Guide for a roller support

I have roller support in a 1500ft long pipe. The pipe has a curved shape. I used V-stop to replicate the roller support. But the pipe has movements in the negative Z direction (isometric view). I am trying to use guide support to restrict the movement in that direction. But I still have deflection in negative Z direction after I used Guide support. Can someone please tell me a way to fix this issue or a way to design a support to take care of that movement. 

Thank You very much

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  • Hello Ebin, 

    There is no image to indicate which direction is set to X, Y, Z. Which is the vertical axis?

    Assuming:

    a. X - Z axis make up the horizontal plane

    b. using guide supports with 0.00 vertical and lateral gap settings

    c. guidde supports are connected to the ground

    It is possible that there may be a little lateral movement at the node point as it slips past the support. However, if you were to look at support itself, you may find that there is no lateral movement. 

    Regards,

    Mike Dattilio
    Bentley Product Advantage Group Analyst
    AutoPIPE Product Line Bentley Systems, Inc.
    ===================================================

  • Mike,

    I am trying to reduce the deflections in Z direction. I put .125" gap in left and right gap box but the deflection went more than that. I got about .87". Is that normal?. Is there anyway to restrict movements in Z direction. Attached is the screenshot. Please let me know

    Thank You

       

  • Hello Ebin, 

    Yes the movement can easily exceed the gaps settings. One needs to understand a few concepts:

    1. Load sequence - only look at the operating conditions and not the individual load cases. 

    2. Difference between Local coordinates and Global coordinates. 

    Support report has both coordinate results where the Displacement report on has results in Global coordintes. 

    See Example here:

    Model input listing:

    -------------------------------------------------------------------------------
    *** SEGMENT A

    -------------------------------------------------------------------------------
    From A00 to A01, DX= 1.29 ft, DZ= 4.83 ft, L= 5.00 ft Run

    PIPE DATA:
    Pipe Id= 23, Material= A53-A, Composition= Carbon Steel, Poisson= 0.300, Nom Size= 8 in, OD= 8.625 inch,
    Sch= STD, Wall Thk= 0.322 inch, Mill= 0.040 inch, Cor= 0 inch, Pipe Density= 489.00 lb/cu.ft,
    Pipe Unit Wgt= 28.52 lb/ft, Insul Thk= 0 inch, Cladding Thickness = 0 inch, Lining Thk= 0 inch,
    Long Weld E factor= 1.00, Long Weld W factor= 1.00, Long Modulus= 29.50000 E6 psi,
    Hoop Modulus= 29.50000 E6 psi, Shear Modulus= 11.34615 E6 psi, Sc= 16000.0 psi, Syc= 30000.0 psi, Suc= 48000.0 psi

    OPERATING DATA:
    P1= 0 psi, T1= 70.00 deg F, Exp1= 0 in/100ft, E1= 29.50000 E6 psi, Sh1= 16000.00 psi, Sy1= 30000.00 psi

    POINT DATA:
    A00, Coordinates, X= 0.00 ft, Y= 0.00 ft, Z= 0.00 ft

    SUPPORT DATA:
    A00, Anchor, KTX= Rigid, KTY= Rigid, KTZ= Rigid, KRX= Rigid, KRY= Rigid, KRZ= Rigid

    -------------------------------------------------------------------------------
    From A01 to A02, DX= 2.50 ft, DZ= 4.33 ft, L= 5.00 ft Bend

    COMPONENT DATA (Bend, TIP= A01, Near= A01 N, Far= A01 F):
    Long Elbow, Radius= 12.00 inch, Bend angle= 15.00 deg, End flanges= 0, Flex= Auto, SIFI= 2.44, SIFO= 2.03

    POINT DATA:
    A01, Coordinates, X= 1.29 ft, Y= 0.00 ft, Z= 4.83 ft
    A01 N, Coordinates, X= 1.26 ft, Y= 0.00 ft, Z= 4.70 ft
    A01 F, Coordinates, X= 1.36 ft, Y= 0.00 ft, Z= 4.94 ft

    SUPPORT DATA:
    A01 N, Guide, Support Id= A01 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless

    -------------------------------------------------------------------------------
    From A02 to A03, DX= 3.54 ft, DZ= 3.54 ft, L= 5.00 ft Run

    POINT DATA:
    A02, Coordinates, X= 3.79 ft, Y= 0.00 ft, Z= 9.16 ft
    A03, Coordinates, X= 7.33 ft, Y= 0.00 ft, Z= 12.70 ft

    SUPPORT DATA:
    A02, Guide, Support Id= A02 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless
    A03, Guide, Support Id= A03 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless

    -------------------------------------------------------------------------------

    THERMAL ANCHOR MOVEMENTS AND DISPLACEMENTS

    POINT DX DY DZ RX RY RZ
    NAME LOAD CASE (in ) (in ) (in ) (deg ) (deg ) (deg )
    ----- ---------- -------- -------- -------- -------- -------- --------
    A00 Thermal 1 1.00 0.00 1.00 0.000 0.000 0.000

    Results:

    Noticed that the local displacement does not exceed the gap setting. However the global displacement does exceed the gap settings. 

    Summary:

    Always look at the support report for local displacement to understand exactly what is occurring. In addition  only look at operating conditions not the individual load cases. 

    Please review this correspondence and let me know if you require further assistance on this issue or if there are no further questions that this Service Request may be closed.

    Thank you for your time.

    Regards

    Mike Dattilio
    Bentley Product Advantage Group Analyst
    AutoPIPE Product Line Bentley Systems, Inc.
    =====================================================

Reply
  • Hello Ebin, 

    Yes the movement can easily exceed the gaps settings. One needs to understand a few concepts:

    1. Load sequence - only look at the operating conditions and not the individual load cases. 

    2. Difference between Local coordinates and Global coordinates. 

    Support report has both coordinate results where the Displacement report on has results in Global coordintes. 

    See Example here:

    Model input listing:

    -------------------------------------------------------------------------------
    *** SEGMENT A

    -------------------------------------------------------------------------------
    From A00 to A01, DX= 1.29 ft, DZ= 4.83 ft, L= 5.00 ft Run

    PIPE DATA:
    Pipe Id= 23, Material= A53-A, Composition= Carbon Steel, Poisson= 0.300, Nom Size= 8 in, OD= 8.625 inch,
    Sch= STD, Wall Thk= 0.322 inch, Mill= 0.040 inch, Cor= 0 inch, Pipe Density= 489.00 lb/cu.ft,
    Pipe Unit Wgt= 28.52 lb/ft, Insul Thk= 0 inch, Cladding Thickness = 0 inch, Lining Thk= 0 inch,
    Long Weld E factor= 1.00, Long Weld W factor= 1.00, Long Modulus= 29.50000 E6 psi,
    Hoop Modulus= 29.50000 E6 psi, Shear Modulus= 11.34615 E6 psi, Sc= 16000.0 psi, Syc= 30000.0 psi, Suc= 48000.0 psi

    OPERATING DATA:
    P1= 0 psi, T1= 70.00 deg F, Exp1= 0 in/100ft, E1= 29.50000 E6 psi, Sh1= 16000.00 psi, Sy1= 30000.00 psi

    POINT DATA:
    A00, Coordinates, X= 0.00 ft, Y= 0.00 ft, Z= 0.00 ft

    SUPPORT DATA:
    A00, Anchor, KTX= Rigid, KTY= Rigid, KTZ= Rigid, KRX= Rigid, KRY= Rigid, KRZ= Rigid

    -------------------------------------------------------------------------------
    From A01 to A02, DX= 2.50 ft, DZ= 4.33 ft, L= 5.00 ft Bend

    COMPONENT DATA (Bend, TIP= A01, Near= A01 N, Far= A01 F):
    Long Elbow, Radius= 12.00 inch, Bend angle= 15.00 deg, End flanges= 0, Flex= Auto, SIFI= 2.44, SIFO= 2.03

    POINT DATA:
    A01, Coordinates, X= 1.29 ft, Y= 0.00 ft, Z= 4.83 ft
    A01 N, Coordinates, X= 1.26 ft, Y= 0.00 ft, Z= 4.70 ft
    A01 F, Coordinates, X= 1.36 ft, Y= 0.00 ft, Z= 4.94 ft

    SUPPORT DATA:
    A01 N, Guide, Support Id= A01 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless

    -------------------------------------------------------------------------------
    From A02 to A03, DX= 3.54 ft, DZ= 3.54 ft, L= 5.00 ft Run

    POINT DATA:
    A02, Coordinates, X= 3.79 ft, Y= 0.00 ft, Z= 9.16 ft
    A03, Coordinates, X= 7.33 ft, Y= 0.00 ft, Z= 12.70 ft

    SUPPORT DATA:
    A02, Guide, Support Id= A02 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless
    A03, Guide, Support Id= A03 1, Connected to Ground, Comp.Wt = 0.000 lb, Stiffness= RIGID,
    Gap-Down= 0.00 inch, Gap-Above= 100.00 inch, Gap-Left= 0.50 inch, Gap-Right= 0.50 inch, Friction= 0.00,
    Gaps setting= Weightless

    -------------------------------------------------------------------------------

    THERMAL ANCHOR MOVEMENTS AND DISPLACEMENTS

    POINT DX DY DZ RX RY RZ
    NAME LOAD CASE (in ) (in ) (in ) (deg ) (deg ) (deg )
    ----- ---------- -------- -------- -------- -------- -------- --------
    A00 Thermal 1 1.00 0.00 1.00 0.000 0.000 0.000

    Results:

    Noticed that the local displacement does not exceed the gap setting. However the global displacement does exceed the gap settings. 

    Summary:

    Always look at the support report for local displacement to understand exactly what is occurring. In addition  only look at operating conditions not the individual load cases. 

    Please review this correspondence and let me know if you require further assistance on this issue or if there are no further questions that this Service Request may be closed.

    Thank you for your time.

    Regards

    Mike Dattilio
    Bentley Product Advantage Group Analyst
    AutoPIPE Product Line Bentley Systems, Inc.
    =====================================================

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