Question: why this integral does not return anything ?

July 29 2014 mehdi jafari 340

0


``

restart:

l := 16; m := .75; EIy := 0.2e5; EIz := 0.400e7; GJ := 0.1e5; mj := .1; Pz := 5000;

16

 

.75

 

0.2e5

 

0.400e7

 

0.1e5

 

.1

 

5000

(1)

eq1 := m*(diff(diff(w(x, t), t), t))+diff(diff(EIy*(diff(diff(w(x, t), x), x))+(EIz-EIy)*(diff(diff(w(x, t), x), x))*(theta(x)+phi(x, t))^2, x), x)-Pz = 0;

.75*(diff(diff(w(x, t), t), t))+0.2e5*(diff(diff(diff(diff(w(x, t), x), x), x), x))+0.398e7*(diff(diff(diff(diff(w(x, t), x), x), x), x))*(theta(x)+phi(x, t))^2+0.1592e8*(diff(diff(diff(w(x, t), x), x), x))*(theta(x)+phi(x, t))*(diff(theta(x), x)+diff(phi(x, t), x))+0.796e7*(diff(diff(w(x, t), x), x))*(diff(theta(x), x)+diff(phi(x, t), x))^2+0.796e7*(diff(diff(w(x, t), x), x))*(theta(x)+phi(x, t))*(diff(diff(theta(x), x), x)+diff(diff(phi(x, t), x), x))-5000 = 0

(2)

w := unapply(q[1](t)*cosh(1.8751*x/l),x, t);

proc (x, t) options operator, arrow; q[1](t)*cosh(.1171937500*x) end proc

(3)

theta := proc (x) options operator, arrow; 0 end proc;

proc (x) options operator, arrow; 0 end proc

(4)

#theta(x);eq1;

phi := unapply(q[4](t)*sin(1.5708*x/l),x, t);

proc (x, t) options operator, arrow; q[4](t)*sin(0.9817500000e-1*x) end proc

(5)

eq2:=unapply(lhs(eq1),x,t);

proc (x, t) options operator, arrow; .75*(diff(diff(q[1](t), t), t))*cosh(.1171937500*x)+3.772661154*q[1](t)*cosh(.1171937500*x)-302.9569534*q[1](t)*cosh(.1171937500*x)*q[4](t)^2*sin(0.9817500000e-1*x)^2+2515.691179*q[1](t)*sinh(.1171937500*x)*q[4](t)^2*sin(0.9817500000e-1*x)*cos(0.9817500000e-1*x)+1053.716523*q[1](t)*cosh(.1171937500*x)*q[4](t)^2*cos(0.9817500000e-1*x)^2-5000 end proc

(6)

f[1] := int(expand(eq2(x,t)*cosh(1.8751*x/l)), x = 0 .. l);

int(.75*(diff(diff(q[1](t), t), t))*cosh(.1171937500*x)^2+3.772661154*q[1](t)*cosh(.1171937500*x)^2-302.9569534*q[1](t)*cosh(.1171937500*x)^2*q[4](t)^2*sin(0.9817500000e-1*x)^2+2515.691179*cosh(.1171937500*x)*q[1](t)*sinh(.1171937500*x)*q[4](t)^2*sin(0.9817500000e-1*x)*cos(0.9817500000e-1*x)+1053.716523*q[1](t)*cosh(.1171937500*x)^2*q[4](t)^2*cos(0.9817500000e-1*x)^2-5000*cosh(.1171937500*x), x = 0 .. 16)

(7)

 

 

``


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