Engineering Mechanics
Solution
choice=menu(‘Which solution do you want’,’Solution 1′, ‘Solution 2’, ‘Solution 3′);
if choice==1
%order of forces in members-CD,BC,BD,DE,BE,AB,AE,EF,AF
A=[5/sqrt(29) 0 0 0 0 0 0 0 0;2/sqrt(29) 1 0 0 0 0 0 0 0;5/sqrt(29) 0 5/sqrt(29) 0 0 0 0 0 0;-2/sqrt(29) 0 2/sqrt(29) 1 0 0 0 0 0;…
0 0 5/sqrt(29) 0 5/sqrt(29) 0 0 0 0; 0 -1 -2/sqrt(29) 0 2/sqrt(29) 1 0 0 0;0 0 0 0 5/sqrt(29) 0 5/sqrt(29) 0 0;0 0 0 -1 -2/sqrt(29) 0 2/sqrt(29) 1 0;…
0 0 0 0 0 0 5/sqrt(29) 0 1];
b=[80;0;0;0;60;0;0;0;0];
x=A\b;
C=cell(10,3);
C{1,1}=’Member’;
C{1,2}=’Force(kN)’;
C{1,3}=’Type’;
C{2,1}=’CD’;C{3,1}=’BC’;C{4,1}=’BD’;C{5,1}=’DE’;C{6,1}=’BE’;C{7,1}=’AB’;C{8,1}=’AE’;C{9,1}=’EF’;C{10,1}=’AF’;
for i=2:1:10
C{i,2}=x(i-1);
if x(i-1)<0
C{i,3}=’Compression’;
else
C{i,3}=’Tension’;
end
end
C
end
if choice==2
vo=20;
theta=30;
alpha=25;
g=9.81;
vx=vo*sind(theta)*cosd(alpha);
vy=vo*sind(theta)*sind(alpha);
vz=vo*cosd(theta);
tb=(2*vz)/g;
t=linspace(0,tb,200);
xin=0;yin=0;zin=0;
for i=1:5
tb=(2*vz)/g;
t=linspace(0,tb,200);
for j=1:200
x1(j,i)=xin+vx*t(j);
y1(j,i)=yin+vy*t(j);
z1(j,i)=zin+vz*t(j)-0.5*g*t(j)^2;
end
xin=x1(200,i);
yin=y1(200,i);
zin=0;
vx=0.8*vx;
vy=0.8*vy;
vz=0.8*vz;
end
x=[x1(:,1);x1(:,2);x1(:,3);x1(:,4);x1(:,5)];
y=[y1(:,1);y1(:,2);y1(:,3);y1(:,4);y1(:,5)];
z=[z1(:,1);z1(:,2);z1(:,3);z1(:,4);z1(:,5)];
plot3(x,y,z);
grid on;
xlabel(‘x(m)’);
ylabel(‘y(m)’);
zlabel(‘z(m)’);
end
if choice==3
k=1;
d=linspace(0,4,1000);
w=linspace(0,8,1000);
S=0.001;
n=0.05;
for i=1:1000
for j=1:1000
Q(i,j)=((k*d(i)*w(j)/n)*(w(j)*d(i)/(w(j)+2*d(i)))^(2/3))*sqrt(S);
end
end
surf(Q);
end