A universal device for torsion test of space truss structure and use method thereof

Abstract

The present invention discloses a universal device for torsion experiment of a space truss structure and a method for using the device, comprising a fixed end device and a loading end device, wherein the fixed end device comprises a first fixed support, a lower fixed end clamp, an upper fixed end clamp, a first screw rod, and a first nut, wherein two groups of the first fixed supports are fixed to the ground, two first screw rods are installed on the first fixed supports, and two groups of the first nuts are tightened at the same horizontal position of the two groups of first screw rods, and the two groups of the upper fixed end clamps and the lower fixed end clamps are both connected to the two groups of first screw rods in a "well" shape, and the upper fixed end clamp and the lower fixed end clamp are fixedly connected to the two groups of first screw rods through the first nut.

Description

Technical Field

[0001] The present invention provides a universal device for a torsion test of a space truss structure and a use method thereof, and in particular relates to a universal device for a torsion test of a space truss structure and a use method thereof. Background Art

[0002] Space truss structures are widely used due to their simple force-bearing and material-saving properties. Under the action of vertical eccentric loads and lateral wind loads, the structure will twist. Therefore, it is particularly important to study its torsional performance. Given that there are relatively few reference examples of space truss structure torsion test devices and methods of use and they are not universal, we provide a universal space truss structure torsion test device and method of use to solve the problems raised in the above background technology. Summary of the invention

[0003] The purpose of the present invention is to provide a universal device for torsion testing of a space truss structure and a method for using the same, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a universal device for torsion test of a space truss structure and a method of using the same, comprising a fixed end device and a loading end device, wherein the fixed end device comprises a first fixed support, a lower fixed end clamp, an upper fixed end clamp, a first screw rod, and a first nut, wherein two groups of the first fixed supports are fixed to the ground, two first screw rods are mounted on the first fixed supports, and two groups of the first nuts are tightened at the same horizontal position of the two groups of the first screw rods, and the two groups of the upper fixed end clamps and the lower fixed end clamps are both connected to the two groups of the first screw rods in a "well" shape, and the upper fixed end clamp and the lower fixed end clamp are fixedly connected to the two groups of the first screw rods through the first nut;

[0005] The loading end device includes a second fixed support, a polytetrafluoroethylene plate, a second screw, a second nut, a rectangular support, a lower rotating support, an upper rotating support, a loading end lower fixture, a loading end upper fixture, and a latch. The second fixed support is fixed to the ground, a lower rotating support is welded to the upper part of the second fixed support, an upper rotating support is welded to the lower part of the loading end lower fixture, and the upper rotating support is placed on the lower rotating support, and the upper rotating support and the lower rotating support are connected by a latch. The two groups of the loading end upper fixture and the loading end lower fixture are connected in a "well" shape through two groups of second nuts and two groups of second screws. A pair of concentrated forces of equal magnitude and opposite direction are applied to the loading end lower fixture by two series hydraulic jacks to provide torque for the structure, and a curve of torque and torsion angle is derived using data acquisition and processing software according to the installed inclination meter and displacement meter.

[0006] Preferably, the surfaces of the loading end and the fixed end are both paved with polytetrafluoroethylene plates.

[0007] Preferably, rectangular supports are fixed to the upper surfaces of the loading end lower clamp and the fixed end lower clamp.

[0008] Preferably, the specific steps of the method for using the universal device for torsion test of a spatial truss structure are as follows:

[0009] Step 1: Fix two fixed supports on the ground or experimental site;

[0010] Step 2: insert two first screws into the reserved holes of the first fixed support, fix the first screws on the first fixed support with the first nuts, tighten the two first nuts at the same height of the two first screws, insert the lower clamp of the fixed end for laying or wrapping the polytetrafluoroethylene sheet into the two first screws and place it on the first nuts;

[0011] Step 3: A second fixed support is fixed to the bottom surface or the experimental site, a lower rotating support is welded on the fixed support, an upper rotating support is welded on the lower fixture of the loading end on which the polytetrafluoroethylene plate is laid or wrapped, and the upper rotating support is installed on the lower rotating support, and a latch is inserted;

[0012] Step 4, place the experimental structure, level the experimental structure with a level, install the upper fixture of the fixed end of the PTFE plate laid or wrapped through two first screws, and fix the experimental structure with a first nut, and simultaneously install the upper fixture of the loading end of the PTFE plate laid or wrapped, two second screws pass through the upper fixture of the loading end of the PTFE plate laid or wrapped and the lower fixture of the loading end of the PTFE plate laid or wrapped, fix the experimental structure with a second nut, and perform leveling calibration again with a level;

[0013] Step 5: Install the goniometer and displacement meter;

[0014] Step 6: Apply a pair of concentrated forces of equal magnitude and opposite direction to the clamp on the loading end through two series hydraulic jacks to provide torque for the structure;

[0015] Step 7: Calculate the torsion angle and torsional stiffness of the experimental structure.

[0016] Torsion angle value:

[0017] Assume that the longitudinal direction of the experimental structure is the x-axis, the horizontal direction is the y-axis, and the vertical direction is the z-axis.

[0018] Twist Angle:

[0019] 1. Calculate from the displacement meter measurement results:

[0020] 2. Measured directly by the goniometer:

[0021] In formula ①② is the torsion angle calculated for the section at x; L is the lateral distance of the symmetrical measuring points of the section at x; Zx With Z -x is the vertical displacement of the symmetrical measuring point on the cross section at x; The torsion angle is measured by the cross-section goniometer at position x.

[0022] Torsional stiffness: In formula ③, F is the concentrated loading force; X is the loading arm; b and a are the longitudinal distances from the fixed end; and They are the torsion angles of the cross-section structure at x=b and x=a respectively.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention can realize torsion experiments of space truss structures of different sizes by adjusting the spacing of fixed supports and the distance between upper and lower clamps.

[0025] 2. The present invention adopts a method of laying or wrapping a polytetrafluoroethylene plate with a low friction coefficient on the fixture to reduce the influence of longitudinal constraints.

[0026] 3. The present invention can adopt the method of setting arc-shaped supports, rectangular supports or supports of other structural forms at the contact positions between the fixed end lower clamp, the fixed end upper clamp, the loading end lower clamp and the loading end upper clamp and the structure to adapt to torsion tests of different structural forms, including beams.

[0027] 4. The present invention provides a rotating support at the lower clamp of the loading end and the fixed support to facilitate free twisting of the structure.

[0028] 5. The experimental projects that can be performed by the present invention include: measuring the torsional stiffness of the experimental structure by linear loading within the elastic range; measuring the stress characteristics of the structure under bending-torsion conditions; and measuring the ultimate torque of the experimental structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the fixed end of the present invention;

[0031] Figure 3 It is a structural schematic diagram of the loading end of the present invention;

[0032] Figure 4 It is a schematic diagram of the operation of the fixed end of the present invention;

[0033] Figure 5 It is a schematic diagram of the operation of the loading end of the present invention.

[0034] In the figure: 1 first fixed support, 1-1 second fixed support, 2 lower clamp of fixed end, 3 upper clamp of fixed end, 4 polytetrafluoroethylene plate, 5 first screw, 5-1 second screw, 6 first nut, 6-1 second nut, 7 rectangular support, 8-1 lower rotating support, 8-2 upper rotating support, 9 lower clamp of loading end, 10 upper clamp of loading end, 11 pin. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figure 1-5 As shown, the present invention provides a technical solution: a universal device for torsion test of a space truss structure and a method for using the same, comprising a fixed end device and a loading end device, wherein the fixed end device comprises a first fixed support 1, a fixed end lower clamp 2, a fixed end upper clamp 3, a first screw 5, and a first nut 6, two groups of the first fixed supports 1 are fixed to the ground, two first screws 5 are installed on the first fixed support 1, two groups of the first nuts 6 are tightened at the same horizontal position of the two groups of the first screws 5, the two groups of the fixed end upper clamps 3 and the fixed end lower clamps 2 are both connected with the two groups of the first screws 5 in a "well" shape, and the fixed end upper clamp 3 and the fixed end lower clamp 2 are fixedly connected with the two groups of the first screws 5 through the first nuts 6;

[0037] The loading end device includes a second fixed support 1-1, a polytetrafluoroethylene plate 4, a second screw 5-1, a second nut 6-1, a rectangular support 7, a lower rotating support 8-1, an upper rotating support 8-2, a loading end lower clamp 9, a loading end upper clamp 10, and a pin 11. The second fixed support 1-1 is fixed to the ground, the lower portion of the second fixed support 1-1 is welded with a lower rotating support 8-1, the lower portion of the loading end lower clamp 9 is welded with an upper rotating support 8-2, and the upper rotating support 8-2 is placed on the lower rotating support 8-1, and the upper rotating support 8-2 and the lower rotating support 8-1 are connected by a pin 11, and the two groups of the loading end upper clamp 10 and the loading end lower clamp 9 are connected in a "well" shape through two groups of second nuts 6-1 and two groups of second screws 5-1. A pair of concentrated forces of equal magnitude and opposite direction are applied to the lower clamp 9 at the loading end by two series hydraulic jacks to provide torque for the structure. According to the installed inclination meter and displacement meter, the curve of torque and torsion angle is derived by data acquisition and processing software.

[0038] Furthermore, the surfaces of the loading end and the fixed end are both paved with polytetrafluoroethylene plates 4.

[0039] Furthermore, a rectangular support 7 is fixed to the upper surface of the loading end lower clamp 9 and the fixed end lower clamp 2 .

[0040] Furthermore, the specific steps of the method for using the universal device for torsion test of a spatial truss structure are as follows:

[0041] Step 1: two fixed supports 1 are fixed on the ground or the experimental site;

[0042] Step 2: insert the two first screw rods 5 into the reserved holes of the first fixed support 1, fix the first screw rods 5 on the first fixed support 1 with the first nut 6, tighten the two first nuts 6 at the same height of the two first screw rods 5, insert the fixed end lower clamp 2 for laying or wrapping the polytetrafluoroethylene plate 4 into the two first screw rods 5 and place it on the first nuts 6;

[0043] Step 3, a second fixed support 1-1 is fixed to the bottom surface or the experimental site, the lower rotating support 8-1 is welded on the fixed support 1-1, the upper rotating support 8-2 is welded on the lower clamp 9 of the loading end of the PTFE plate 4, and it is installed on the lower rotating support 8-1, and the latch 11 is inserted;

[0044] Step 4, place the experimental structure, and after leveling the experimental structure with a level, install the upper fixture 3 on the fixed end of the laying or wrapping polytetrafluoroethylene plate 4 through the two first screws 5 and fix the experimental structure with the first nut 6, and simultaneously install the upper fixture 10 on the loading end of the laying or wrapping polytetrafluoroethylene plate 4, and the two second screws 5-1 pass through the upper fixture 10 on the loading end of the laying or wrapping polytetrafluoroethylene plate 4 and the lower fixture 9 on the loading end of the laying or wrapping polytetrafluoroethylene plate 4, fix the experimental structure with the second nut 6-1, and perform leveling calibration again with a level;

[0045] Step 5: Install the goniometer and displacement meter;

[0046] Step 6: Apply a pair of concentrated forces of equal magnitude and opposite direction to the clamp 10 on the loading end through two hydraulic jacks in series to provide torque for the structure;

[0047] Step 7: Calculate the torsion angle and torsional stiffness of the experimental structure.

[0048] Torsion angle value:

[0049] Assume that the longitudinal direction of the experimental structure is the x-axis, the horizontal direction is the y-axis, and the vertical direction is the z-axis.

[0050] Twist Angle:

[0051] 1. Calculate from the displacement meter measurement results:

[0052] 2. Measured directly by the goniometer:

[0053] In formula ①② is the torsion angle calculated for the section at x; L is the lateral distance of the symmetrical measuring points of the section at x; Z x With Z -x is the vertical displacement of the symmetrical measuring point on the cross section at x; The torsion angle is measured by the cross-section goniometer at position x.

[0054] Torsional stiffness:

[0055] In formula ③, F is the concentrated loading force; X is the loading arm; b and a are the longitudinal distances from the fixed end; and are the torsion angles of the cross-section structure at x=b and x=a respectively;

[0056] A pair of concentrated forces of equal magnitude and opposite direction are applied to the lower clamp 9 at the loading end by two series hydraulic jacks to provide torque for the structure. According to the installed inclinometer and displacement meter, the torque and torsion angle curve is exported by data acquisition and processing software. The position of the screw rod on the nut can be adjusted to adapt to the torsion test of truss structures with different truss heights. The spacing of the fixed support 1 can be adjusted to adapt to the torsion test of truss structures with different truss widths. The contact position of the fixed end lower clamp 2, the fixed end upper clamp 3, the loading end lower clamp 9 and the loading end upper clamp 10 with the structure can be adjusted to adapt to the torsion test of different structural forms, including beams. The method of laying or wrapping polytetrafluoroethylene plates 4 on the fixed end lower clamp, the fixed end upper clamp 3, the loading end lower clamp 9 and the loading end upper clamp 10 releases the longitudinal constraint effect, and the lower rotating support 8-1 and the upper rotating support 8-2 are set. Inserting the pin 11 can facilitate the free torsion of the structure.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for using a universal device for a spatial truss structure torsion test, characterized in that: A universal device for torsion test of a space truss structure comprises a fixed end device and a loading end device, characterized in that: the fixed end device comprises a first fixed support (1), a fixed end lower clamp (2), a fixed end upper clamp (3), a first screw rod (5), and a first nut (6); two groups of the first fixed supports (1) are fixed to the ground; two first screw rods (5) are installed on the first fixed supports (1); two groups of the first nuts (6) are tightened at the same horizontal position of the two groups of the first screw rods (5); and the two groups of the fixed end upper clamps (3) are fixed to the ground. The loading end device comprises a second fixed support (1-1), a polytetrafluoroethylene plate (4), a second screw (5-1), a second nut (6-1), a rectangular support (7), a lower rotating support (8-1), an upper rotating support (8-2), a loading end lower clamp (9), and a loading end upper clamp (10). The second fixed support (1-1) is fixed to the ground, a lower rotating support (8-1) is welded to the upper part of the second fixed support (1-1), an upper rotating support (8-2) is welded to the lower part of the loading end lower clamp (9), and the upper rotating support (8-2) is placed on the lower rotating support (8-1), and the upper rotating support (8-2) and the lower rotating support (8-1) are connected by the bolt (11), and the two groups of the loading end upper clamp (10) and the loading end lower clamp (9) are connected by two The second nut (6-1) is connected to the two second screw rods (5-1) in a "well" shape; a pair of concentrated forces of equal magnitude and opposite direction are applied to the loading end lower clamp (9) by two series-connected hydraulic jacks to provide torque for the structure, and a curve of torque and torsion angle is drawn using data acquisition and processing software based on the installed inclination meter and displacement meter; polytetrafluoroethylene plates (4) are laid on the surfaces of the loading end and the fixed end; and rectangular supports (7) are fixed to the upper surfaces of the loading end lower clamp (9) and the fixed end lower clamp (2); Based on the method of using the above-mentioned universal device for torsion test of spatial truss structure, the specific steps are as follows: Step 1: two first fixed supports (1) are fixed on the ground or on a test site; Step 2: insert two first screw rods (5) into the reserved holes of the first fixed support (1), fix the first screw rods (5) on the first fixed support (1) with the first nut (6), tighten the two first nuts (6) at the same height of the two first screw rods (5), insert the fixed end lower clamp (2) for laying or wrapping the polytetrafluoroethylene plate (4) into the two first screw rods (5) and place it on the first nut (6); Step 3: A second fixed support (1-1) is fixed to the bottom surface or the experimental site, a lower rotating support (8-1) is welded to the second fixed support (1-1), an upper rotating support (8-2) is welded to the lower fixture (9) at the loading end of the polytetrafluoroethylene plate (4) is laid or wrapped, and the upper rotating support (8-2) is installed on the lower rotating support (8-1), and a latch (11) is inserted; Step 4: Place the experimental structure, and after leveling the experimental structure with a level, install the upper fixture (3) on the fixed end of the polytetrafluoroethylene plate (4) through the two first screw rods (5) and fix the experimental structure with the first nut (6), and simultaneously install the upper fixture (10) on the loading end of the polytetrafluoroethylene plate (4) being laid or wrapped, and the two second screw rods (5-1) pass through the upper fixture (10) on the loading end of the polytetrafluoroethylene plate (4) being laid or wrapped and the lower fixture (9) on the loading end of the polytetrafluoroethylene plate (4) being laid or wrapped, and fix the experimental structure with the second nut (6-1), and perform leveling calibration again with a level; Step 5: Install the goniometer and displacement meter; Step 6: Apply a pair of concentrated forces of equal magnitude and opposite directions to the clamp (10) on the loading end by two hydraulic jacks in series to provide torque for the structure; Step 7: Calculate the torsion angle and torsional stiffness of the experimental structure; Torsion angle value: Assume that the longitudinal direction of the experimental structure is the x-axis, the horizontal direction is the y-axis, and the vertical direction is the z-axis; Twist Angle:

1. Calculate from the displacement meter measurement results:

2. Measured directly by the goniometer: In formula ①② Calculate the torsion angle of the section at x; L is the lateral distance of the symmetrical measuring point of the section at x; Zx and Zx are the vertical displacements of the symmetrical measuring points of the section at x; is the torsion angle measured by the cross-section goniometer at x; Torsional stiffness: In formula ③, F is the concentrated load force; b and a are the longitudinal distances from the fixed end; and They are the torsion angles of the cross-section structure at x=b and x=a respectively.

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