Worked examples to EC3 quiz

From SteelConstruction.info

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

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

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

Which bending modulus should be used with a Class 2 section?

Elastic modulus
Plastic Modulus
Effective Modulus
Young's Modulus

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

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

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

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

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

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