Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 2K views

    Vessel Davit Design (Based On Pressure Vessel Design Manual by Dennis R Moss)

    Uploaded by

    pandiangv
    This document provides design details for a vessel davit system. Key details include: - The davit has a maximum rated capacity of 500 kg and supports a boom and brace weighing 125 kg. - Stress analyses were performed to check that axial and bending stresses in the davit mast meet allowable limits. - Equivalent radial loads of up to 162481 N and a longitudinal moment of 6116535 N-mm were calculated for local stress analysis at supports. - All stress levels were found to be below allowable limits, indicating the davit design is structurally sound.

    Copyright:

    © All Rights Reserved
    Download as XLS, PDF, TXT or read online from Scribd

    Vessel Davit Design (Based On Pressure Vessel Design Manual by Dennis R Moss)

    Uploaded by

    pandiangv
    2K views8 pages
    This document provides design details for a vessel davit system. Key details include: - The davit has a maximum rated capacity of 500 kg and supports a boom and brace weighing 125 kg. - Stress analyses were performed to check that axial and bending stresses in the davit mast meet allowable limits. - Equivalent radial loads of up to 162481 N and a longitudinal moment of 6116535 N-mm were calculated for local stress analysis at supports. - All stress levels were found to be below allowable limits, indicating the davit design is structurally sound.

    Original Description:

    Original Title

    Davit Calculation

    Copyright

    © © All Rights Reserved

    Available Formats

    XLS, PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    This document provides design details for a vessel davit system. Key details include: - The davit has a maximum rated capacity of 500 kg and supports a boom and brace weighing 125 kg. - Stress analyses were performed to check that axial and bending stresses in the davit mast meet allowable limits. - Equivalent radial loads of up to 162481 N and a longitudinal moment of 6116535 N-mm were calculated for local stress analysis at supports. - All stress levels were found to be below allowable limits, indicating the davit design is structurally sound.

    Copyright:

    © All Rights Reserved
    Download as XLS, PDF, TXT or read online from Scribd
    Download as xls, pdf, or txt
    2K views8 pages

    Vessel Davit Design (Based On Pressure Vessel Design Manual by Dennis R Moss)

    Uploaded by

    pandiangv
    This document provides design details for a vessel davit system. Key details include: - The davit has a maximum rated capacity of 500 kg and supports a boom and brace weighing 125 kg. - Stress analyses were performed to check that axial and bending stresses in the davit mast meet allowable limits. - Equivalent radial loads of up to 162481 N and a longitudinal moment of 6116535 N-mm were calculated for local stress analysis at supports. - All stress levels were found to be below allowable limits, indicating the davit design is structurally sound.

    Copyright:

    © All Rights Reserved
    Download as XLS, PDF, TXT or read online from Scribd
    Download as xls, pdf, or txt
    of 8

    VESSEL DAVIT DESIGN (BASED ON PRESSURE VESSEL DESIGN MANUAL BY DENNIS R

    MOSS)

    L2=1000

    L1=2000

    R=750
    2000

    M2

    M1

    Pipe Material : SA 106 GR. B


    Minimum Yield Stress, Sy
    =
    Allowable Bending Stress, Fb =
    Pipe = 6" Sch 120, OD
    =
    tp = thickness of pipe
    =
    di = ID of Pipe

    r = Radius of Gyration
    A = Cross sectional Area
    a = Outside radius of pipe
    L1
    L2
    L3
    L4
    R
    B (Guide plate width)

    =
    =
    =
    =
    =
    =
    =
    =
    =

    241.32 MPa
    144.79 MPa
    168.3 mm
    18.26
    131.78
    53.4
    8607
    84.2
    2000
    1000
    1000
    290
    750
    210

    mm
    mm
    mm2
    mm
    mm
    mm
    mm
    mm
    mm
    mm

    I = Moment of Inertia of Pipe =


    Z= Section modulous of Pipe =
    WL= Maximum rated capacity =
    W1=Weight of boom & brace =
    WD = Total Weight of davit
    =
    Cv
    =

    24579160
    292087
    500
    125
    350

    mm4
    mm3
    Kgs
    Kgs
    Kgs

    1.8

    Ch

    0.5

    fv = Cv WL

    900 Kgs

    fh = Ch WL

    250 Kgs

    Axial load on davit mast, P:


    P =2fv + WD
    =

    2150 Kgs
    21092 N

    Bending Moment in davit mast, M1 (TYPE 1):


    Type 1: M1 =2fvL1+0.5W1L1+fhL2 =
    For Type B Davit:
    Axial Stress:
    fa = P/A

    3975000 Kgf - mm
    38994750 N-mm

    2.45 MPa

    Bending Moment, M2:


    M2 = M1 (L2-R)/L2

    9748688 N-mm

    Coefficients:
    = tp R/a2 =

    1.93
    0.22
    0.84

    = 6 / (5+6 ) =
    K = 1 - 9 / (10+12) =

    Bending Stress, fb :
    Sy, Yield Stress for SA 106 Gr. B is 241.32 MPa.
    Fb, Allowable bending Stress (0.6 x Sy) is 144.8 MPa.
    At M1, fb = M1/Z

    133.50 MPa
    < Fb, Hence Safe

    At M2, fb = (M2 a/I)*(2 / 3K Sqrt(3))

    32.86 MPa
    <Fb, Hence Safe

    Combined Stress:
    Slenderness Ratio = 2.1*L2/r =

    39

    Fa = Allowable Axial Stress =

    132.86 MPa

    (From Table C-36 of Manual of Steel Construction by AISC)


    fa/Fa + fb/Fb =
    0.94
    <1.0, Hence Safe

    FINDING EQUIVALENT RADIAL LOAD, Fre


    Radial Force At Guide & Support, Fr

    M1/L3
    38994.8 N

    =
    Fr is max when davit rotation is at 0o
    Circumferential moment at guide and support, M = Fr * L4
    M is max when davit rotation is at 90o,
    Longitudinal moment at guide, Mx=P*L4

    11308478 N-mm
    6116535 N-mm

    Equivalent Unit load, w = (Fr*Cos/ B) + (6*Fr*L4*Sin / B2 )

    N/mm

    Equivalent Radial Load, Fre = w*B/2

    o
    0
    20
    40
    50
    60
    65
    70
    75
    80
    90

    w (N/mm)
    185.7
    700.7
    1131.2
    1298.0
    1425.3
    1472.9
    1509.3
    1534.2
    1547.4
    1538.6

    Loads for Local Stress Analysis:


    At Guide: Radial Load, Fre
    At Support: Radial Load, Fre
    Longitudinal Moment, Mx

    =
    =
    =

    Fre (N)
    19497
    73575
    118778
    136287
    149655
    154654
    158476
    161091
    162481
    161550

    162481 N
    162481 N
    6116535 N-mm

    Table C-36 (AISC)


    kl/r
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46

    Fa (ksi)
    Fa (Mpa)
    21.56
    148.65
    21.52
    148.38
    21.48
    148.10
    21.44
    147.82
    21.39
    147.48
    21.35
    147.20
    21.3
    146.86
    21.25
    146.51
    21.21
    146.24
    21.16
    145.89
    21.1
    145.48
    21.05
    145.13
    21
    144.79
    20.95
    144.45
    20.89
    144.03
    20.83
    143.62
    20.78
    143.27
    20.72
    142.86
    20.66
    142.45
    20.6
    142.03
    20.54
    141.62
    20.48
    141.20
    20.41
    140.72
    20.35
    140.31
    20.28
    139.83
    20.22
    139.41
    20.15
    138.93
    20.08
    138.45
    20.01
    137.96
    19.94
    137.48
    19.87
    137.00
    19.8
    136.52
    19.73
    136.03
    19.65
    135.48
    19.58
    135.00
    19.5
    134.45
    19.42
    133.90
    19.35
    133.41
    19.27
    132.86
    19.19
    132.31
    19.11
    131.76
    19.03
    131.21
    18.95
    130.66
    18.86
    130.04
    18.78
    129.48
    18.7
    128.93

    102
    88.59767

    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96

    18.61
    18.53
    18.44
    18.35
    18.26
    18.17
    18.08
    17.99
    17.9
    17.81
    17.71
    17.62
    17.53
    17.43
    17.33
    17.24
    17.14
    17.04
    16.94
    16.84
    16.74
    16.64
    16.53
    16.43
    16.33
    16.22
    16.12
    16.01
    15.9
    15.79
    15.69
    15.58
    15.47
    15.36
    15.24
    15.13
    15.02
    14.9
    14.79
    14.67
    14.56
    14.44
    14.32
    14.2
    14.09
    13.97
    13.84
    13.72
    13.6
    13.48

    128.31
    127.76
    127.14
    126.52
    125.90
    125.28
    124.66
    124.04
    123.42
    122.80
    122.11
    121.49
    120.87
    120.18
    119.49
    118.87
    118.18
    117.49
    116.80
    116.11
    115.42
    114.73
    113.97
    113.28
    112.59
    111.83
    111.14
    110.39
    109.63
    108.87
    108.18
    107.42
    106.66
    105.90
    105.08
    104.32
    103.56
    102.73
    101.97
    101.15
    100.39
    99.56
    98.73
    97.91
    97.15
    96.32
    95.42
    94.60
    93.77
    92.94

    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146

    13.35
    13.23
    13.1
    12.98
    12.85
    12.72
    12.59
    12.47
    12.33
    12.2
    12.07
    11.94
    11.81
    11.67
    11.54
    11.4
    11.26
    11.13
    10.99
    10.85
    10.71
    10.57
    10.43
    10.28
    10.14
    9.99
    9.85
    9.7
    9.55
    9.41
    9.26
    9.11
    8.97
    8.84
    8.7
    8.57
    8.44
    8.32
    8.19
    8.07
    7.96
    7.84
    7.73
    7.62
    7.51
    7.41
    7.3
    7.2
    7.1
    7.01

    92.05
    91.22
    90.32
    89.49
    88.60
    87.70
    86.81
    85.98
    85.01
    84.12
    83.22
    82.32
    81.43
    80.46
    79.57
    78.60
    77.63
    76.74
    75.77
    74.81
    73.84
    72.88
    71.91
    70.88
    69.91
    68.88
    67.91
    66.88
    65.84
    64.88
    63.85
    62.81
    61.85
    60.95
    59.98
    59.09
    58.19
    57.36
    56.47
    55.64
    54.88
    54.05
    53.30
    52.54
    51.78
    51.09
    50.33
    49.64
    48.95
    48.33

    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196

    6.91
    6.82
    6.73
    6.64
    6.55
    6.46
    6.38
    6.3
    6.22
    6.14
    6.06
    5.98
    5.91
    5.83
    5.76
    5.69
    5.62
    5.55
    5.49
    5.42
    5.35
    5.29
    5.23
    5.17
    5.11
    5.05
    4.99
    4.93
    4.88
    4.82
    4.77
    4.71
    4.66
    4.61
    4.56
    4.51
    4.46
    4.41
    4.36
    4.32
    4.27
    4.23
    4.18
    4.14
    4.09
    4.05
    4.01
    3.97
    3.93
    3.89

    47.64
    47.02
    46.40
    45.78
    45.16
    44.54
    43.99
    43.44
    42.89
    42.33
    41.78
    41.23
    40.75
    40.20
    39.71
    39.23
    38.75
    38.27
    37.85
    37.37
    36.89
    36.47
    36.06
    35.65
    35.23
    34.82
    34.40
    33.99
    33.65
    33.23
    32.89
    32.47
    32.13
    31.78
    31.44
    31.10
    30.75
    30.41
    30.06
    29.79
    29.44
    29.16
    28.82
    28.54
    28.20
    27.92
    27.65
    27.37
    27.10
    26.82

    197
    198
    199
    200

    3.85
    3.81
    3.77
    3.73

    26.54
    26.27
    25.99
    25.72

    You might also like