BS tables of properties for universal beams

[Gclark]

Hi I am a HNC student an am having trouble with this question below...

A universal I section beam is simply supported at each end and must withstand concentrated shear force of 240kN vertically downwards.
if the maximum allowable shear stress in the beam is to be 65MkN/m^2 determine the suitable section for a beam using the BS tables of properties for universal beams.
ignore the mass of the beam.

work be greatly appreciated for any help

thanks :)

-Gclark

 

[phinds]

According to the forum rules, you need to show some work of your own first, then we can see where you might best be helped.

 

[Gclark]

I have the BS tables just need the formulas. i just have some basic knowledge and am looking for some advice.

thanks.

 

[pongo38]

When you say "concentrated shear force", do you mean "concentrated force? When you say "65MkN/m^2", do you mean "65 MN/m^2" or "65 kN/m^2" ? Tell us more what you can say about this problem.

 

[rezeew]

I understand your struggle with this question and I am happy to provide some guidance. First, it is important to understand the concept of shear stress and how it relates to the structural properties of a beam. Shear stress is the force per unit area that a material experiences when subjected to a force parallel to its surface. In the case of a beam, shear stress is caused by the vertical load acting on the beam and is distributed along the cross-section of the beam.

To determine the suitable section for a beam using the BS tables of properties for universal beams, we will need to refer to the British Standard (BS) 4-1:2005 "Structural steel sections. Specification for hot-rolled sections" which provides the necessary information for the design of steel beams. Specifically, we will need to refer to Table 3 which lists the properties of universal beams, including their dimensions, section modulus, and shear area.

To determine the suitable section for a beam, we will need to calculate the maximum shear stress in the beam using the given load and the formula for shear stress (maximum shear stress = load / shear area). In this case, the maximum shear stress is 240kN / shear area. We can then compare this value to the maximum allowable shear stress of 65MkN/m^2 to determine the suitable section for the beam.

Using the dimensions and properties listed in Table 3, we can calculate the shear area for different universal beam sections and determine which one meets the requirements. It is important to note that the shear area is dependent on the cross-sectional shape and size of the beam, so it is crucial to choose the appropriate section that can withstand the given load without exceeding the maximum allowable shear stress.

I hope this explanation helps you in solving the question and understanding the importance of using the BS tables of properties for universal beams in structural design. If you need further assistance, do not hesitate to seek help from your instructor or a qualified engineer. Good luck with your studies!