Example 2 - stresses in a thick wall cylinder, Example 2 – stresses in a thick wall cylinder ,7-2 – HP 50g Graphing Calculator User Manual
Page 239
Page 7-2
Use command SOLVE at this point (from the S.SLV menu: „Î) After about
40 seconds, maybe more, you get as result a list:
{ ‘t = (x-x0)/(COS(
θ0)*v0)’
‘y0 = (2*COS(
θ0)^2*v0^2*y+(g*x^2(2*x0*g+2*SIN(θ0))*COS(θ0)*v0^2)*x+
(x0^2*g+2*SIN(
θ0)*COS(θ0)*v0^2*x0)))/(2*COS(θ0)^2*v0^2)’]}
Press μ to remove the vector from the list, then use command OBJ , to get
the equations listed separately in the stack.
Example 2 – Stresses in a thick wall cylinder
Consider a thick-wall cylinder for inner and outer radius a and b, respectively,
subject to an inner pressure P
i
and outer pressure P
o
. At any radial distance r
from the cylinder’s axis the normal stresses in the radial and transverse
directions,
σ
rr
and
σ
θθ
, respectively, are given by
Notice that the right-hand sides of the two equations differ only in the sign
between the two terms. Therefore, to write these equations in the calculator, I
suggest you type the first term and store in a variable T1, then the second term,
and store it in T2. Writing the equations afterwards will be matter of recalling
Note: This method worked fine in this example because the unknowns t and
y0 were algebraic terms in the equations. This method would not work for
solving for
θ0, since θ0 belongs to a transcendental term.
,
)
(
)
(
2
2
2
2
2
2
2
2
2
a
b
r
P
P
b
a
a
b
P
b
P
a
o
i
o
i
−
⋅
−
⋅
⋅
+
−
⋅
−
⋅
=
θθ
σ
.
)
(
)
(
2
2
2
2
2
2
2
2
2
a
b
r
P
P
b
a
a
b
P
b
P
a
o
i
o
i
rr
−
⋅
−
⋅
⋅
−
−
⋅
−
⋅
=
σ