WORKSHEET1 General Structural Concepts

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WORKSHEET1General Structural Concepts
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A. fundamental concepts
Q1. A person has a mass of 70 kgs. What is
their weight in (kN)
Weight is a force . Weight Mass x g where g
10 m/s2 on earth 1kg of mass 10N of force on
earth. 100kg of mass 1kN weight on earth
0.7 kN
a) on Earth (g 10 m/s2)?
We 70 x 10 /1000
b) on a roller coaster (g1 3 x g)?
Wr 70 x 30 /1000
2.1 kN
Wr 0.7 x 3
c) on the moon (g2 0.17 x g)?
Wm 70 x 1.7 /1000
0.12 kN
Wm 0.7 x 0.17
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A. fundamental concepts
Q2. What is the force
3 kN
(100 200) 10 / 1000 )
3 kN
The table pushes back with the same force that is
put on it
Q3. What is the pressure exerted
On Surface S if the base of Block B is 200 x 150
mm?
P F / A
100 kPa
P 3 / 0.20 x 0.15 100 kN/m2
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A. fundamental concepts
Moment is a turning effect and equals force x
distance
M F D
10 kNm
a) A?
MA 2 x 5
6 kNm
b) B?
MB 2 x 3
0 kNm
c) C?
MC 2 x 0
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A. fundamental concepts
Q5. a) Indicate the force or (forces) necessary
to establish equilibrium (show the
forces graphically)
Equilibrant v(102 102) 10 / sin45 14.1
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A. fundamental concepts
Q5. a) Indicate the force or (forces) necessary
to establish equilibrium (show the
forces graphically)
R1 ? kN
Taking moments about B,
Clockwise moment 12 1
12 kNm
Anticlockwise moment F2 3
? M 0
12 kNm
4 kN
F2 12 / 3
b) What is the reaction at B (after you have
restored equilibrium)
? V 0
16 kNm
R1 12 4
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A. fundamental concepts
Q6. Figures (a) to (d) show 4 structural
assemblies. Identify the assemblies
that have
a) the same topology.
same no. of joints and same connectivity at each
joint
(a, c)
(b, d)
b) the same geometry and different topology
joints in the same place but connectivity
different
(a, b)
(c, d)
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B. general principles
Q7. What is the function of structure?
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B. general principles
Q8. What are the three main considerations we
are concerned with when dealing with
structure?

• stability - equilibrium
• building must not move - up, sideways or
  overturn
• all forces and moments must balance

• strength
• building elements must not break / collapse

• functionality
• building elements must continue to serve
  their purpose
• must not deform too much

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B. general principles
Q9. Given the post-and beam arrangement as
shown, describe Three ways of stabilising it.
Draw and name them.

• a) cross-bracing

• b) knee-bracing

• c) rigid joints

• d) solid infill (shear panels)

• e) build-in posts
• (rigid joints)