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smegal

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**1. I am trying to analyse the hydrostatic pressures exerted on a submarine at depth**

Firstly If I model the submarine as being two hemispherical ends with a cylindrical section. Am I correct to model them seperately then combine the results at the end to calculate the deformation or is there a better method of doing this.

Variables p=pressure R=radius t=wall thickness E=youngs modulus Pr=poissons ratio

2. I have used the equations

(please ignore the way the equations are laid out it is my personal notation in MATLAB)

sphere_stress=-(p*R)/(2*t);

hoop_stress= -(p*R)/t

longitudinal_stress =-(p*R)/(2*t)

then to calcualte the strains on the cylindrical part.

Circumferential_strain=(1/E)*(hoop_stress-Pr*longitudinal_stress)

Longitudinal_strain= (1/E)*(longitudinal_stress-Pr*hoop_stress)

I am struggling with the equation for the strain acting upon the spherical ends.

Once I have the strain acting upon the sphere I can then calculate the change in length diameter and volume

Variables p=pressure R=radius t=wall thickness E=youngs modulus Pr=poissons ratio

2. I have used the equations

(please ignore the way the equations are laid out it is my personal notation in MATLAB)

sphere_stress=-(p*R)/(2*t);

hoop_stress= -(p*R)/t

longitudinal_stress =-(p*R)/(2*t)

then to calcualte the strains on the cylindrical part.

Circumferential_strain=(1/E)*(hoop_stress-Pr*longitudinal_stress)

Longitudinal_strain= (1/E)*(longitudinal_stress-Pr*hoop_stress)

I am struggling with the equation for the strain acting upon the spherical ends.

Once I have the strain acting upon the sphere I can then calculate the change in length diameter and volume

Basically I am after a hint to how to calculate the strain on the spherical ends and to have my method of modelling the submarine confirmed as being accurate or being informed if there is a better way.

I apologise if this is in the wrong section.

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