Pressure Range. The following information is provided for a tube analysis as a function of the
selected pressure range:
Depth (equivalent water Depth of selected pressure)
Max Axial Stress (Maximum Stress in tube wall in direction of tube centerline axis)
Max Hoop Stress (Maximum Stress in tube wall in direction normal to tube cross
section)
Max Equiv Stress (Maximum uniaxial stress that is equivalent to the three dimensional
stress state that exists in the tube wall for predicting failure of ductile materials by
comparison to the uniaxial yield strength)
dID (displacement of tube Inner Diameter)
dOD (displacement of tube Outer Diameter)
dLength (Change in tube length)
Under Pressure Ver.4.52
19:25:54
07-14-2012
TUBE CONFIGURATION (External Pressure)
Inner Diameter : 110.00 mm
Outer Diameter : 120.00 mm
Wall Thickness : 5.0000 mm
Tube Length : 150.00 mm
Weight in air : 0.31276 kg
Weight in water: -1.4266 kg
Failure Mode: Shell failure at 63.889 psi (Thick wall eq's)
Thin Wall Buckling at 244.55 psi by 3 nodes
Seat failure N/A
Shear failure N/A
PLASTIC, ACRYLIC Properties:
Ultimate Strength : 8 Ksi (Ksi = 1000 psi)
Working Strength : 0.8 Ksi
Elastic Modulus : 0.35 Mpsi
Density : 0.0417 lb/cu in
Poisson's Ratio : 0.35 (The Poisson ratio is the ratio of the fraction (or percent) of expansion
divided by the fraction (or percent) of compression, for small values of these changes.)
Gortex, the Teflon based material used in athletic clothing is the only known
material with a negative Poisson's ratio: When stretched in one direction, it
expands in the other directions. (See Science Magazine, Vol.247,p630, Feb9,
1990.)
Comments :
Cast Rods or Sheets
Compressive Ultimate Strength = 11 kpsi
Known Commercially as Plexiglass etc.
Tube distortion values:
Pressure Depth
Max Axial
psi
Ft (fresh) Stress, Kbar
Max Hoop
Stress, Kbar
Max Equiv
Stress, Kbar
14.504
29.008
43.511
58.015
63.889
*72.519
*87.023
*101.53
*116.03
*130.53
*145.04
*159.54
*174.05
*188.55
*203.05
*217.56
*232.06
*246.56
*261.07
*275.57
*290.08
-0.012522
-0.025043
-0.037565
-0.050087
-0.055158
-0.062609
-0.075130
-0.087652
-0.10017
-0.11270
-0.12522
-0.13774
-0.15026
-0.16278
-0.17530
-0.18783
-0.20035
-0.21287
-0.22539
-0.23791
-0.25043
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
33.197
66.392
99.585
132.78
146.22
165.97
199.16
232.35
265.53
298.72
331.90
365.08
398.26
431.44
464.62
497.79
530.97
564.14
597.31
630.48
663.65
-0.0062609
-0.012522
-0.018783
-0.025043
-0.027579
-0.031304
-0.037565
-0.043826
-0.050087
-0.056348
-0.062609
-0.068870
-0.075130
-0.081391
-0.087652
-0.093913
-0.10017
-0.10643
-0.11270
-0.11896
-0.12522
d ID
cm
-0.0047090
-0.0094179
-0.014127
-0.018836
-0.020743
-0.023545
-0.028254
-0.032963
-0.037672
-0.042381
-0.047090
-0.051798
-0.056507
-0.061216
-0.065925
-0.070634
-0.075343
-0.080052
-0.084761
-0.089470
-0.094179
dO
cm
dLength
cm
-0.0044657
-0.0089314
-0.013397
-0.017863
-0.019671
-0.022329
-0.026794
-0.031260
-0.035726
-0.040191
-0.044657
-0.049123
-0.053589
-0.058054
-0.062520
-0.066986
-0.071452
-0.075917
-0.080383
-0.084849
-0.089314
-0.0011675
-0.0023350
-0.0035025
-0.0046700
-0.0051429
-0.0058375
-0.0070051
-0.0081726
-0.0093401
-0.010508
-0.011675
-0.012843
-0.014010
-0.015178
-0.016345
-0.017513
-0.018680
-0.019848
-0.021015
-0.022183
-0.023350
* = after housing failure
Under Pressure Ver. 4.5208:56:0907-17-2012Page 1 of 2
PLATE ENDCAP CONFIGURATION (External Pressure)
Outer Diameter : 120.00 mm
Free Diameter : 110.00 mm
Plate Thickness : 5.0000 mm
Edge Restraint : Simply Supported
Weight in air : 0.065271 kg
Weight in water: 0.0072941 kg
Failure Mode: Radial Stress Failure at 5.2629 psi (plate center)
Tangential Stress Failure at 5.2629 psi (plate center) Seat failure at 127.78 psi
Flat Circular Plate distortion: Table eval dia., De = plate center for Max Radial Table eval dia., De = plate
center for Max Tangential
Pressure Depth
De Max Radial
Psi
Ft (fresh) Stress, psi
De Max Tan
Stress psi
Avg Seat
Stress, psi
CL Deflection
mm
14.504* 33.197
2204.7
29.008* 66.392
4409.3
43.511* 99.585
6614.0
58.015* 132.78
8818.7
72.519* 165.97
11023
87.023* 199.16
13228
* = after housing failure
2204.7
4409.3
6614.0
8818.7
11023
13228
-90.806
-181.61
-272.42
-363.22
-454.03
-544.84
-1.9780
-3.9560
-5.9339
-7.9119
-9.8899
-11.868
The maximum shear stress occurs at the plate free diameter and is equal to (Pxd)/(4xt) where P= applied
pressure, d = plate free diameter and t = plate thickness. Shear stresses are insignificant as compared to
radial and tangential stresses for flat circular plates unless the ratio of the plate thickness to plate free
diameter (t/d) approaches 3/8 for a fixed edge restraint or 5/8 for a simply supported edge restraint
(these ratios assume a Poissons’s Ratio of .3 and a shear strength equal to ½ of the uniaxial strength).
DEFINITION OF MATERIAL PROPERTIES
-Ultimate Strength (tensile) (for Main Categories Glass, Ceramics): Maximum uniaxial tensile
stress material can withstand without failure.
-Ultimate Strength (compressive) (for Main Categories Glass, Ceramics): Maximum uniaxial
compressive stress material can withstand without failure.
-Yield Strength (for Main Category Metals): Uniaxial stress at which yield (permanent deformation)
of the material is initiated.
-Ultimate Strength (for Main Category Plastics): Maximum uniaxial stress material can withstand
without failure.
-Working Strength (for Main Category Plastics): Maximum stress allowed in material during service
as defined by pressure vessel designer.
-Young’s Modulus (for all Main Categories): Average ratio of stress to strain for stress below the
proportional limit, measurement of material stiffness.
-Density (for all Main Categories): Mass or weight per unit volume of material.
-Poisson’s Ratio (for all Main Categories): Absolute value of the ratio of lateral strain over axial
strain.
-Clicking on Pipe Tables allows the user to load standard pipe cross section geometries for analysis.
-If the ratio of the tube mean radius/tube wall thickness is greater than 10, the program uses thin wall
formulas to calculate stresses. If the ratio of the tube mean radius/tube wall thickness is less than or
equal to 10, the program uses thick wall formulas to calculate stresses.
Axial stress = ½ Hoop stress for thin wall equations
for both external and internal pressure loading.
Axial stress = ½ Hoop stress at Tube I.D. for thick
wall equations for external pressure loading.





Simply Supported Edge Restraint:
Maximum radial stress = maximum
tangential stress and occurs at the inner
and outer surfaces of the plate at the plate
center line.