Worked examples 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

Worked examples to EC3

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

When is the factor αLT used?

When calculating flexural buckling resistance
When calculating lateral-torsional buckling resistance
When classifying webs subject to axial load and bending
When calculating torsional buckling resistance

Which partial factor should be used when calculating buckling resistance?

γM0
γM1
γM2
It depends on the mode of buckling

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

In flexural buckling, what non-dimensional slenderness is approximately equivalent to a slenderness L/ryy = 160?

1.0
2.0
3.0
4.0

Which class of sections use the Gross Area, A when calculating the resistance?

Class 1
Class 2
Class 3
Class 4

When must the moment resistance of a section be reduced due to shear?

When the maximum design shear force coincides with the maximum design moment
When the design shear is more than 60% of the shear resistance
When the design shear is more than 50% of the shear resistance
Whenever UKB are specified, due to the thin web

When designing, 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

How is ε calculated?

No need - its given in the tables
ε = (235/fy)1/2
ε = (275/fy)1/2
ε = (355/fy)1/2

Why does torsional-flexural buckling not apply to UKC sections?

It does, but it's never critical
Because UKC sections have a high torsional rigidity
Because the flanges are relatively thick
Because UKC sections are not asymmetric