Loop structure for looped track acceleration loading test

Abstract

The utility model provides a kind of loop structure for loop acceleration loading test, including loop body and the double-ring track being located in the both sides of loop body;The surface of loop body forms test pavement, and double-ring track is used to connect loading device and makes loading device load test pavement;Loop body includes two straight sections, two curved sections and four bend straight transition sections in turn butted into ring, one end of each bend straight transition section is respectively connected with the end of one of straight sections, and the other end is respectively connected with the end of one of curved sections;Curved section has fixed lateral slope, and bend straight transition section has gradual lateral slope, and gradual lateral slope gradually increases from the end of bend straight transition section and straight section to the other end.The loop structure for loop acceleration loading test provided by the utility model can reduce the turning radius under the premise of meeting the operating speed requirement of loading device, and improve the operating stability of loading device.

Description

Technical Field

[0001] This utility model belongs to the field of road performance testing technology, specifically relating to a ring track structure for accelerated loading tests. Background Technology

[0002] Accelerated loading tests are used to comprehensively simulate the actual service conditions of road materials and structures in special geographical environments, simulate different vehicle axle load compositions, and conduct scientific research on the accelerated loading of new structures, new materials, and new processes using full-scale tests. Accelerated loading tests mainly include two methods: straight-track accelerated loading tests and loop accelerated loading tests. For loop accelerated loading tests, the loop structure typically consists of two semi-circular curves and two straight sections (mainly used for accelerating the loading device). Typically, the two semi-circular curves need to have a large turning radius; otherwise, the loading device will be constrained by the centrifugal force during cornering and unable to achieve high-speed cornering. Therefore, the loops currently used for accelerated loading tests occupy a large area, and even so, the loading device still experiences significant lateral tilting forces when passing through curves. This results in the track providing guidance and reaction forces to the loading device generating extremely high impact forces, which is highly detrimental to the stability and safety of the test process and urgently needs improvement. Utility Model Content

[0003] This utility model provides a ring structure for a ring-track accelerated loading test, which aims to reduce the ring track footprint and improve the operational stability of the ring-track accelerated loading test.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a ring track structure for a ring track accelerated loading test is provided, including a ring track body and double-ring tracks disposed on both sides of the ring track body; the surface of the ring track body forms a test road surface, and the double-ring tracks are used to connect a loading device and enable the loading device to load the test road surface; the ring track body includes two straight sections, two curved sections, and four curved-straight transition sections connected in sequence to form a ring, one end of each curved-straight transition section is aligned and connected to the end of one of the straight sections, and the other end is aligned and connected to the end of one of the curved sections; the curved sections have a fixed lateral slope, and the curved-straight transition sections have a gradually changing lateral slope, and the gradually changing lateral slope gradually increases from the end where the curved-straight transition section connects to the straight section to the other end.

[0005] In one possible implementation, the double-ring track includes an inner ring track and an outer ring track; both the inner and outer ring tracks include two straight rails, two curved rails, and four curved-straight transition rails that are connected in sequence to form a ring; wherein, the upper and lower rail surfaces of the curved rails have an inclination angle consistent with the fixed transverse slope; the upper and lower rail surfaces of the curved-straight transition rails have a gradual inclination angle consistent with the gradual transverse slope.

[0006] In some embodiments, both the inner and outer ring tracks are connected to both sides of the test road surface by a number of fixed supports distributed circumferentially; wherein, the distribution spacing of the fixed supports used to fix the outer ring track is smaller than the distribution spacing of the fixed supports used to fix the inner ring track, and the distribution spacing of the fixed supports used to fix the curved track and the curved-to-straight transition track is smaller than the distribution spacing of the fixed supports used to fix the straight track.

[0007] For example, the fixing bracket has a slot with a side opening; wherein the inner edge of the inner ring track is engaged in the slot and fixedly connected to the bottom wall of the slot; the outer edge of the outer ring track is engaged in the slot and fixedly connected to the bottom wall of the slot.

[0008] For example, each section of the inner and outer ring tracks includes two fixed rails and one movable rail. The ends of the two fixed rails that are far apart from each other are connected to one of the curved-to-straight transition rails, and a material channel is formed between the two fixed rails. The two ends of the movable rail are connected to the two fixed rails respectively.

[0009] In one possible implementation, the movable rail is provided with separate supports at both ends; the separate supports include a base and a top frame, the base is fixedly connected to the side of the test surface, the top frame is detachably connected to the base, and the top frame is fixedly connected to the movable rail.

[0010] In some embodiments, the top of the base is provided with an upwardly extending fixed shaft, the top frame has a sleeve adapted to engage the fixed shaft, the lower end of the sleeve is provided with a pin that passes through the fixed shaft.

[0011] For example, the ring road body includes an earthwork layer, a crushed stone base course, and an asphalt concrete surface course laid sequentially from bottom to top; wherein the thickness of the earthwork layer is greater than that of the crushed stone base course, and the thickness of the crushed stone base course is greater than that of the asphalt concrete surface course.

[0012] For example, both sides of the ring road body are provided with concrete foundations, and there are curb stones between the concrete foundations and the ring road body. The lower end of the curb stone is flush with the bottom surface of the earthwork layer, and the upper end of the curb stone is flush with the top surface of the asphalt concrete surface layer. The double-ring track is fixedly connected to the concrete foundation.

[0013] The beneficial effects of the ring track structure for accelerated loading tests provided by this utility model are as follows: Compared with the prior art, the ring track structure for accelerated loading tests of this utility model utilizes a double-ring track as a guide for the loading device and provides reverse support force to the loading device, which is beneficial to improving the stability of the loading device when loading the test road surface along the ring track body; on this basis, by dividing the ring track body into two straight sections, two curved sections, and four curved-straight transition sections, the loading device enters the curved section from the straight section through the curved-straight transition section, and enters the next curved section from the curved-straight transition section in the curved section, thus realizing the ring track structure. The cyclic operation utilizes a gradual and fixed lateral slope to counteract the centrifugal force of the loading device when it passes through the straight-to-curved transition section and the curved section. This not only improves the operational stability of the loading device but also reduces the turning radius while meeting the speed requirements of the loading device, thereby reducing the footprint of the ring track. In addition, the straight-to-curved transition section allows the loading device to gradually change its tilt attitude between the straight and curved sections, avoiding sudden changes in the attitude of the loading device that could affect its cornering stability. This further enhances the operational stability and safety of the ring track accelerated loading test. Attached Figure Description

[0014] Figure 1 A top view of the ring structure for accelerated loading test provided in an embodiment of this utility model;

[0015] Figure 2 For along Figure 1 Schematic diagram of the cross-sectional structure cut along lines AA, BB, and CC;

[0016] Figure 3 This is a schematic diagram of the axonal structure of the double-ring track used in the embodiment of this utility model;

[0017] Figure 4 This is a three-dimensional structural diagram of the fixing bracket used in the embodiment of this utility model;

[0018] Figure 5 This is a side view of the split support structure used in the embodiment of this utility model;

[0019] Figure 6 This is a schematic diagram of the cross-sectional structure of the ring track body used in the embodiment of this utility model.

[0020] In the diagram: 10. Ring road body; 101. Straight section; 102. Curved section; 103. Curved-straight transition section; 11. Earthwork layer; 12. Crushed stone base layer; 13. Asphalt concrete surface layer; 14. Concrete foundation; 15. Curvestone; 20. Double ring track; 201. Straight rail; 2011. Fixed rail; 2012. Movable rail; 202. Curved rail; 203. Curved-straight transition rail; 21. Inner ring track; 22. Outer ring track; 30. Loading device; 40. Fixed bracket; 41. Slot; 50. Split bracket; 51. Base; 511. Fixed shaft; 52. Top frame; 521. Sleeve; 53. Pin. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on the other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, 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 of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0023] Please refer to the following: Figures 1 to 6The present invention provides a description of the ring track structure for accelerated loading tests. The ring track structure for accelerated loading tests includes a ring track body 10 and double-ring tracks 20 disposed on both sides of the ring track body 10. The surface of the ring track body 10 forms a test road surface. The double-ring tracks 20 are used to connect a loading device 30 and enable the loading device 30 to load the test road surface. The ring track body 10 includes two straight sections 101, two curved sections 102, and four curved-to-straight transition sections 103 connected in sequence. One end of each curved-to-straight transition section 103 is aligned and connected to the end of one of the straight sections 101, and the other end is aligned and connected to the end of one of the curved sections 102. The curved sections 102 have a fixed lateral slope M1, and the curved-to-straight transition sections 103 have a gradually changing lateral slope M2, with the gradually changing lateral slope M2 gradually increasing from the end of the curved-to-straight transition section 103 connected to the straight section 101 to the other end.

[0024] It should be understood that the loading device 30 has rollers on both sides. The double-ring track 20 can be understood as two ring tracks of different sizes. The rollers on both sides of the loading device 30 roll on the two ring tracks respectively. Moreover, each side of the roller includes an upper roller that rolls on the upper track surface, a lower roller that rolls on the lower track surface, and a side roller that rolls on the side track surface, thereby avoiding derailment and ensuring the safe operation of the loading device 30 along the double-ring track 20.

[0025] During the accelerated loading test on the ring track, the loading device 30 applies a downward loading force to the test surface using the reaction force of the double-ring track 20. At this time, the loading device 30 basically does not generate lateral impact on the double-ring track 20. When the loading device 30 runs to the straight-curve transition section 103, it begins to change from linear motion to circular motion. At this time, the loading device 30 will generate a gradually increasing centrifugal force due to the change in its motion trajectory. At this time, based on the gradually increasing lateral slope M2 of the straight-curve transition section 103, the test surface provides lateral tilt support force to the loading device 30, thereby offsetting or reducing the lateral impact force generated by the loading device 30 on the double-ring track 20 due to the centrifugal force. When the loading device 30 runs to the curve section 102, the lateral slope of the test surface reaches its maximum value, i.e., the fixed lateral slope M1. At this time, the turning centrifugal force of the loading device 30 also reaches its maximum, and the lateral tilt support force of the test surface on the loading device 30 also reaches its maximum, which basically offsets the turning centrifugal force. This can reduce the lateral impact of the loading device 30 on the double-ring track 20 when passing through the curve section 102.

[0026] Due to the presence of the gradually changing lateral slope M2 and the fixed lateral slope M1, the test road surface can provide lateral support force during the turning process of the loading device 30 through the curve section 102. Therefore, compared to a conventional planar curve structure, it can meet the higher turning speed requirements of the loading device 30 while keeping the radius of the curve section 102 constant, or, while meeting the turning speed requirements of the loading device 30, it can reduce the turning radius to a certain extent, thus reducing the footprint of the ring track. Furthermore, since the lateral support force of the test road surface can counteract the centrifugal force during turning, it reduces the lateral impact force of the loading device 30 on the double-ring track 20, thereby reducing the deformation and damage to the double-ring track 20. This improves the safety and stability of the ring track accelerated loading test.

[0027] The ring track structure for accelerated loading tests provided in this embodiment, compared with the prior art, utilizes a double-ring track 20 as a guide for the loading device 30 and provides reverse support force to the loading device 30, which is beneficial to improving the stability of the loading device 30 during loading operation on the test road surface along the ring track body 10. Based on this, by dividing the ring track body 10 into two straight sections 101, two curved sections 102, and four curve-to-straight transition sections 103, the loading device 30 enters the curved section 102 from the straight section 101 through the curve-to-straight transition section 103, and then enters the next curved section 102 from the curve-to-straight transition section 103, thus achieving cyclic operation. During operation, the gradual lateral slope M2 and the fixed lateral slope M1 can be used to counteract the centrifugal force of the loading device 30 when it passes through the straight-to-curved transition section 103 and the curved section. This not only improves the operational stability of the loading device 30, but also reduces the turning radius while meeting the operating speed requirements of the loading device 30, thereby reducing the footprint of the ring track body 10. In addition, the straight-to-curved transition section 103 allows the loading device 30 to gradually change its tilt attitude between the straight section 101 and the curved section 102, avoiding sudden changes in the attitude of the loading device 30 that could affect its cornering stability. This is beneficial for further improving the operational stability and safety of the ring track accelerated loading test.

[0028] In some embodiments, see Figures 1 to 3 The double-ring track 20 includes an inner ring track 21 and an outer ring track 22; both the inner ring track 21 and the outer ring track 22 include two straight rails 201, two curved rails 202 and four curved-straight transition rails 203 connected in sequence to form a ring; wherein, the upper and lower rail surfaces of the curved rails 202 have an inclination angle N1 consistent with the fixed transverse slope M1; the upper and lower rail surfaces of the curved-straight transition rails have a gradual inclination angle N2 consistent with the gradual transverse slope M2.

[0029] Since the loading device 30 achieves stable operation based on the upper and lower rollers on both sides cooperating to clamp the inner ring track 21 and the outer ring track 22, when the loading device 30 passes through the straight-bend transition section 103 and the curve section 102, it will tilt due to the presence of the gradual lateral slope M2 and the fixed lateral slope M1. Therefore, the axial direction of the rollers on both sides of the loading device 30 will tilt accordingly. In order to ensure that the rollers are in full contact with the rail surface, the upper and lower rail surfaces of the curved rail 202 are both set with an inclination angle N1 that is consistent with the fixed lateral slope M1, while the straight-bend transition rail 203 is set with a gradual inclination angle N2 that is consistent with the gradual lateral slope M2. In this way, the rollers on both sides of the loading device 30 can always be in full contact with the rail surface, and the phenomenon of roller biting the rail can also be avoided, thereby improving the bending stability of the loading device 30.

[0030] It should be noted that, as Figure 3 As shown, both the inner ring track 21 and the outer ring track 22 are connected to both sides of the test road surface by a number of fixed supports 40 distributed circumferentially. The distribution spacing of the fixed supports 40 used to fix the outer ring track 22 is smaller than that of the fixed supports 40 used to fix the inner ring track 21. In addition, the distribution spacing of the fixed supports 40 used to fix the curved track 202 and the curved-to-straight transition track 203 is smaller than that of the fixed supports 40 used to fix the straight track 201.

[0031] Since the rollers on both sides of the loading device 30 need to clamp the inner ring track 21 and the outer ring track 22, a fixed bracket 40 is set to support the inner ring track 21 and the outer ring track 22 in a suspended state. At the same time, considering that the centrifugal force during the ring track acceleration loading test will cause the outer ring track 22 to bear a certain lateral force, the fixed brackets 40 used to fix the outer ring track 22 are appropriately densified. In particular, for the curved track 202 and the straight-to-curved transition track 203, the smaller the distance between adjacent fixed brackets 40, the more sufficient the lateral support force can be provided, thereby ensuring the stability and safety of the loading device 30 when bending.

[0032] As one specific structural form of the aforementioned fixed bracket 40, please refer to Figure 4The fixed bracket 40 has a side-opening slot 41; wherein, the inner edge of the inner ring track 21 is embedded in the slot 41 and fixedly connected to the bottom wall of the slot 41; the outer edge of the outer ring track 22 is embedded in the slot 41 and fixedly connected to the bottom wall of the slot 41. In existing technologies, a hanging rail structure is typically used, which only utilizes the lower rail surface to provide reaction force to the loading device 30. This is detrimental to the operational stability and safety of the loading device 30. Therefore, in this embodiment, a side-mounted method is used to embed the inner ring rail 21 and the outer ring rail 22 into the slot 41 of the fixed bracket 40. The upper and lower groove walls of the slot 41 provide vertical constraints to the inner ring rail 21 and the outer ring rail 22. At the same time, the bottom of the slot 41 is fixed to the inner side wall of the inner ring rail 21 and the outer side wall of the outer ring rail 22. This allows the loading device 30 to form a three-sided rolling constraint with the inner ring rail 21 and the outer ring rail 22 by arranging upper and lower rollers and side rollers, thereby preventing the rollers from derailing and greatly improving the operational stability and safety of the loading device 30.

[0033] For some possible implementations, please refer to [link / reference]. Figure 3 Each section of straight rail 201 corresponding to the inner ring track 21 and the outer ring track 22 includes two fixed rails 2011 and one movable rail 2012. The ends of the two fixed rails 2011 that are far apart from each other are respectively connected to one of the curved-to-straight transition rails 203, and a material channel is formed between the two fixed rails 2011. Both ends of the movable rail 2012 are respectively connected to the two fixed rails 2011. Since the inner ring track 21 has a large internal area, this area can be used to install other testing devices such as linear acceleration loading testing devices. The material channel can be opened by removing the movable rail 2012, thus enabling material transport between the internal space of the inner ring track 21 and the outside. When conducting the ring track acceleration loading test, only the movable rail 2012 needs to be reinstalled and reset, thereby greatly improving the space utilization rate of the testing site.

[0034] Specifically, such as Figure 5 As shown, in this embodiment, both ends of the movable rail 2012 are provided with split brackets 50; the split brackets 50 include a base 51 and a top frame 52. The base 51 is fixedly connected to the side of the test road surface, and the top frame 52 is detachably connected to the base 51 and fixedly connected to the movable rail 2012. The movable rail 2012 can be removed after the top frame 52 is separated from the base 51. When installing the movable rail 2012, it is only necessary to assemble the top frame 52 and the base 51, which is convenient for disassembly and assembly.

[0035] To further improve the ease of assembly and disassembly of the 2012 sliding rail, such as Figure 5As shown, the top of the base 51 has an upwardly extending fixed shaft 511, and the top frame 52 has a sleeve 521 suitable for engaging the fixed shaft 511. A pin is radially inserted through the lower end of the sleeve 521, and the pin passes through the fixed shaft 511. By removing the pin and lifting the movable rail 2012 upward, the sleeve 521 can be disengaged from the fixed shaft 511, thereby removing the movable rail 2012. During installation, simply lift the movable rail 2012, align the sleeve 521 with the fixed shaft 511, and then lower the movable rail 2012 to engage the sleeve 521 with the fixed shaft 511. Finally, insert the pin. The operation is simple and convenient.

[0036] As one specific embodiment of the aforementioned ring road body 10, please refer to Figure 6 The ring road body 10 includes, from bottom to top, an earthwork layer 11, a crushed stone base course 12, and an asphalt concrete surface course 13; wherein, the thickness of the earthwork layer 11 is greater than that of the crushed stone base course 12, and the thickness of the crushed stone base course 12 is greater than that of the asphalt concrete surface course 13. Specifically, the asphalt concrete surface course 13 consists of, from top to bottom, a 5cm thick medium-grained asphalt concrete SMA-16, a 6cm thick dense-graded medium-grained asphalt concrete, and a 7cm thick coarse gravel asphalt concrete; the crushed stone base course 12 consists of, from top to bottom, a 20cm thick cement-stabilized crushed stone, a 20cm thick gravel, and a 20cm thick lime-fly ash stabilized crushed stone or gravel.

[0037] Based on the above, such as Figure 6 As shown, concrete foundations 14 are provided on both sides of the ring track body 10. A curbstone 15 is provided between the concrete foundation 14 and the ring track body 10. The lower end of the curbstone 15 is flush with the bottom surface of the earthwork layer 11, and the upper end of the curbstone 15 is flush with the top surface of the asphalt concrete surface layer 13. The double-ring track 20 is fixedly connected to the concrete foundation 14. By setting the curbstone 15 and the concrete foundation 14, lateral support can be provided on both sides of the ring track body 10, avoiding the collapse of the test road surface and improving the service life of the ring track body 10. At the same time, the concrete foundation 14 can also be used as the connecting foundation of the double-ring track 20, thereby improving the structural stability of the double-ring track 20, and thus ensuring the operational stability and safety of the ring track accelerated loading test.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A ring structure for accelerated loading tests, characterized in that, The system includes a ring road body and double-ring tracks on both sides of the ring road body. The surface of the ring road body forms a test road surface, and the double-ring tracks are used to connect a loading device and enable the loading device to load the test road surface. The ring road body includes two straight sections, two curved sections, and four curved-straight transition sections connected in sequence. One end of each curved-straight transition section is aligned and connected to the end of one of the straight sections, and the other end is aligned and connected to the end of one of the curved sections. The curved sections have a fixed lateral slope, and the curved-straight transition sections have a gradually increasing lateral slope, which gradually increases from the end of the curved-straight transition section connected to the straight section to the other end.

2. The ring structure for accelerated loading tests as described in claim 1, characterized in that, The double-ring track includes an inner ring track and an outer ring track; both the inner ring track and the outer ring track include two straight rails, two curved rails, and four curved-straight transition rails that are connected in sequence to form a ring; wherein, the upper and lower rail surfaces of the curved rails have an inclination angle consistent with the fixed transverse slope; the upper and lower rail surfaces of the curved-straight transition rails have a gradual inclination angle consistent with the gradual transverse slope.

3. The ring structure for accelerated loading tests as described in claim 2, characterized in that, Both the inner and outer ring tracks are connected to both sides of the test road surface by a plurality of fixed supports distributed circumferentially at intervals; wherein, the distribution spacing of the fixed supports used to fix the outer ring track is smaller than the distribution spacing of the fixed supports used to fix the inner ring track, and the distribution spacing of the fixed supports used to fix the curved track and the curved-to-straight transition track is smaller than the distribution spacing of the fixed supports used to fix the straight track.

4. The ring structure for accelerated loading tests as described in claim 3, characterized in that, The fixed bracket has a side-opening slot; wherein, the inner edge of the inner ring track is fitted into the slot and fixedly connected to the bottom wall of the slot; the outer edge of the outer ring track is fitted into the slot and fixedly connected to the bottom wall of the slot.

5. The ring structure for accelerated loading tests as described in claim 2, characterized in that, Each of the corresponding sections of the inner and outer ring tracks includes two fixed rails and one movable rail; wherein the ends of the two fixed rails that are far apart from each other are respectively connected to one of the curved-straight transition rails, and a material channel is formed between the two fixed rails; and the two ends of the movable rail are respectively connected to the two fixed rails.

6. The ring structure for accelerated loading tests as described in claim 5, characterized in that, Both ends of the movable rail are provided with split supports; the split supports include a base and a top frame, the base is fixedly connected to the side of the test road surface, the top frame is detachably connected to the base, and the top frame is fixedly connected to the movable rail.

7. The ring structure for accelerated loading tests as described in claim 6, characterized in that, The base has an upwardly extending fixed shaft at its top end, and the top frame has a sleeve adapted to fit the fixed shaft. A pin is radially inserted through the lower end of the sleeve, and the pin passes through the fixed shaft.

8. The ring structure for accelerated loading tests as described in any one of claims 1-7, characterized in that, The ring road body includes an earthwork layer, a crushed stone base layer, and an asphalt concrete surface layer laid sequentially from bottom to top; wherein, the thickness of the earthwork layer is greater than that of the crushed stone base layer, and the thickness of the crushed stone base layer is greater than that of the asphalt concrete surface layer.

9. The ring structure for accelerated loading tests as described in claim 8, characterized in that, Both sides of the ring road body are provided with concrete foundations, and a curb stone is provided between the concrete foundation and the ring road body. The lower end of the curb stone is flush with the bottom surface of the earthwork layer, and the upper end of the curb stone is flush with the top surface of the asphalt concrete surface layer. The double-ring track is fixedly connected to the concrete foundation.

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