Loading Systems
A reinforced concrete floor slab of 225mm thick, 3m wide and 5m long, is supported by four columns on the corners. The floor is designed to carry a live load of 3kN/m2 plus floor finishes and ceiling loads of 1kN/m2 . Determine the total load carried by each column. Assume unit weight of concrete =24kN/m3
thickness=225/1000= 0.225 m
v=0.225x3x5= 3.375 m3
Dead load 0.225x24=5.4 kN/m3
1x15=15 kN
5.4x15=81 kN
3x15=45 kN
81+15+45=141 kN
141/4=35.25
Determine the magnitude and direction of the resultants of the concurrent coplanar force systems shown
fx=100+80cos135°=43.4315
fy=0+80sin135°=56.5685
R=√43.4315²+56.5685²=71.32 KN
Ø=tan-1(43.4315 / 56.5685)=52.48°
Determine the magnitudes and natures of the forces acting in members P and Q shown
If q < 0
If q = 0
If q > 0
-Structure is unstable
-Called an Imperfect Frame
-Has too few members
-Cannot be analysed
-Prone to collapse
-Statically determinate (if stable)
-Called a Perfect Frame
-Has just enough members for stability
-Statically indeterminate (if stable)
-Called a Redundant Frame
-Has extra members or supports
If:
-q = 1 → Indeterminate to first degree
-q = 2 → Indeterminate to second degree
Still must check visually for stability.
Use the method of joints to determine the magnitudes and types of the lettered members for the pin-jointed trusses shown
TRUSSES Load Cases
Load cases are the different ways loads (forces) can act on a truss.
How the truss behaves
Which members are in tension or compression
If the structure is safe
is used to predict whether members in a truss are in tension or compression without doing calculations.
COLUMNS AND WALLS
long COLUMNS
Support and reaction
BEAMS
Shear Force and Bending Moment Diagrams
Beam defelction
Qualitative Analysis
BENDING STRESSES IN BEAMS
BENDING STRESSES IN BEAMS (part 2)
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