creep

Back 66

time concrete sets over 2 year period after pouring

Front 67

segmental post-tensioning

Back 67

tensioning bit by bit

(example olympic stadium)

Front 68

clevis

Back 68

holds suspension cable (never fixed) it's like a yoke

Front 69

HSS (Hollow steel section)

Back 69

tube of steel-spandrel beams no torsion

Front 70

fixed end moment

Back 70

moment incurred in a fixed connection

Front 71

negative moment

Back 71

moment below neutral axis...compression is on the bottom

Front 72

negative moment reinforcing

Back 72

compression flange reinforcment

Front 73

elastic limit

Back 73

before yield plateau

Front 74

permanent set

Back 74

steel not going back on the yield plateau

Front 75

plastic

Back 75

state at which steel becomes after elastic

Front 76

plastic hinge

Back 76

after loaded past capacity.. in a fixed connection forms a mechanism after 2 hinges

Front 77

plastic moment

Back 77

xxx

Front 78

mechanism

Back 78

xxx

Front 79

ductile frame

Back 79

xxx

Front 80

induced moment

Back 80

xxx