% Bolt Calculations for Pressure Vessels
% Last Updated: 3/4/2023
clear all;
%% Constants:
sigma_AL = 35000; %yield stress for aluminum 6061, psi

% ADJUSTABLE VALUES %
P = 3000; %design pressure, psi
N = 10; %number of bolts
d = 0.25; %major diameter of bolt, inches
dh = 0.25; %bolt head diameter, inches
Cdo = 3.75; %case OD, inches
Cdi = 3.0; %case ID, inches
%------------------%

ri = Cdi/2; %case inner radius
ro = Cdo/2; %case outer radius
t = ro-ri; %case thickness, inches
e = 1.25*d; %minimum edge distance
F = P*pi*ri^2; %Forward force load

%% Compressive Stress:

Ab = N*t*d; %projected bolt area

sigma_c = F/Ab;

FoSc = sigma_AL/sigma_c

%% Shear Stress:

As = 2*t*(N*e); %shear area (one ring)

sigma_s = F/As;

FoSs = sigma_AL/sigma_s

%% Tensile Stress:

Ac = (ro^2 - ri^2)*pi - (N*t*dh); 

sigma_t = F/Ac;

FoSt = sigma_AL/sigma_t