Design method for releasing thermal stress of steel structure frame

Abstract

The present invention discloses a design method for releasing thermal stress of a steel structure frame, comprising the steps of: determining whether the distances between the two ends of a thermal stress release device and the bearing surface of the steel structure frame to which the two ends are connected are equal, so as to select the type of thermal stress release device; establishing a coordinate system, establishing the origin of the coordinate system at the axis of the thermal stress release device, defining the direction parallel to the length of the thermal stress release device as the x-axis, and the directions of the y-axis and the z-axis as perpendicular to the surface of the thermal stress release device; and determining the specific dimensions of the thermal stress release device according to the components of the thermal stress that the steel structure frame needs to bear on the x-axis, y-axis, and z-axis. The present invention determines the specific dimensions of the thermal stress release device by calculating the specific dimensions of the thermal stress release device according to the thermal stress that the steel structure frame needs to bear, and can effectively release the axial thermal stress or bending moment generated by the thermal expansion of the steel structure frame due to high temperature in a specific direction, while ensuring that the steel structure frame has sufficient stability in the direction in which thermal stress does not need to be released.

Description

Technical Field

[0001] The invention relates to the field of nuclear reactor pressure vessel joining, and in particular to a design method for releasing thermal stress of a steel structure frame. Background Art

[0002] During the operation of a nuclear power plant, the environment is complex. The ambient temperature in some areas can reach over 300°C under specific operating conditions, causing thermal expansion of the steel structure supporting the pipeline and generating axial thermal stress. The axial thermal stress will be transmitted to the connected steel structure, which will produce additional bending moment. If this thermal stress or bending moment is not effectively released, it will increase the load on the steel structure itself and its rooted anchor plates and other structural components, and further transmit it to the concrete, causing adverse effects and affecting the safe operation of the nuclear power plant.

[0003] This patented technology, based on the design requirements of RCC-M and drawing on theories of material mechanics, mechanical design theory, and elasticity, proposes a design method for relieving thermal stress in steel structural frames. The mechanical classification process proposed in this patented technology allows for rapid and effective verification and assessment according to the requirements of the RCC-M specification, obtaining calculated data corresponding to the acceptance criteria and thereby determining the rationality of the standard support. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a design method for releasing thermal stress of a steel structure frame.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a design method for releasing thermal stress of a steel structure frame, comprising the following steps:

[0006] S1. Determine whether the distances between the two ends of the thermal stress relief device and the bearing surface of the steel structure frame to which the two ends are connected are equal, so as to select the type of the thermal stress relief device;

[0007] S2. Establish a coordinate system, establish the origin of the coordinate system at the axis of the thermal stress relief device, define the direction parallel to the length of the thermal stress relief device as the x-axis, and define the directions of the y-axis and the z-axis as perpendicular to the surface of the thermal stress relief device;

[0008] S3. Determine the specific size of the thermal stress relief device according to the components of the thermal stress that the steel structure frame needs to bear on the x-axis, y-axis and z-axis.

[0009] Furthermore, the step S1 includes:

[0010] S11. If the distances between the two ends of the thermal stress release device and the bearing surface of the steel structure frame to which the two ends are connected are equal, the thermal stress release device adopts an axial thermal stress release device; if the distances between the two ends of the thermal stress release device and the bearing surface of the steel structure frame to which the two ends are connected are not equal, the thermal stress release device adopts a bending moment release device.

[0011] Furthermore, the step S1 further includes:

[0012] S12. The axial thermal stress release device includes a first steel section and a first positioning plate connected to each other, and a second steel section and a second positioning plate connected to each other; the first positioning plate is provided with a first through hole, and the second steel section is passed through the first through hole; the second positioning plate is placed inside the first steel section; the end of the first steel section away from the first positioning plate and the end of the second steel section away from the second positioning plate are used to be connected to the steel structure frame.

[0013] Furthermore, step S3 includes:

[0014] S31. Determine the components of the thermal stress that the steel structure frame needs to bear on the x-axis, y-axis, and z-axis. If the x-axis component is zero, and one of the y-axis and z-axis components is zero and the other is non-zero, use formula (1) to determine the shear area S of the first section steel. A , the sum L1 of the length of the first section steel and the thickness of the first positioning plate;

[0015]

[0016] in:

[0017] F yz1 : The actual stress borne by the first steel section on the y-axis or z-axis, N;

[0018] S y1 : Yield strength of the first steel section at working temperature, MPa;

[0019] S u1 : tensile strength of the first steel section at working temperature, MPa;

[0020] W g1 : Bending section coefficient of the first steel section, mm 3 ;

[0021] S1: Basic allowable stress strength of the first steel section, MPa.

[0022] Furthermore, the step S33 further includes:

[0023] S32. If the x-axis component is zero and the y-axis and z-axis components are non-zero, then use formula (2) to determine the shear area S of the first section steel. A , the sum L1 of the length of the first section steel and the thickness of the first positioning plate;

[0024]

[0025] in:

[0026] F y1 : actual stress borne by the first steel section on the y-axis, N;

[0027] F z1 : The actual stress borne by the first steel section on the z-axis, N.

[0028] Furthermore, the step S3 further includes:

[0029] S33. If the x-axis component is zero, one of the y-axis and z-axis components bears thermal stress, and the other only bears friction, then the shear area S of the first section steel is determined using formula (3): A1 , the sum L1 of the length of the first section steel and the thickness of the first positioning plate;

[0030]

[0031] Furthermore, the step S3 further includes:

[0032] S34, according to S A1 The wall thickness t1 of the first section steel is determined, and the thickness t2 of the first positioning plate is set to be 1.5t1; the first positioning plate extends outwards by a length of 2t1 relative to the first section steel.

[0033] Furthermore, the step S3 further includes:

[0034] S35. The second steel section adopts appropriate standard specifications based on the actual size of the first steel section, and the thickness t of the second positioning plate is set to t4=1.5t3 based on the thickness t3 of the second steel section; the inner walls of the first positioning plate are in contact with the second steel section, and the side walls of the second positioning plate are in contact with the inner wall of the first steel section.

[0035] Furthermore, the step S1 further includes:

[0036] S12', the bending moment release device includes a third steel section and a third positioning plate connected to each other, a fourth steel section and a fourth positioning plate connected to each other, and a pin shaft; the third positioning plate is provided with a second through hole, and the fourth steel section is passed through the second through hole; the fourth positioning plate is placed inside the third steel section; the pin shaft is passed through the third steel section and the fourth steel section; the end of the third steel section away from the third positioning plate and the end of the fourth steel section away from the fourth positioning plate are used to be connected to the steel structure frame.

[0037] Furthermore, step S3 includes:

[0038] S31', define the direction parallel to the length of the pin as the z-axis; determine the components of the thermal stress that the steel structure frame needs to bear on the x-axis, y-axis and z-axis; if the component on the x-axis is non-zero and the components on the y-axis and z-axis are both zero, use formula (4) to determine the diameter D of the pin;

[0039]

[0040] in:

[0041] F xp : actual stress borne by the pin on the x-axis, N;

[0042] S yp : Yield strength of the pin at working temperature, MPa;

[0043] S up : Tensile strength of the pin at working temperature, MPa.

[0044] Furthermore, the step S3 further includes:

[0045] S32', if the components of the x-axis, y-axis and z-axis are all non-zero, then the diameter D of the pin is determined;

[0046]

[0047] in:

[0048] F yp : The actual stress borne by the pin on the y-axis, N.

[0049] Furthermore, the step S3 further includes:

[0050] S33', if the x-axis component is non-zero and the y-axis and z-axis components are both zero, then use formula (6) to determine the distance L3 from the third positioning plate to the pin shaft and the thickness t5 of the third section steel, and use formula (7) to determine the distance L4 from the fourth positioning plate to the pin shaft and the thickness t7 of the fourth section steel;

[0051]

[0052]

[0053] in:

[0054] F x3 : actual stress borne by the third section steel on the x-axis, N;

[0055] F x4 : actual stress borne by the fourth section steel on the x-axis, N;

[0056] S y3 : Yield strength of the third section steel at working temperature, MPa;

[0057] S u3 : tensile strength of the third section steel at working temperature, MPa;

[0058] S y4 : Yield strength of the fourth type steel at working temperature, MPa;

[0059] S u4 : Tensile strength of the fourth type steel at working temperature, MPa.

[0060] Furthermore, the step S3 further includes:

[0061] S34', if the components of the x-axis, y-axis and z-axis are all non-zero, then use formula (8) to determine the distance L3 from the third positioning plate to the pin shaft and the thickness t5 of the third section steel, and use formula (9) to determine the distance L4 from the fourth positioning plate to the pin shaft and the thickness t7 of the fourth section steel;

[0062]

[0063]

[0064] in:

[0065] F y3 : actual stress borne by the third steel section on the y-axis, N;

[0066] F y4 : actual stress borne by the fourth section steel on the y-axis, N;

[0067] F xy3 : actual stress borne by the third section steel on the x-axis or y-axis, N;

[0068] F xy4 : The actual stress borne by the fourth section steel on the x-axis or y-axis, N.

[0069] Furthermore, the step S3 further includes:

[0070] S35', if the components of the x-axis, y-axis and z-axis are all non-zero, then the shear area S of the third section steel is determined using formula (10): A3 , the sum L2 of the length of the third section steel and the thickness of the third positioning plate, and the distance H between the center of the pin and the end of the third section steel away from the third positioning plate;

[0071]

[0072] in:

[0073] F z3 : actual stress borne by the third steel section on the z-axis, N;

[0074] F xyz : actual stress borne by the third section steel on the x-axis, y-axis or z-axis, N;

[0075] W g3 : Bending section coefficient of the third steel, mm 3 ;

[0076] S3: Basic allowable stress strength of the third section steel, MPa.

[0077] Furthermore, the step S3 further includes:

[0078] S36', set the thickness of the third positioning plate t6 = 1.5t5; the third positioning plate extends outwardly by a length of 2t5 relative to the third steel section, and the inner wall of the third positioning plate perpendicular to the y-axis is on the same horizontal plane as the inner wall of the third steel section.

[0079] Furthermore, the step S3 further includes:

[0080] S37', the thickness t8 of the fourth positioning plate is set to t8=1.5t7; the inner wall of the third positioning plate perpendicular to the z-axis abuts against the fourth steel section, the side wall of the fourth positioning plate perpendicular to the z-axis abuts against the inner wall of the third steel section, and the side wall of the fourth positioning plate perpendicular to the y-axis is located on the same horizontal plane as the outer wall of the fourth steel section.

[0081] Furthermore, both ends of the pin shaft are provided with a cotter pin inserted therethrough to achieve axial positioning of the pin shaft.

[0082] Furthermore, a shaft sleeve for reducing friction is provided between the pin shaft and the fourth steel section.

[0083] The present invention has the following beneficial effects: according to the thermal stress that the steel structure frame needs to bear, by calculating and approving the specific size setting of the thermal stress release device, the axial thermal stress or bending moment caused by the thermal expansion of the steel structure frame due to high temperature can be effectively released in a specific direction, while ensuring that the steel structure frame has sufficient stability in the direction where no thermal stress release is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0085] Figure 1 It is a flowchart of the design method for releasing thermal stress of a steel structure frame according to the present invention;

[0086] Figure 2 It is a schematic structural diagram of the axial thermal stress release device of the present invention;

[0087] Figure 3 It is a structural schematic diagram of the front view of the bending moment release device of the present invention;

[0088] Figure 4 It is a schematic structural diagram of a side view of a bending moment release device of the present invention;

[0089] Figure 5 2. It is a structural schematic diagram of the axial thermal stress release device of the present invention applied to a door-shaped steel structure frame;

[0090] Figure 6 It is a structural schematic diagram of the bending moment release device of the present invention applied to an asymmetric portal steel structure frame. DETAILED DESCRIPTION

[0091] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings and are constructed and operated in specific directions. They are only for the convenience of describing the technical solution and do not indicate that the devices or components referred to must have specific directions. Therefore, they should not be understood as limiting the present invention.

[0092] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected", "fixed", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intervening elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0093] Figure 1 A design method for releasing thermal stress of a steel structure frame according to the present invention is shown, comprising the following steps:

[0094] S1. Determine whether the distances between the two ends of the thermal stress relief device 1 and the bearing surface of the steel structure frame 2 to which the two ends are connected are equal, so as to select the type of the thermal stress relief device 1.

[0095] The specific steps are:

[0096] S11. If the distances between the ends of the thermal stress relief device 1 and the bearing surface of the steel structure frame 2 to which they are connected are equal, the thermal stress relief device 1 uses an axial thermal stress relief device 10. If the distances between the ends of the thermal stress relief device 1 and the bearing surface of the steel structure frame 2 to which they are connected are unequal, the thermal stress relief device 1 uses a bending moment relief device 20. It is understood that the steel structure frame 2 may be an embedded plate, an anchor plate, or a steel section.

[0097] S12, such as Figure 2 As shown, the axial thermal stress release device 10 includes a first steel section 11 and a first positioning plate 12 connected to each other, and a second steel section 13 and a second positioning plate 14 connected to each other; the first positioning plate 12 is provided with a first through hole 121, and the second steel section 13 is passed through the first through hole 121; the second positioning plate 14 is placed inside the first steel section 11; the end of the first steel section 11 away from the first positioning plate 12 and the end of the second steel section 13 away from the second positioning plate 14 are used to connect with the steel structure frame 2.

[0098] S12', such as Figure 3 and Figure 4As shown, the bending moment release device 20 includes a third steel section 21 and a third positioning plate 22 connected to each other, a fourth steel section 23 and a fourth positioning plate 24 connected to each other, and a pin 25; the third positioning plate 22 is provided with a second through hole 221, and the fourth steel section 23 is passed through the second through hole 221; the fourth positioning plate 24 is placed inside the third steel section 21; the pin 25 is passed through the third steel section 21 and the fourth steel section 23; the end of the third steel section 21 away from the third positioning plate 22 and the end of the fourth steel section 23 away from the fourth positioning plate 24 are used to connect with the steel structure frame 2.

[0099] S2. Establish a coordinate system, establish the origin of the coordinate system at the axis center of the thermal stress release device 1, define the direction parallel to the length of the thermal stress release device 1 as the x-axis, and the directions of the y-axis and the z-axis are both perpendicular to the surface of the thermal stress release device 1.

[0100] S3. Determine the specific size of the thermal stress relief device 1 according to the components of the thermal stress that the steel structure frame 2 needs to bear on the x-axis, y-axis and z-axis.

[0101] The specific steps are:

[0102] S31. Determine the components of the thermal stress that the steel structure frame 2 needs to bear on the x-axis, y-axis, and z-axis. If the x-axis component is zero, and one of the y-axis and z-axis components is zero and the other is non-zero, use formula (1) to determine the shear area S of the first section steel 11. A1 , the sum L1 of the length of the first steel section 11 and the thickness of the first positioning plate 12;

[0103]

[0104] in:

[0105] F yz1 : actual stress borne by the first section steel 11 on the y-axis or z-axis, N;

[0106] S y1 : Yield strength of the first steel section 11 at operating temperature, MPa;

[0107] S u1 : tensile strength of the first steel section 11 at operating temperature, MPa;

[0108] W g1 : Bending section coefficient of the first steel section 11, mm 3 ;

[0109] S1: basic allowable stress strength of the first section steel 11, MPa.

[0110] S32. If the x-axis component is zero and the y-axis and z-axis components are non-zero, then use formula (2) to determine the shear area S of the first steel section 11. A1, the sum L1 of the length of the first steel section 11 and the thickness of the first positioning plate 12;

[0111]

[0112] in:

[0113] F y1 : actual stress borne by the first section steel 11 on the y-axis, N;

[0114] F z1 : The actual stress borne by the first steel section 11 on the z-axis, N.

[0115] S33. If the x-axis component is zero, one of the y-axis and z-axis components bears thermal stress, and the other only bears friction, then the shear area S of the first steel section 11 is determined using formula (3): A1 , the sum L1 of the length of the first steel section 11 and the thickness of the first positioning plate 12;

[0116]

[0117] S34, according to S A1 The wall thickness t1 of the first section steel 11 is determined, and the thickness t2 of the first positioning plate 12 is set to 1.5t1. The first positioning plate 12 extends outward from the first section steel 11 by a length of 2t1 to facilitate welding. It is understood that the length of the first positioning plate 12 extending outward from the first section steel 11 does not need to be 2t1.

[0118] S35. The second section steel 13 is constructed using appropriate standard specifications based on the actual dimensions of the first section steel 11. The thickness t4 of the second positioning plate 14 is set to t4 = 1.5t3 based on the thickness t3 of the second section steel 13. The inner walls of the first positioning plate 12 abut against the second section steel 13, and the side walls of the second positioning plate 14 abut against the inner walls of the first section steel 11, thereby preventing the second section steel 13 from rotating relative to the first section steel 11 in the XOZ plane or the XOY plane.

[0119] S31', define the direction parallel to the length of the pin 25 as the z-axis; determine the components of the thermal stress that the steel structure frame 2 needs to bear on the x-axis, y-axis and z-axis; if the component on the x-axis is non-zero and the components on the y-axis and z-axis are both zero, use formula (4) to determine the diameter D of the pin 25;

[0120]

[0121] in:

[0122] F xp : actual stress borne by the pin 25 on the x-axis, N;

[0123] S yp: Yield strength of pin 25 at working temperature, MPa;

[0124] S up : Tensile strength of pin 25 at working temperature, MPa.

[0125] S32', if the components of the x-axis, y-axis and z-axis are all non-zero, then use 5 to determine the diameter D of the pin shaft 25;

[0126]

[0127] in:

[0128] F yp : The actual stress borne by the pin 25 on the y-axis, N.

[0129] S33', if the x-axis component is non-zero and the y-axis and z-axis components are both zero, then use formula (6) to determine the distance L3 from the third positioning plate 22 to the pin 25 and the thickness t5 of the third section steel 21, and use formula (7) to determine the distance L4 from the fourth positioning plate 24 to the pin 25 and the thickness t7 of the fourth section steel 23;

[0130]

[0131]

[0132] in:

[0133] F x3 : actual stress borne by the third section steel 21 on the x-axis, N;

[0134] F x4 : actual stress borne by the fourth section steel 23 on the x-axis, N;

[0135] S y3 : Yield strength of the third section steel 21 at working temperature, MPa;

[0136] S u3 : tensile strength of the third section steel 21 at working temperature, MPa;

[0137] S y4 : Yield strength of the fourth section steel 23 at working temperature, MPa;

[0138] S u4 : Tensile strength of the fourth section steel 23 at working temperature, MPa.

[0139] S34', if the components of the x-axis, y-axis and z-axis are all non-zero, then use formula (8) to determine the distance L3 from the third positioning plate 22 to the pin 25 and the thickness t5 of the third section steel 21, and use formula (9) to determine the distance L4 from the fourth positioning plate 24 to the pin 25 and the thickness t7 of the fourth section steel 23;

[0140]

[0141]

[0142] in:

[0143] F y3 : actual stress borne by the third section steel 21 on the y-axis, N;

[0144] F y4 : actual stress borne by the fourth section steel 23 on the y-axis, N;

[0145] F xy3 : actual stress borne by the third section steel 21 on the x-axis or y-axis, N;

[0146] F xy4 : The actual stress borne by the fourth section steel 23 on the x-axis or y-axis, N.

[0147] S35', if the components of the x-axis, y-axis and z-axis are all non-zero, then the shear area S of the third section steel 21 is determined using formula (10): A3 , the sum L2 of the length of the third section steel 21 and the thickness of the third positioning plate 22, and the distance H from the center of the pin 25 to the end of the third section steel 21 away from the third positioning plate 22;

[0148]

[0149] in:

[0150] F z3 : actual stress borne by the third section steel 21 on the z-axis, N;

[0151] F xyz : actual stress borne by the third section steel 21 on the x-axis, y-axis or z-axis, N;

[0152] W g3 : Bending section coefficient of the third steel 21, mm 3 ;

[0153] S3: Basic allowable stress strength of the third section steel 21, MPa.

[0154] It is understandable that for the existing axial thermal stress release device or bending moment release device, the maximum stress that the first section steel 11, the third section steel 21, the fourth section steel 23 and the pin 25 can bear can also be calculated using formulas (1) to (10).

[0155] S36', set the thickness t6 of the third positioning plate 22 to 1.5t5. The third positioning plate 22 extends outwardly relative to the third section steel 21 by a length of 2t5 to facilitate welding. It is understandable that the length of the third positioning plate 22 extending outwardly relative to the third section steel 21 may not be 2t5. The inner wall of the third positioning plate 22 perpendicular to the y-axis is located on the same horizontal plane as the inner wall of the third section steel 21, providing space for the fourth section steel 23 to rotate relative to the third section steel 21 in the XOY plane.

[0156] S37', the thickness t8 of the fourth positioning plate 24 is set to t8 = 1.5t7. The inner wall of the third positioning plate 22, perpendicular to the z-axis, abuts the fourth section steel 23. The side wall of the fourth positioning plate 24, perpendicular to the z-axis, abuts the inner wall of the third section steel 21, thereby preventing the fourth section steel 23 from rotating relative to the third section steel 21 in the XOZ plane. The side wall of the fourth positioning plate 24, perpendicular to the y-axis, is coplanar with the outer wall of the fourth section steel 23, providing space for the fourth section steel 23 to rotate relative to the third section steel 21 in the XOY plane.

[0157] In order to make the purpose, technical solution and technical effect of the present invention clearer, the following will take the thermal stress release device 1 using Q235 carbon structural steel and the pin 25 using 42CrMo alloy structural steel as an example, and further describe the embodiment of the present invention in detail with reference to the accompanying drawings.

[0158] For Q235 carbon structural steel, its yield strength is 235MPa, tensile strength is 370MPa, and bending section coefficient is 7537.6mm 3 , the basic allowable stress intensity is 92.5MPa. For 42CrMo alloy structural steel, its yield strength is 900MPa and its tensile strength is 1090MPa.

[0159] like Figure 5 As shown, using the method disclosed in the present invention, for a door-shaped steel structure frame, the design method of the thermal stress relief device 1 includes the following steps:

[0160] S1. The distances between the two ends of the thermal stress release device 1 and the bearing surface of the gate-shaped steel structure frame to which the two ends are connected are equal, so the thermal stress release device 1 adopts an axial thermal stress release device 10.

[0161] S2. Establish a coordinate system, establish the origin of the coordinate system at the axis of the axial thermal stress release device 10, define the direction parallel to the length of the axial thermal stress release device 10 as the x-axis, and define the directions of the y-axis and the z-axis as perpendicular to the surface of the axial thermal stress release device 10;

[0162] S31. Assume that the portal steel structure frame needs to bear a thermal stress of 55000N in the y-axis direction. According to formula (1), we can get:

[0163]

[0164] When S A1 Take 2700mm 2 , when L1 is 15 mm, formula (1) can be satisfied.

[0165] S32~S33. Since S31 is used in this example, formula (2) and formula (3) are no longer used for verification.

[0166] S34. Based on the conditions determined in S31, the first section steel 11 may be a 140mm*140mm*10mm square steel. The thickness of the first positioning plate 12 is set to t2=1.5t1=15mm. Preferably, the first positioning plate 12 extends outward from the first section steel 11 by a length of 2t1=20mm.

[0167] S35. Based on the fact that the first section steel 11 is a 140mm*140mm*10mm square steel and the second section steel 13 is a 100mm*100mm*8mm square steel, the thickness of the second positioning plate 14 is set to t4=1.5t3=12mm. The inner walls of the first positioning plate 12 abut against the second section steel 13, and the side walls of the second positioning plate 14 abut against the inner wall of the first section steel 11.

[0168] like Figure 6 As shown, using the method disclosed in the present invention, for an asymmetric portal steel structure frame, the design method of the thermal stress relief device 1 includes the following steps:

[0169] S1. The distances between the two ends of the thermal stress release device 1 and the bearing surface of the asymmetric portal steel structure frame to which the two ends are connected are not equal, so the thermal stress release device 1 adopts a bending moment release device 20.

[0170] S2. Establish a coordinate system, establish the origin of the coordinate system at the axis of the bending moment release device 20, define the direction parallel to the length of the axial thermal stress release device 10 as the x-axis, and define the directions of the y-axis and the z-axis as perpendicular to the surface of the axial thermal stress release device 10;

[0171] S31', define the direction parallel to the length of the pin 25 as the z-axis; assuming that the portal steel structure frame needs to bear a thermal stress of 60000N in the x-axis direction, according to formula (4), it can be obtained:

[0172]

[0173] When D ≥ 11.90 mm, formula (4) can be satisfied.

[0174] S32', Since S31' is used in this example, formula (5) is no longer used for verification.

[0175] S33', according to formula (6) and (7), we can get:

[0176]

[0177]

[0178] When D is 14 mm, L3 is 30 mm, L4 is 30 mm, t5 is 10 mm, and t7 is 8 mm, equations (6) and (7) are satisfied.

[0179] S34'~S35', Since S31' is used in this example, equations (8), (9) and (10) are no longer used for verification.

[0180] S36'. Based on the conditions determined in S33', the third section steel 21 may be a 140mm*140mm*10mm square steel. The thickness of the third positioning plate 22 is set to t6 = 1.5t5 = 15mm. The inner wall of the third positioning plate 22, perpendicular to the y-axis, is coplanar with the inner wall of the third section steel 21. Preferably, the third positioning plate 22 extends outward from the third section steel 21 by a length of 2t5 = 20mm.

[0181] S37'. Based on the fact that the third section steel 21 is a 140mm*140mm*10mm square steel and the fourth section steel 23 is a 100mm*100mm*8mm square steel, the thickness of the fourth positioning plate 24 is set to t8 = 1.5 t7 = 12 mm. The inner wall of the third positioning plate 22, perpendicular to the z-axis, abuts against the fourth section steel 23. The side wall of the fourth positioning plate 24, perpendicular to the z-axis, abuts against the inner wall of the third section steel 21. The side wall of the fourth positioning plate 24, perpendicular to the y-axis, is coplanar with the outer wall of the fourth section steel 23.

[0182] Furthermore, both ends of the pin shaft are provided with a cotter pin inserted therein to achieve axial positioning of the pin shaft. A shaft sleeve is provided between the pin shaft and the fourth section steel for reducing friction.

[0183] The present invention calculates and determines the specific size settings of the thermal stress release device based on the thermal stress that the steel structure frame needs to bear. It can effectively release the axial thermal stress or bending moment generated by the thermal expansion of the steel structure frame due to high temperature in a specific direction, while ensuring that the steel structure frame has sufficient stability in the direction where no thermal stress release is required.

[0184] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A design method for releasing thermal stress of a steel structure frame, characterized in that: The following steps are involved: S1. Determine whether the distance between one of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) to which the end is connected is equal to the distance between the other of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) to which the end is connected, so as to select the type of the thermal stress release device (1); The step S1 comprises: S11, if the distance between one of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) connected to the end is equal to the distance between the other of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) connected to the end, then the thermal stress release device (1) adopts an axial thermal stress release device (10); if the distance between one of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) connected to the end is not equal to the distance between the other of the two ends of the thermal stress release device (1) and the bearing surface of the steel structure frame (2) connected to the end, then the thermal stress release device (1) adopts a bending moment release device (20); S2. Establish a coordinate system, establish the origin of the coordinate system at the axis of the thermal stress release device (1), define the direction parallel to the length of the thermal stress release device (1) as the x-axis, and define the directions of the y-axis and the z-axis as perpendicular to the surface of the thermal stress release device (1); S3. Determine the specific size of the thermal stress release device (1) based on the components of the thermal stress that the steel structure frame (2) needs to bear on the x-axis, y-axis and z-axis; The specific dimensions of the thermal stress relief device (1) are determined by at least the following steps: The step S1 further includes: S12, the axial thermal stress release device (10) includes a first steel section (11) and a first positioning plate (12) connected to each other, and a second steel section (13) and a second positioning plate (14) connected to each other; the first positioning plate (12) is provided with a first through hole (121), and the second steel section (13) is passed through the first through hole (121); the second positioning plate (14) is placed inside the first steel section (11); an end of the first steel section (11) away from the first positioning plate (12) and an end of the second steel section (13) away from the second positioning plate (14) are used to be connected to the steel structure frame (2); The step S3 comprises: S31, determining the components of the thermal stress that the steel structure frame (2) needs to bear on the x-axis, y-axis and z-axis; if the component on the x-axis is zero, one of the components on the y-axis and the z-axis is zero and the other is non-zero, then using formula (1) to determine the shear area of ​​the first steel section (11) S A1 , the sum of the length of the first steel section (11) and the thickness of the first positioning plate (12) L 1 ; （1） in: F yz1 : the actual stress borne by the first steel section (11) on the y-axis or z-axis, N; S y1 : Yield strength of the first steel (11) at working temperature, MPa; S u1 : tensile strength of the first steel (11) at working temperature, MPa; W g1 : Bending section coefficient of the first steel (11), mm 3 ; S 1 : basic allowable stress strength of the first steel (11), MPa; Alternatively, the specific dimensions of the thermal stress relief device (1) are determined by at least the following steps: The step S1 further includes: S12', the bending moment release device (20) includes a third steel section (21) and a third positioning plate (22) connected to each other, a fourth steel section (23) and a fourth positioning plate (24) connected to each other, and a pin (25); the third positioning plate (22) is provided with a second through hole (221), and the fourth steel section (23) is passed through the second through hole (221); the fourth positioning plate (24) is placed inside the third steel section (21); the pin (25) is passed through the third steel section (21) and the fourth steel section (23); one end of the third steel section (21) away from the third positioning plate (22) and one end of the fourth steel section (23) away from the fourth positioning plate (24) are used to be connected to the steel structure frame (2); The step S3 comprises: S31', defining the direction parallel to the length of the pin (25) as the z-axis; determining the components of the thermal stress that the steel structure frame (2) needs to bear on the x-axis, y-axis and z-axis; if the component on the x-axis is non-zero and the components on the y-axis and z-axis are both zero, then using formula (4) to determine the diameter D of the pin (25); （4） in: F xp : actual stress borne by the pin (25) on the x-axis, N; S yp : yield strength of the pin (25) at working temperature, MPa; S up : Tensile strength of the pin (25) at working temperature, MPa.

2. The design method for releasing thermal stress of a steel structure frame according to claim 1 is characterized in that: The step S3 further includes: S32. If the x-axis component is zero and the y-axis and z-axis components are non-zero, then the shear area of ​​the first steel section (11) is determined using formula (2). S A1 , the sum of the length of the first steel section (11) and the thickness of the first positioning plate (12) L 1 ; （2） in: F y1 : actual stress carried by the first steel section (11) on the y-axis, N; F z1 : The actual stress carried by the first steel section (11) on the z-axis, N.

3. The design method for releasing thermal stress of a steel structure frame according to claim 2 is characterized in that: The step S3 further includes: S33. If the x-axis component is zero, one of the y-axis and z-axis components bears thermal stress, and the other only bears friction, then the shear area of ​​the first steel section (11) is determined using formula (3): S A1 , the sum of the length of the first steel section (11) and the thickness of the first positioning plate (12) L 1 ; （3）。 4. The design method for releasing thermal stress of a steel structure frame according to any one of claims 1 to 3, characterized in that: The step S3 further includes: S34, according to S A1 Determine the wall thickness of the first steel section (11) t 1 , let the thickness of the first positioning plate (12) be t 2 =1.5 t 1 The first positioning plate (12) extends outward relative to the first steel section (11) by 2 t 1 length.

5. The design method for releasing thermal stress of a steel structure frame according to claim 4 is characterized in that: The step S3 further includes: S35, the second section steel (13) adopts appropriate standard specifications according to the actual size of the first section steel (11), and the thickness of the second positioning plate (14) is t 4 According to the thickness of the second steel section (13) t 3 Set to t 4 =1.5 t 3 Each inner wall of the first positioning plate (12) abuts against the second steel section (13), and each side wall of the second positioning plate (14) abuts against the inner wall of the first steel section (11).

6. The design method for releasing thermal stress of a steel structure frame according to claim 1 is characterized in that: The step S3 further includes: S32', if the components of the x-axis, y-axis and z-axis are all non-zero, then use (5) to determine the diameter D of the pin (25); （5） in: F yp : The actual stress borne by the pin (25) on the y-axis, N.

7. The design method for releasing thermal stress of a steel structure frame according to claim 6, characterized in that: The step S3 further includes: S33', if the x-axis component is non-zero and the y-axis and z-axis components are both zero, then use formula (6) to determine the distance from the third positioning plate (22) to the pin (25) L 3 , the thickness of the third steel (21) t 5 , and use formula (7) to determine the distance from the fourth positioning plate (24) to the pin (25) L 4 , the thickness of the fourth steel (23) t 7 ; （6） （7） in: F x3 : actual stress carried by the third steel (21) on the x-axis, N; F x4 : actual stress carried by the fourth steel (23) on the x-axis, N; S y3 : Yield strength of the third type steel (21) at working temperature, MPa; S u3 : tensile strength of the third steel (21) at working temperature, MPa; S y4 : Yield strength of the fourth type steel (23) at working temperature, MPa; S u4 : Tensile strength of the fourth type steel (23) at working temperature, MPa.

8. The design method for releasing thermal stress of a steel structure frame according to claim 7 is characterized in that: The step S3 further includes: S34', if the components of the x-axis, y-axis and z-axis are all non-zero, then the distance from the third positioning plate (22) to the pin (25) is determined using formula (8): L 3 , the thickness of the third steel (21) t 5 , and use formula (9) to determine the distance from the fourth positioning plate (24) to the pin (25) L 4 , the thickness of the fourth steel (23) t 7 ; （8） （9） in: F y3 : actual stress carried by the third steel section (21) on the y-axis, N; F y4 : The actual stress carried by the fourth steel section (23) on the y-axis, N.

9. The design method for releasing thermal stress of a steel structure frame according to claim 8, characterized in that: The step S3 further includes: S35', if the components of the x-axis, y-axis and z-axis are all non-zero, then the shear area of ​​the third steel section (21) is determined using formula (10): S A3 , the sum of the length of the third steel section (21) and the thickness of the third positioning plate (22) L 2 and a distance H between the center of the pin shaft (25) and one end of the third section steel (21) away from the third positioning plate (22); （10） in: F z3 : actual stress borne by the third steel (21) on the z-axis, N; W g3 : Bending section coefficient of the third steel (21), mm 3 ; S 3 : Basic allowable stress strength of the third type steel (21), MPa.

10. The design method for releasing thermal stress of a steel structure frame according to any one of claims 6 to 9, characterized in that: The step S3 further includes: S36', making the thickness of the third positioning plate (22) t 6 =1.5 t 5 The third positioning plate (22) extends outward relative to the third steel section (21) by 2 t 5 The inner wall of the third positioning plate (22) perpendicular to the y-axis is located on the same horizontal plane as the inner wall of the third section steel (21).

11. The design method for releasing thermal stress of a steel structure frame according to claim 10, characterized in that: The step S3 further includes: S37', thickness of the fourth positioning plate (24) t 8 Set to t 8 =1.5 t 7 The inner wall of the third positioning plate (22) perpendicular to the z-axis abuts against the fourth steel section (23), the side wall of the fourth positioning plate (24) perpendicular to the z-axis abuts against the inner wall of the third steel section (21), and the side wall of the fourth positioning plate (24) perpendicular to the y-axis is located on the same horizontal plane as the outer wall of the fourth steel section (23).

12. The design method for releasing thermal stress of a steel structure frame according to any one of claims 6 to 9, characterized in that: Both ends of the pin shaft (25) are provided with a cotter pin (251) inserted therethrough to achieve axial positioning of the pin shaft (25).

13. The design method for releasing thermal stress of a steel structure frame according to any one of claims 6 to 9, characterized in that: A shaft sleeve (252) for reducing friction is provided between the pin shaft (25) and the fourth steel section (23).

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