Programs/code

Tether Tension Calculator:

This MATLAB code calculates the tension in tether for any configuration input by the user. Input includes information on burrow segments in the order of each segment: length, inclination, bend angle. Constants needed as well are the coefficient of friction of the tether with soil (or PVC etc), and the weight (mass/length) of the tether.

code:

%% Ultimate Tether Force Calculator

% Jiuqi Wang

% A14732037

% 04/24/2020

clear all; clc; close all;

format long;

%% Introductions

   disp('     ');

disp('This is a MATLAB file focus on the total tether force based on several');

disp('sections of different types of burrow (straight or turn).');

disp('     ');

disp('If you dont know some of parameters, please enter values below');

disp('     ');

disp('Default Friction Coefficient = 0.67');

disp('Default Total Cable Assembly Weight = 0.0414');

disp('Default Bending Section Radius = 0.05');

disp('     ');

%% Initialization

Tin = 0; % Tension into a section [N]

w = 1; % Weight correction factor (Assume solid tether)

miu = input('Please input the coefficient of friction: '); % Coefficient of friction

W = input('Please input the total cable assembly weight [kg/m]: '); % Total Cable Assembly Weight [kg/m]

W = W*9.8; % Calculate force [N]

n = input('Please enter number of sections: ');

disp('     ');

%% Loop

i = 1;

T = [Tin, zeros(1,n)];

while i <= n

    fprintf('Section %d\n',i);

    Type = input('Please input section type straight [s] or turn [t]: ','s');

    % Calculation

    switch Type

        case 's'

            L = input('Please input the length of this section [m]: '); % Length [m]

            disp('Range of the Angle ¦È should be [-90,90]');

            theta = input('Please input the inclination angle [Degree]: '); % Angle [Degree]

            T(i+1) = T(i)+W*L*(sind(theta)+w*miu*cosd(theta));

        case 't'

            R = input('Please input the length of the bending section radius [m]: '); % Bending Section Radius [m]

            disp('Range of the Angle ¦Õ should be (-180,180)');

            phiD = input('Please input the turning angle [Degree]: '); % Turning Anle [Degree]

            phi = phiD*2*pi/360; % Convert into Radius

            Lr = pi*R*2*phiD/360;

            T(i+1) = T(i)*cosh(w*miu*phi)+sinh(w*miu*phi)*(T(i)^2+(W*R)^2)^0.5;%+W*Lr*w*miu;

        otherwise

            disp('Wrong input');

            T(i+1) = 0;

    end

    i = i+1;

    disp('     ');

end

%% Results

% Plot

N = 0:n;

figure (1);

plot(N,T,'-o');

xlabel('Section Number');

ylabel('Tether Force [N]');

title('Tether Force at each Nodes');

box on; grid on;

% Output Force

Tout = T(end);

fprintf('The output force is %.2f N! \n',Tout);