Device for static load and stability test of plate
Technical Field
The invention relates to a device for static load and stability test of a plate.
Background
The plate type structure is a common structural form of engineering structure, and can bear out-of-plane load and in-plane load. When the plate bears an out-of-plane load or an in-plane stretching load, when the load reaches a certain degree, the surface fiber stress exceeds the ultimate tensile strength of the material, and the plate can be subjected to tensile failure; when the plate bears the in-plane pressure load, the width and thickness of the plate are smaller, and when the load is added to the surface fiber stress to reach the ultimate compression strength of the material, the plate can be compressed and damaged; another situation is a large aspect ratio of the plate, where when the load is applied to a certain extent and the surface fibre stresses have not yet reached the ultimate compressive strength of the material, the plate will suddenly deform too much to take up the load-carrying capacity, a phenomenon known as buckling or instability.
In research or actual structural design, the ultimate strength or stability coefficient of the plate structure is often verified through experiments, and the simulation of the loading mode and the boundary conditions directly influences the accuracy of the test results.
Generally, the loading direction of the tester is mainly vertical pulling or pressing. When static load and stability test of the plate are carried out, a vertical loading mode is generally adopted, load is difficult to act on the plate surface, namely, the normal direction of the curved surface, eccentricity often exists, and the plate is not in line with the actual stress state of the plate. Because the plate unsteady moment displacement suddenly increases, the contact part of the plate and the testing machine and the device which is in simulated hinge connection with the lower end of the plate can slide, the plate is extruded, and the safety of equipment and personnel is endangered. For the curved plate structure, in addition to the problems of the two aspects, the lower end of the plate must be provided with a powerful tool to resist the horizontal force of the plate.
Simulation of boundary conditions is critical when conducting static load and stability tests of the panel. Typical boundary conditions are mainly three types of simple, fixed and free. If the test plate is a part of an actual plate structure, and two sides are non-free edges, the boundary condition is assumed to be simple, the upper end and the lower end of the plate are hinged, and loading is carried out on the upper end. Special tools are welded at the upper end and the lower end of the plate to simulate the hinging boundary conditions of the plate, but the plate and the tools are often damaged firstly during the test, so that the test purpose cannot be met.
Disclosure of Invention
In order to solve the problems, the invention aims to provide a device for plate static load and stability test, which realizes the aims of simulating four-side constraint of plates, universality of plates with different thicknesses and widths and universality of straight plate and curved plate test pieces.
The invention aims at realizing the following technical scheme:
a device for static load and stability testing of a panel, comprising:
the whole frame is formed by welding steel plates, is shaped like a Chinese character 'kou', and is horizontally placed, the whole frame is fixed on the ground through 4 upright posts, has enough strength and rigidity, can ensure that the whole frame cannot be damaged in strength before the plate is damaged, and cannot be deformed wholly or locally to influence the test result.
The lifting jack, the front loading block and the rear constraint plate are sequentially arranged in the integral frame along the length direction of the integral frame, the plate is arranged between the front loading block and the rear constraint plate, and the simple supporting clamps are respectively arranged on two sides of the plate; the jack and the front loading block are both placed on the bracket, and a jack limiting part is arranged above the bracket and used for limiting the jack to roll left and right in the test process.
Further, the plate is a flat plate or a curved plate made of steel, aluminum or a composite material, or a flat plate or a curved plate with stiffening ribs made of steel, aluminum or a composite material, and the edges of the front end and the rear end of the plate are semicircular.
Furthermore, the front loading block is formed by welding steel plates, has enough strength and rigidity, and can ensure that the external force of the jack is uniformly applied to the edges of the plates. The rear end restraint board is fixed on the integral frame through high-strength bolts, and can transfer the force from the plate and the force perpendicular to the plate surface to the integral frame.
The front loading block and the rear constraint plate are provided with grooves with semicircular bottoms and horn mouth shapes on the side faces of the plates, the grooves are matched with semicircular edges of the plates, the simulated hinging boundary conditions are achieved, the front end and the rear end of the plates can be guaranteed to freely rotate, the front loading block or the rear constraint plate is guaranteed not to deform perpendicular to the plates, and the load can be always acted in the plates.
If the plate is provided with stiffening ribs, grooves are formed in positions, corresponding to the stiffening ribs, of the plate, of the front loading block and the rear constraint plate.
Further, the bracket is a steel plate with stiffening ribs and is used for supporting the jack and the front loading block, the center of the jack is guaranteed to be aligned with the centroid of the plate, the bracket is fixed on the integral frame through the bracket connecting piece and the high-strength bolt, and the height of the bracket can be adjusted up and down through the steel plates with different thicknesses.
Furthermore, the polytetrafluoroethylene plate is arranged between the jack limiting piece and the bracket, so that friction between the jack and the bracket can be reduced, and the jack can be ensured to move freely back and forth.
Further, the stand is formed by steel plate welding, the top of stand passes through stand connecting piece and high strength bolted connection integral frame, the bottom of stand passes through the earth anchor bolt to be fixed in ground.
Further, a width adjusting block is arranged between the integral frame and the simple supporting clamp and is suitable for plates with different widths; the width adjusting block is formed by welding steel plates and is connected with the integral frame and the simple supporting clamp through high-strength bolts.
Furthermore, the jack limiting part is made of angle steel or steel plates.
Further, the simple support clamps on two sides of the plate consist of clamps welded with round steel bars, and simple support boundary conditions on two sides of the plate are simulated.
The beneficial effects of the invention are as follows:
(1) The device adopts the integral frame of a Chinese character 'kou' shape as a bearing structure to carry out static load and stability test of the plate, and external force and supporting counter force from the jack are self-balanced in the integral frame and are not limited by test sites and test loading equipment.
(2) The device adopts the horizontal loading mode to carry out the test of plate, has reduced the frock that is used for installing the protection, has reduced the risk that the plate breaks suddenly and forms equipment and personnel safety when experimental.
(3) The front end and the rear end of the plate of the device are made into semicircular shapes, and are respectively matched with the grooves of the front loading block and the rear end constraint plate, so that the load can be uniformly applied to the neutral axis of the cross section of the end of the plate, the front end and the rear end of the plate can be ensured to freely rotate, and the hinging boundary conditions of the front end and the rear end of the plate are truly simulated.
(4) The device adopts the bracket supporting jack of adjustable height, guarantees that the load of jack can effectively act on the neutral axle of plate end cross-section. Meanwhile, the width adjusting block is adopted, so that the plate with different widths and thicknesses can be suitable for plates with stiffening ribs.
(5) The device is provided with the polytetrafluoroethylene plate on the bracket, so that friction between the jack and the bracket can be reduced.
(6) The device is characterized in that a jack limiting piece is arranged on the bracket to prevent the jack from rolling left and right during a jack test.
(7) The device is provided with the upright posts to support the whole frame, so that the sensor is convenient to install and arrange by the plate.
(8) The device has the advantages of good rigidity, high rigidity, compact structure, convenient operation, small deformation during test, definite force transmission and reliable test data, and all the components are connected through welding or bolts.
(9) The device simulates four-side constraint stress of the plate, and the side surface is simulated by simple constraint, so that the plate can be deformed freely, and has better fitting property compared with the actual situation.
(10) The device disclosed by the invention is wide in application range, is suitable for test pieces with different plate thicknesses, is suitable for test of curved plate test pieces, breaks through the situations of the prior bilateral constraint test and the test of replacing the curved plate with a straight plate, and makes up for the blank of the four-side constraint test and the curved plate test of the plate, thereby greatly improving the reliability of the test result of the plate.
Drawings
FIG. 1 is a schematic top view of a device for static load and stability testing of a plate according to the present invention;
FIG. 2 is a cross-sectional view of the position A-A of FIG. 1;
FIG. 3 is a cross-sectional view of the B-B position of FIG. 1;
FIG. 4 is a cross-sectional view of the C-C position of FIG. 1;
FIG. 5 is a cross-sectional view of the D-D position of FIG. 1;
FIG. 6 is a cross-sectional view of the E-E position of FIG. 1;
FIG. 7 is a cross-sectional view of the F-F position of FIG. 1;
FIG. 8 is a cross-sectional view of the G-G position of FIG. 1;
FIG. 9 is a cross-sectional view of the H-H position of FIG. 1;
FIG. 10 is a cross-sectional view of the width adjustment block of FIG. 1 in the C-C position;
FIGS. 11a to 11e are schematic views of different test plate structures;
the device comprises a 1-integral frame, a 2-front loading block, a 3-rear constraint plate, a 4-simple support clamp, a 5-plate, a 6-jack, a 7-bracket, a 71-bracket connecting piece, an 8-polytetrafluoroethylene plate, a 9-jack limiting piece, a 10-upright post, a 101-upright post connecting piece and an 11-width adjusting block.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
A device for static load and stability test of a plate, as shown in fig. 1, comprising: the integral frame 1 is formed by welding steel plates, is shaped like a Chinese character 'kou' and is horizontally arranged, and the integral frame 1 is fixed on the ground through 4 upright posts 10; the stand 10 is formed by welding steel plates, the top end of the stand 10 is connected with the integral frame 1 through a stand connecting piece 101 and a high-strength bolt, and the bottom end of the stand 10 is fixed on the ground through a ground anchor bolt.
A jack 6, a front loading block 2 and a rear constraint plate 3 are sequentially arranged in the integral frame 1 along the length direction, a plate 5 is arranged between the front loading block 2 and the rear constraint plate 3, and simply supported clamps 4 are respectively arranged on two sides of the plate 5; the jack 6 and the front loading block 2 are both arranged on the bracket 7, and a jack limiting piece 9 is arranged above the bracket 7 and used for limiting the jack 6 to roll left and right in the test process.
The plate 5 is a flat plate or a curved plate made of steel, aluminum or composite materials, or a flat plate or a curved plate with stiffening ribs made of steel, aluminum or composite materials, and the edges of the front end and the rear end of the plate 5 are semicircular.
The front end loading block 2 is formed by welding steel plates, and the rear end constraint plate 3 is fixed on the integral frame 1 through high-strength bolts;
grooves with semicircular bottoms and horn mouth shapes are formed in the side faces, close to the plate 5, of the front end loading block 2 and the rear end constraint plate 3, and the grooves are matched with semicircular edges of the plate 5.
If the plate 5 is provided with stiffening ribs, grooves are formed in positions corresponding to the stiffening ribs of the plate, on the front loading block 2 and the rear constraint plate 3.
The bracket 7 is a steel plate with stiffening ribs and is used for supporting the jack 6 and the front loading block 2, the bracket 7 is fixed on the integral frame 1 through the bracket connecting piece 71 and the high-strength bolt, and the height of the bracket 7 can be adjusted up and down by padding steel plates with different thicknesses.
A polytetrafluoroethylene plate 8 is arranged between the jack limiting piece 9 and the bracket.
A width adjusting block 11 is arranged between the integral frame 1 and the simple supporting clamp 4 and is suitable for plate pieces 5 with different widths; the width adjusting block 11 is formed by welding steel plates and is connected with the integral frame 1 and the simple supporting clamp 4 through high-strength bolts.
The jack limiting part 9 is made of angle steel or steel plates.
As shown in fig. 1, the integral frame is formed by sequentially welding two outer frame rear top plates and two outer frame side plates, and the outer frame top plates and the outer frame side plates are vertically arranged; two support steel plates are further arranged on two sides of the inside of the integral outer frame, are connected with two outer frame top plates and are arranged in parallel with the outer frame side plates, and are vertically placed; the two sides of the inside of the integral frame are provided with horizontally arranged steel frame main boards which are welded with the outer frame top plate, the outer frame side plates and the support steel plates, specifically, the steel frame main boards are arranged between the support steel plates and the outer frame side plates adjacent to the support steel plates, and the steel frame main boards are respectively connected with the middle parts of the outer frame top plate and the outer frame side plates; and the whole frame is internally welded with an outer frame main board stiffening plate, and the outer frame main board stiffening plate is connected with two outer frame side plates and is flush with the front end loading block.
The two side simply supported clamps 4 are arranged between the two support steel plates.
The rear end of the rear end constraint plate 3 is also connected with a rear end stress device.
The two sides of the rear end stress device are respectively provided with a bracket steel plate, the front and the rear of the rear end stress device are respectively welded and connected with the bracket steel plate through a front top plate of the rear stress device and a rear top plate of the rear stress device, the front top plate of the rear stress device and the rear top plate of the rear stress device are respectively arranged parallel to the top plate of the outer frame, the rear top plate of the rear stress device is level with the rear top plate of the outer frame, a main steel plate of the rear stress device is welded between the front top plate of the rear stress device and the rear top plate of the rear stress device, and the main steel plates of the rear stress device are horizontally arranged; a plurality of stiffening plates of the rear stress device are welded between the front top plate of the rear stress device and the rear top plate of the rear stress device and are arranged parallel to the support steel plate.
The front end of the jack 6 is also provided with a front end stress device.
The front end stress device is characterized in that two sides of the front end stress device are respectively provided with a support steel plate, a front top plate of the front end stress device and a rear top plate of the front end stress device are respectively connected with the support steel plate in a welded mode, the front top plate of the front stress device and the rear top plate of the front stress device are respectively parallel to the rear top plate of the outer frame, and the front top plate of the front stress device and the rear top plate of the outer frame are flush. A plurality of stiffening plates of the front stress device are welded between the front top plate of the front stress device and the rear top plate of the front stress device and are arranged parallel to the support steel plate.
The present invention is applicable to the test panel structure shown in fig. 11a to 11e, in which fig. 11a is a curved outer rib, fig. 11b is a curved inner rib, fig. 11c is a planar outer rib, fig. 11d is a curved plate, and fig. 11e is a flat plate.
The two-side simply supported clamps are respectively fixed with an upper clamp and a lower clamp along the upper side and the lower side of each support steel plate;
the upper clamp comprises an upper vertical plate and an upper flat plate, the upper vertical plate and the upper flat plate are welded to form a right angle, a plurality of upper stiffening plates which are arranged in parallel are welded in the right angle, and the upper stiffening plates are respectively connected with the upper vertical plate and the upper flat plate in a welding way; an upper round steel bar is welded on the lower surface of the upper flat plate;
the lower clamp comprises a lower vertical plate and a lower flat plate, the lower vertical plate and the lower flat plate are welded into a right angle shape, a plurality of lower stiffening plates which are arranged in parallel are welded in the right angle shape, and the lower stiffening plates are respectively welded and connected with the lower vertical plate and the lower flat plate; a lower round steel bar is welded on the upper plane of the lower flat plate;
the plate is arranged between the upper flat plate and the lower flat plate and is embedded between the upper round steel bar and the lower round steel bar.
The upper flat plate, the lower flat plate, the upper round steel bar and the lower round steel bar can be horizontal or arc-shaped, and are suitable for straight paper pieces or curved plate test pieces with different curvatures. The upper vertical plate is provided with an elliptical high-strength bolt hole so as to adjust the position of the upper clamp to adapt to test pieces with different plate thicknesses.
The installation steps of the device during the test are as follows:
(1) Fixing the rear end constraint plate on the integral frame through a high-strength bolt;
(2) After the plate is propped against the rear end constraint plate, installing the simple supporting clamps on two sides, and primarily positioning;
(3) Installing a front loading block and primarily positioning;
(4) Installing a jack, starting the jack after the jack is in place, and applying external force to enable the front loading block to tightly prop against the plate, and enabling the plate to tightly prop against the rear constraint plate;
(5) The plate is mounted in place and a test can be performed.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.