A standardized variable cross-section steel beam structure and a design method

Abstract

The application relates to a standardized variable cross-section steel beam structure and a design method, and relates to the field of steel structure buildings. The standardized variable cross-section steel beam structure comprises two steel columns, two cantilever beams connected with the two steel columns respectively, and a variable cross-section beam connected with the two cantilever beams at two ends; the variable cross-section beam is symmetrical relative to a center line, and the length of the cantilever beam connected with one end of the variable height beam section is h; when the bending moment diagram is a broken line, the inflection point is taken; when the bending moment diagram is a curve and the maximum point of the curve is in the left half of the variable cross-section beam, the maximum point of the curve to the left side of the steel column is taken at a distance of one fourth; when the bending moment diagram is a curve and the maximum point of the curve is in the right half of the variable cross-section beam, the maximum point of the curve to the right side of the steel column is taken at a distance of one fourth; when the bending moment diagram is a curve and there is no maximum point of the curve in the beam span range, the zero point of the curve to the side of the steel column is taken at a distance of one fourth in the falling direction of the curve. The standardized variable cross-section steel beam structure and the design method can unify the design form of the variable cross-section steel beam, reduce weight and save cost.

Description

Technical Field

[0001] This application relates to the field of steel structure buildings, and more specifically, to a standardized variable cross-section steel beam structure and its design method. Background Technology

[0002] A variable cross-section beam is a beam with a larger cross-section where the bending moment is large and a smaller cross-section where the bending moment is small. The advantages of variable cross-section beams are material savings and reduced beam weight. When the beam span is small, using a constant cross-section beam is more convenient. However, when the beam span is large, using a variable cross-section beam is more advantageous. Under the condition of satisfying the stress requirements, the cross-section of the variable cross-section beam is structurally optimized and reduced at the corresponding positions, improving economic indicators and thus effectively reducing costs while ensuring structural strength.

[0003] However, it is currently difficult to determine the length of the variable height section of existing variable cross-section beams, which makes it impossible to balance strength and cost in the design process of variable cross-section beams. Summary of the Invention

[0004] The purpose of this application is to provide a standardized variable cross-section steel beam structure and design method, which can unify the design form of variable cross-section steel beams under different support and load conditions, simplify the design work, reduce the self-weight of the standardized variable cross-section steel beam structure to save costs, and expand the usable space under the beam.

[0005] This application is implemented as follows:

[0006] This application provides a standardized variable cross-section steel beam structure, comprising two oppositely arranged steel columns, two cantilever beams connected at one end to the two steel columns respectively, and a variable cross-section beam connected at both ends to the other ends of the two cantilever beams respectively. The variable height beam segments at points a and b at both ends satisfy the following requirements: the length of the corresponding cantilever beam connected at point a is h; point b is the inflection point when the bending moment diagram is a broken line; when the bending moment diagram is a curve and the maximum value of the curve is in the left half of the variable cross-section beam, the maximum value of the curve is taken to the left at a distance of one-quarter from the left steel column; when the bending moment diagram is a curve and the maximum value of the curve is in the right half of the variable cross-section beam, the maximum value of the curve is taken to the right at a distance of one-quarter from the right steel column; when the bending moment diagram is a curve and there is no maximum value of the curve within the beam span, the zero value of the curve is taken in the downward direction of the curve at a distance of one-quarter from the steel column on that side; points a and b are symmetrical with respect to the midline of the span of the variable cross-section beam.

[0007] In some alternative implementations, the two ends of the variable cross-section beam are connected to the ends of two cantilever beams via connecting plates.

[0008] In some alternative implementations, the connecting plates are respectively connected to multiple connecting bolts passing through the variable cross-section beam and the cantilever beam.

[0009] In some alternative implementations, stiffening plates are connected inside the steel column.

[0010] In some alternative implementations, the top and bottom of the stiffening plate are aligned with the upper and lower flanges of the cantilever beam, respectively.

[0011] In some alternative implementations, the variable cross-section beam includes a beam segment of equal height and two beam segments of variable height symmetrically connected to the two ends of the beam segment of equal height.

[0012] This application also provides a design method for a standardized variable cross-section steel beam structure, including the following steps:

[0013] The bending moment diagram is obtained based on the support and load conditions of the standardized variable cross-section steel beam structure.

[0014] The positions of points a and b at both ends of the variable height beam segment of the standardized variable cross-section steel beam structure are determined by the following method: the length of the corresponding cantilever beam connected to point a is h; point b is the inflection point when the bending moment diagram is a broken line; when the bending moment diagram is a curve and the maximum value of the curve is in the left half of the variable cross-section beam, the distance from the maximum value of the curve to the left quarter of the distance to the left steel column is taken; when the bending moment diagram is a curve and the maximum value of the curve is in the right half of the variable cross-section beam, the distance from the maximum value of the curve to the right quarter of the distance to the right steel column is taken; when the bending moment diagram is a curve and there is no maximum value of the curve within the beam span, the distance from the zero value of the curve to the steel column on that side is taken in the downward direction of the curve; points a and b are symmetrical with respect to the centerline of the span of the variable cross-section beam.

[0015] The beneficial effects of this application are as follows: The standardized variable cross-section steel beam structure provided by this application includes two steel columns arranged opposite to each other, two cantilever beams connected at one end to the two steel columns respectively, and a variable cross-section beam connected at both ends to the other ends of the two cantilever beams respectively; the two ends of the variable height beam segment of the variable cross-section beam, points a and b, meet the following requirements: the length of the corresponding cantilever beam connected to point a is h; point b is the inflection point when the bending moment diagram is a broken line; when the bending moment diagram is a curve and the maximum value of the curve is in the left half of the variable cross-section beam, the maximum value of the curve is taken to the left at a distance of one-quarter from the left steel column; when the bending moment diagram is a curve and the maximum value of the curve is in the right half of the variable cross-section beam, the maximum value of the curve is taken to the right at a distance of one-quarter from the right steel column; when the bending moment diagram is a curve and there is no maximum value of the curve within the beam span, the zero value of the curve is taken in the downward direction of the curve at a distance of one-quarter from the steel column on that side; points a and b are symmetrical with respect to the centerline of the span of the variable cross-section beam. The standardized variable cross-section steel beam structure and design method provided in this application can unify the design form of variable cross-section steel beams under different support and load conditions, simplify the design work, reduce the self-weight of the standardized variable cross-section steel beam structure to save costs, and expand the usable space under the beam. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the standardized variable cross-section steel beam structure and bending moment diagram provided in Embodiment 1 of this application;

[0018] Figure 2 This is a schematic diagram of the standardized variable cross-section steel beam structure and bending moment diagram provided in Embodiment 2 of this application;

[0019] Figure 3 A schematic diagram of the standardized variable cross-section steel beam structure and bending moment diagram provided in Embodiment 3 of this application.

[0020] Figure 4 This is a schematic diagram of the standardized variable cross-section steel beam structure and bending moment diagram provided in Embodiment 4 of this application;

[0021] Figure 5 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0022] Figure 6 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0023] Figure 7 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0024] Figure 8 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0025] Figure 9 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0026] Figure 10 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0027] Figure 11 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0028] Figure 12 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0029] Figure 13 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0030] Figure 14 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0031] Figure 15 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0032] Figure 16 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0033] Figure 17 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0034] Figure 18 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0035] Figure 19 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0036] Figure 20 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0037] Figure 21 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0038] Figure 22 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0039] Figure 23 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0040] Figure 24 A schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application;

[0041] Figure 25 This is a schematic diagram of a standardized variable cross-section steel beam structure and bending moment diagram provided for another embodiment of this application.

[0042] In the diagram: 100, steel column; 110, cantilever beam; 120, variable cross-section beam; 121, constant height beam segment; 122, variable height beam segment; 130, connecting plate; 140, connecting bolt; 150, stiffening plate. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0047] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0050] The following detailed description of the features and performance of the standardized variable cross-section steel beam structure of this application is provided in conjunction with embodiments.

[0051] Example 1

[0052] like Figure 1 As shown, this application embodiment provides a standardized variable cross-section steel beam structure, which includes two steel columns 100 arranged opposite each other, two cantilever beams 110 connected at one end to the two steel columns 100 respectively, and a variable cross-section beam 120 connected at both ends to the other ends of the two cantilever beams 110 respectively. The two ends of the variable cross-section beam 120 are connected to the ends of the two cantilever beams 110 respectively through connecting plates 130. The variable cross-section beam 120 includes a beam segment 121 of equal height and two beam segments 122 symmetrically connected to the two ends of the beam segment 121 of equal height. The connecting plates 130 are connected with connecting bolts 140 arranged at intervals and passing through the variable cross-section beam 120 and the cantilever beam 110 respectively. A stiffening plate 150 is connected inside the steel column 100. The top and bottom of the stiffening plate 150 are aligned with the upper flange and lower flange of the cantilever beam 110 respectively. The two ends of this standardized variable cross-section steel beam structure are hinged and subjected to uniformly distributed load conditions. The variable cross-section beam 120 has an I-shaped cross-section.

[0053] The design method for the standardized variable cross-section steel beam structure provided in this application embodiment is as follows: A bending moment diagram is obtained based on the support and load conditions of the standardized variable cross-section steel beam structure. This bending moment diagram is a curve and symmetrical about the beam span midline. The height of the equal-height beam segment 121 is higher than that of the two variable-height beam segments 122. The starting point of the variable web height of the variable-height beam segment of the variable cross-section beam 120 is selected: one left-side point a is at a distance h from the corresponding steel column 100; another left-side point a is at a point corresponding to a quarter-distance (L / 8) from the maximum value of the curve to the left of the left-side steel column 100; the right-side point b is symmetrical to the left-side point b about the beam span midline. An overall beam segment model is established based on the determined points a and b. After calculation and verification, it can be fabricated.

[0054] Example 2

[0055] like Figure 2As shown, this application provides a standardized variable cross-section steel beam structure, which is roughly the same as the standardized variable cross-section steel beam structure provided in Embodiment 1. The difference is that in this embodiment, the two ends of the standardized variable cross-section steel beam structure are fixed and subjected to a uniformly distributed load on the left side of the unfinished span.

[0056] The design method for the standardized variable cross-section steel beam structure provided in this application embodiment is as follows: A bending moment diagram is obtained based on the support and load conditions of the standardized variable cross-section steel beam structure. This bending moment diagram is a curve and symmetrical about the beam mid-span. The height of the constant-height beam segment 121 is lower than that of the two variable-height beam segments 122. The starting point of the variable web height of the variable-height beam segment of the variable cross-section beam 120 is selected: one left-side point a corresponds to a distance h from the steel column 100, and the other left-side point a is taken to the left of the curve's maximum point, a distance of one-quarter of the distance from the left-side steel column 100 (a(2L)). 3 -2La 2 +a 3 ) / 8L 3 The points corresponding to the points at the specified locations are symmetrical about the beam span centerline to the right and left points. A model of the entire beam segment is established based on the determined points, and the beam can be fabricated after the calculations are passed.

[0057] Example 3

[0058] like Figure 3 As shown, this application provides a standardized variable cross-section steel beam structure, which is roughly the same as the standardized variable cross-section steel beam structure provided in Embodiment 1. The difference is that in this embodiment, one end of the standardized variable cross-section steel beam structure is fixed and the other end is hinged, and it is subjected to a concentrated force load on the left side.

[0059] The bending moment diagram is obtained based on the support and load conditions. This bending moment diagram is a broken line. The height of the constant-height beam segment 121 is lower than that of the two variable-height beam segments 122. The starting point of the variable web height of the variable-height beam segment 120 is selected: one left point a corresponds to the distance h of the steel column 100, and the other left point a is the inflection point of the broken line. The right point and the left point are symmetrical about the beam span centerline. The overall beam segment model is established based on the determined points. After the calculation and verification are passed, it can be processed and manufactured.

[0060] Example 4

[0061] like Figure 4 As shown, this application provides a standardized variable cross-section steel beam structure, which is roughly the same as the standardized variable cross-section steel beam structure provided in Embodiment 1. The difference is that in this embodiment, one end of the standardized variable cross-section steel beam structure is fixed and the other end slides in a directional manner, and it is subjected to a uniformly distributed load condition.

[0062] The bending moment diagram is obtained based on the support and load conditions. This bending moment diagram is a curve and there is no maximum value point of the curve within the beam span. The cross-sectional form of the variable cross-section beam segment is that the cross-section of the cantilever beam segments on both sides is higher than that of the beam segment with equal web height in the middle. The starting point of the variable web height of the variable cross-section beam segment with variable height of 120 is selected: one left point a corresponds to the distance h of the steel column 100. The other left point a is taken to the right at the point corresponding to the distance of one-quarter of the distance from the zero point of the curve to the left column end ((15-3)L / 12). The right point b is symmetrical to the left point a about the center line of the beam span. The overall beam segment model is established based on the determined points. After the calculation and verification are passed, it can be processed and manufactured.

[0063] In other alternative embodiments, such as Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 The figures show the positions of the starting points a and b of the variable web height of the variable cross-section beam 120, which is a standardized variable cross-section steel beam with hinged ends and designed using the above design method.

[0064] In other alternative embodiments, such as Figure 10 , Figure 11 , Figure 12 , Figure 13 and Figure 14 As shown, these are the positions of the starting points a and b of the variable web height of the standardized variable cross-section steel beam 120, which is designed using the above design method and has two fixed ends.

[0065] In other alternative embodiments, such as Figure 15 , Figure 16 , Figure 17 , Figure 18 , Figure 19 , Figure 20 and Figure 21 The figures show the positions of the starting points a and b of the variable web height of a standardized variable cross-section steel beam 120, which is designed using the above design method and is hinged at one end and fixed at the other.

[0066] In other alternative embodiments, such as Figure 22 , Figure 23 , Figure 24 , Figure 25 The figures show the positions of the starting points a and b of the variable web height of a standardized variable cross-section steel beam 120, which is designed using the above design method and has one end fixedly connected and the other end directionally sliding.

[0067] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A standardized variable cross-section steel beam structure, characterized in that, It includes two steel columns arranged opposite each other, two cantilever beams with one end connected to the two steel columns respectively, and a variable cross-section beam with both ends connected to the other ends of the two cantilever beams respectively. The two ends of the variable height beam segment of the variable cross-section beam, points a and b, meet the following requirements: the length of the cantilever beam connected to point a is h; point b is the inflection point when the bending moment diagram is a broken line; when the bending moment diagram is a curve and the maximum value of the curve is in the left half of the variable cross-section beam, the maximum value of the curve is taken to the left at a distance of one-quarter of the distance from the left steel column; when the bending moment diagram is a curve and the maximum value of the curve is in the right half of the variable cross-section beam, the maximum value of the curve is taken to the right at a distance of one-quarter of the distance from the right steel column; when the bending moment diagram is a curve and there is no maximum value of the curve within the beam span, the zero value of the curve is taken in the downward direction of the curve at a distance of one-quarter of the distance from the steel column on that side; points a and b are symmetrical with respect to the centerline of the span of the variable cross-section beam.

2. The standardized variable cross-section steel beam structure according to claim 1, characterized in that, The two ends of the variable cross-section beam are respectively connected to the ends of the two cantilever beams via connecting plates.

3. The standardized variable cross-section steel beam structure according to claim 2, characterized in that, The connecting plate is connected to multiple connecting bolts that pass through the variable cross-section beam and the cantilever beam.

4. The standardized variable cross-section steel beam structure according to claim 1, characterized in that, The steel column is internally connected with stiffening plates.

5. The standardized variable cross-section steel beam structure according to claim 4, characterized in that, The top and bottom of the stiffening plate are aligned with the upper and lower flanges of the cantilever beam, respectively.

6. The standardized variable cross-section steel beam structure according to claim 1, characterized in that, The variable cross-section beam includes a beam segment of equal height and two beam segments of variable height symmetrically connected to both ends of the beam segment of equal height.

7. The design method for standardized variable cross-section steel beam structures according to claim 1, characterized in that, Includes the following steps: The bending moment diagram is obtained based on the support and load conditions of the standardized variable cross-section steel beam structure. The positions of points a and b at both ends of the variable height beam segment of the standardized variable cross-section steel beam structure are determined by the following method: point a corresponds to the cantilever beam with a length of h; point b is the inflection point when the bending moment diagram is a broken line; when the bending moment diagram is a curve and the maximum value of the curve is in the left half of the variable cross-section beam, the maximum value of the curve is taken to the left at a distance of one-quarter of the distance from the left steel column; when the bending moment diagram is a curve and the maximum value of the curve is in the right half of the variable cross-section beam, the maximum value of the curve is taken to the right at a distance of one-quarter of the distance from the right steel column; when the bending moment diagram is a curve and there is no maximum value of the curve within the beam span, the zero value of the curve is taken in the downward direction of the curve at a distance of one-quarter of the distance from the steel column on that side; points a and b are symmetrical with respect to the midline of the span of the variable cross-section beam.

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