求解PV ELITE中的错误（有图少真相）（2）

ming05130202 · 发表于 2013-12-9 21:14:07

1605.rar(46.93KB)

请求专家帮助答疑解惑，不胜感激。

文件1605中有关裙座的错误

Skirt Support Analysis Per EN 13445-3: 2009(E) Issue 1 (2009-07):

Item: Node 10 to 20

Type B Skirt per EN 13445 Figure 16.12-2:

Design Pressure                         P          7.600  MPa
Total vessel (empty) weight          Fg    3197611.750  N
Head Weight below section 2-2    DeltaFg       168320.812  N
Weight of vessel contents (liquid)    Ff          0.000  N
Vessel Gross Weight          Fg + Ff = F4    3197611.750  N

Skirt Mean Diameter                   Dz       4170.000  mm
Skirt Analysis Thickness (Corroded)    ez          70.000  mm
Skirt Height                            H       7500.000  mm

Force  at section 1-1                F1    3029291.000  N
Moment at section 1-1                M1    364067104.000  N-mm
Applied Moment - Bottom of Skirt       Mb    725978112.000  N-mm
Weight Above the Skirt                W    3197611.750  N

                        Layout Cntr. Dist.  Obround
Access No Diameter Angle From Bottom  Cntr-Cntr
               mm       Deg       mm       mm
-------------------------------------------------------
   1    600.0000    0.0000  1000.0000    0.0000
   2    1369.0000    0.0000  2900.0000    0.0000
   3    108.0000    0.0000  6600.0000    0.0000
   4    108.0000 60.0000  6600.0000    0.0000
   5    108.0000 120.0000  6600.0000    0.0000
   6    600.0000 180.0000  1000.0000    0.0000
   7    108.0000 180.0000  6600.0000    0.0000
   8    108.0000 240.0000  6600.0000    0.0000
   9    108.0000 300.0000  6600.0000    0.0000

Access Opening Frame Dimension
Access No    Width Thick
               mm    mm
-------------------------------
   1    250.0000 70.0000
   2    220.0000 10.0000
   3    110.0000    4.0000
   4    110.0000    4.0000
   5    110.0000    4.0000
   6    250.0000 70.0000
   7    110.0000    4.0000
   8    110.0000    4.0000
   9    110.0000    4.0000

Interference check:
Access    Access    Pitch    Ligament
                           mm       mm
---------------------------------------------
   1       2    1897.4601    912.9601
   2       3    3697.4602 2958.9602
   3       4    2183.4084 2075.4084
   4       5    2183.4084 2075.4084
   5       6    6012.9629 5658.9624
   6       7    5597.4600 5243.4600
   7       8    2183.4084 2075.4084
   8       9    2183.4084 2075.4084
   1       9    12268.3828 11914.3828

INTERFERENCE CHECK:  No Interference Detected between Openings

Minimum Pitch between openings is: 1897.4601 mm
Minimum Ligament between Openings is: 912.9601 mm

Recommended minimum Ligament:
= 2 * Sqrt( D * t )
= 2 * Sqrt( 4170.000 * 70.000 ) = 1080.555 mm
   Please evaluate the suitability of this result

Warning: Ligament is smaller than 2 * Sqrt( Dz * ez ) - Evaluate with care
   = 2 * Sqrt(4170.000 * 70.000 ) = 1080.5554 mm

Section properties at least metal area [A]:

Number of Openings At Critical Height = 2

Access No       Layout Angle 1    Layout Angle 2
                     Deg.                Deg.
---------------------------------------------------
   2             -19.1655             19.1655

The points for integrating Ixx, Iyy is as follows:
FROM THETA1    TO THETA2
      Deg          Deg
--------------------------
   0.000       -19.165
-340.835       0.000

Height of Weakest Section       H          2900.125  mm
Rotation of Principle Axes       a             0.000  Deg.
Centroid Position in X direction g          -137.595  mm
Centroid Position in Y direction h             0.000  mm
Principle Moment of Inertia    Ixx 1979875983360.000  mm^4
Principle Moment of Inertia    Iyy 1737443246080.000  mm^4
Distance to Extreme Fiber    ybar          2120.000  mm
Distance to Extreme Fiber    xbar          2257.595  mm
Minimum Section Modulus          W4    769600000.000  mm ^3
Metal Area at the Cutting Plane A4       858790.312  mm^2

Half Opening Width Subtended Angle at Weakest Section: [Delta]:
= Asin(Largest(Opening Width) / Dz)
= Asin(1369.000/4170.000 ) = 0.3345 rad (19.1655 deg)

Skirt Mean Radius at Section 4-4 [r]:
= Dz/2 = 4170.000/2 = 2085.0000 mm

Opening Ratio At Weakest Section: EN 13445 Equation 16.12-76 [ratio]:
= Delta * Sqrt(r/ez)
= 0.335 * Sqrt(2085.000/70.000 ) = 1.8256
   Ok as the ratio < 2 - See EN 13445 16.12.76(a).

Analysis of the Section at Weakest Section Modulus [Section 4-4]:

Skirt Corroded Thickness [ez]:
= ex(new) - ci - cext = 70.000 - 0.000 - 0.000 = 70.0000 mm

PLEASE NOTE: There is more than one opening in the skirt
            EN 13445 and AD 2000 considers only one opening per Figure 16.12-4
            this skirt has 9 openings. Please check results

Find the moment acting at the Critical Height [M4]:
= (Mbottom - Mtop)*(H - CutHeight)/H + Mtop
= (.72598E+09 - .36407E+09)*(90000.000 - 34801.504 )/90000.000 + .36407E+09
= .58603E+09 N-mm

Compute the section modulus [Zxx and Zyy]
Zxx = Ixx/ybar = .19799E+13/2120.000 = .93390E+09 mm^(3)
Zyy = Iyy/xbar = .17374E+13/2257.595 = .76960E+09 mm^(3)
Z = Min(Zxx, Zyy) = Min(.93390E+09,.76960E+09) = .76960E+09 mm^(3)

The balance of the calculations are per EN13445, and
they may be treated as academic if the designated code
is not EN 13445

Radius of Gyration of Skirt at 4-4 [rg]:
(rg is not included in the analysis of EN 13445)
= Sqrt( Min( Ixx, Iyy ) / Area(A4) )
= Sqrt( Min( .19799E+13, .17374E+13 )/858790 ) )
= 1422.368 mm

Skirt Slenderness Ratio [r/L]:
= 1422.368/7500.000 = 0.190

Location of the Skirt Centroid at critical height [e]:
ex = -137.595 : ey = 0.000
   e = Sqrt(ex^(2) + ey^(2)) = Sqrt(-137.595^(2)+0.000^(2))
   = 137.595 mm

Moment Increment at Centroid [DeltaM4]:
= ( Fg + Ff ) * e = F4 * e
= ( 3197611 + 0.00 ) * 137.59464 = .44015E+09 N-mm

Nomenclature per EN 13445 (not AD2000)

For the skirt at the opening/weakest part: Equations 16.12-70 & 71:
Actual Stresses:
Sm4p = ( M4 + DeltaM4 ) / W4 - F4 / A4
      = (.58603E+09 + .44015E+09)/.76960E+09 - 3197611/858790
      = -2.39 MPa - Equation 16.12-70

Sm4q = -( M4 + DeltaM4 ) / W4 - F4 / A4
      = -(.58603E+09+ .44015E+09)/.76960E+09- 3197611/858790
      = -5.06 MPa - Equation 16.12-71

Allowable stresses at the opening/weakest part: Equations 16.12-72 & 73:
Max stress for Sm4p and Sm4q: Equations 16.12 72 & 73:
= fz = 115.15 MPa

Skirt stress at the openings / critical section:
Sm4p             -2.39       115.15    Pass    70
Sm4q             -5.06       115.15    Pass    71

The stresses are satisfactory in the region with the opening(s).