A method for calculating the ring stiffness of a structural wall pipe

Abstract

The present invention relates to a method for calculating the ring stiffness of a structural wall pipe. The cross-section of the pipe wall structural unit of the structural wall pipe is symmetrical about its axis of symmetry. The outer contour line of the cross-section on one side of the axis of symmetry includes a first line type and a second line type connected in sequence, and the inner contour line includes at least a third line type and a fourth line type. The method includes the following steps: obtaining the relevant parameters of the structural wall pipe; taking the axis of symmetry as the Y-axis and the straight line where any line type perpendicular to the Y-axis is located as the X-axis; calculating the analytical expressions of all line types of the outer contour line and the inner contour line respectively according to the relevant parameters; calculating the coordinates of the characteristic points where each adjacent line type intersects according to the analytical expressions; calculating the area s of the cross-section of the pipe wall structural unit respectively according to the analytical expressions and the coordinates of each characteristic point. 波 , the area moment S 波 and the moment of inertia I 波 ; furthermore, the centroid of the pipe wall structural unit, the centroid moment of inertia of the pipe wall structural unit, the moment of inertia per meter of the cross-section of the pipe wall structural unit, and the neutral axis distance are calculated according to the pipe material parameters and material parameters; thereby obtaining the ring stiffness of the structural wall pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of structural wall pipes, and more specifically, to a method for calculating the ring stiffness of a structural wall pipe. Background Art

[0002] Currently, the design elements of the pipe wall structure unit of a structural wall pipe require multiple variable parameters such as wave pitch, wave width, and wave height, resulting in a rather complex calculation of the moment of inertia and centroid of the pipe wall structure unit cross-section, and the calculation difficulty is quite large. At present, R & D personnel generally use CAD software for auxiliary calculation. First, draw the cross-sectional view of the pipe wall structure unit on the CAD software, establish the region of the pipe wall structure unit cross-section, and then calculate the parameters such as the moment of inertia and centroid of the pipe wall structure unit cross-section through the region calculation function built in CAD. Finally, substitute the results calculated by CAD into the ring stiffness theoretical formula to calculate the ring stiffness of the pipe wall structure unit cross-section. The method of using CAD for auxiliary calculation requires drawing first, then letting the CAD software calculate, and finally manually substituting the software calculation results into the formula for calculation. The process is cumbersome and the operation is very inconvenient. Moreover, the parameters of the pipe wall structure unit involve multiple variables, and different combinations of these variables have a great impact on the final ring stiffness of the pipe wall structure unit cross-section. The combinations between multiple variables are endless. It is almost impossible to exhaust all the combination forms between parameters by simply drawing manually. Therefore, the design of the pipe wall structure unit cross-section often highly depends on experience and can only be continuously modified and verified on the basis of predecessors, seriously restricting the theory and creativity of the design of the pipe wall structure unit cross-section. Furthermore, the traditional method only considers the regular, simple, and original pipe wall structure unit cross-section parameters, and it is impossible and difficult to simulate the possible changes in the actual production and forming of the pipe, such as the change in the height of the pipe wall structure unit caused by the cooling shrinkage of the material, the change in the radian of the wave top arc and wave top fillet, and the upper thin and lower thick outer wall thickness caused by the material sag. As a result, the ring stiffness calculated by the traditional method is often much higher than that of the actual production product, and the calculation distortion is very serious. R & D personnel can only modify the calculation results based on their own experience, resulting in a large uncertainty in the parameters of the pipe wall structure unit designed by the traditional method. Summary of the Invention

[0003] The present invention provides a method for calculating the ring stiffness of a structural wall pipe to overcome the problems of complex ring stiffness calculation and inaccurate calculation involved in the design of the pipe wall structure unit of the structural wall pipe in the above-mentioned prior art.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a method for calculating the ring stiffness of a structural wall pipe, wherein the cross-section of the pipe wall structure unit of the structural wall pipe is symmetrical about its axis of symmetry. The outer contour line of the cross-section on one side of the axis of symmetry successively includes a plurality of first line types from top to bottom, and each of the first line types is one of a straight line or an arc. The inner contour line of the cross-section on the same side of the axis of symmetry successively includes a plurality of second line types from top to bottom, and each of the second line types is one of a straight line or an arc. The calculation method includes the following steps:

[0005] S1: Obtain the pipe material parameters, pipe wall structure unit parameters, and material parameters of the structural wall pipe;

[0006] S2: Take the axis of symmetry as the Y-axis and the straight line where any line type perpendicular to the Y-axis is located as the X-axis to establish an XY coordinate system;

[0007] S3: According to the XY coordinate system and the pipe wall structure unit parameters obtained in step S1, calculate the analytical formulas of all line types of the outer contour line and the inner contour line respectively;

[0008] S4: According to the analytical formulas obtained in step S3, calculate the coordinates of the characteristic points where each adjacent line type intersects;

[0009] S5: According to the analytical formulas of each line type obtained in step S3 and the coordinates of each characteristic point obtained in step S4, calculate the area s 波 of the cross-section of the pipe wall structure unit, the area moment S 波 and the moment of inertia I 波 respectively;

[0010] S6: According to the area s 波 of the cross-section of the pipe wall structure unit, the area moment S 波 and the moment of inertia I 波 obtained in step S5, as well as the pipe material parameters and material parameters, calculate the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance;

[0011] S7: Obtain the ring stiffness of the structural wall pipe according to the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance.

[0012] Preferably, the structural wall pipe is a double-wall corrugated pipe. The multiple first line types of the outer contour line are, in sequence, the wave crest arc ab, the wave crest fillet bc, the outer bevel cd, the wave bottom fillet de, the first horizontal line segment ef, the first vertical line segment fg, and the second horizontal line segment hg. The multiple second line types of the inner contour line are, in sequence, the third vertical line segment ai, the inner wave crest arc ij, the inner wave crest fillet jk, the inner bevel kl, the third horizontal line segment ml, and the second vertical line segment mh. The wave crest arc ab is tangent to the wave crest fillet bc at point b, and the wave crest fillet bc is tangent to the outer bevel cd at point c. The inner wave crest arc ij is tangent to the inner wave crest fillet jk at point j, and the inner wave crest fillet jk is tangent to the inner bevel kl at point k.

[0013] In the step S1, the pipe material parameters include the average inner diameter ID of the pipe; the pipe wall structure unit parameters include the outer wall thickness E 外 , the inner wall thickness E 内 , the laminated wall thickness E 层 , the wave pitch L, the wave width B, the wave height H, the inclination angle α, the radius of the wave crest arc ab is R r1 , the radius of the wave crest fillet bc is R r2 , and the radius of the wave bottom fillet de is R r3 ; the material parameters include the material modulus E and the material density ρ;

[0014] In the step S2, taking the straight line where the first horizontal line segment ef is located as the X-axis and the straight line where the third vertical line segment ai is located as the Y-axis, an XY coordinate system is established;

[0015] In the step S3, the analytical expressions of the wave crest arc ab, the outer bevel cd, the wave bottom fillet de, the wave crest fillet bc, the inner wave crest arc ij, the inner wave crest fillet jk, the inner bevel kl, the second horizontal line segment hg, the third horizontal line segment ml, and the first vertical line segment fg are calculated respectively;

[0016] In the step S4, according to the analytical expressions obtained in the step S3, the coordinates of the characteristic points a, b, c, d, e, f, g, h, i, m, and n are calculated;

[0017] In the step S5, according to the analytical expressions of each line type obtained in the step S3 and the coordinates of each characteristic point obtained in the step S4, the area s 波 , the area moment S 波 , and the moment of inertia I 波 of the cross-section of the pipe wall structure unit are calculated respectively;

[0018] In the step S6, based on the area s, the area moment S, the moment of inertia I of the cross-section of the pipe wall structure unit obtained in the step S5, the density of the material, the bending modulus, the average inner diameter ID of the pipe, and the pipe length L 管Calculate the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance;

[0019] In the step S7, obtain the ring stiffness of the structural wall pipe according to the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance.

[0020] Preferably, in the step S3:

[0021] The analytical formula of the wave crest arc ab is: where the radius of the wave crest arc ab is R r1 , and its center r1 is (a r1 , b r1 ), a r1 = 0, b r1 = H - R r1 ;

[0022] The analytical formula of the outer hypotenuse cd is: y = k cd (x - b cd ), where k cd = -tanα,

[0023] The analytical formula of the wave bottom fillet de is: where the radius of the wave bottom fillet de is R r3 , and its center r3 is (a r3 , b r3 ), b r3 = R r3 ;

[0024] The solving process of the analytical formula of the wave crest arc bc is as follows:

[0025] With point r1 as the center and line segment r1r2 as the radius, draw an auxiliary arc r4, and assume its analytical formula is: where: a r4 = 0, b r4 = H - R r1 , R r4 = R r1 - R r2 ;

[0026] Parallel to the line segment cd, draw an auxiliary line L2 through point r2, and assume its analytical formula is: y = k cd (x - b L2 ), where: k cd = -tanα,

[0027] Set the analytical expressions of the auxiliary arc r4 and the auxiliary line L2 to be equal. By simplification, a quadratic equation A can be obtained. r4L2 x 2 +B r4L2 x+C r4L2 =0, where A r4L2 =1+k cd 2 , B r4L2 =-2(a r4 +k cd 2 b L2 +b r4 k cd ), C r4L2 =a r4 2 +(b r4 +k cd b L2 ) 2 -R r4 2 . By calculation, the coordinates of point r2 can be obtained as (x r2 , y r2 );

[0028] That is, the analytical expression of the wave crest arc bc is: where a r2 =x r2 , b r2 =y r2 ;

[0029] The analytical expression of the inner wave crest arc ij is: where: a r1 =0, b r1 =H-R r1 , R r1 ’=R r1 -E 外 ;

[0030] The analytical expression of the inner wave crest fillet jk is: where: a r2 =x r2 , b r2 =y r2 , R r2 ’=R r2 -E 外 ;

[0031] The analytical expression of the inner hypotenuse kl is: y=k kl (x-b kl ), where: k kl =-tanα,

[0032] The analytical expression of the third horizontal line segment ml is: y=bml , where: b ml = E 内 - E 层 ;

[0033] The analytical formula of the second horizontal line segment hg is: y = b hg , where: b hg = - E 层 ;

[0034] Preferably, in the step S4, the coordinates of the feature point a are (0, H), and the coordinates of the feature point i are (0, H - E 外 );

[0035] Find the coordinates of the feature point b as follows. First, set the line segment r1b as the auxiliary line L3, and set its analytical formula as: y = k L3 x + b L3 , where: b L3 = b r2 - a r2 k L3 ; Let the analytical formulas of the wave crest arc ab and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1L3 x2 + B r1L3 x + C r1L3 = 0 can be obtained, where A r1L3 = 1 + k L3 2 , B r1L3 = -2(a r1 - k L3 2 b L3 + b r1 k L3 ), C r1L3 = a r1 2 +(b r1 - b L3 ) 2 - R r1 2 , and the coordinates of point b (xb, yb) can be obtained by calculation;

[0036] Let the analytical formulas of the inner wave crest arc ij and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1’L3 x 2 + B r1’L3 x + C r1’L3 = 0 can be obtained, where A r1’L3 = 1 + k L3 2 , B r1’L3 = -2(a r1 - k L3 2 bL3 +b r1 k L3 ),C rl’L3 =a r1 2 +(b r1 -b L3 ) 2 -R r1 ’ 2 , By calculation, the coordinates of point j can be obtained as (x j , y j );

[0037] The coordinates of the feature point c are obtained as follows. Let the outer wave crest fillet r2, that is, the analytical formula of the arc bc and the outer hypotenuse L, that is, the line segment cd, be equal. By simplification, a quadratic equation A r2Lx 2 +B r2L x + C r2L =0 is obtained, where A r2L =1 + k cd 2 , B r2L =-2(a r2 +k cd 2 b cd +b r2 k cd ), C r2L =a r2 2 +(b r2 +k cd b cd ) 2 -R r2 2 , By calculation, the coordinates of point c can be obtained as (x c , y e );

[0038] Let the analytical formulas of the inner wave crest fillet jk and the inner hypotenuse kl be equal. By simplification, a quadratic equation A r2’L’ x 2 +B r2’L’ x + C r2’L’ =0 is obtained, where A r2’L’ =1 + k kl 2 , B r2’L’ =-2(a r2’ +k kl 2 b kl +b r2 , k kl ), C r2’L’ =a r2’ 2 +(b r2’ +kkl b kl ) 2 -R r2 ’ 2 , the coordinates of point k, (x k , y k ), can be obtained by calculation;

[0039] For the coordinates of feature point d, make the analytical expressions of the bottom fillet de and the outer bevel cd equal. By simplification, a quadratic equation A r3L x 2 +B r3L x + C r3L = 0 can be obtained, where A r3L = 1 + k cd 2 , B r3L = -2(a r3 +k cd 2 b cd +b r3 k cd ), C r3L = a r3 2 +(b r3 +k cd b cd ), 2 -R r3 2 . The coordinates of point d, (x d , y d ), can be obtained by calculation; the coordinates of point e are (a r3 , 0), the coordinates of point f are The coordinates of point g are The coordinates of point h are (0, -E 层 ), the coordinates of point l are The coordinates of point m are (0, E 内 -E 层 ), the coordinates of point n are

[0040] Preferably, in the step S5, the cross-sectional area s 波 of the pipe wall structure unit is the difference between the area s 外 of the figure formed by the feature points abcdefgh on the outer contour of the cross-section and the area s 内 of the figure formed by the feature points ijklm on the inner contour of the cross-section; the area moment S 波 of the cross-section of the pipe wall structure unit is the difference between the area moment of the figure formed by the feature points abcdefgh on the outer contour of the cross-section and the area moment of the figure formed by the feature points ijklm on the inner contour of the cross-section; the moment of inertia I 波The difference between the moment of inertia of the figure formed by the characteristic points a, b, c, d, e, f, g, and h on the outer contour of the cross-section and the moment of inertia of the figure formed by the characteristic points i, j, k, l, and m on the inner contour of the cross-section.

[0041] Preferably, the area s 外 , the first moment of area S 外 and the moment of inertia I 外 of the figure formed by the characteristic points a, b, c, d, e, f, g, and h on the outer contour of the cross-section are respectively the sum of the areas, the sum of the first moments of area, and the sum of the moments of inertia of the wave crest arc ab, the wave crest fillet bc, the outer hypotenuse cd, the wave bottom fillet de, and the first horizontal line segment ef; the area s 内 , the first moment of area S 内 and the moment of inertia I 内 of the figure formed by the characteristic points i, j, k, l, and m on the inner contour of the cross-section are the sum of the areas, the sum of the first moments of area, and the sum of the moments of inertia of the inner wave crest arc ij, the inner wave crest fillet jk, and the inner hypotenuse kl.

[0042] Preferably, the area of the wave crest arc ab is:

[0043]

[0044] The area of the wave crest fillet bc is:

[0045] The area of the outer hypotenuse cd is:

[0046] The area of the wave bottom arc de is:

[0047] The area of the first horizontal line segment ef is:

[0048] s 外 = s ab + s bc + s cd + s de + s ef ;

[0049] The area of the inner top arc ij is:

[0050] The area of the inner top fillet jk is:

[0051] The area of the inner hypotenuse kl is:

[0052] where y ml is the analytical formula of the third horizontal line segment ml, and y hg is the analytical formula of the second horizontal line segment hg;

[0053] s内 = s ij + s jk + s kl ;

[0054] Therefore, the cross-sectional area s of the pipe wall structure unit 波 = 2×(s 外 - s 内 ).

[0055] Preferably, the area moment of inertia of the wave crest arc ab is:

[0056] The area moment of inertia of the wave crest fillet bc is:

[0057] The area moment of inertia of the outer hypotenuse cd is:

[0058] The area moment of inertia of the wave bottom fillet de is:

[0059] The area moment of inertia of the first horizontal line segment ef is:

[0060] S 外 = S ab + S bc + S cd + S de + S ef ;

[0061] The area moment of inertia of the inner wave crest arc ij is:

[0062] The area moment of inertia of the inner wave crest fillet jk is:

[0063] The area moment of inertia of the inner hypotenuse kl is:

[0064] S 内 = S ij + S jk + S kl ;

[0065] The area moment of inertia S of the cross-section of the pipe wall structure unit 波 = 2×(S 外 - S 内 ).

[0066] Preferably, the moment of inertia of the wave crest arc ab is:

[0067] The moment of inertia of the wave crest fillet bc is:

[0068] The moment of inertia of the outer hypotenuse cd is:

[0069] The moment of inertia of the round corner at the bottom of the wave is:

[0070] The moment of inertia of the first horizontal line segment ef is:

[0071] I 外 = I ab + I bc + I cd + I de + I ef ;

[0072] The moment of inertia of the inner wave crest arc ij is:

[0073] The moment of inertia of the inner wave crest round corner jk is:

[0074] The moment of inertia of the inner hypotenuse kl is:

[0075] I 内 = I ij + I jk + I kl ;

[0076] The moment of inertia I of the cross-section of the pipe wall structure unit 波 = 2×(I 外 - I 内 ).

[0077] Preferably, in the step S6,

[0078]

[0079] The centroid moment of inertia I of the pipe wall structure unit 质心 = The moment of inertia I of the pipe wall structure unit 波 - M 质心 2×The area s of the pipe wall structure unit 波 ;

[0080]

[0081] The neutral axis distance D 中 = The average inner diameter ID of the pipe + 2×(E 层 + The centroid M of the pipe wall structure unit);

[0082] In the step S7,

[0083] Preferably, the pipe parameters further include the pipe length L 管 , and the calculation formula of the pipe weight W is as follows:

[0084]

[0085] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention changes the traditional design of the pipe wall structure unit from graphic design to function formula design. By geometrically analyzing the parameters of each pipe wall structure unit, a functional formula relationship between each parameter is established, so that each parameter is associated with each other, and the main data such as the moment of inertia and centroid of the cross-section of the pipe wall structure unit are accurately obtained, and then the ring stiffness and weight of the corresponding product are calculated. And according to the actual production situation, the function of the pipe wall structure unit is adjusted and supplemented by fully considering the actual conditions, making the theoretical calculation closer to the actual situation, greatly optimizing the existing calculation method, and greatly improving the design efficiency of the structured-wall pipe. Description of the Drawings

[0086] Figure 1 is a flowchart of the ring stiffness calculation method for the structured-wall pipe of the present invention;

[0087] Figure 2 is a cross-sectional view of the pipe wall structure unit of the double-wall corrugated pipe of the present invention;

[0088] Figure 3 is a coordinate system diagram of the pipe wall structure unit in the double-wall corrugated pipe of the present invention. Detailed Embodiments

[0089] The drawings are only for illustrative purposes and should not be construed as limitations on this patent; to better illustrate this embodiment, some components in the drawings will be omitted, enlarged or reduced, and do not represent the actual size of the product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationships described in the drawings are only for illustrative purposes and should not be construed as limitations on this patent.

[0090] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "long", "short", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as limitations on this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0091] The technical solutions of the present invention will be further specifically described below through specific embodiments and in conjunction with the drawings:

[0092] Embodiment 1

[0093] AsFigure 1 As shown in Figure 1 , a method for calculating the ring stiffness of a structural wall pipe, the cross-section of the pipe wall structure unit of the structural wall pipe is symmetric about its axis of symmetry. The outer contour line of the cross-section on one side of the axis of symmetry successively includes a plurality of first line types from top to bottom, and each of the first line types is one of a straight line or an arc. The inner contour line of the cross-section on the same side of the axis of symmetry successively includes a plurality of second line types from top to bottom, and each of the second line types is one of a straight line or an arc. The calculation method includes the following steps:

[0094] S1: Obtain the pipe material parameters, pipe wall structure unit parameters, and material parameters of the structural wall pipe;

[0095] S2: Take the axis of symmetry as the Y-axis and the straight line where any line type perpendicular to the Y-axis is located as the X-axis to establish an XY coordinate system;

[0096] S3: According to the XY coordinate system and the pipe wall structure unit parameters obtained in step S1, calculate the analytical formulas of all line types of the outer contour line and the inner contour line respectively;

[0097] S4: According to the analytical formulas obtained in step S3, calculate the coordinates of the characteristic points where each adjacent line type intersects;

[0098] S5: According to the analytical formulas of each line type obtained in step S3 and the coordinates of each characteristic point obtained in step S4, calculate the area s 波 、area moment S 波 and moment of inertia I 波 of the pipe wall structure unit cross-section;

[0099] S6: According to the area s 波 、area moment S 波 、moment of inertia I 波 of the pipe wall structure unit cross-section obtained in step S5, as well as the pipe material parameters and material parameters, calculate the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the pipe wall structure unit cross-section, and the neutral axis distance;

[0100] S7: Obtain the ring stiffness of the structural wall pipe according to the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the pipe wall structure unit cross-section, and the neutral axis distance.

[0101] It should be noted that the explanation of "the outer contour line of the cross-section on one side of the symmetry axis successively includes a plurality of first line types from top to bottom, and each of the first line types is one of a straight line or an arc" is as follows. Suppose the outer contour line includes 5 successively connected first line types. The first first line type can be one of a straight line or an arc, the second first line type can also be one of a straight line or an arc, and the third first line type can be one of a straight line or an arc. The explanation of "the inner contour line of the cross-section on the same side of the symmetry axis successively includes a plurality of second line types from top to bottom, and each of the second line types is one of a straight line or an arc" is also as above.

[0102] Embodiment 2

[0103] As Figures 2 to 3 shown, the structural wall pipe is a double-wall corrugated pipe. The multiple first line types of the outer contour line are successively the wave crest arc ab, the wave crest fillet bc, the outer hypotenuse cd, the wave bottom fillet de, the first horizontal line segment ef, the first vertical line segment fg, and the second horizontal line segment hg. The multiple second line types of the inner contour line are successively the third vertical line segment ai, the inner wave crest arc ij, the inner wave crest fillet jk, the inner hypotenuse kl, the third horizontal line segment ml, and the second vertical line segment mh. The wave crest arc ab is tangent to the wave crest fillet bc at point b, and the wave crest fillet bc is tangent to the outer hypotenuse cd at point c; the inner wave crest arc ij is tangent to the inner wave crest fillet jk at point j, and the inner wave crest fillet jk is tangent to the inner hypotenuse kl at point k;

[0104] In step S1, the pipe material parameters include the average inner diameter ID of the pipe; the pipe wall structure unit parameters include the outer wall thickness E 外 , the inner wall thickness E 内 , the laminated wall thickness E 层 , the wave pitch L, the wave width B, the wave height H, the inclination angle α, the radius of the wave crest arc ab is R r1 , the radius of the wave crest fillet bc is R r2 , and the radius of the wave bottom fillet de is R r3 ; the material parameters include the material modulus E and the material density ρ;

[0105] In step S2, taking the straight line where the first horizontal line segment ef is located as the X-axis and the straight line where the third vertical line segment ai is located as the Y-axis, an XY coordinate system is established;

[0106] In step S3, the analytical expressions of the wave crest arc ab, the outer hypotenuse cd, the wave bottom fillet de, the wave crest fillet bc, the inner wave crest arc ij, the inner wave crest fillet jk, the inner hypotenuse kl, the second horizontal line segment hg, the third horizontal line segment ml, and the first vertical line segment fg are calculated respectively;

[0107] In step S4, according to the analytical expressions obtained in step S3, the coordinates of each characteristic point a, b, c, d, e, f, g, h, i, m, and n are calculated;

[0108] In the step S5, according to the analytical expressions of each line type obtained in step S3 and the coordinates of each feature point obtained in step S4, the area s of the cross-section of the pipe wall structure unit is calculated respectively 波 , the area moment S 波 and the moment of inertia I 波 ;

[0109] In the step S6, according to the area s, area moment S, moment of inertia I of the cross-section of the pipe wall structure unit obtained in step S5, the density of the material, the bending modulus, the average inner diameter ID of the pipe material, and the pipe length L 管 the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance are calculated;

[0110] In the step S7, the ring stiffness of the structural wall pipe is obtained according to the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the cross-section of the pipe wall structure unit, and the neutral axis distance.

[0111] Preferably, in step S3:

[0112] The analytical expression of the wave crest arc ab is: where the radius of the wave crest arc ab is R r1 , and its center r1 is (a r1 , b r1 ), a r1 = 0, b r1 = H - R r1 ;

[0113] The analytical expression of the outer hypotenuse cd is: y = k cd (x - b cd ), where k cd = -tanα,

[0114] The analytical expression of the wave bottom fillet de is: where the radius of the wave bottom fillet de is R r3 , and its center r3 is (a r3 , b r3 ), b r3 = R r3 ;

[0115] The solution process of the analytical expression of the wave crest arc bc is as follows:

[0116] Taking point r1 as the center and the line segment r1r2 as the radius, an auxiliary arc r4 is made, and its analytical expression is set as: where: a r4 = 0, b r4= H - R r1 , R r4 = R r1 - R r2 ;

[0117] Parallel line segments cd. Draw auxiliary line L2 through point r2, and assume its analytical formula is: y = k cd (x - b L2 ), where: k cd = -tanα,

[0118] Let the analytical formulas of auxiliary arc r4 and auxiliary line L2 be equal. By simplification, a quadratic equation A r4L2 x 2 + B r4L2 x + C r4L2 = 0 can be obtained, where A r4L2 = 1 + k cd 2 , B r4L2 = -2(a r4 + k cd 2 b L2 + b r4 k cd ), C r4L2 = a r4 2 +(b r4 + k cd b L2 ) 2 - R r4 2 , and the coordinates of point r2 (x r2 , y r2 ) can be obtained through calculation;

[0119] That is, the analytical formula of the wave crest arc bc is: where, a r2 = x r2 , b r2 = y r2 ;

[0120] The analytical formula of the inner wave crest arc ij is: where: a r1 = 0, b r1 = H - R r1 , R r1 ’ = R r1 - E 外 ;

[0121] The analytical formula of the inner wave crest fillet jk is: where: a r2 = x r2 , b r2 = yr2 , R r2 ’ = R r2 - E 外 ;

[0122] The analytical formula of the inner bevel edge kl is: y = k kl (x - b kl ), where: k kl = -tanα,

[0123] The analytical formula of the third horizontal line segment ml is: y = b ml , where: b ml = E 内 - E 层 ;

[0124] The analytical formula of the second horizontal line segment hg is: y = b hg , where: b hg = -E 层 ;

[0125] Preferably, in step S4, the coordinates of the feature point a are (0, H), and the coordinates of the feature point i are (0, H - E 外 ),

[0126] The coordinates of the feature point b are obtained as follows. First, set the line segment r1b as the auxiliary line L3, and set its analytical formula as: y = k L3 x + b L3 , where: b L3 = b r2 - a r2 k L3 ; Let the analytical formulas of the wave crest arc ab and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1L3 x 2 + B r1L3 x + C r1L3 = 0 can be obtained, where A r1L3 = 1 + k L3 2 , B r1L3 = -2(a r1 - k L3 2 b L3 + b r1 k L3 ), C r1L3 = a r1 2 + (b r1 - b L3 ) 2 - R r1 2 , and the coordinates of point b (x b , yb );

[0127] Let the analytical expressions of the inner wave crest arc ij and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1’L3 x 2 +B r1’L3 x + C r1’L3 = 0 can be obtained, where A r1’L3 = 1 + k L3 2 , B r1’L3 = -2(a r1 -k L3 2 b L3 +b r1 k L3 ), C rl’L3 = a r1 2 +(b r1 -b L3 ) 2 -R r1 ’ 2 , and the coordinates of point j (x j , y j ) can be obtained by calculation;

[0128] The coordinates of the characteristic point c are obtained as follows. Let the outer wave crest fillet r2, that is, the arc bc, and the outer hypotenuse L, that is, the line segment cd, have equal analytical expressions. By simplification, a quadratic equation A r2L x 2 +B r2L x + C r2L = 0 can be obtained, where A r2L = 1 + k cd 2 , B r2L = -2(a r2 +k cd 2 b cd +b r2 k cd ), C r2L = a r2 2 +(b r2 +k cd b cd ) 2 -R r2 2 , and the coordinates of point c (x c , y e ) can be obtained by calculation;

[0129] Let the analytical expressions of the inner wave crest fillet jk and the inner hypotenuse kl be equal. By simplification, a quadratic equation A r2’L’ x 2 +Br2’L’ x + C r2’L’ = 0, where A r2’L’ = 1 + k kl 2 , B r2’L’ = -2(a r2’ + k kl 2 b kl + b r2’ k kl ), C r2’L’ = a r2’ 2 +(b r2’ + k kl b kl ), 2 - R r2 ’ 2 , by calculation, the coordinates of point k can be obtained as (x k , y k );

[0130] For the coordinates of feature point d, make the analytical expressions of the bottom fillet de and the outer bevel cd equal. By simplification, a quadratic equation Ax r3L x 2 + B r3L x + C r3L = 0 is obtained, where A r3L = 1 + k cd 2 , B r3L = -2(ar3 + k cd 2 b cd + b r3 k cd ), C r3L = a r3 2 +(b r3 + k cd b cd ), 2 - R r3 2 , and the coordinates of point d can be calculated as (x d , y d ); The coordinates of point e are (a r3 , 0), the coordinates of point f are The coordinates of point g are The coordinates of point h are (0, -E 层 ), the coordinates of point l are The coordinates of point m are (0, E 内 - E 层 ), the coordinates of point n are

[0131] In step S5, the cross-sectional area of the tube wall structure unit s 波 The area s of the figure formed by the characteristic points abcdefgh on the outer contour of the cross section 外 The area s of the figure formed by each characteristic point ijklm on the inner contour of the cross section 内 The difference between the area moment S of the cross section of the pipe wall structure unit 波 The difference between the area moment of the figure formed by each characteristic point abcdefgh on the outer contour of the cross section and the area moment of the figure formed by each characteristic point ijklm on the inner contour of the cross section; the moment of inertia of the unit section of the pipe wall structure I 波 It is the difference between the moment of inertia of the figure formed by the characteristic points abcdefgh on the outer contour of the cross section and the moment of inertia of the figure formed by the characteristic points ijklm on the inner contour of the cross section.

[0132] In addition, the area s of the figure formed by each characteristic point abcdefgh of the cross-section outer contour 外 , area moment S 外 and moment of inertia I 外 The sum of the areas, area moments and moments of inertia of the wave top arc ab, wave top fillet bc, outer hypotenuse cd, wave bottom fillet de and the first horizontal line segment ef respectively; the area s of the figure formed by each characteristic point ijklm on the inner contour of the cross section 内 , area moment S 内 and moment of inertia I 内 It is the sum of the areas of the inner wave top arc ij, the inner wave top fillet jk, the inner hypotenuse kl, the sum of the area moments and the sum of the moments of inertia.

[0133] Among them, the area of the wave top arc ab is:

[0134]

[0135] The area of the wave top fillet bc is:

[0136] The area of the outer hypotenuse cd is:

[0137] The area of the bottom arc de is:

[0138] The area of the first horizontal line segment ef is:

[0139] s 外 =s ab +s bc +s cd +s de +s ef ;

[0140] The area of the inner vertex arc ij is:

[0141] The area of the inner top-round corner jk is:

[0142] The area of the inner hypotenuse kl is:

[0143] where y ml is the analytical formula of the third horizontal line segment ml, and y hg is the analytical formula of the second horizontal line segment hg;

[0144] s 内 = s ij + s jk + s kl ;

[0145] Therefore, the cross-sectional area s of the pipe wall structure unit 波 = 2×(s 外 - s 内 ).

[0146] Preferably, the area moment of the wave-top arc ab is:

[0147] The area moment of the wave-top round corner bc is:

[0148] The area moment of the outer hypotenuse cd is:

[0149] The area moment of the wave-bottom round corner de is:

[0150] The area moment of the first horizontal line segment ef is:

[0151] S 外 = S ab + S bc + S cd + S de + S ef ;

[0152] The area moment of the inner wave-top arc ij is:

[0153] The area moment of the inner wave-top round corner jk is:

[0154] The area moment of the inner hypotenuse kl is:

[0155] S 内 = S ij + S jk + S kl ;

[0156] The area moment S of the cross-sectional view of the pipe wall structure unit 波 = 2×(S 外 - S 内 ).

[0157] Among them, the moment of inertia of the wave crest arc ab is:

[0158] The moment of inertia of the wave crest fillet bc is:

[0159] The moment of inertia of the outer hypotenuse cd is:

[0160] The moment of inertia of the wave bottom fillet de is:

[0161] The moment of inertia of the first horizontal line segment ef is:

[0162] I 外 = I ab + I bc + I cd + I de + I ef ;

[0163] The moment of inertia of the inner wave crest arc ij is:

[0164] The moment of inertia of the inner wave crest fillet jk is:

[0165] The moment of inertia of the inner hypotenuse kl is:

[0166] I 内 = I ij + I jk + I kl ;

[0167] The moment of inertia I of the cross-sectional view of the pipe wall structure unit 波 = 2×(I 外 - I 内 ).

[0168] In addition, in step S6,

[0169]

[0170] The centroid moment of inertia I of the pipe wall structure unit 质心 = The moment of inertia I of the pipe wall structure unit 波 - M 质心 2 × The area s of the pipe wall structure unit 波 ;

[0171]

[0172] Neutral axis distance D 中 = Average inner diameter ID of the pipe + 2 × (E 层 + Centroid M of the pipe wall structural unit);

[0173] In step S7,

[0174] Example 3

[0175] The difference from Example 2 is also that the pipe parameters further include the pipe length L 管 , and the calculation formula for the pipe weight W is as follows:

[0176]

[0177] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for calculating the ring stiffness of a structural wall pipe, characterized in that, The cross-section of the pipe wall structure unit of the structural wall pipe is symmetrical about its axis of symmetry. The outer contour line of the cross-section on one side of the axis of symmetry successively includes a plurality of first line types from top to bottom, and each of the first line types is one of a straight line or an arc. The inner contour line of the cross-section on the same side of the axis of symmetry successively includes a plurality of second line types from top to bottom, and each of the second line types is one of a straight line or an arc. The calculation method includes the following steps: S1: Obtain the pipe material parameters, pipe wall structure unit parameters, and material parameters of the structural wall pipe; S2: Establish an XY coordinate system with the axis of symmetry as the Y-axis and any straight line where a line type perpendicular to the Y-axis is located as the X-axis; S3: According to the XY coordinate system and the pipe wall structure unit parameters obtained in step S1, calculate the analytical expressions of all line types of the outer contour line and the inner contour line respectively; S4: According to the analytical expressions obtained in step S3, calculate the coordinates of the characteristic points where each adjacent line type intersects; S5: Calculate the area s of the cross-section of the pipe wall structure unit respectively according to the analytical expressions of each line type obtained in step S3 and the coordinates of each characteristic point obtained in step S4 波 , the area moment S 波 and the moment of inertia I 波 ; S6: The area s of the cross-section of the pipe wall structure unit obtained according to step S5 波 , the area moment S 波 , the moment of inertia I 波 and the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per meter of the cross-section of the pipe wall structure unit, and the neutral axis distance are calculated based on the pipe material parameters and material parameters; S7: Obtain the ring stiffness of the structural wall pipe based on the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the pipe wall structure unit cross-section, and the neutral axis distance.

2. The ring stiffness calculation method of the structural wall pipe according to claim 1, characterized in that, The structural wall pipe is a double-wall corrugated pipe. The multiple first line types of the outer contour line are successively the wave crest arc ab, the wave crest fillet bc, the outer bevel cd, the wave bottom fillet de, the first horizontal line segment ef, the first vertical line segment fg, and the second horizontal line segment hg. The multiple second line types of the inner contour line are successively the third vertical line segment ai, the inner wave crest arc ij, the inner wave crest fillet jk, the inner bevel kl, the third horizontal line segment ml, and the second vertical line segment mh. The wave crest arc ab is tangent to the wave crest fillet bc at point b, and the wave crest fillet bc is tangent to the outer bevel cd at point c; the inner wave crest arc ij is tangent to the inner wave crest fillet jk at point j, and the inner wave crest fillet jk is tangent to the inner bevel kl at point k; In the step S1, the pipe parameters include the average inner diameter ID of the pipe; the wall structure unit parameters include the outer wall thickness E 外 , the inner wall thickness E 内 , the laminated wall thickness E 层 , the wave pitch L, the wave width B, the wave height H, the inclination angle α, the radius of the wave crest arc ab is R r1 , the radius of the wave crest fillet bc is R r2 and the radius of the wave bottom fillet de is R r3 ; the material parameters include the material modulus E and the material density ρ; In step S2, establish an XY coordinate system with the straight line where the first horizontal line segment ef is located as the X-axis and the straight line where the third vertical line segment ai is located as the Y-axis; In step S3, calculate the analytical expressions of the wave crest arc ab, the outer bevel cd, the wave bottom fillet de, the wave crest fillet bc, the inner wave crest arc ij, the inner wave crest fillet jk, the inner bevel kl, the second horizontal line segment hg, the third horizontal line segment ml, and the first vertical line segment fg respectively; In step S4, according to the analytical expressions obtained in step S3, calculate the coordinates of the characteristic points a, b, c, d, e, f, g, h, i, m, and n; In the step S5, according to the analytical expressions of each line type obtained in the step S3 and the coordinates of each feature point obtained in the step S4, the area s of the cross-section of the pipe wall structure unit is calculated respectively 波 , the area moment S 波 and the moment of inertia I 波 ; In the step S6, according to the area s, area moment S, moment of inertia I of the cross-section of the pipe wall structure unit obtained in step S5, as well as the density of the material, bending modulus, average inner diameter ID of the pipe, and pipe length L 管 Calculate the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per meter of the cross-section of the pipe wall structure unit, and the neutral axis distance; In step S7, obtain the ring stiffness of the structural wall pipe based on the centroid of the pipe wall structure unit, the centroid moment of inertia of the pipe wall structure unit, the moment of inertia per unit length of the pipe wall structure unit cross-section, and the neutral axis distance.

3. The ring stiffness calculation method for the structural wall pipe according to claim 2, characterized in that In step S3: The analytical formula of the wave crest arc ab is: Among them, the radius of the wave crest arc ab is R r1 , and its center r1 is (a r1 , b r1 ), a r1 = 0, b r1 = H - R r1 ; The analytical formula of the outer bevel edge cd is: y = k cd (x - b cd ), where k cd = -tanα, The analytical formula for the bottom wave fillet is: Among them, the radius of the bottom wave fillet is R r3 , and its center r3 is (a r3 , b r3 ), b r3 = R r3 ; The specific solution process of the analytical expression of the wave crest arc bc is as follows: With point r1 as the center and line segment r1r2 as the radius, construct an auxiliary arc r4. Let its analytical formula be: Where: a r4 = 0, b r4 = H - R r1 , R r4 = R r1 - R r2 ; Parallel line segments cd. Draw an auxiliary line L2 through point r2, and assume its analytical formula is: y = k cd (x - b L2 ), where: k cd = -tanα, Let the analytical expressions of the auxiliary arc r4 and the auxiliary line L2 be equal, and a quadratic equation can be obtained by simplification A r4L2 x 2 +B r4L2 x + C r4L2 =0, where A r4L2 =1 + k cd 2 , B r4L2 =-2(a r4 +k cd 2 b L2 +b r4 k cd ), C r4L2 =a r4 2 +(b r4 +k cd b L2 ) 2 -R r4 2 , and by calculation, the coordinates of point r2 can be obtained as (x r2 , y r2 ); That is, the analytical formula of the wave crest arc bc is: where a r2 = x r2 , b r2 = y r2 ; The analytical formula of the inner wave crest arc ij is as follows: Where: a r1 = 0, b r1 = H - R r1 , R r1 ’ = R r1 - E 外 ; The analytical formula for the inner wave top fillet jk is as follows: Where: a r2 = x r2 , b r2 = y r2 , R r2 ' = R r2 - E 外 ; The analytical formula of the inner bevel edge kl is: y = k kl (x - b kl ), where: k kl = -tanα, The analytical formula of the third horizontal line segment ml is: y = b ml , where: b ml = E 内 - E 层 ; The analytical formula of the second horizontal line segment hg is: y = b hg , where: b hg = -E 层 .

4. The method for calculating the ring stiffness of the structural wall pipe according to claim 3, characterized in that In the step S4, the coordinates of the feature point a are (0, H), and the coordinates of the feature point i are (0, H - E 外 ). The coordinates of the feature point b are obtained as follows. First, set the line segment r1b as the auxiliary line L3, and assume its analytical formula is: y = k L3 x + b l3 , where: b L3 = b r2 - a r2 k L3 ; Let the analytical formulas of the wave crest arc ab and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1L3 x 2 + B r1L3 x + C r1L3 = 0 can be obtained, where A r1L3 = 1 + k L3 2 , B r1L3 = -2(a r1 - k L3 2 b L3 + b r1 k L3 ), C r1L3 = a r1 2 +(b r1 - b L3 ) 2 - R r1 2 . By calculation, the coordinates of point b can be obtained as (x b , y b ); Let the analytical expressions of the inner wave crest arc ij and the auxiliary line L3 be equal. By simplification, a quadratic equation A r1’L3 x 2 +B r1’L3 x+C r1’L3 =0 can be obtained, where A r1’L3 =1 + k L3 2 , B r1’L3 =-2(a r1 -k L3 2 b L3 +b r1 k L3 ), C r1’L3 =a r1 2 +(b r1 -b L3 ) 2 -R r1 ’ 2 . By calculation, the coordinates of point j (x j , y j ) can be obtained; The coordinates of the feature point c are obtained as follows. Let the outer wave crest fillet r2, that is, the analytical formula of the arc bc, be equal to the outer hypotenuse L, that is, the analytical formula of the line segment cd. By simplification, a quadratic equation A r2L x 2 +B r2L x+C r2L =0 can be obtained, where A r2L =1+k cd 2 , B r2L =-2(a r2 +k cd 2 b cd +b r2 k cd ), C r2L =a r2 2 +(b r2 +k cd b cd ) 2 -R r2 2 . By calculation, the coordinates of point c are (x c , y c ); Let the analytical expressions of the inner wave top rounded corner jk and the inner hypotenuse kl be equal. By simplification, a quadratic equation A can be obtained. r2’L’ x 2 +B r2’L’ x+C r2’L’ =0, where A r2’L’ =1+k kl 2 , B r2’L’ =-2(a r2’ +k kl 2 b kl +b r2’ k kl ), C r2’L’ =a r2’ 2 +(b r2’ +k kl b kl ) 2 -R r2 ’ 2 . By calculation, the coordinates of point k can be obtained as (x k , y k ); For the coordinates of the feature point d, make the analytical expressions of the bottom fillet de and the outer bevel cd equal. After simplification, a quadratic equation A r3L x 2 +B r3L x+C r3L =0 can be obtained, where A r3L =1+k cd 2 , B r3L =-2(a r3 +k cd 2 b cd +b r3 k cd ), C r3L =a r3 2 +(b r3 +k cd b cd ) 2 -R r3 2 . The coordinates of point d (x d , y d ) can be calculated; the coordinates of point e are (a r3 , 0), the coordinates of point f are The coordinates of point g are The coordinates of point h are (0, -E 层 ), the coordinates of point l are The coordinates of point m are (0, E 内 -E 层 ), the coordinates of point n are 5. The ring stiffness calculation method of the structural wall pipe according to claim 4, characterized in that In the step S5, the cross-sectional area s of the pipe wall structure unit 波 is the difference between the area s of the figure formed by the characteristic points abcdefgh on the outer contour of the cross-section 外 and the area s of the figure formed by the characteristic points ijklm on the inner contour of the cross-section; the area moment S of the cross-section of the pipe wall structure unit 内 is the difference between the area moment of the figure formed by the characteristic points abcdefgh on the outer contour of the cross-section and the area moment of the figure formed by the characteristic points ijklm on the inner contour of the cross-section; the moment of inertia I of the cross-section of the pipe wall structure unit 波 波 is the difference between the moment of inertia of the figure formed by the characteristic points abcdefgh on the outer contour of the cross-section and the moment of inertia of the figure formed by the characteristic points ijklm on the inner contour of the cross-section.​ 6. The method for calculating the ring stiffness of the structural wall pipe according to claim 5, wherein The area s of the figure formed by the characteristic points a, b, c, d, e, f, g, and h on the outer contour of the cross-section 外 , the area moment S 外 and the moment of inertia I 外 are respectively the sum of the areas, the sum of the area moments, and the sum of the moments of inertia of the wave crest arc ab, the wave crest fillet bc, the outer hypotenuse cd, the wave bottom fillet de, and the first horizontal line segment ef; the area s of the figure formed by the characteristic points i, j, k, l, and m on the inner contour of the cross-section 内 , the area moment S 内 and the moment of inertia I 内 are the sum of the areas, the sum of the area moments, and the sum of the moments of inertia of the inner wave crest arc ij, the inner wave crest fillet jk, and the inner hypotenuse kl.

7. The method for calculating the ring stiffness of the structural wall pipe according to claim 6, wherein The area of the wave crest arc ab is: The area of the wave crest fillet bc is: The area of the outer bevel cd is: The area of the bottom wave arc de is: The area of the first horizontal line segment ef is: s 外 = s ab + s bc + s cd + s de + s ef ; The area of the inner top arc ij is: The area of the inner top rounded corner jk is: The area of the inner bevel edge kl is: Among them, y ml is the analytical formula of the third horizontal line segment ml, and y hg is the analytical formula of the second horizontal line segment hg; s 内 = s ij + s jk + s kl ; Therefore, the cross-sectional area s of the pipe wall structure unit 波 = 2×(s 外 - s 内 ).

8. The method for calculating the ring stiffness of the structural wall pipe according to claim 7, wherein The area moment of the wave crest circular arc ab is as follows: The area moment of the wave crest fillet bc is: The area moment of the outer hypotenuse cd is: The area moment of the bottom wave fillet has: The area moment of the first horizontal line segment ef is as follows: S 外 = S ab + S bc + S cd + S de + S ef ; The area moment of the inner wave crest arc ij is as follows: The area moment of the inner wave top fillet jk is: The area moment of the inner bevel edge kl is as follows: S 内 = S ij + S jk + S kl ; The area moment S of the cross-sectional view of the pipe wall structure unit 波 = 2 × (S 外 - S 内 ).

9. The method for calculating the ring stiffness of the structural wall pipe according to claim 8, wherein The moment of inertia of the wave crest arc ab is: The moment of inertia of the wave crest fillet bc is: The moment of inertia of the outer bevel cd is: The moment of inertia of the rounded corner at the bottom of the wave is: The moment of inertia of the first horizontal line segment ef is: I 外 = I ab + I bc + I cd + I de + I ef ; The moment of inertia of the inner wave crest arc ij is as follows: The moment of inertia of the inner wave top fillet jk is as follows: The moment of inertia of the inner bevel edge kl is: I 内 = I ij + I jk + I kl ; Moment of inertia I of the cross-sectional view of the pipe wall structural unit 波 = 2 × (I 外 - I 内 ).

10. The ring stiffness calculation method of the structural wall pipe according to claim 9, characterized in that, In step S6, Centroid moment of inertia I of the pipe wall structure unit 质心 = Moment of inertia I of the pipe wall structure unit 波 - M 质心 2 × Area s of the pipe wall structure unit 波 ; Neutral axis distance D 中 = Average inner diameter ID of the pipe + 2 × (E 层 + Centroid M of the pipe wall structural unit); In the step S7,

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