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
Last changed3 days ago
