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

When would a designer need to refer to BS EN 1993-1-5 and its UK National Annex?

When determining snow loads
When calculating the resistance of the webs of rolled sections
When selecting a steel sub-grade
For design guidance on stainless steel

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

0.5
1.5
2.5
3.5

Must all connections be classified by calculation?

No, classification by experience of satisfactory performance is permitted
Only for elastic design
Only for plastic design
Only if being used outside the UK

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

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

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

In expressions 6.61 and 6.62, what structural mechanics do the k factors account for?

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

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

When calculating the buckling resistance of a member what is the value of the partial factor, γM1 specified in the UK National Annex?

1.0
1.05
1.1
1.15

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