Question

The beam below will be subjected to a live load of 600 lb/ft, a concentrated live load of 25 kip, and a dead load of 300 lb/ft. a) What is the maximum positive moment that can be produced at G? b) What is the maximum negative moment that can be produced at G?

Answer 1

hello some part of your question is missing below is the complete question

answer :

A) 162750 Ib.ft

B) - 64950 Ib.ft

Step-by-step explanation:

Applying Muller-Breslau's law

we will make assumptions which include assuming an imaginary hinge at G

therefore the height of I.LD for B.M at G = ( 12 * 8 ) / 20 = 4.8

height of I.L.D at C = 2.4 ( calculated )

height of I.L.D at F = 1.5 ( calculated )

A) Determine Maximum positive moment produced at G

`M ^+` = [ (1/2 * 20 * 4.8 ) ( 600 + 300 ) ] + [ ( 25 * 4.8 * 10^3 ) ] - [ ( 1/2 *2.4*20 ) * 300 ] + [ (1/2 * 1.5 * 10 ) ( 600 + 300 ) ]

= 162750 Ib.ft

B) Determine the maximum negative moment produced at G

`M ^-` = [ ( 1/2 * 20 * 4.8 ) * 300 ] - [ ( 1/2 * 2.4 * 20 ) ( 600 + 300 ) ] - [ (2.5 * 10^3 * 2.4 ) ] + [ ( 1/2 * 1.5 * 10) * 300 ]

= - 64950 Ib.ft