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

For designs to be constructed in the UK, where should the steel strength be taken from?

The designer may choose
The UK National Annex to BS EN 1993-1-1
The product Standard
BS EN 1993-1-1

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

If a web is Class 2 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 bending modulus should be used with a Class 2 section?

Elastic modulus
Plastic Modulus
Effective Modulus
Young's Modulus

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

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

Which combination of checks are required for elements in tension?

Gross area using yield strength, and γM0
Gross area using yield strength, and γM1
Net area using yield strength, and γM1
Net area using ultimate strength and γM2

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

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

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