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

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

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 value of ξ is specified in the UK National Annex?

The recommended value of 0.85
0.925
0.950
0.875

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

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 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

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

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

1.0
2.0
3.0
4.0