UNIVERSITY OF MALTA
FACULTY FOR THE BUILT ENVIRONMENT
B.Sc.(Hons.) IN BUILT ENVIRONMENT STUDIES
YEAR I
JANUARY/FEBRUARY 2013 EXAMINATION SESSION
Unit Code: CVE 1611
Unit Title: Introduction to Structure Date: 30th January 2013
Systems
Time: 09:15 – 10:45
SPECIFIC INSTRUCTIONS
ANSWER ANY THREE QUESTIONS
(Each question carries 25 marks – the total will be converted to a percentage for grading)
1.
When loads act normal to a linear structure, such as a beam, the structure deflects,
but in so doing, internal stresses are set up which can provide the beam the ability to
resist the loads on it. Discuss, explaining how equilibrium is established in such a
structural system.
(10 marks)
What material properties should such a beam have, in order to provide adequate
flexural strength?
(5 marks)
Given a specific volume of material to be used for a beam of a given span, how best
would the material be distributed in order to give the greatest efficiency in bending?
Illustrate your answer with examples. What modes of failure, other than material
rupture, would you need to guard against?
(10 marks)
2.
Designing for safety of a structure can be simply defined as ensuring that the
strength of the structure is greater than the actions on the structure. Explain the meaning,
and implications, of the following terms, giving examples:
(i)
permanent and variable load;
(ii)
static and dynamic actions;
(iii)
climatic and accidental actions.
(5 marks each)
Explain the meaning of the following terms, as used in the definition of the value of
actions on a structure:
(iv)
normal distribution and characteristic value of actions;
(v)
partial safety factor and combination coefficient.
(5 marks each)
3. Discuss the main differences between membrane structural systems that make use of
the compressive strength of building materials, and those that make use of the tensile
strength. Why are compression membrane systems likely to be heavier than tension
membrane systems?
(10 marks)
Illustrate your answer with examples of structural forms based on these two different
characteristics.
(10 marks)
Why is curvature a basic requirement for all of these structural forms?
(5 marks)
4. The term “strength” is used to describe the load at which a structure fails. Explain the
meaning of these types of failures, using examples:
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(i)
(ii)
(iii)
translational failure, or rigid body motion;
material rupture or overstress;
elastic instability.
(5 marks each)
A stress-strain relationship for a given material gives information about its ability to
sustain loads. What additional information, about the behavior of the material under
loading, can it give? Sketch and annotate a typical stress-strain diagram for one common
building material.
(10 marks)
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