Structural Behaviour

Flashcards detailing the primary functions and requirements of structural systems in building design based on the lecture notes.

Main function of a structure

To supply the strength, rigidity, and stability required to prevent a building from collapsing.

to support a building a structure must possess what 3 properties

To support a building, a structure must possess $1$) strength, $2$) rigidity, and $3$) stability.

Satisfactory design

The creation of a safe and economic building.

strength definition

the ability to bear loads without breaking

what does strength refer to

how much weight or force a structure can handle

what should you consider when referring to strength

material the structure is built out of

rigidity definition

resistance to bending or deformation

what does rigidity refer to

ensures that a structure holds its shape without excessive bending

what should you consider when referring to rigidity

the design of the building

stability definition

the ability to resist movement or toppling over

what does stability refer to

prevents structures from tilting or collapsing due to forces like wind, earthquakes or uneven weight distribution

what to consider when referring to stability

the distance of the center of gravity from the ground

strength summary

resista breaking under weight

rigidity summary

maintains shape under force

stability summary

prevents tipping or collapsing

structural definition for strength

materials able to safely support their own weight and resisting applied loads without distortion

structural definition for stability

ability of a structure to resist overall movement and deformation

structural definition for force

forces change the state of a structure by application of weight and energy

types of forces (6)

tension, compression, shearing, torsion, bending, bucking

tension definition

when a member is being stretched or in tension the force produced is tension. when forces act upon a member in opposite directions, pulling it apart

compression definition

when a member is squeezed by converging forces

shear definition

causes one member to slide past another

torsion definition

when a member is twisted by forces acting upon it

elasticity

change in shape when subjected to force

ultimate stress = failing point

the stress when a member fails by crushing or breaking apart

bending definition

when tensile and compressive forces occur on opposite sides

true or false: depth of a beam is more important than its breadth

true

what is a cantilever beam

when the beam projects over the supports

cantilever reactions include

point loads, uniformly distributed loads

a column behaves depending on…

it’s materials and ratio of thickness to height

(the lower the ratio the weaker it is)

point load

a single force acting on a single point on a structural member

crushing is prevented by

increasing cross section area

buckling is prevented by

distributing this area symmetrically around the center of the column

three types of rock classes

igneous, sedimentary, metamorphic

igneous example

granite

sedimentary example

sandstone, limestone, slate

metamorphic example

marble

why is stone used in design

aesthetic appearance, durability, maintenance free

why is stone used in design

aesthetic appearance, durability, maintenance free

brick

one of the oldest building materials 5000 years

brick made from

varied clays that are fired in a kiln at different temps to produce diff colours, textures, strengths and finishes

can be made out of cement too

brick dimensions

D110x W220x H80mm

brick properties

durable, weather resistant, fireproof

concrete made of

cement, sand, aggregate and water

types of concrete

precast or insitu

concrete is both

structural and aesthetic

structural properties of concrete

good in compression, appropriate to use in walls and columns, weak in tension, heavy, rigid, high density, high strength, hardness, durable, impervious, frost resistant, thermal conductivity

concrete fixing methods

cast in - embedded during pouring process

drilled mechanical- concrete screws (post casting), chemical anchor bolts, expansion bolts

adhesive - export resin anchors

timber types

hard/ soft wood

timber pros

excellent insulator, renewable, easy to cut and shape, easy to work with

timber cons

affected by moisture - warping and shrinking

timber structural properties

used in compression (resists loads of pressure), and tension (resistance to bending), tensile strength (cantilever construction), lightweight yet strong, fibrous and elastic (good physical strength but weaker than steel, used to span long distances, vertical posts hold up floors and used for trusses and roofs

timber fixings

mechanical - nails and screws

flat pack - cam lock ans dowel pack

wood joints - traditional: dovetail, mortise and tenon, finger

adhesives - wood glue and clamps

steel/ metal fixings

structural - nuts and bolts

welded - melting of metals to form a bond between them

glass properties

tranparent, heat resistant, chemical resistant, pressure resistant, thermal conductivity, doesn’t have high tensile strength, great thickness to prevent breaking, required to resist loads like wind impact pedestrians and thermal stresses, elastic up to breaking point then completely brittle

glass fixings

mechanical - stand off, spider

channel

lamination

bonding