Structural Theory | Beam Deflection using Virtual Work Method Part 2 of 2

[@viralcat-w4x]

This problem can also be solved using three-moment equation. First by identifying the reactions which is Ra = Re = 75 kN, Then followed by getting the moment equation of the entire beam starting at point A which is M = 75x - 150, therefore, other parameters will be:
Ma = 0
Mb = 75(3) - 0 = 225 kNm
Md = 75(9) - 150 = 225 kNm
L1 = 3 m
L2 = 6 m
I_2 = 2(I_1)
EI = 200(10^6)*(300*10^-6) = 60000 kNm^2
6Aa/L = 0
6Ab/L = (Pb/L)(L^2 - b^2) = [150(3)/6](6^2 - 3^2) = 2025
Since the deflection at B is equal to the deflection at D, therefore, we use the reference line at deflection at B which means that h1 = ?? and h2 = 0
Substitute all the values to three-moment equation
0 + 2(225)(3 + 6/2) + 225(6/2) + 0 + 2025/2 = 6(60000)(h/3 + 0/6)
Therefore, h = 0.0365625 m = 36.5625 mm

[@maditmichaelmalangatem6366]

Thanks
I understand your lectures very well. 💯

[@samuelgosaye5071]

well explained, we love you man

[@esthermuthomi600]

Finally,I understood virtual method...thumbs up😘

[@mihrabanjabar1607]

Thank you ❤️

[@florenceting9824]

May i know how to determine the boundary of equation? i am confused when you always start x from A but set your boundary within the segment itself only... Does the x always start from same point? and the boundary always follow back the segment itself?

[@justtrendycontent79]

well explained sir❤

[@natanimkore]

thank you sir

[@Msaigon13]

12:29 sir hindi po ba kau nagkamali ng input sa point load na 1? sa D po ba talaga siya or sa C?

[@nyakunimartin2230]

Is this the same method used when solving engineering Mechanics principles with the principle of virtual work

[@vicentssekyanzi9567]

Moment equation for section DE on the real part is75x-150(x-9)

[@RakiaKun]

no, only x-6

[@speakthetruth-o4i]

Thanks

[@ryansingculan453]

Hi Sir! Very helpful tutorial. I have a question about whether to consider the segments CD and DE when computing for the deflection at B?

[@viralcat-w4x]

By symmetry, we can see that the deflection at B is just equal to deflection at D

[@vicentssekyanzi9567]

Section DE.its x-9