Method for calculating the ultimate load of a high-energy penetration element

Abstract

The application discloses a kind of high-energy penetration piece limit connecting pipe load calculation method.The high-energy penetration piece limit connecting pipe load calculation method is according to the initial value of penetration piece wall thickness and heat preservation layer thickness, on this basis, connecting pipe load suffered by penetration piece is combined into axial force, shear force, bending moment and torsional moment, and according to the limit value of penetration piece primary stress, limit axial force, limit shear force, limit bending moment and limit torsional moment are obtained by iterative calculation.The high-energy penetration piece limit connecting pipe load calculation method method is not affected by the progress of pipe system analysis, in the preliminary stage of container design, in order to speed up engineering progress, the connecting pipe load analysis method with container as main part can be used.

Description

Technical Field

[0001] This invention relates to the field of ultimate load calculation technology for high-energy penetrating components, specifically a method for calculating the ultimate nozzle load of high-energy penetrating components. Background Technology

[0002] Penetration components are an important part of the containment structure. During nuclear island operation and in the event of an accident, they must ensure the structural integrity and airtightness of the containment. Therefore, the design of penetration components must meet the mechanical performance requirements under various operating conditions. High-energy pipeline penetration components are a type of penetration component with relatively complex stress states. They not only bear high-energy loads (such as pressure, forces acting on connecting pipes, etc.) but also the thermal loads of the pipeline fluid. Therefore, the mechanical behavior of high-energy pipeline penetration components under various operating conditions must meet the requirements of the ASME design code.

[0003] When the wall thickness of the through-hole and the insulation layer cannot be determined in the early design stage, it is necessary to set an appropriate initial thickness based on experience. Then, the ultimate pipe load is calculated and the finite element temperature field and stress-strain are checked according to the through-hole size. The through-hole size is continuously modified to meet the check standards. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a method for calculating the ultimate nozzle load of high-energy penetrating components, thus solving the problems mentioned in the background art.

[0006] (II) Technical Solution

[0007] A method for calculating the ultimate load of a high-energy penetrating component involves setting initial values ​​for the wall thickness and insulation layer thickness of the penetrating component based on experience. On this basis, the loads on the penetrating component are combined into axial force, shear force, bending moment, and torsional moment. Based on the ultimate value of the primary stress of the penetrating component, the ultimate axial force, ultimate shear force, ultimate bending moment, and ultimate torque are obtained through iterative calculation.

[0008] The allowable load of the vessel nozzle is determined by considering its geometric parameters, material properties, force-moment relationships, and stress evaluation criteria under various load conditions. This method is unaffected by piping system design progress and can quickly analyze the ultimate nozzle load.

[0009] The load on the high-energy penetrating component is combined into axial force P, shear force, and bending moment M. B and torsional moment M t 4. The high-energy penetrating component size design and temperature field, stress-strain verification process according to claim 1, characterized in that: the axial force P and shear force V are set as xN, and the bending moment M B Torsional moment Mt Set to 0.3x N·m

[0010] The axial stress, circumferential stress, radial stress, and shear stress are calculated according to formula 1 of elasticity; the three principal stresses of the cross section are calculated according to formula 2 of elasticity; the stress difference and total stress intensity of the cross section are calculated according to formula 3 of elasticity; by comparing the stress intensity with the stress limit, the x value is iteratively accumulated to obtain the final ultimate nozzle load.

[0011] The calculation formula for the aforementioned elasticity formula 1 is as follows:

[0012] Axial stress:

[0013]

[0014] In the formula, p i R is the internal pressure (Pa); A is the cross-sectional area (m2); r i r is the inner radius (m); rm is the average radius (m); o t is the outer radius, m; t is the wall thickness, m; I is the moment of inertia, m⁴; M B The total bending moment is (N·m).

[0015] Circumferential stress:

[0016]

[0017] Radial stress:

[0018]

[0019] Shear stress:

[0020]

[0021] The calculation formula for the aforementioned elasticity formula 2 is as follows:

[0022]

[0023]

[0024] The calculation formula for the aforementioned elasticity formula 3 is as follows:

[0025] The stress difference on the cross section is:

[0026] S 12 =|σ1-σ2|

[0027] S 23 =|σ2-σ3|

[0028] S 13 =|σ3-σ1|

[0029] The total stress intensity is:

[0030] S I =max(S) 12 S 23 S 13 )

[0031] (III) Beneficial Effects

[0032] This invention provides a method for calculating the ultimate nozzle load of a high-energy penetrating component. It has the following beneficial effects:

[0033] The calculation method for the ultimate nozzle load of the high-energy penetrating component is not affected by the progress of piping system analysis. In the initial stage of vessel design, in order to speed up the project progress, the nozzle load analysis method based on the vessel can be adopted.

[0034] This method combines the loads on the through-hole component into axial force, shear force, bending moment, and torsional moment, and obtains the ultimate axial force, ultimate shear force, ultimate bending moment, and ultimate torque through iterative calculation based on the ultimate value of the primary stress of the through-hole component. Attached Figure Description

[0035] Figure 1 This is a schematic diagram illustrating the principle of iterative calculation of the ultimate load of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Taking a certain type of through-hole component L5 as an example, the outer diameter of the tube is 168mm, the wall thickness is 14mm, and the design pressure is 17.2Mpa.

[0038] First, assume that the axial force P, shear force V are xN, and bending moment M is... B Torsional moment M t 0.3x N·m

[0039] According to elasticity mechanics, the stress calculation for the evaluation section is as follows:

[0040] Axial stress:

[0041]

[0042] In the formula, p i R is the internal pressure (Pa); A is the cross-sectional area (m2); r ir is the inner radius (m); rm is the average radius (m); o t is the outer radius, m; t is the wall thickness, m; I is the moment of inertia, m⁴; M B The total bending moment is (N·m).

[0043] Circumferential stress:

[0044]

[0045] Radial stress:

[0046]

[0047] Shear stress:

[0048] τ=τ1+τ2

[0049]

[0050] The three principal stresses σ1, σ2, and σ3 of the cross section are:

[0051]

[0052]

[0053] σ3=σ r

[0054] The stress difference on the cross section is:

[0055] S 12 =|σ1-σ2|

[0056] S 23 =|σ2-σ3|

[0057] S 13 =|σ3-σ1|

[0058] The total stress intensity is:

[0059] S I =max(S) 12 S 23 S 13 )

[0060] Verify S I ≤S limit S limit The value is 2.07 * 10⁸ Pa, obtained from the table.

[0061] Iteratively accumulate the value of x until S I >S limit At this point, x is the desired limit value, and P, V, MB, and Mt are obtained from this, which are the maximum allowable pipe load values.

[0062] Using MATLAB iterative solutions, the axial force P = 76427 N, the shear force V = 76427 N, and the bending moment M were obtained. B =20245 N·m, Torsional moment M t =20245 N·m.

[0063] It should be noted that in the description of the invention, the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the description of the structure of the invention shown in the accompanying drawings. They are only for the convenience of describing the invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0064] The terms "first" and "second" in this technical solution are merely designations for corresponding structures that are identical or similar, or that perform similar functions. They do not represent an arrangement of the importance of these structures, nor do they imply any ranking, comparison of size, or other meaning.

[0065] Furthermore, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two structures. Those skilled in the art can understand the specific meaning of the above terms in this invention by considering the overall concept of the invention and the specific context of the solution.

Claims

1. A method for calculating the ultimate load of a high-energy penetrating component, comprising setting initial values ​​for the wall thickness of the penetrating component and the thickness of the insulation layer based on experience, characterized in that: Includes the following steps: Step 1: Set a very small x value; Step Two: Settings Where: P is the axial force, and V is the shear force. For bending moment, Torsional moment; Step 3: Calculate axial stress Circumferential stress Radial stress And shear stress τ; Axial stress: ; In the formula: Internal pressure; It is the cross-sectional area; The inner radius; The outer radius; For wall thickness; It is the moment of inertia; This represents the total bending moment; Circumferential stress: ; In the formula: Internal pressure; The inner radius; For wall thickness; Radial stress: ; In the formula: Internal pressure; Shear stress: ； In the formula: The outer radius; It is the moment of inertia; For wall thickness; Step 4: Calculate the principal stresses and total stress intensity , cross-sectional stress difference S; ； Cross-sectional stress difference: ； Total stress intensity: ; Step 5: Judgment Is it less than or equal to? ,if Then, after setting x = x + 1, proceed to step two (B); for example... Then proceed to step six; Step Six: Record the current state. ; Step 7: Verification complete.

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