Determine the width and depth of the beam, Mechanical Engineering

Determine the width and depth of the beam:

A timber beam of rectangular section is only supported over a span of 5 m. It carries an uniformly distributed load of 15 kN/m over the entire span. Determine the width and depth of the beam, if the bending stress is restricted to 8 N/mm2. The depth to width ratio might be taken as 1.5.


Span of beam, l = 5 m

Uniformly distributed load, w = 15 kN/m

Maximum bending moment at centre, M = wl 2/8

Thus,   M =15 × (5) 2/ 8

= 46.875 kN m

= 46.875 × 106 N mm

From the relationship, M / I = σ/ y , we get, I = (M × y )/ σ


 (1/12) bd3   = ((46.875 ×106)/8 )×      (d /12)

bd2 = (46.875 × 10 6× 12) / 16

= 35.15625 × 106

Depth to width ratio, d/ b  = 1.5 or d = 1.5 b,

On substituting,   ∴ b (1.5b)2 = (35.15625 × 106 ) /2.25

b3 = 35.15625 × 10

= 15.625 × 106

Therefore, we get        b = 250 mm

d = 1.5 × 250 = 375 mm.

Thus, width of beam = 250 mm, and

Depth of beam = 375 mm

Posted Date: 1/22/2013 12:21:32 AM | Location : United States

Related Discussions:- Determine the width and depth of the beam, Assignment Help, Ask Question on Determine the width and depth of the beam, Get Answer, Expert's Help, Determine the width and depth of the beam Discussions

Write discussion on Determine the width and depth of the beam
Your posts are moderated
Related Questions
Construction of Lacashire boiler: CONSTRUCTION : Consists of boiler shell which contains water and steam. Diameter can vary from 1.75 to 2.75 m and length can be 7.25 - 9 m

A rod of 80mm diameter and 10mm length with thermal conductivity 16W/m-deg protrudes from a surface at 160 o C. The rod is exposed to air at 30 o C with convective coefficient of

Bending moment

Titanium Alloys Pure titanium is a light weight and strong ductile metal. This is very strong and as well as highly resistant to corrosion of all kinds but has the drawback su

Q. What is Erosion Loss? Additional metal thickness must be added in specific locations where metal loss is expected, due to stream flow that is of high velocity, or is abrasiv

What is load? Sol. : A load can be defined as the combined effect of external forces acting on the body. The load is applied on body whereas stress is induced in material of

Description about Various Sections and Terminologies of Spark Plug Stud This is fixed to the insulator. The high-tension cord is also connected to this. Corrugations

a) By Gauss elimination method, solve x+2y+z =3 ; 2x+3y+3z =10 ; 3x-y+2z =13 b) Write a ‘C' program to find the solution of the above system of equations by Gauss Jordan meth

Applications with Medium Laser Power   Several laser welding applications have recently evolved in this power range of 1 to 10 kW. Because, the laser provides a basis for co

Improvements Required - Industrial Safety The outlining of association of safety engineering, as done above, with quality, productivity, profit etc. has also tended to make im