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.

Good luck

Introduction to EC3

Which approach to lateral-torsional buckling of UKB is recommended for manual calculations in the UK?

The general method
The simplified assessment method
Buckling curves - the general case
Buckling curves - for rolled sections and equivalent welded sections

Which forms of buckling might apply to a UKC, subject to an axial compression and a bending moment?

Flexural
Torsional
Torsional-flexural
Lateral-torsional

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

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

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

Which country's National Annex should be used?

No NA is needed if the recommended values are chosen
The NA for the country where design is carried out
The NA for the country where construction is to be carried out
The choice of NA should be specified by the client

Which of the following statements about columns in 'simple construction' are correct?

Only open sections (UKC) can be used
Design moments in the columns are based on nominal eccentricities
Beams are designed as simply supported
The approach cannot be used in Eurocode design

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

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

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