Introduction to EC3 quiz

Please answer the following 10 multiple choice questions, then click 'submit' to check the result. The pass mark for a CPD certificate is 8 out of 10, and you may retake the quiz as many times as you wish, but the questions will vary! Please note that one, two, three or all of the possible answers presented for each question may be right, and to gain a mark for that question all correct answers must be identified.

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Introduction to EC3

Having calculated the non-dimensional slenderness, how might the reduction factor, χ be determined?

Using the expressions given in EN 1993
Using the figure given in EN 1993
Using look-up tables in NCCI
Using look-up tables in EN 1993

When might the typical 25% increase in LTB resistance (EC3, compared to BS 5950) be of particular value?

When the design is governed by deflection
In composite construction
When floor dynamics is a critical check
All other cases

If a web is Class 3 and a flange is Class 1, what Class is the section?

There must be some mistake; both elements should be the same Class
Class 1
Class 2
Class 3

In flexural buckling, what non-dimensional slenderness is approximately equivalent to a slenderness L/ryy = 200?

0.5
1.5
2.5
3.5

What structural mechanics is allowed for in the C1 factor when calculating Mcr?

The influence of the axial load
The influence of residual stresses
The shape of the bending moment diagram
Initial imperfections in the member

How is ε calculated?

No need; it's given in the tables
ε = (235/fy)1/2
ε = (275/fy)1/2
ε = (355/fy)1/2

What does a value of αcr = 11 indicate?

A very sensitive frame
That second-order analysis must be used
That the second-order effects are small enough to be ignored
That the approximate allowances for second-order effects cannot safely be used

When determining ULS loads to the Eurocodes, which statements are true?

Wind loads are likely to increase, compared to previous British Standards
Gravity loads are likely to increase, compared to previous British Standards
Calculations using 6.10 will be conservative, compared to the use of both 6.10a and 6.10b
The UK NA simply adopts the recommended values for load factors and combination factors

When can the Eurocodes be used?

When Approved Document A in the Building Regulations is revised
Only when the client specifies design to the Eurocodes
Immediately
Only for projects outside the UK

Which of the following increase the risk of brittle fracture?

Colder temperatures
Tension
Thicker steelwork
Higher strain rates