You are here:

Civil Engineering/Steel section size

Advertisement

Expert: - 11/4/2011


Question
frames
frames  
Hi,thanks first for this opportunity.
Can you please give me a simple way of checking the size of a section of steel for bending and compression.
I am planning to put three beams on top of a frame and load the beams with some weights for creep test.
the beams span is 5800mm support to support, weight of a single beam 150kg and weight of additional loads 600kg each beam.Hence each beam will have a total of 150+600=750kg.
These beams will be placed on top of the frames(end and front)5800mm apart.My question is can the section assumed carry the loads.I have assumed 7kN in each beam and 3.5kN for each support as shown in the diagram.

Answer
Hi Mulugheta,

You have not given me enough information to give you a precise answer, as I need to know the section properties of the beam.

Basically, if the load is uniformly distributed, then the maximum bending momnent will be (750x 5.8^2)/8 = 3154 kgm, and the maximum support shear will be 750x5.8/2 = 2175 kg.

The bending stress will be +/- 3154/Z, where Z is the section modulus. The shear stress will be 2175/A, where A is the section area.

There is a formula for determining the deflection too, if that is a governing criteria.

Civil Engineering

All Answers

Answers by Expert:

Ask Experts

Volunteer

Arshad Khan

Expertise

I can answer any questions to do with civil and structural engineering consultancy and construction industry in East Africa and the Middle East, and specifically with the analysis and design of reinforced concrete structures. My particular expertise is in the aseismic design and optimisation of tall buildings.

Experience

Employment history: 36 years in Construction and consultancy in the UK, Kenya, Tanzania, Uganda, Ethiopia, Eritrea, South Africa, Somalia, Zambia, Austria, Bahrain, Kuwait, Doha and the U.A.E.

Organizations
.Fellow of Institution of Structural Engineers (UK) .Fellow of Institution of Civil Engineers(UK) .Member of the Institution of Engineers, Kenya .Registered Engineer, ERB, Kenya .Member of the Architectural Association of Kenya (Engineers Chapter) .Chartered Engineer (UK)

Publications
•1984: International Conference on the Art and Practice of Structural Design, London •1994: 3rd Int. Kerensky Conference in Structural Engineering, Singapore •2008: International Conference on High-Rise Towers, Abu Dhabi

Education/Credentials
BSc, 1st Class Hons, in Building Engineering, University of Bath, UK MSc in Concrete Structures and Technology, University of London. Diploma of Imperial College, UK.

Awards and Honors
•Science Congress Special Award (for 2-seater Hovercraft - 1968) •Institution of Civil Engineers Award for outstanding performance at Bath University (1975) •Concrete Society Postgraduate study Bursary Award (1976) •Consular Representative for British High Commission, Nairobi. (1995 to 1998) •Examiner for Institution of Civil Engineers Professional Interviews, Nairobi. (1997 to 1998) •Branch Representative in Vienna for PI assessment for Inst. of Struct. Engrs. (1999 to date)

©2012 About.com, a part of The New York Times Company. All rights reserved.