Method for checking distributed supporting stand columns between cylindrical FPSO (Floating Production Storage and Offloading) main deck and process deck

Abstract

The invention discloses a method for checking distributed supporting stand columns between a cylindrical FPSO main deck and a process deck. The method for checking the distributed supporting stand columns between the cylindrical FPSO main deck and the process deck comprises the following checking methods that S1, a finite element calculation software model is established; s2, applying a load on the finite element model; s3, module supports are established and arranged, and stand columns are arranged between the main deck and the process deck to serve as supports; s4, pre-analyzing the finite element model; s5, performing finite element model optimization analysis; s6, the screened stand columns are subjected to refining treatment; and S7, performing result analysis on the model, and returning to S6 for adjustment if the overall structural strength meets the requirements of operation, extreme and cabin breaking working conditions, the structural fatigue exceeds the specified service life and the local part does not meet the requirements. According to the checking method for the distributed supporting stand columns between the cylindrical FPSO main deck and the process deck, the calculation result is more accurate, the professional iteration workload of upstream and downstream is reduced, the design period is shortened, and the efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of offshore petroleum gas floating platforms, and in particular relates to a method for calibrating distributed support columns between a main deck and a process deck of a cylindrical FPSO. Background Art

[0002] The cylindrical FPSO has a circular structure and a large waterline area. With its good stability and high deck load, the use of a multi-point mooring system can avoid the technical problems of a single-point mooring system. It also has advantages such as relatively low construction costs and has good prospects for promotion and application in the development of deepwater oil and gas fields in China.

[0003] Cylindrical FPSO platforms are usually equipped with two or three decks for the layout of oil, gas and water treatment facilities. Usually, the top deck of the platform is the main deck, and a process deck is set several meters above the main deck, on which various modules and functional facilities such as living buildings are arranged. That is, it must play a supporting role in the modules, and it must not occupy the layout space as much as possible, and it must also meet a certain ventilation volume for heat dissipation. Therefore, support columns are usually used as the main connecting structure between the two decks to solve the above problems and meet the requirements of continuous safe production operations for up to 20 to 30 years. However, there is currently a problem of poor rationality in the layout of support columns, which increases the design and modification cycle, resulting in inaccurate precision during construction and installation.

[0004] Therefore, it is urgent to design a method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO to solve the problem that the arrangement of the support columns is not rational, which increases the design and modification cycle and leads to inaccurate precision during construction and installation. Summary of the invention

[0005] In order to solve the technical problems mentioned in the background technology, such as poor rationality in the arrangement of supporting columns, increased design and modification cycle, and inaccurate precision control during construction and installation, a method for calibrating distributed supporting columns between the main deck and the process deck of a cylindrical FPSO is provided to solve the above problems.

[0006] To achieve the above-mentioned purpose, the specific technical scheme of the method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO of the present invention is as follows: A method for checking distributed support columns between a main deck and a process deck of a cylindrical FPSO includes the following checking methods: S1. Establish a finite element calculation software model, starting from the height of the first horizontal beam below the main deck and modeling upward to the process deck and above the modules, fixed facilities and equipment; S2. Apply loads to the finite element model, including the deadweight of electromechanical instruments, the operating or non-operating weight of equipment, the inertial force load caused by the overall movement of the platform, the deck loads of the main deck and process deck, wind loads, and green water loads; S3. Establish and arrange module supports, and arrange support columns between the main deck and the process deck as supports; S4, finite element model pre-analysis, the support column is established using BEAM units, and the pre-analysis only checks the strength of the support column; S5. Finite element model optimization analysis. After the model is adjusted, the strength of the support column of the BEAM unit is checked to meet the standard criterion value. The support columns with the first maximum value and the second maximum value of the result are selected according to different categories, and the internal force of the selected support columns is extracted; S6. Refine the selected support columns, design the pier nodes for the internal forces of the support columns extracted in S5, and perform PLATE unit refinement on the upper and lower support column specifications, upper and lower brackets, pier end covers, local adjustment of the beam panel under the process deck, large and small cone pipes and diagonal brace pipe nodes aligned with the module legs, and adjust the model grid to meet the requirements of structural strength and fatigue analysis; S7. Analyze the results of the model. The overall structural strength meets the requirements of the operation, extreme and damaged conditions. The structural fatigue exceeds the specified service life. If the local structure does not meet the requirements, return to S6 for adjustment.

[0007] Furthermore, the upper loads in S1 are all transferred to the main deck, and the model is intercepted to the height of the first horizontal beam under the deck to simulate the stress transfer of the support; when it is necessary to verify the stability of the beam frame under the main deck, the model is extended to the height of the second horizontal beam.

[0008] Furthermore, in S2, three load conditions, namely, operation, extreme and damage, are checked respectively according to the requirements of the specification.

[0009] Furthermore, the operating conditions in S2 need to consider the operating weight of the equipment. The inertial force load and wind load under each condition determine a loading direction every 45° on the circumference, and are combined and analyzed with other loads respectively. The overall force of the model is obtained by superposition, and stress calculation and verification are performed.

[0010] Furthermore, the support positions of the support columns in S3 are aligned with the upper module legs, and the main deck is aligned with the process deck strong frames.

[0011] Furthermore, in S4, the formulas for yield check and buckling check of supporting columns are integrated into the same formula. In the preliminary analysis stage, the strength check capability of supporting columns is adjusted to within the standard criterion value range and not exceeding 80% of the criterion value.

[0012] Furthermore, in S5, the upper and lower ends of the BEAM unit support column in the finite element model are sliced, and their internal forces are read as input loads for the detailed design of the pier node.

[0013] Furthermore, in S6, the internal forces of the slices at the upper and lower ends of the supporting column are extracted for refining the pier node, including the adjustment of the wall thickness and size of the supporting column at the end, the placement position, plate thickness, free edge arc transition and soft toe form of the end bracket, the wall thickness of the pier end cover plate and the outer contour that meets the height of the bracket toe end, the shape of the beam panel under the process deck is partially adjusted to adapt to the contour of the supporting column, the bracket adjustment at the upper end of the supporting column is the same as that at the lower end, and the bearing capacity of the node is checked by not more than 50% of the yield strength.

[0014] Furthermore, the mesh of the strength calculation model in S6 is refined to 100 x 100 mm according to the key focus area and gradually coarsened outward to the size of the beam grid width; the mesh of the fatigue calculation model is refined to a size close to the plate thickness in the key focus area to accurately read the principal stress value.

[0015] Furthermore, when the fatigue life of the structure in S7 is insufficient, the form of the typical pier is adjusted, the wall thickness of the bracket, the arc transition of the free edge and the soft toe form are optimized.

[0016] The distributed support column calibration method between the main deck and the process deck of a cylindrical FPSO of the present invention has the following advantages: The finite element calculation software has a wide modeling coverage and can directly take into account the mutual influence between the modules, fixed facilities and equipment above the process deck, so that the calculation simulation of the load transferred downward is more in line with the actual situation and the calculation results are more accurate; it also reduces the iterative workload of upstream and downstream professionals, saves design and modification time, and can quickly select typical specifications from dozens to hundreds of supporting columns, and confirm the rationality of the support layout, thus reducing the design cycle, improving efficiency, and improving and ensuring the stability of the upper module operation, the safety of the hull structure and the efficiency of the entire system.

[0017] The upper and lower ends of the typical support columns of the BEAM unit in the finite element model are sliced ​​to extract internal forces, which not only meets the load requirements of the detailed design of the pier in this specialty, but also can be used as the design input of other specialties, providing convenience with multiple effects. Using the top cover of the pier as the construction interface can significantly reduce the complexity of assembly and installation, and make the precision control of construction and installation more efficient and accurate. Moreover, under the premise of unchanged use method, each structural design can be optimized, which is suitable for all kinds of platforms that need to rely on support structures to meet strength requirements, and has certain promotion potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a flow chart of the method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to the present invention; Figure 2 A side view of a support column of the present invention; Figure 3 It is a structural diagram of the hull and process deck and various modules, facilities and equipment above it in the present invention; Figure 4 This is a structural diagram of the arrangement of the support columns above the main deck in the present invention; Figure 5 It is a side view of the supporting columns and piers in the present invention.

[0019] Description of the markings in the figure: 1. Main deck; 2. Process deck; 3. Various modules; 4. Flare arm; 5. External transmission structure; 6. Crane column; 7. Lifeboat rack; 8. Living building; 9. Helicopter deck; 10. Electrical room; 11. Wave-breaking wall; 12. Support column; 13. Various functional rooms; 14. Pier alignment column; 15. Pier bracket; 16. Pier top cover plate; 17. Upper bracket; 18. Half-height diagonal brace; 19. Diagonal brace bracket; 20. Beam special-shaped panel; 21. Large and small cone pipes; 22. Module legs. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0021] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0022] Please refer to the attached Figure 1 To Attachment Figure 5 The present invention describes a method for checking distributed support columns between a main deck and a process deck of a cylindrical FPSO.

[0023] The existing analysis methods of FPSO module support structure are mostly independent verification by region and profession. The present invention aims to provide a method for verifying the distributed support columns between the main deck and the process deck of a cylindrical FPSO. Figures 1 to 4As shown in the figure, it includes support layout and specification selection, node refinement and adjustment, and finite element strength and fatigue analysis of the upper part of the platform. Figure 1 As shown, a method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO in the present invention includes the following checking methods:

[0024] S1. Establish a finite element calculation software model, starting from the height of the first horizontal beam below the main deck 1 and modeling upward to the process deck 2 and above modules, fixed facilities and equipment; Among them, when the bottom is modeled upward from the height of the first horizontal beam below the main deck 1, if the layer height is not enough, it can be extended to the second layer. The modeling mainly includes: all the main structures below the selected main deck 1, the process deck 2, various modules 3, the living building 8, the helicopter deck 9, the electrical room 10, the external transmission structure 5, the crane column 6, the torch arm 4, the lifeboat rack 7, various functional rooms 13 and the outer wave wall 11.

[0025] S2. Loads are applied to the finite element model. According to the requirements of the specifications, the three load conditions of operation, extreme and damage are checked respectively. The applied loads include the dead weight of the structure and electromechanical instruments, the operating or non-operating weight of the equipment, the inertia force load caused by the overall movement of the platform, the deck loads of the main deck 1 and the process deck 2, the wind load and the green water load, etc.

[0026] S3. Establish and arrange module supports, and arrange support columns 12 between the main deck 1 and the process deck 2 as supports; generally, a circular tube structure of the same diameter with good structural symmetry and small space occupation is preferred, and the initial arrangement is performed based on the rationality of the arrangement and the weight of the supported structure and equipment.

[0027] S4, finite element model pre-analysis, support column 12 is established using BEAM unit, pre-analysis only checks the strength of support column 12; the strength of support column 12 exceeds the standard value required by the specification, the analysis reasons mainly include the following points: (1) The bearing capacity of the supporting column 12 is insufficient. Its geometry and wall thickness should be adjusted to increase the section modulus, or piers should be added around it to share the load. (2) If the bending resistance of some supporting columns 12 is insufficient, a half-height diagonal brace 18 may be added, or the supporting position may be adjusted; (3) The large-area support column 12 has insufficient bending resistance. Check the horizontal displacement trend of the model. This is usually caused by excessive horizontal acceleration. If necessary, adjust the support layout or add large diagonal braces to offset the horizontal load. (4) The support column 12 is located in an area with special requirements, such as vibration of the host, and the support properties or layout can be additionally adjusted; (5) If the strength check result of some supporting columns 12 is small, they can be cancelled according to the actual situation, and the load can be shared by the surrounding supporting columns 12.

[0028] S5. Finite element model optimization analysis. After the model is adjusted, the strength check of the support column 12 of the BEAM unit meets the standard criterion value. The support column 12 with the first maximum value and the second maximum value of the result is selected according to different categories, and the internal force of the selected support column 12 is extracted for subsequent node refinement. The support column 12 can be classified according to the diameter, cross section, wall thickness, position, whether it has a diagonal brace, whether it is located on the bulkhead, etc.

[0029] S6. Refine the selected support columns 12, design the pier nodes for the internal force of the support columns 12 extracted in S5, and refine the PLATE units, such as the specifications of the upper and lower support columns 12, the upper and lower brackets, the pier end covers, the local adjustment of the beam panel under the process deck 2, the large and small cone pipes 21 aligned with the module legs 22, and the diagonal brace pipe nodes, and adjust the model grid according to the specifications to meet the requirements of structural strength and fatigue analysis; S7. Analyze the results of the model. The overall structural strength meets the requirements of the operation, extreme and damaged conditions. The structural fatigue exceeds the specified service life. If the local structure does not meet the requirements, return to S6 for adjustment.

[0030] The finite element calculation software has a wide modeling coverage, and can directly take into account the mutual influence between the modules, fixed facilities and equipment above the process deck 2, so that the calculation simulation of the downward load transfer is more in line with the actual situation, and the calculation result is more accurate; and it reduces the iterative workload of upstream and downstream professionals, saves design and modification time, and can quickly select typical specifications from dozens to hundreds of support columns 12, and confirm the rationality of the support layout, reducing the design cycle, improving efficiency, and improving and ensuring the stability of the upper module operation, the safety of the hull structure and the efficiency of the entire system. The connection method between all structural parts in the application of this embodiment is welding.

[0031] Further, if Figure 2 As shown, the upper loads in S1 are all transferred to the main deck 1, and the model is intercepted to the height of the first horizontal beam below the deck to simulate the stress transfer of the support; when it is necessary to verify the stability of the beam frame under the main deck 1, the model is extended to the height of the second horizontal beam, and the structural model above the main deck 1 is simulated as completely as possible, which has a certain reference basis for the layout of the equipment, the weight center of gravity and the application of related loads in step 2.

[0032] Further, if Figure 5As shown, the main deck 1 and the following structures are mainly for the alignment and reinforcement of the pier alignment columns 14 and the pier brackets 15, which need to provide sufficient strength to meet the load-bearing requirements. If additional reinforcement is required, its material and form should be the same as those of the adjacent structural members; in addition, the Z-direction performance plate is used in the contact area between the pier and the main deck 1, so as to improve the tensile properties of the deck surface, avoid the lamellar tearing of the structural plate, and further improve the fatigue life. The pier brackets 15 use a straight or cross connection to cut the pier alignment columns 14 into several pieces, and the fillet welds of each piece with the surrounding structure are all fully penetrated, which can reduce welding defects, improve welding quality, and improve fatigue stress levels.

[0033] Further, if Figure 5 As shown, within a certain range of the toe end of the bottom edge of the pier bracket 15, full penetration welding is adopted. If the stress level is high, the weld foot can be polished to improve the welding quality and the fatigue stress level. The middle free edge of the bracket is treated with an arc transition so that the welding stress is distributed along the arc surface of the free edge, further reducing the stress concentration.

[0034] Further, if Figure 5 As shown, the pier part includes a pier alignment column 14, a pier bracket 15 and a pier top cover 16. The pier alignment column 14 should be aligned with the upper supporting column 12 to ensure the continuity of the structure, and it is the main load transfer path; the pier bracket 15 is arranged in a straight line or cross according to the analysis results, and is preferably placed along the direction of the structure under the main deck 1. The bracket bears part of the load and avoids the stress concentration phenomenon between the pier alignment column 14 and the main deck 1; the pier top cover 16 usually uses a thicker plate to bear the main tensile and compressive stress, and serves as the rooting point of the upper toe of the pier bracket 15.

[0035] The support column 12 is the main load-bearing object of the support group. In order to better reduce the stress level at the connection, an upper bracket 17 is set at the top to connect the support column 12 and the beam panel to prevent stress concentration; the half-height diagonal brace 18 and the diagonal brace bracket 19 are designed according to the bending resistance and rationality of the arrangement of the support column 12. The pipe node of the diagonal brace needs to consider the influence of the punching shear stress, and the ratio of the material selection of the support column 12 and the diagonal brace should also be considered, which will affect the node punching shear stress results, the saddle shape of the contact surface and the welding quality, etc. Usually, the outer diameter of the diagonal brace is smaller than the specification of the support column 12.

[0036] Further, if Figure 5 As shown, if the angle between the half-height diagonal brace 18 and the supporting column 12 is too small, a reverse groove angle will appear. The groove of the connected saddle mouth needs to be prefabricated in advance to ensure a smooth transition of the edge contour and improve the welding quality of the parent material. Toggle plates are set at both ends of the diagonal brace to effectively reduce the stress concentration at the end of the pipe.

[0037] The process deck 2 and the lower beam are the areas supported by the support columns 12. The beam special-shaped panel 20 is locally adjusted in size and thickness according to the outer diameter of the support column 12 and the form of the half-height diagonal brace 18; the large and small conical tubes 21 are the alignment and reinforcement structural parts for the support columns 12 and the module legs 22, and whether they need to be set can be determined based on the stress analysis results.

[0038] Further, if Figure 5 As shown, the large and small conical tubes 21 are cut into semicircular or quarter-circular pieces by the lower beam of the process deck 2, and are welded with a single-sided groove. The accuracy must be ensured during the positioning installation to reduce the stress level at the connection and improve the fatigue stress level.

[0039] Furthermore, the operating conditions in S2 need to consider the operating weight of the equipment. The inertial force load and wind load under each condition determine a loading direction every 45° on the circumference, and are combined and analyzed with other loads respectively. The overall force of the model is obtained by superposition, and stress calculation and verification are performed.

[0040] Further, if Figure 4 As shown, in S3, due to the different layouts of the main structures of the main deck 1 and the process deck 2, there are many difficulties in the design of structural continuity. Priority is given to aligning the support position of the support column 12 with the upper module leg 22, aligning the strong frames of the main deck 1 and the process deck 2, and appropriately strengthening the rooting point range as required; finally, if the support occupies the necessary space, it can be adjusted by shifting and adding diagonal braces to ensure structural continuity, or local area adjustments can be coordinated between professionals.

[0041] Further, if Figure 4 As shown, in the finite element model of S4, BEAM units are used to model the support column 12, and the rod strength check is used for preliminary analysis. In common software, the formulas for the yield check and buckling check of the support column 12 are integrated into the same formula to facilitate reading the results. In the preliminary analysis stage, the strength check capability of the support column 12 is debugged to within the standard criterion value range, and no more than 80% of the criterion value is retained as a design to cope with subsequent changes.

[0042] Further, if Figure 4 and Figure 5 As shown, in S5, the upper and lower ends of the BEAM unit support column 12 in the finite element model are sliced, and the internal force is read as the input load for the detailed design of the pier node. It is more accurate to select a slice height of no more than 50 mm.

[0043] Further, if Figure 4 and Figure 5As shown, the purpose of designing the pier in S6 is mainly to consider the construction interface. With the top cover plate 16 of the pier as the flush plane, the upper supporting column 12 can be brought into the construction range of the process deck 2, and the installation margin can be left at the bottom of the supporting column 12, which plays a good role in simplifying the construction process and precision control.

[0044] The internal forces of the slices at the upper and lower ends of the supporting column 12 are extracted to refine the pier node, including the adjustment of the wall thickness and size of the supporting column 12 at the end, the placement position, plate thickness, free edge arc transition and soft toe form of the end bracket, the wall thickness of the pier end cover plate and the outer contour that meets the height of the bracket toe, and the shape of the beam panel under the process deck 2 is partially adjusted to adapt to the contour of the supporting column 12. The adjustment of the bracket at the upper end of the supporting column 12 is similar to that at the lower end. The pipe node of the half-height diagonal brace 18 needs to additionally consider the effect of punching shear stress. The bearing capacity of the node is based on no more than 50% of the yield strength as a verification criterion. At the same time, the ratio of the material selection of the supporting column 12 and the diagonal brace should be considered, which will affect the punching shear stress result of the node, the saddle mouth shape of the contact surface, and the welding quality.

[0045] Furthermore, the mesh of the strength calculation model in S6 is refined to 100 x 100 mm according to the key focus area and gradually coarsened outward to the size of the beam grid width; the mesh of the fatigue calculation model is refined to a size close to the plate thickness in the key focus area to accurately read the principal stress value.

[0046] Further, if Figure 5 As shown, when the structural strength in S7 does not meet the requirements, it is usually due to insufficient support capacity, unsatisfactory reinforcement form or local stress concentration, etc., and you can return to S6 for optimization and adjustment; when the structural fatigue life is insufficient, it usually occurs at the toe end of the pier bracket 15, the contact surface between the support column 12 and the deck, or the contact surface between the upper and lower end cover plates, etc., adjust the form of the typical pier, optimize the wall thickness of the bracket, the arc transition of the free edge and the soft toe form. The strength check of the support column 12 was completed through the optimization analysis in S5, and the yield strength check and the punching shear stress check of the pipe node were completed through the adjustment model after refinement in S6 and S7, and all the check contents were completed.

[0047] The present invention provides a calibration method for distributed support columns 12 between the main deck and the process deck of a cylindrical FPSO, aiming to improve the accuracy of finite element analysis results, reduce the iterative workload between upstream and downstream professionals, and at the same time reduce the complexity of assembly and mounting, making the precision control of construction and installation more efficient and accurate. It plays a key role in ensuring the stable operation of the upper module, the safety of the hull structure and the efficient operation of the entire system, and has a certain degree of promotion.

[0048] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO, characterized in that: The following verification methods are included: S1. Establish a finite element calculation software model, starting from the height of the first horizontal beam below the main deck and modeling upward to the process deck and above the modules, fixed facilities and equipment; S2. Apply loads to the finite element model, including the deadweight of electromechanical instruments, the operating or non-operating weight of equipment, the inertial force load caused by the overall movement of the platform, the deck loads of the main deck and process deck, wind loads, and green water loads; S3. Establish and arrange module supports, and arrange support columns between the main deck and the process deck as supports; S4, finite element model pre-analysis, the support column is established using BEAM units, and the pre-analysis only checks the strength of the support column; S5. Finite element model optimization analysis. After the model is adjusted, the strength of the support column of the BEAM unit is checked to meet the standard criterion value. The support columns with the first maximum value and the second maximum value of the result are selected according to different categories, and the internal force of the selected support columns is extracted; S6. Refine the selected support columns, design the pier nodes for the internal forces of the support columns extracted in S5, and perform PLATE unit refinement on the upper and lower support column specifications, upper and lower brackets, pier end covers, local adjustment of the beam panel under the process deck, large and small cone pipes and diagonal brace pipe nodes aligned with the module legs, and adjust the model grid to meet the requirements of structural strength and fatigue analysis; S7. Analyze the results of the model. The overall structural strength meets the requirements of the operation, extreme and damaged conditions. The structural fatigue exceeds the specified service life. If the local structure does not meet the requirements, return to S6 for adjustment.

2. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: The upper loads in S1 are all transferred to the main deck, and the model is intercepted to the height of the first horizontal beam under the deck to simulate the stress transfer of the support; when it is necessary to verify the stability of the beam frame under the main deck, the model is extended to the height of the second horizontal beam.

3. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that ,In S2, three load conditions, namely, operation, extreme and damage, are checked according to the requirements of the specification.

4. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: The operating conditions in S2 need to consider the operating weight of the equipment. The inertia force load and wind load under each condition determine a loading direction every 45° on the circumference, and are combined and analyzed with other loads respectively. The overall force of the model is obtained by superposition, and stress calculation and verification are performed.

5. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: The support positions of the support columns in S3 are aligned with the upper module legs, and the main deck is aligned with the process deck strong frames.

6. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: In S4, the formulas for yield check and buckling check of supporting columns are integrated into the same formula. In the preliminary analysis stage, the strength check capability of supporting columns is adjusted to within the standard criterion value range and not exceeding 80% of the criterion value.

7. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: In S5, the upper and lower ends of the BEAM unit supporting column in the finite element model are sliced, and its internal force is read as the input load for the detailed design of the pier node.

8. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: In S6, the internal forces of the slices at the upper and lower ends of the supporting column are extracted to refine the pier node, including the adjustment of the wall thickness and size of the supporting column at the end, the placement position, plate thickness, free edge arc transition and soft toe form of the end bracket, the wall thickness of the pier end cover plate and the outer contour that meets the height of the bracket toe end. The shape of the beam panel under the process deck is partially adjusted to adapt to the contour of the supporting column. The bracket adjustment at the upper end of the supporting column is the same as that at the lower end. The bearing capacity of the node is checked and calibrated according to no more than 50% of the yield strength.

9. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1 is characterized in that: The mesh of the strength calculation model in S6 is refined to 100 x 100 mm according to the key focus area and gradually coarsened outward to the size of the beam grid width; the mesh of the fatigue calculation model is refined to a size close to the plate thickness in the key focus area to accurately read the principal stress value.

10. The method for checking the distributed support columns between the main deck and the process deck of a cylindrical FPSO according to claim 1, characterized in that: When the fatigue life of the structure in S7 is insufficient, the form of the typical pier is adjusted, the wall thickness of the bracket, the arc transition of the free edge and the soft toe form are optimized.

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