JP3456479B2 - Concrete filled circular steel tubular column - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to joining when a beam flange is attached to a concrete filled circular steel tubular column (hereinafter referred to as "CFT") having a ring diaphragm shown in FIG. 1 or a ring integrated type shown in FIG. This paper presents a concrete-filled circular steel tubular column designed by a load-bearing design method based on an evaluation formula that allows the local yield strength of a part to be evaluated with high precision and relatively easy calculation.

[0002]

2. Description of the Related Art Conventionally, for example, the strength of beam-column joints of a steel pipe column with a ring diaphragm is evaluated by a calculation formula based on a tensile test as shown in FIG. It was calculated by applying it to each beam flange. The obtained values are regarded as the local proof stress under tensile load and compressive load, and the relationship between the beam flanges has been ignored.

[0003]

However, this calculation formula is an empirical formula derived based on a series of tensile test results, and its applicable range is limited. In general, it is assumed that the proof stress will be calculated in an earthquake area. It cannot be said that the correct evaluation is performed under the earthquake load, that is, in the case where the tensile force and the compressive force act on the beam flanges attached to both sides of the steel pipe as shown in FIG. Further, since it is an empirical formula, the designer cannot recognize the basis of the calculation, and cannot be applied to a special case outside the applicable range specified in the experiment. The conventional technology has the above-mentioned problems.

The present invention has been made in view of such problems, and an object of the present invention is to provide a simple and general-purpose steel pipe column while maintaining a constant accuracy of the beam-column joint strength of the steel pipe column. The point is to present a concrete-filled circular steel tubular column designed by the method to obtain the proof stress of the beam-column joints in.

In the concrete-filled circular steel pipe column to which the beam is attached, the steel pipe wall surface in the vicinity of the beam to which the beam is attached is bent and deformed and the flow component (P ₁ ) of the force transmitted and the beam component of the beam are transmitted. According to the sum of the ring to which the flange is attached and the flow component (P ₂ ) of the force transmitted in the circumferential direction due to the bending of the steel pipe sheet near the ring, the yield strength (P) of the beam-column joint portion of the steel pipe column is calculated by The column-beam joint portion is designed, and P = P ₁ + P ₂ (1) P ₁ and P ₂ are concrete-filled circular steel tubular columns characterized by being obtained from the following formulas.

[Equation 15]

[Equation 16] M = M _A · P ₂ , N = N _A · P ₂ , Q = Q _A · P ₂ , M _θ = M
_θA · P ₂ , T _R = T _RA · P ₂ where:

[Equation 17]

[Equation 18] ν: Poisson's ratio of the steel pipe D: Diameter of the steel pipe t _c : Plate thickness of the steel pipe σ _yt : Yield strength of the steel pipe S: Effective circumferential length X _{1 to} X ₅ : Coefficient M: Bending moment N at the study site N: Shaft at the study site power Q: shear M _theta in consideration point: bending plane in consideration portion moment T _R: torque above M～T _R subscript with p in consideration points travel in each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
In the concrete-filled circular steel pipe column to which the beam is attached, the flow component (P ₁ ) of the force transmitted by bending and deforming the wall surface of the steel pipe in the vicinity to which the beam is attached, and the flange of the beam. By the method of determining the proof stress (P) of the beam-column joint portion of the steel pipe column from the sum of the ring attached to the pipe and the flow component (P ₂ ) of the force transmitted in the circumferential direction by bending of the steel pipe sheet near the ring. A column-beam joint portion is designed, and P = P ₁ + P ₂ (1) P ₁ and P ₂ are concrete-filled circular steel tubular columns characterized by being obtained from the following formulas.

[Formula 19]

[Equation 20] here,

[Equation 21]

[Equation 22] ν: Poisson's ratio of steel pipe D: Diameter of steel pipe t _c : Thickness of steel pipe σ _yt : Yield strength of steel pipe S: Effective circumferential length M: Bending moment N at the examination point N: Axial force at the examination point Q: Shear at the examination point power M _theta: plane bending moment T _R in consideration point: torque above M～T _R subscript with p in consideration points travel in each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
Torque: The gist of the invention of claim 3 is that a beam is attached.
In a concrete-filled circular steel pipe column, the wall surface of the steel pipe near the beam is bent and deformed, and the flow component of the transmitted force (P
_1), and decomposed into the beam flanges attach ring and the ring near the steel plate force flow component transmitted by the bending in the circumferential direction of the (P _2), the flow of force transmitted to the circumferential direction
From the component (P ₂ ) of the steel pipe column
The beam-column joint is designed by the method to obtain the force (P).
And the P ₂ is obtained from the following equation.
It is in a concrete-filled circular steel pipe column.

[Equation 23] M = M _A · P ₂ , N = N _A · P ₂ , Q = Q _A · P ₂ , M _θ = M
_θA · P ₂ , T _R = T _RA · P ₂ where : X _{1 to} X ₅ : Coefficient M: Bending moment N at the study location N: Axial force at the study location Q: Shearing force M _{θ at the} study location M _θ : At the study location plane bending moment T _R: subscript w p of the torque the M～T _R in consideration points travel in each parameter
Takes full plastic resistance force of the ring member M _A: put into consideration locations when P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
The torque of the invention is the concret to which a beam is attached.
G. In a filled circular steel pipe column, the flow component (P ₁ ) of the force transmitted by bending deformation of the steel pipe wall surface in the vicinity of the beam attachment, the ring attached to the beam flange and the bending of the steel pipe sheet in the vicinity of the ring To the flow component (P ₂ ) of the force transmitted to the
Minute (P ₂ ) to yield strength of beam-column joints in steel pipe columns
The beam-column joint is designed by the method of obtaining (P), and the above P ₂ is obtained from the following equation.
It is in a concrete-filled circular steel pipe column.

[Equation 24] Here, M: bending moment in the study locations N: axial force in consideration point Q: shear M _theta in consideration point: plane bending moment T in consideration point _R: subscript torque the M～T _R in consideration point-shaped p Appended: for each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
The torque according to claim 5 is characterized in that the proof stress examination point is a flange edge-containing corner processed portion end.
The concrete-filled circular steel pipe column according to any one of 1 to 4. The gist of the invention according to claim 6 is to obtain the flow component (P ₂ ) of the force transmitted in the circumferential direction by using an angle θ _A formed between the flange edge-containing corner processed portion end and the flange center axis. The concrete-filled circular steel pipe column according to any one of claims 1 to 4, characterized in that. The gist of the invention according to claim 7 is that the θ _A is represented by the following formula: θ _A or θ _B

[Equation 25] The concrete-filled circular steel pipe column according to claim 6, wherein Here, B _f : Beam flange width D: Steel pipe diameter H _S : Ring protrusion r: Beam flange welded portion corner processing radius The gist of the invention according to claim 8 is that the steel pipe column has a long flange axial force. under load, the long-term permissible yield strength P _a (long term), beam joint portion so as not to exceed the respective short-term permissible yield strength P _a (short term) and the maximum strength P _u which corresponds to the time of each of the load at the time of short-term load and at maximum load The concrete-filled circular steel tubular column according to any one of claims 1 to 7, characterized in that

[Equation 26]

[Equation 27]

[Equation 28] The gist of the invention according to claim 9 is a steel tube column with a ring diaphragm, which is the concrete-filled circular steel tube column according to any one of claims 1 to 8. Claim 1
The gist of the invention according to claim 0 is a ring-integrated type steel tube column having an increased thickness at the joint with the beam, wherein the concrete-filled circular steel tube column according to any one of claims 1 to 8. is there. The gist of the invention according to claim 11 resides in a structure constructed by the concrete-filled circular steel pipe pillar according to any one of claims 1 to 10.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. It is assumed that the flow of the axial force of the beam flange to the column is decomposed into two flow components as shown in Fig. 6 (a) and Fig. 6 (b), and each component is subjected to proof stress by an analytical method. Calculated by the evaluation formula and evaluate the sum as the proof stress of the joint.

As shown in FIG. 7, the flow of component 1 (hereinafter,
P ₁ is the flow of force that is transmitted mainly in the axial direction of the steel pipe due to bending deformation of the steel pipe wall in the vicinity where the beam is attached, and is the flow of component 2 (hereinafter referred to as “ring proof stress”).
P ₂ is a flow of force transmitted in the ring circumferential direction due to bending of the ring and the steel tube sheet near the ring.

Therefore, the proof stress P of the joint transmitted by the beam flange is the sum of the two,

[0009]

[Equation 29]

Long-term allowable yield strength P _A used in the yield strength design method
(Long-term), short allowable strength _{P A} (short term) and the maximum strength _{P u}
Respectively,

[0011]

[Equation 30]

[0012]

[Equation 31]

[0013]

[Equation 32]

It is assumed that

In designing, the flange axial force obtained from the structural analysis should not exceed the long-term allowable yield strength, short-term acceptable yield strength and maximum yield strength corresponding to each load.

The front shear force P ₁ is obtained from the cylindrical shell theory. The calculation formula of P ₁ is given as follows regardless of the load condition.

[0017]

[Expression 33]

Here,

[0019]

[Equation 34]

[0020]

[Equation 35]

[0021]

[Equation 36]

The effective circumference S (see FIG. 8) was set as shown in equation (9) from the results of experiments and finite element analysis (hereinafter referred to as FEM).

[0023]

[Equation 37]

The ring strength P ₂ is, T-section, including effective width α of the steel pipe portion shown in FIG. 9 (hereinafter, referred to as "ring form") arch / ring effective radius Re consisting Arch / ring skeleton Theory Is calculated by applying. Here, the flange axial force is regarded as a two-point concentrated load acting on the load acting position ψ as shown in FIG. 10.

The effective width α is (1
0) or (11), (12) and (13).

[0026]

[Equation 38]

However, the effective width α of the ring integrated type is

[0028]

[Formula 39]

The effective radius Re is

[0030]

[Formula 40]

However, g is

[0032]

[Formula 41]

When the beam flange axial force is regarded as a two-point concentrated load, its load acting position ψ is set according to the formula (18) from the experiment and FEM results.

[0034]

[Equation 42]

However,

[Equation 43] At the time of

[0036]

[Equation 44]

The ring strength _{P 2} is the full plastic Strength _M P of the ring _body, N _{P, Q} P, M against _θP and _{T R P,} the bending moment M in the study location below, the axial force N, shear force Q , The out-of-plane bending moment M _θ and the torque T _R have plasticity conditional expressions:

[0038]

[Equation 45]

It is obtained by applying

Total plastic proof stress of the ring body M _P , N _P , Q _P ,
M _θP and T _RP are calculated according to the following formulas:

[0041]

[Equation 46]

[0042]

[Equation 47]

[0043]

[Equation 48]

Is regarded as effective only in the ring portion (ignoring the steel pipe portion), and the equations (25) and (2
It is calculated by the equations 6) and (27).

[0045]

[Equation 49]

[0046]

[Equation 50]

In the ring integrated type, the effective width α is (1
1), (12) and (13), and in the expressions (21) to (27), H _s = 0 and T _s =
It is _calculated by substituting t _f and t _c = t _p .

Bending moment M, axial force N, shearing force Q, out-of-plane bending moment M _θ and torque T _R (hereinafter referred to as “section force of ring body”) of the ring body necessary for calculating P ₂
Is the load condition, the presence or absence of concrete filling, the presence or absence of eccentricity,
The calculation method is different depending on the shape of the ring, etc.

(1) Hollow steel tubular column with symmetrical load (2) Hollow steel tubular column with anti-symmetrical load (3) Hollow steel tubular column with unidirectional load (4) CFT Among these, the present invention (4) Vertical eccentricity with CFT And when there is no horizontal eccentricity.

[0050] Among the cross-sectional strength of the ring body, plane bending moments M _theta and torque T _R is common to the above case (1) to (4), than occurs when a vertical eccentric,

[0051]

[Equation 51]

[0052]

[Equation 52]

In the present invention, which deals with the case where there is no vertical eccentricity, _ev = 0, so that M _{θ = 0 and TR} = 0.

On the other hand, the bending moment M, the axial force N, and the shearing force Q of the sectional force of the ring body are derived from the arch / ring frame theory by appropriately assuming the boundary conditions corresponding to the respective cases. Below, the calculation method of the bending moment M, the axial force N, and the shearing force Q when the load P ₂ acts on the beam flange is (4) CFT according to the present invention.
Regarding.

(4) CFT In the case of CFT, due to the effect of the filled concrete, the multiple beams attached to the same column do not affect each other, and the local proof stress of the joint is compressed under any load condition. It has been confirmed by experiments and FEM that the yield strength is not determined by the side flanges and is determined by the minimum local yield strength of each tensile side flange. Therefore, the CFT yield strength calculation results in obtaining the tensile flange local yield strength of the column.

The tensile flange joint of the CFT is considered to be an arch having a fulcrum at an angle θo shown in FIG. However, the angle θo is an unknown number and must be obtained by the following method.

When a tensile axial force from the beam flange acts on the column-beam joint of the CFT, there is a point where the ring body separates from the filled concrete surface (point B in FIG. 12). At this point B, the bending moment is zero and the rotation angle is also zero. Here, if the point of intersection of the beam flange central axis and the NT ring is point O, the effective width part of the NT ring + steel pipe tube wall will not go inside the filled concrete part between OB.

13 and 14 illustrate the deformation when a tensile force is applied from the beam flange. Since the moment at point B is zero, if pin support is made at point B,
The extensional deformation due to the axial force N acting on the ring (which varies depending on θ) becomes Δ, and the deformation due to only the extensional deformation becomes the deformation state shown in FIG. 13. The rotation angle of the point B thereby is set to θ _a .

When the rotation angle of the point B due to the bending deformation between AB (see FIG. 15) is θ _b , θ o is a value of θ that satisfies the following equation.

[0060]

[Equation 53] However, if there is no θ satisfying θ _a + θ _b = 0,
Let θ _o = θ _s or θ _o = π / 2 (rad). Where θ _s is

[0061]

[Equation 54] And Even if the rigidity of the ring changes in the middle of the circumference, if the rigidity of the ring does not change within θ _o , it is considered that there is a ring of the same rigidity over the entire circumference.

The axial force changes between (the rotation angle θ _{a of the} point B due to Δ) AB. In addition, the axial force is not zero at the point B, and is stretched and deformed up to the point C until the ring axial force becomes zero due to the frictional force between the concrete and the ring. Therefore, at the point B, the ring is displaced in the A direction. Ignore this gap here. The average value of the axial force between AB is θ
_It is assumed to be represented by Nd at the position of _d = (θs + θo) / 2. Nd is shown by the following equation.

[0063]

[Equation 55]

When the cross-sectional area of the ring including the effective width is A and the Young's modulus is E, the elongation Δ is given by the following equation.

[0065]

[Equation 56]

The rotation angle θ _{a of} point B due to Δ is given by the following equation from the geometrical relation.

[0067]

[Equation 57]

[0068] The bending moment M between AB (rotation angle theta _b due to bending deformation) is a function of theta, and zero rotation angle of the point A by bending deformation, the bending stiffness of the ring I, when the Young's modulus E , The rotation angle θ _b due to the bending of the B point is given by the following equation.

[0069]

[Equation 58]

[0070] (Determination of theta ₀₎ (33) to determine the theta ₀ by formula and (34) and (30) below. That is, some θ
Assuming ₀ , the provisional P ₂ is determined by applying the total plasticity condition (17) to the sectional force at the examination point of the ring, which is assumed to be this position as a fulcrum. From these, N _d , M (α) are determined. Is required. If θ _a and θ _b are obtained from the equations (33) and (34) and the equation (30) is satisfied, it is true θ ₀ . (Proof strength of CFT column) If true θ ₀ is obtained, the axial force N, the shearing force Q, and the bending moment M at the angle θ on the arch can be obtained by the following equation.

[0071]

[Equation 59] However, V _A , V _B , and H are based on the equation (31). Definition of θ _s

[Equation 60]

Finally, FIG. 16 and FIG. 17 show a flow of a method of designing a beam-column joint portion of a steel pipe column with a ring diaphragm using the above-described method for obtaining proof stress. In addition,
Since P ₁ is relatively small with respect to P ₂ , P ₁ can be ignored (in both figures). The method for obtaining the yield strength of the beam-column joint portion of the steel pipe column according to the embodiment has the following effects because it is configured as described above. It has become possible to comprehensively and accurately evaluate the strength of column-beam joints of circular steel pipe columns with ring diaphragms. Since it is based on the analytical load bearing formula, the designer can recognize the force flow to some extent and can be applied to a special case. In particular, the present invention makes it possible to handle CFT.

(Embodiment 1) In the equation (20), since all numerator terms are in proportion to P ₂ , the coefficient X ₁ to
When X ₅ is X ₁ = X ₂ = X ₃ = X ₄ = X ₅ = 2, P ₂ can be easily obtained. That, M when the P ₂ = 1 (unit _{load), N, Q, M θ} , T R , respectively,
If M _A , N _A , Q _A , M _θA , and T _RA , then the formula for P ₂ is

[0074]

[Equation 61]

It can be written as

According to the equation (20), it is possible to set an arbitrary position on the circumference as the examination point.
From the results, it is known that the most critical point to be examined is the edge of the corner processed portion including the flange edge. That is,
Points A and B, which are the corners of the beam flange edge (Fig. 11)
Is the examination point of the present invention. The angles θ _A and θ _B formed by the points A and B and the flange center axis are given by the equations (39) and (40).

[0077]

[Equation 62]

Here, r is a corner processing radius with the beam flange welded portion (normally r = 1 cm).

Circular steel tubular column with ring diaphragm filled with concrete φ-318.5 × 10.3, Hs = 1
6, when the beam flange PL-100x16 is attached symmetrically at Ts = 16, the yield stress degrees of the steel pipe and the ring are σ, respectively.
It is assumed that ys = 3.3 (tf / cm ² ) and σyt = 3.3 (tf / cm ² ). When a symmetrical load acts, according to the evaluation formula of the present invention, P ₁ = 10.10 (tf) and P ₂ = 38.77.
(Tf) and P = 48.87 (tf). Therefore, the maximum yield strength Pu = 60.63 (tf), short-term allowable yield strength P _A (short term) =
42.50 (tf) and long-term allowable proof stress P _A (long-term) = 2
It is 8.33 (tf).

(Embodiment 2) In this evaluation formula, the coefficients X ₁ to
FIG. 18 shows a comparison between the calculation result when X ₅ is X ₁ = X ₂ = X ₃ = X ₄ = X ₅ = 2 and the experimental result or the FEM analysis result.

The number, position, shape, etc. of the above-mentioned constituent members are not limited to those in the above-mentioned embodiment, and any number, position, shape, etc. suitable for carrying out the present invention can be adopted. For example, the flange of the beam can be rounded. In such a case, it is preferable to perform the assay with the edge of the are.

Further, in each drawing, the same components are designated by the same reference numerals.

[0083]

Since the present invention is configured as described above, it has the following effects. Since it is calculated using the analytical load-bearing formula instead of the empirical formula, a simple and general-purpose method for determining the load-bearing strength of the beam-column joint of the steel pipe column while maintaining a certain degree of accuracy of the beam-column joint strength of the steel pipe column Designed concrete filled circular steel tubular columns can be presented.
In particular, the present invention makes it possible to handle CFT.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a steel pipe column with a ring diaphragm to which the present invention is applied.

FIG. 2A is a partially cutaway perspective view of a thickened steel pipe column to which the present invention is applied, and FIG. 2B is a partially cutaway perspective view of a steel pipe column with a special ring diaphragm.

3 is a detailed cross-sectional view of a joined portion of the steel pipe column shown in FIG.

FIG. 4 is a diagram showing a long-term load (symmetrical load) state according to a conventional technique.

FIG. 5 is a diagram showing an earthquake load (antisymmetric load) state according to a conventional technique.

FIG. 6 is a diagram showing decomposition of axial force of a beam flange into two components according to the embodiment of the present invention.

FIG. 7 is a diagram showing details of decomposition of the axial force of the beam flange shown in FIG. 6 into two components.

FIG. 8 is a diagram showing a definition of an effective circumference length S according to the embodiment of the present invention.

FIG. 9 is a diagram showing a definition of an effective width α of an NT ring according to the embodiment of the present invention.

FIG. 10 is a diagram showing a working position ψ of a two-point concentrated load according to the embodiment of the present invention.

FIG. 11 is a diagram showing examination points of the ring body according to the embodiment of the present invention.

FIG. 12 is a diagram showing a CFT arch model according to an embodiment of the present invention.

FIG. 13 is a diagram showing a modification of the CFT ring body according to the embodiment of the present invention.

FIG. 14 is a diagram showing _a fulcrum rotation angle θ _a due to extension of a CFT ring body according to an embodiment of the present invention.

FIG. 15 is a diagram showing a fulcrum rotation angle θ _b due to bending of a CFT ring body according to the embodiment of the present invention.

FIG. 16 is a flowchart showing a flow of a beam-column joint design method for a concrete-filled circular steel tubular column according to the embodiment of the present invention.

FIG. 17 is a flowchart showing a continuation of the flow shown in FIG.

FIG. 18 is a diagram showing a comparison between the calculation result according to the present embodiment and the experimental result or FEM.

[Explanation of symbols]

α: Effective width S: Effective circumferential length ψ: Position where load is applied D: Steel pipe diameter t _c : Steel pipe plate thickness t _p : Plate thickness of thickened part of joint l _p : Extra length H of thickened part of joint _s: ring out _{T s:} ring of thickness _{B f:} beam flange width _{t f:} beam flange thickness σ _yt: the yield strength of the steel pipe σ _ys: the yield strength of the ring

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Nobuyuki Nakamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Pipe Co., Ltd. (72) Toshiaki Miyao 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Pipe Incorporated (72) Inventor Junichi Takagi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Steel Tube Co., Ltd. (56) Reference JP-A-5-340032 (JP, A) JP-A-9-137547 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E04B 1/30 E04B 1/24 JISST file (JOIS)

Claims (11)

(57) [Claims] 1. In a concrete-filled circular steel pipe column to which a beam is attached, a flow component (P ₁ ) of force transmitted by bending deformation of a steel pipe wall surface near the beam to be attached, a ring attached to the flange of the beam, and the vicinity of the ring. From the sum of the flow component (P ₂ ) of the force transmitted in the circumferential direction due to the bending of the steel tube sheet,
A method to determine the proof stress (P) of the beam-column joint in a steel pipe column
The column-beam joint is designed by: P = P ₁ + P ₂ (1) The P ₁ and P ₂ are concrete-filled circular steel tubular columns characterized by being obtained from the following formulas. [Equation 1] [Equation 2] M = M _A · P ₂ , N = N _A · P ₂ , Q = Q _A · P ₂ , M _θ = M
_θA · P ₂ , T _R = T _RA · P ₂ where : [Equation 4] ν: Poisson's ratio of the steel pipe D: Diameter of the steel pipe t _c : Plate thickness of the steel pipe σ _yt : Yield strength of the steel pipe S: Effective circumferential length X _{1 to} X ₅ : Coefficient M: Bending moment N at the study site N: Shaft at the study site power Q: shear M _theta in consideration point: bending plane in consideration portion moment T _R: torque above M～T _R subscript with p in consideration points travel in each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
Torque 2. In a concrete-filled circular steel pipe column to which a beam is attached, a flow component (P ₁ ) of force transmitted by bending deformation of a steel pipe wall surface near the beam to be attached, a ring attached to the flange of the beam, and the vicinity of the ring. From the sum of the flow component (P ₂ ) of the force transmitted in the circumferential direction due to the bending of the steel tube sheet,
A method to determine the proof stress (P) of the beam-column joint in a steel pipe column
The column-beam joint is designed by: P = P ₁ + P ₂ (1) The P ₁ and P ₂ are concrete-filled circular steel tubular columns characterized by being obtained from the following formulas. [Equation 5] [Equation 6] Here, [Equation 7] [Equation 8] ν: Poisson's ratio of steel pipe D: Diameter of steel pipe t _c : Thickness of steel pipe σ _yt : Yield strength of steel pipe S: Effective circumferential length M: Bending moment N at the examination point N: Axial force at the examination point Q: Shear at the examination point power M _theta: plane bending moment T _R in consideration point: torque above M～T _R subscript with p in consideration points travel in each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
Torque 3. A concrete-filled circular steel pipe to which a beam can be attached
In the column, the flow component (P ₁ ) of the force transmitted by bending and deforming the steel pipe wall surface near the beam is transmitted in the circumferential direction by bending the ring to which the beam flange is attached and the steel pipe sheet near the ring. Decomposes into a force flow component (P ₂ ),
From the flow component (P ₂ ) of the force transmitted in the circumferential direction , the steel pipe
By the method to obtain the proof stress (P) of the beam-column joints in the column
Therefore, the column-beam joint is designed, and P ₂ is obtained from the formula given below.
Concrete-filled circular steel tubular columns. [Equation 9] M = M _A · P ₂ , N = N _A · P ₂ , Q = Q _A · P ₂ , M _θ = M
_θA · P ₂ , T _R = T _RA · P ₂ where : X _{1 to} X ₅ : Coefficient M: Bending moment N at the study location N: Axial force at the study location Q: Shearing force M _{θ at the} study location M _θ : At the study location plane bending moment T _R: subscript w p of the torque the M～T _R in consideration points travel in each parameter
Takes full plastic resistance force of the ring member M _A: put into consideration locations when P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
Torque 4. A concrete-filled circular steel pipe to which a beam can be attached
In the column, the flow component (P ₁ ) of the force transmitted by bending and deforming the steel pipe wall surface near the beam is transmitted in the circumferential direction by bending the ring to which the beam flange is attached and the steel pipe sheet near the ring. Decomposes into a force flow component (P ₂ ),
From the flow component (P ₂ ) of the force transmitted in the circumferential direction , the steel pipe
By the method to obtain the proof stress (P) of the beam-column joints in the column
Therefore, the column-beam joint is designed, and P ₂ is obtained from the formula given below.
Concrete-filled circular steel tubular columns. [Equation 10] Here, M: bending moment in the study locations N: axial force in consideration point Q: shear M _theta in consideration point: plane bending moment T in consideration point _R: subscript torque the M～T _R in consideration point-shaped p Appended: for each parameter
At the point of study when the total plastic proof stress of the ring body M _A : P ₂ = 1 (unit load)
Bending moment N _A : P ₂ = 1 (unit load)
Axial force Q _A : P ₂ = 1 (unit load)
Shear force M _θA : P ₂ = 1 (unit load)
The out-of-plane bending moment T _RA : P ₂ = 1 (unit load)
Torque 5. The concrete-filled circular steel tubular column according to claim 1, wherein the proof stress examination point is a corner edge processing portion end with a flange edge. 6. The flow component (P ₂ ) of the force transmitted in the circumferential direction is obtained by using an angle θ _A formed by an end of a flanged corner processed portion and a flange center axis. Item 6. A concrete-filled circular steel tubular column according to any one of items 1 to 4. Wherein said theta _A a, theta _A or theta _B Equation 11] of the formula listed below The concrete-filled circular steel tubular column according to claim 6, characterized in that Here, B _f : Beam flange width D: Steel pipe diameter H _S : Ring protrusion r: Beam flange welded part corner processing radius 8. The steel pipe column comprises a long-term permissible load P _A (long-term), a short-term permissible load P _A (short-term), which corresponds to long-term load, short-term load, and maximum load of the flange axial force. Pillars so that they do not exceed the maximum yield strengths P _u
The concrete-filled circular steel tubular column according to any one of claims 1 to 7, wherein the beam joint portion is designed. [Equation 12] [Equation 13] [Equation 14] 9. The concrete-filled circular steel pipe column according to claim 1, which is a steel pipe column with a ring diaphragm. 10. A ring-integrated type steel pipe column having an increased thickness at the connection portion with the beam.
A concrete-filled circular steel tubular column according to any one of 1 to 8. 11. A structure constructed by the concrete-filled circular steel pipe column according to claim 1.