# Deflection of the hull

Discussion in 'Boat Design' started by JoshTruman, Feb 8, 2024.

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### JoshTrumanJunior Member

Good Day Sirs!
I would like to ask if somebody has some explained proceduree regarding calculation of ship hull deflection based on bending moment?
Best wishes!

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### gonzoSenior Member

Is this localized deflection or global?

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### JoshTrumanJunior Member

Hello! It can be in specified cross section but it will be also ok to count deflection on the midships of the ship.

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### TANSLSenior Member

Much simplifying the problem, the attached file indicates how to calculate the slope and deflection of a uniform beam subjected to simple bending.
The real problem of this calculation is to know the bending moment at each point of the ship-beam. Although in theory it is very simple - some experts would tell you that just calculating the weights and buoyancy and they would be so pleased with themselves - calculating the distribution of those weights and buoyancy is complicated and very laborious.

#### Attached Files:

• ###### Slope and deflection.pdf
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### CacciatoreNaval Architect and Marine Engineer

Hello Josh,

You are definitely referring to the longitudinal strength calculation of a ship, particularly the sizing of the midship section (Cargo Region). It's one of the most straightforward aspects to develop, which will enable you to accurately size both the hull plating and all the longitudinal elements of a ship beam with a cylindrical trunk.

https://civamblog.files.wordpress.com/2016/11/ts301.pdf

Look Section 5 for any doubts just reply.

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### gonzoSenior Member

By localized I mean deflection from local loads like blocking at a drydock.

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