Sandwich energy dissipation structure and its design method based on origami engineering

Abstract

The present invention discloses a sandwich energy-dissipating structure based on origami engineering and a design method thereof, which belongs to the field of urban road engineering. The sandwich energy-dissipating structure is an annular column structure as a whole, including an outer shell and a folding structure located in the outer shell. The outer shell and the folding structure are rigid structures. The outer shell is enclosed by an upper panel, a lower panel, an inner panel and an outer panel. The inner part of the outer shell is a cavity, and the folding structure is arranged in the cavity. The folding structure is composed of a plurality of folding circles, and each folding circle is formed by connecting a plurality of Miura folding units end to end. In different folding circles, the number of Miura folding units is the same, but the length of the Miura folding units in each folding circle gradually increases from the inside to the outside. The sandwich energy-dissipating structure of the present invention can reduce the huge gap in material properties between the road material around the well and the manhole cover of the inspection well, reduce the impact of vehicles on the road surface around the well, and extend the service life of the road surface around the well.

Description

Technical Field

[0001] The invention relates to the field of urban road engineering, and in particular to a sandwich energy dissipation structure based on origami engineering and a design method thereof. Background Art

[0002] At present, the current status of reducing the damage of the road surface around the well is mainly to control the damage of the road surface around the well by improving the material or structure strength, dispersing the load and other methods.

[0003] At present, the main methods to improve the strength of materials or structures are to set up concrete well rings and adopt new inspection well structures. However, the roadbed and pavement based on semi-rigid or flexible materials and the inspection wells based on rigid concrete casting have huge performance differences in material stiffness and deformation. Although these two methods have improved the strength of the inspection wells to a certain extent, they do not consider the performance differences between the balanced roadbed, pavement and inspection wells, so it is difficult to solve the problems of frequent fragmentation, settlement and bulge of the road surface around the wells.

[0004] At present, the main methods of dispersing the load are to control the quality of backfill soil and lay geogrids. Controlling the quality of backfill soil means selecting easily compacted soil for backfilling in the trench around the well to enhance the interaction between the soil and the inspection well and to disperse the load; laying geogrids means laying a layer of circular geogrids around the well ring after the well cover is completed and before the road surface is constructed to strengthen the integrity of the structure around the well ring and the road structure, increase the load-bearing surface to disperse the load. Although these two methods improve the strength of the road surface around the well, can disperse the load to a certain extent and reduce the damage to the road surface around the well, they cannot effectively dissipate energy.

[0005] In addition, the setting of concrete well rings and the laying of geogrids need to be replaced frequently, which is also troublesome. Moreover, once cracks or damage appear in the concrete well rings or geogrids, the repair work is relatively cumbersome and requires large-scale repairs, which increases the cost. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a sandwich energy dissipation structure based on origami engineering with a simple structure and the ability to effectively dissipate energy, and provides a design method for the sandwich energy dissipation structure based on origami engineering.

[0007] The technical solution of the present invention to solve the above technical problems is: a sandwich energy-absorbing structure based on origami engineering, which is an annular column structure as a whole, including an outer shell and a folding structure located inside the outer shell, the outer shell and the folding structure are rigid structures, the outer shell is surrounded by an upper panel, a lower panel, an inner panel and an outer panel, the interior of the outer shell is a cavity, the folding structure is arranged in the cavity, the folding structure is composed of a plurality of folding circles, each folding circle is composed of a plurality of Miura folding units, that is, Miura folding units are connected end to end; in different folding circles, the number of Miura folding units is the same, but the length of the Miura folding units in each folding circle gradually increases from the inside to the outside.

[0008] The above sandwich energy dissipation structure based on origami engineering, the folds of the Miura folding unit are unfolded in two different directions on the plane, the first direction is an arc line, and the arc line alternates as a peak line and a valley line on the unit cell; the second direction is a fold line, and the fold line alternately passes through the peak line and the valley line in turn, and each fold line is mirror-symmetrical at the intersection with the arc line.

[0009] In the above-mentioned sandwich energy dissipation structure based on origami engineering, the peak line of the Miura folding unit is fixedly connected to the upper panel, the inner panel and the outer panel, and the valley line of the Miura folding unit is fixedly connected to the lower panel.

[0010] The above-mentioned sandwich energy dissipation structure based on origami engineering, wherein the folding structure is formed by pressing with a mold.

[0011] The energy-dissipating sandwich structure based on origami engineering can adjust the width of the energy-dissipating sandwich structure by increasing or decreasing the number of folding circles.

[0012] The height of the energy-dissipating sandwich structure based on origami engineering can be adjusted by adjusting the length of the Miura folding unit and the angle between adjacent Miura folding units.

[0013] A design method for a sandwich energy dissipation structure based on origami engineering includes the following steps:

[0014] Step S1: Establishing a model of the inspection well and the road surface around the well;

[0015] Step S2: Determine the appearance and size of the sandwich energy dissipation structure according to the established inspection well and the road surface model around the well, and construct the sandwich energy dissipation structure;

[0016] Step S3: Install the constructed sandwich energy dissipation structure in the well surrounding pavement model, determine the load level and method, perform mechanical analysis, and compare it with the well surrounding pavement model without the sandwich energy dissipation structure installed to obtain the performance of the sandwich energy dissipation structure.

[0017] In the above-mentioned design method of sandwich energy-absorbing structure based on origami engineering, in step S1, the inspection well model is composed of a well cover, a well shaft and a well chamber from top to bottom, and all of them are cylindrical structures; the well surrounding pavement model is composed of an asphalt pavement layer, a lime fly ash gravel layer and a lime fly ash soil layer from top to bottom, wherein the asphalt pavement layer is divided into fine-grained asphalt concrete and medium-grained asphalt concrete.

[0018] In the design method of the sandwich energy dissipation structure based on origami engineering, the specific steps of step S2 are:

[0019] Step S21: Compare various types of roadway inspection wells and manhole cover structures to determine the appearance of the sandwich energy dissipation structure. The roadway manhole covers are all cylindrical, so the sandwich energy dissipation structure is determined to be an annular cylindrical structure, and the roadway manhole cover diameter is obtained as the inner diameter of the sandwich energy dissipation structure;

[0020] Step S22: Investigate the damaged area of ​​the road surface around the well to determine the size of the sandwich energy-absorbing structure, wherein the value of the crack area radius of the road surface around the well is investigated to obtain the average value of the crack area radius and use it as the single-side width size of the sandwich energy-absorbing structure; investigate the settlement value of the road surface around the well to obtain the average value of the settlement value and use it as the thickness size of the sandwich energy-absorbing structure.

[0021] In the above-mentioned design method of sandwich energy-absorbing structure based on origami engineering, in step S3, a five-axle truck is used for mobile loading, a rectangular uniformly distributed load is taken to perform equivalent loading on the wheel load, and a moving speed is given, and the two models of the inspection well and the road surface around the well before and after the sandwich energy-absorbing structure is added are loaded respectively. The force characteristics analysis and vibration response analysis and calculation of the two models are performed under the action of the moving constant load by using the ANSYS finite element software, and the mechanical indicators of the inspection well and the road surface around the well without the sandwich energy-absorbing structure installed and the mechanical indicators of the inspection well and the road surface around the well after the sandwich energy-absorbing structure is installed are obtained, and the obtained mechanical indicators are compared to obtain the performance of the sandwich energy-absorbing structure.

[0022] The beneficial effects of the present invention are:

[0023] 1. The sandwich energy dissipation structure of the present invention can reduce the huge gap in material performance between the road material around the well and the manhole cover of the inspection well, reduce the impact of vehicles on the road surface around the well, and extend the service life of the road surface around the well. The sandwich energy dissipation structure embodies a sandwich-like sandwich structure, which is rigid but flexible. The folding structure in the middle can be regarded as a rigid structure, so it can well transition between two materials with very different performances.

[0024] 2. The sandwich energy dissipation structure of the present invention is installed on the road surface, and because of its own compressibility, expandability and negative Poisson's ratio, when subjected to external force, the external force will diffuse along the "creases" of the internal structure, accelerating the diffusion of structural deformation to the undeformed area, thereby effectively dissipating energy and effectively reducing the damage caused by various stresses.

[0025] 3. The folding structure of the sandwich energy-absorbing structure of the present invention is reversible and can be quickly restored after being subjected to load. At the same time, the load on its own structure is reduced by effectively dissipating energy, thereby greatly extending the service life of the sandwich energy-absorbing structure itself and eliminating the need for frequent replacement. Furthermore, since the sandwich energy-absorbing structure is an integrated structure, it is easy to replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the structural diagram of the classic Miura origami unit.

[0027] Figure 2 This is a basic structure diagram composed of classic Miura origami units.

[0028] Figure 3 It is a schematic diagram of the overall structure of the sandwich energy dissipation structure based on origami engineering of the present invention.

[0029] Figure 4 for Figure 3 One-side cross-section view.

[0030] Figure 5 for Figure 4 Schematic diagram of the structure of the folded structure.

[0031] Figure 6 for Figure 5 Top view of the .

[0032] Figure 7 for Figure 5 Side view of.

[0033] Figure 8 It is a schematic diagram of the road surface model around the well after adding a sandwich energy dissipation structure in the design method of the sandwich energy dissipation structure based on origami engineering of the present invention.

[0034] Fig. 9 It is a load movement path diagram in the design method of the sandwich energy dissipation structure based on origami engineering of the present invention.

[0035] Fig.10 This is a comparison chart of the Mises equivalent stress peak before and after the installation of the sandwich energy dissipation structure.

[0036] Fig.11 This is a comparison chart of the shear stress peak before and after the installation of the sandwich energy dissipation structure.

[0037] Fig.12 This is a comparison chart of the peak axial displacement before and after installing the sandwich energy-absorbing structure.

[0038] In the figure, 1 is the outer shell, 2 is the folding structure, 3 is the upper panel, 4 is the lower panel, 5 is the inner panel, 6 is the outer panel, 7 is the manhole cover, 8 is the shaft, 9 is the manhole chamber, 10 is the asphalt pavement layer, 11 is the lime fly ash gravel layer, 12 is the lime fly ash soil layer, 13 is the sandwich energy dissipation structure, and 14 is the loading area. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] The Miura origami unit is a four-fold paper unit proposed by Miura. The classic Miura origami unit consists of four completely equal parallelograms, where the fold angles α1=α2<90°. Its structure is as follows Figure 1 shown.

[0041] The basic structure consists of classic Miura origami units such as Figure 2 As shown, Figure 2 The dotted line is the peak line, and the dotted line is the valley line. The folds are unfolded in two different directions on the plane. The first direction is a straight line, which alternates between the peak line and the valley line on the unit cell; the second direction is a fold line, which alternates between the peak line and the valley line in turn, and each fold line is mirror-symmetric at the intersection with the straight line. The Miura origami unit has the characteristics of rigid origami, compression and expansion performance, and negative Poisson's ratio performance. When the Miura origami structure is subjected to axial compression, the external force will diffuse along the internal "folds" (i.e., valley lines and peak lines), accelerating the diffusion of structural deformation to the undeformed area, thereby dissipating energy.

[0042] like Figure 3-Figure 7 As shown, a sandwich energy dissipation structure based on origami engineering is an annular column structure as a whole, including an outer shell 1 and a folding structure 2 located inside the outer shell 1, the outer shell 1 is a rigid structure, and the folding structure 2 is a rigid structure, the outer shell 1 is surrounded by an upper panel 3, a lower panel 4, an inner panel 5 and an outer panel 6, the interior of the outer shell 1 is a cavity, the folding structure 2 is arranged in the cavity, the folding structure 2 is composed of a plurality of folding circles, each folding circle is formed by a plurality of Miura folding units connected end to end; in different folding circles, the number of Miura folding units is the same, but the length of the Miura folding units in each folding circle gradually increases from the inside to the outside.

[0043] The folds of the Miura folding unit are unfolded in two different directions on the plane. The first direction is an arc line, which alternates as a peak line and a valley line on the unit cell; the second direction is a fold line, which alternately passes through the peak line and the valley line in sequence, and each fold line is mirror-symmetrical at the intersection with the arc line.

[0044] The peak line of the Miura folding unit is fixedly connected to the upper panel 3 , the inner panel 5 and the outer panel 6 , and the valley line of the Miura folding unit is fixedly connected to the lower panel 4 .

[0045] The folding structure 2 is formed by pressing with a mold. The width of the sandwich energy dissipation structure can be adjusted by increasing or decreasing the number of folding circles. The height of the sandwich energy dissipation structure can be adjusted by adjusting the length of the Miura folding unit and the angle between adjacent Miura folding units.

[0046] A design method for a sandwich energy dissipation structure based on origami engineering includes the following steps:

[0047] Step S1: Establish a model of the inspection well and the road surface around the well.

[0048] The present invention focuses on the sandwich energy dissipation structure 13, so the inspection well and the road surface model around the well are simplified. Figure 8 As shown, the inspection well model is composed of a well cover 7, a well shaft 8 and a well chamber 9 from top to bottom, and all of them are cylindrical structures; the well surrounding pavement model is composed of an asphalt pavement layer 10, a lime fly ash gravel layer 11 and a lime fly ash soil layer 12 from top to bottom, wherein the asphalt pavement layer 10 is divided into fine-grained asphalt concrete and medium-grained asphalt concrete.

[0049] Step S2: Determine the appearance and size of the sandwich energy dissipation structure 13 according to the established inspection well and the road surface model around the well, and construct the sandwich energy dissipation structure 13.

[0050] The specific steps of step S2 are:

[0051] Step S21: Compare the structures of various types of roadway inspection wells and manhole covers 7 to determine the appearance of the sandwich energy dissipation structure 13. The roadway manhole covers 7 are all cylindrical, so the sandwich energy dissipation structure 13 is determined to be an annular cylindrical structure, and the diameter of the roadway manhole cover 7 is obtained as the inner diameter of the sandwich energy dissipation structure 13;

[0052] Step S22: Investigate the damaged area of ​​the road surface around the well to determine the size of the sandwich energy-absorbing structure 13, wherein the value of the crack area radius of the road surface around the well is investigated to obtain the average value of the crack area radius and use it as the single-side width size of the sandwich energy-absorbing structure 13; investigate the settlement value of the road surface around the well to obtain the average value of the settlement value and use it as the thickness size of the sandwich energy-absorbing structure 13.

[0053] Step S3: Install the constructed sandwich energy dissipation structure 13 in the well surrounding pavement model, determine the load level and method, perform mechanical analysis, and compare with the well surrounding pavement model without the sandwich energy dissipation structure 13 to obtain the performance of the sandwich energy dissipation structure 13.

[0054] To simplify the analysis, the present invention uses a five-axle truck for mobile loading, takes a rectangular uniformly distributed load to perform equivalent loading on the wheel load, and gives a moving speed. The load moving path diagram is shown in Fig. 9 As shown, Fig. 9 Reference numeral 14 is the loading area, and the arrow indicates the loading path. The two models of the inspection well and the road surface around the well before and after the sandwich energy dissipation structure 13 is added are loaded respectively, and the force characteristics analysis and vibration response analysis and calculation of the two models are performed under the action of the moving constant load by using the ANSYS finite element software, and the mechanical indicators of the inspection well and the road surface around the well without the sandwich energy dissipation structure 13 and the mechanical indicators of the inspection well and the road surface around the well after the sandwich energy dissipation structure 13 is installed are obtained, and the obtained mechanical indicators are compared to obtain the performance of the sandwich energy dissipation structure 13.

[0055] The present invention uses a manhole cover diameter of 600 mm, an inner and outer diameter of the wellbore of 400 mm and 600 mm respectively, an inner and outer diameter of the well chamber of 1000 mm and 1200 mm respectively, and a well wall thickness of 100 mm. In addition, the well surrounding road surface model is established as a rectangular parallelepiped model, which is 6000 mm long, 3000 mm wide, and 1880 mm high.

[0056] Sandwich energy dissipation structure performance experiment:

[0057] Three positions of the sandwich energy absorbing structure 13, namely, point E1', point C' and point E2', are selected, wherein point E1' is the junction of the left outer diameter of the sandwich energy absorbing structure 13 and the pavement structure, point C' is the midpoint of the left circular ring of the sandwich energy absorbing structure 13, and point E2' is the junction of the left inner diameter of the sandwich energy absorbing structure 13 and the manhole cover; meanwhile, points E1, C and E2 are at the same positions as points E1', C' and E2' in the inspection well and the pavement around the well where the sandwich energy absorbing structure 13 is not installed.

[0058] The comparison results of the Mise equivalent stress, shear stress and axial displacement peak of the inspection well and the road surface around the well at points E1, C, E2 without the sandwich energy dissipation structure 13 and the inspection well and the road surface around the well at points E1', C', E2' after the sandwich energy dissipation structure 13 is added are shown as follows: Fig.10 , Fig.11 , Fig.12As shown; by calculating the three positions E1', C' and E2' of the sandwich energy dissipation structure 13 respectively, it can be concluded that after the installation of the sandwich energy dissipation structure 13, the peak values ​​of the Mises equivalent stress, shear stress and axial displacement are significantly reduced, indicating that the sandwich energy dissipation structure 13 has good energy absorption performance, can significantly reduce the impact and vibration of the road surface around the well, thereby greatly extending the service life of the road surface around the well.

Claims

1. A design method for a sandwich energy dissipation structure based on origami engineering, applied to a sandwich energy dissipation structure based on origami engineering, characterized in that: The sandwich energy dissipation structure based on origami engineering is an annular column structure as a whole, including an outer shell and a folding structure located inside the outer shell. The outer shell and the folding structure are rigid structures. The outer shell is enclosed by an upper panel, a lower panel, an inner panel and an outer panel. The interior of the outer shell is a cavity, and the folding structure is arranged in the cavity. The folding structure is composed of a plurality of folding circles, and each folding circle is formed by connecting a plurality of Miura folding units end to end. In different folding circles, the number of Miura folding units is the same, but the length of the Miura folding units in each folding circle gradually increases from the inside to the outside. The design methodology includes the following steps: Step S1: Establishing a model of the inspection well and the road surface around the well; Step S2: Determine the appearance and size of the sandwich energy dissipation structure according to the established inspection well and the road surface model around the well, and construct the sandwich energy dissipation structure; Step S3: Install the constructed sandwich energy dissipation structure in the well surrounding pavement model, determine the load level and method, perform mechanical analysis, and compare it with the well surrounding pavement model without the sandwich energy dissipation structure installed to obtain the performance of the sandwich energy dissipation structure.

2. The design method of the sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized by: The folds of the Miura folding unit are unfolded in two different directions on the plane. The first direction is an arc line, which alternates as a peak line and a valley line on the unit cell; the second direction is a fold line, which alternately passes through the peak line and the valley line in sequence, and each fold line is mirror-symmetrical at the intersection with the arc line.

3. The design method of the sandwich energy dissipation structure based on origami engineering according to claim 2 is characterized by: The peak line of the Miura folding unit is fixedly connected to the upper panel, the inner panel and the outer panel, and the valley line of the Miura folding unit is fixedly connected to the lower panel.

4. The design method of the sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized by: The folding structure is formed by pressing with a mold.

5. The design method of the sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized by: The width of the sandwich energy dissipation structure can be adjusted by increasing or decreasing the number of folding circles.

6. The design method of sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized by: The height of the sandwich energy dissipation structure can be adjusted by adjusting the length of the Miura folding unit and the angle between adjacent Miura folding units.

7. The design method of sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized in that: In step S1, the inspection well model is composed of a well cover, a well shaft and a well chamber from top to bottom, and all of them are cylindrical structures; the well surrounding pavement model is composed of an asphalt pavement layer, a lime fly ash gravel layer and a lime fly ash soil layer from top to bottom, wherein the asphalt pavement layer is divided into fine-grained asphalt concrete and medium-grained asphalt concrete.

8. The design method of sandwich energy dissipation structure based on origami engineering according to claim 1 is characterized in that: The specific steps of step S2 are: Step S21: Compare various types of roadway inspection wells and manhole cover structures to determine the appearance of the sandwich energy dissipation structure. The roadway manhole covers are all cylindrical, so the sandwich energy dissipation structure is determined to be an annular cylindrical structure, and the roadway manhole cover diameter is obtained as the inner diameter of the sandwich energy dissipation structure; Step S22: Investigate the damaged area of ​​the road surface around the well to determine the size of the sandwich energy-absorbing structure, wherein the value of the crack area radius of the road surface around the well is investigated to obtain the average value of the crack area radius and use it as the single-side width size of the sandwich energy-absorbing structure; investigate the settlement value of the road surface around the well to obtain the average value of the settlement value and use it as the thickness size of the sandwich energy-absorbing structure.

9. The design method of sandwich energy dissipation structure based on origami engineering according to claim 1, characterized in that: In step S3, a five-axle truck is used for mobile loading, a rectangular uniformly distributed load is taken to perform equivalent loading on the wheel load, and a moving speed is given, and the two models of the inspection well and the road surface around the well before and after the sandwich energy-absorbing structure is added are loaded respectively. The force characteristic analysis and vibration response analysis and calculation of the two models are performed under the action of the mobile constant load by using the ANSYS finite element software, and the mechanical indicators of the inspection well and the road surface around the well without the sandwich energy-absorbing structure installed and the mechanical indicators of the inspection well and the road surface around the well after the sandwich energy-absorbing structure is installed are obtained, and the obtained mechanical indicators are compared to obtain the performance of the sandwich energy-absorbing structure.

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