Download Runstream - Shell Buckling

ponding to the material types that you have already indicated.
MATERIAL PROPERTIES FOR MATERIAL TYPE 1
Is this material isotropic (Y or N)?=y
y
Young's modulus,
E( 1)=10.E+06
0.1000000E+08
Poisson's ratio,
NU( 1)=.3
0.3000000
transverse shear modulus,
G13( 1)=3.846154E+06
3846154.
Thermal expansion coeff.,
ALPHA( 1)=0
0
residual stress temperature (positive),TEMPTUR( 1)=0
0
Want to supply a stress-strain "curve" for this mat'l (H)?=n
n
Want to specify maximum effective stress ?=h
For isotropic material the answer is usually
For orthotropic material the answer must be
tropic case you must specify maximum tensile
and shear stresses in the principle material
(along the fibers and normal to them).
Y .
N . In the orthoand compressive
directions
Want to specify maximum effective stress ?=y
y
Maximum allowable effective stress in material type( 1)=60000.
60000.00
2 allowables have now been identified.
50 allowables are permitted.
48 additional allowables are permitted.
Sometimes optimum designs are obtained for composite laminates
with models in which the ENTIRE LAMINATE is treated as one
layer, rather than on a ply-by-ply basis. Input data for stress
allowables are generally obtained from membrane and bending tests
on the ENTIRE LAMINATE. Laminate tests usually reveal that the
maximum bending stress before failure of the laminate is
significantly larger than the maximum membrane stress. In order
to exploit this "bending overshoot" during optimization, it is
necessary to include stress constraints of the form:
max.stress constraint = 1/[S(membrane)/S(a) +S(bending)/(f*S(a))]
in which "S" means "stress" and "a" means "allowable". The quantity
"f" is a "bending overshoot factor", which might be different for
as many as five different conditions:
1. S(membrane) is axial tensile; 2. S(membrane) is axial compressive
3. S(membrane) is "hoop"tensile: 4. S(membrane) is "hoop"compressive
5. S(membrane) is in-plane shear stress.
Accordingly, you will next be prompted whether or not you want to
take advantage of "bending overshoot". If you answer "Y" and the
current material does NOT have a single maximum allowable effective
stress, you will then be prompted for the following five bending
overshoot factors, fxt, fxc, fyt, fyc, fxy (each greater than unity):
1. f(axial tensile) =fxt;
2. f(axial compressive) =fxc