Test system and method for simulating lateral impact of four-side simply supported member

Abstract

The invention relates to the technical field of component disaster simulation devices, and particularly discloses a test system and method for simulating lateral impact of a four-side simply-supported component. Comprising a guide rail type drop hammer device for simulating lateral impact on a component, a support device for realizing four-side simple support boundary conditions, an axial force loading device for applying uniform axial force and a rigid foundation platform. The method comprises the following steps: firstly, enabling the member to reach a boundary condition of four-side simple support through a support device, then applying uniform horizontal axial pressure load to the member through a distribution beam, releasing a drop hammer when the axial force reaches a preset value and is kept stable, and carrying out a test on the four-side simple support member under the coupling action of the axial load and lateral impact.

Description

Technical Field

[0001] The present invention relates to the technical field of component disaster simulation devices, and in particular to a test system and method for simulating a four-side simply supported component being subjected to a lateral impact. Background Art

[0002] In addition to bearing static loads, structural components may also be subject to disasters such as impacts and explosions during their entire life cycle. For example, protective walls and bridge piers are subject to accidental impacts by vehicles; high-rise buildings are subject to accidental impacts by aircraft; flood control walls and offshore platforms are subject to accidental impacts by ships or icebergs; nuclear containment vessels are subject to impacts by missiles during war, etc. Double steel plate concrete composite wall panels are currently widely used in nuclear power plants, housing construction, submarine tunnels, offshore platforms and protective structures. In the face of strong dynamic characteristics of the impact problem, if it is not fully considered in the design stage, the structure may be suddenly damaged during service, causing huge losses. Especially for important buildings such as nuclear power plants, once the structure is damaged or destroyed by internal or external collisions, it may also cause secondary disasters, causing serious harm to society and the environment.

[0003] However, in actual engineering, before the building structure components are subjected to accidental loads such as impact and earthquake, they are often in a loaded working state because they have to bear their own weight or loads transferred from the upper structure. In view of this, it is necessary to consider the design of components under the coupling of axial pressure and impact load to improve the integrity and anti-collapse ability of the structure.

[0004] At present, there are test devices for beam and column components under two-side fixed or two-side simply supported boundary conditions subjected to free fall impact of a drop hammer. However, in the prior art, there is no test loading system and related test method that can realize the guide rail type impact of components such as wall panels with four-side simply supported boundaries under the combined action of axial force and lateral impact load. Therefore, a test system and method for simulating lateral impact of four-side simply supported components are provided. Summary of the invention

[0005] The purpose of the present invention is to address the defects of the prior art and provide a test system and method for simulating a four-side simply supported member subjected to a lateral impact, so as to solve the problems raised by the above-mentioned background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a test system for simulating a four-side simply supported member subjected to a lateral impact, comprising a guide rail type drop hammer device for simulating a member subjected to a lateral impact, a support device for realizing a four-side simply supported boundary condition, an axial force loading device for applying a uniform axial force, and a rigid foundation platform.

[0007] Both ends of the top of the rigid foundation platform are fixedly connected with reaction frames;

[0008] The guide rail type drop hammer device is composed of a vertical guide rail and a drop hammer, and a gap is provided between the vertical guide rail and the drop hammer to ensure that the friction between the two is sufficiently small; the drop hammer is composed of a counterweight and a hemispherical hammer head, and a strain type force sensor is arranged above the impact surface of the hammer head. The strain type force sensor is connected to a dynamic acquisition instrument and is used to measure the contact force between the impact surface of the drop hammer and the component;

[0009] The support device is composed of plain round steel bars, high-strength bolts and a "U"-shaped steel frame, and is used to achieve the boundary condition of four-side simple support;

[0010] The "U"-shaped steel frame is composed of an upper steel frame and a lower steel frame, and the upper steel frame and the lower steel frame are fixed on a rigid foundation platform by high-strength bolts. A component is placed between the upper steel frame and the lower steel frame, and the two ends of the component that bear the axial pressure load extend out of the "U"-shaped steel frame and have circular holes at the positions where the high-strength bolts pass through;

[0011] Plain round steel bars are welded around the contact surfaces between the upper steel frame and the lower steel frame and the components to ensure that the components can rotate around the axis under lateral impact loads to achieve the effect of simply supported boundaries on four sides. The "U"-shaped steel frame, the components with reserved holes and the rigid foundation platform are connected together by high-strength bolts;

[0012] The axial force loading device includes a distribution beam, an axial force sensor, a disc spring sheet, a rigid support, a hydraulic jack and a reaction frame;

[0013] The hydraulic jack is installed on the reaction frame by bolts, the distribution beam is reinforced with stiffening ribs, and a shallow circular groove is provided on one side of the distribution beam flange. One end of the axial force sensor is pressed into the groove on one side of the distribution beam flange, and the other end of the axial force sensor is in contact with the flange on the rigid support, and the gap between the disc spring sheet, the flange and the axial force sensor on the rigid support is reduced by the hydraulic jack.

[0014] As a preferred technical solution of the present invention, the hemispherical hammer head is made of rigid material, the hemispherical hammer head and the counterweight are connected by threads, and an electromagnetic device is installed on the top of the vertical guide rail.

[0015] As a preferred technical solution of the present invention, the center lines of the hydraulic jack, disc spring leaf, axial force sensor and distribution beam coincide with the centroid of the side surface of the component.

[0016] As a preferred technical solution of the present invention, the diameter of the circular hole reserved on the component is not less than twice the diameter of the high-strength screw hole, and the diameter of the plain round steel bar on the "U"-shaped steel frame is 15mm to 25mm.

[0017] As a preferred technical solution of the present invention, the length of the distribution beam is not less than the side length of the axial force loading end of the component, the thickness of the shallow circular groove processed on the distribution beam is 1 / 3 of the thickness of the distribution beam flange, and the length of the component along the axial force direction is greater than the length of the "U"-shaped steel frame.

[0018] As a preferred technical solution of the present invention, the component includes a reinforced concrete wall panel, a steel-concrete composite wall panel or an ECC double steel plate concrete mixed structure wall panel.

[0019] As a preferred technical solution of the present invention, the component passes through the vertical guide rail and the drop weight on the top of the vertical guide rail is on the same vertical line as the mid-span position of the component on the component.

[0020] A test method for simulating a four-side simply supported member subjected to a lateral impact is implemented using a test system, and the specific steps are as follows:

[0021] Step 1: Place the component on top of the lower steel frame, adjust the component position so that the high-strength bolts pass through the reserved circular holes on the component, press the upper steel frame onto the component and tighten the high-strength bolts;

[0022] Step 2: Raise the drop hammer along the vertical guide rail to a predetermined height above the component, and the drop hammer impact position is the mid-span of the component;

[0023] Step 3: Apply axial pressure load through the hydraulic jack, the disc spring sheet is gradually compressed, and the axial force on the component gradually increases. The dynamic acquisition instrument connected to the axial force sensor and the computer monitor the axial force value. After reaching the predetermined axial force value, maintain the oil pressure to keep the axial force relatively stable;

[0024] Step 4: Check whether the high-strength bolts are loose. If they are loose, tighten them with a wrench. After confirming that the acquisition equipment is working normally, perform an impact test.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can simulate the actual working condition of a four-sided simply supported member subjected to lateral impact under axial compression, that is, firstly, the member is made to reach the boundary condition of four-sided simple support through the support device, and then a uniform horizontal axial compression load is applied to the member through the distribution beam. When the axial force reaches a predetermined value and remains stable, the drop hammer is released to conduct a test of the four-sided simply supported member under the coupling effect of axial load and lateral impact.

[0027] 2. The present invention is applicable to testing of various wall panel components, including various common types of wall panels and various new wall panels, including reinforced concrete wall panels, steel-concrete composite wall panels, and external ECC double steel plate concrete mixed structure wall panels.

[0028] 3. The present invention is very simple and convenient for installing and disassembling components, the construction is convenient, and the component force is reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a front view schematic diagram of the impact system of the present invention;

[0030] Figure 2 It is a top view schematic diagram of the impact device of the present invention;

[0031] Figure 3 It shows the support details on the side where the axial force is applied (section AA);

[0032] Figure 4 This is the detailed drawing of the support on the side without axial force (BB section);

[0033] Figure 5 Layout diagram of displacement meter and strain gauge;

[0034] Figure 6 Provide detailed drawings of distributed beam construction;

[0035] (a) Front view of the distribution beam; (b) Top view of the distribution beam; (c) Left view of the distribution beam.

[0036] 1-counterweight, 2-hemispherical hammer head, 3-vertical guide rail, 4-component, 5-plain round steel bar, 6-round hole reserved on the component, 7-high-strength bolts, 8-"U" shaped steel frame, 9-rigid foundation platform, 10-distribution beam, 11-axial force sensor, 12-disc spring leaf, 13-rigid support, 14-hydraulic jack, 15-reaction frame, 16-high-strength bolt hole, 17-mid-span position of the component, 18-groove. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0038] Example: See Figure 1-6 The present invention provides a technical solution: a test system for simulating a four-side simply supported component subjected to a lateral impact, comprising a rail-type drop hammer device for simulating a component subjected to a lateral impact, a support device for realizing a four-side simply supported boundary condition, an axial force loading device for applying a uniform axial force, and a rigid foundation platform 9.

[0039] Both ends of the top of the rigid foundation platform 9 are fixedly connected with reaction frames 15;

[0040] The guide rail type drop hammer device is composed of a vertical guide rail 3 and a drop hammer, and a gap is provided between the vertical guide rail 3 and the drop hammer to ensure that the friction between the two is small enough; the drop hammer is composed of a counterweight 1 and a hemispherical hammer head 2, and a strain force sensor is arranged above the impact surface of the hammer head 2, and the strain force sensor is connected to the dynamic acquisition instrument to measure the contact force between the impact surface of the drop hammer and the component 4, the hemispherical hammer head 2 is made of rigid material, and the hemispherical hammer head 2 is connected to the counterweight 1 by threads, and an electromagnetic device is installed on the top of the vertical guide rail 3 for fixing the drop hammer, and when the electromagnetic device is powered on, the drop hammer is magnetically attracted, and when the electromagnetic device is powered off, the drop hammer will automatically fall;

[0041] The support device is composed of plain round steel bars 5, high-strength bolts 7 and a "U"-shaped steel frame 8, which is used to achieve the boundary condition of four-side simple support;

[0042] The "mouth" shaped steel frame 8 is composed of an upper steel frame and a lower steel frame, which are fixed on a rigid foundation platform 9 by high-strength bolts 7, and a component 4 is placed between the upper steel frame and the lower steel frame, and both ends of the component 4 that bear the axial pressure load extend out of the "mouth" shaped steel frame 8 and circular holes 6 are provided at the positions where the high-strength bolts 7 pass through;

[0043] Plain round steel bars 5 are welded around the contact surfaces between the upper steel frame and the lower steel frame and the component 4 to ensure that the component 4 can rotate around the axis 5 under the lateral impact load to achieve the effect of a four-sided simply supported boundary. The "mouth"-shaped steel frame 8, the component 4 with reserved holes and the rigid foundation platform 9 are connected together by high-strength bolts 7;

[0044] The axial force loading device includes a distribution beam 10, an axial force sensor 11, a disc spring sheet 12, a rigid support 13, a hydraulic jack 14 and a reaction frame 15;

[0045] The hydraulic jack 14 is installed on the reaction frame 15 by bolts, the distribution beam 10 is reinforced with stiffening ribs, and a shallow circular groove 18 is provided on one side of the flange of the distribution beam 10. One end of the axial force sensor 11 is pressed against the groove 18 on one side of the flange of the distribution beam 10, and the other end of the axial force sensor 11 is in contact with the flange on the rigid support 13, and the hydraulic jack 14 is used to reduce the gap between the disc spring sheet 12, the flange and the axial force sensor 11 on the rigid support 13; the center line of the hydraulic jack 14, the disc spring sheet 12, the axial force sensor 11 and the distribution beam 10 coincides with the centroid of the side surface of the component 4.

[0046] The diameter of the reserved circular hole 6 on the component 4 is not less than twice the diameter of the high-strength screw hole 16, and the diameter of the plain round steel bar 5 on the "mouth" shaped steel frame 8 is 15mm to 25mm. The length of the distribution beam 10 is not less than the side length of the axial force loading end of the component 4, and the thickness of the shallow circular groove 18 processed on the distribution beam 10 is 1 / 3 of the thickness of the distribution beam flange. The length of the component 4 along the axial force direction is greater than the length of the "mouth" shaped steel frame 8. The component 4 passes through the vertical guide rail 3 and the drop weight at the top of the vertical guide rail 3 is on the same vertical line as the mid-span position 17 on the component 4.

[0047] A test method for simulating a four-side simply supported member subjected to a lateral impact is implemented using a test system, and the specific steps are as follows:

[0048] Step 1: Place the component 4 above the lower steel frame, and adjust the position of the component 4 so that the high-strength bolts 7 pass through the circular holes 6 reserved on the component 4, press the upper steel frame onto the component 4 and tighten the high-strength bolts 7;

[0049] Step 2: Raise the drop hammer along the vertical guide rail 3 to a predetermined height above the component 4, and the drop hammer impact position is the mid-span 17 of the component;

[0050] Step 3: Apply axial pressure load through the hydraulic jack 14, the disc spring sheet 12 is gradually compressed, and the axial force on the component 4 is gradually increased. The dynamic acquisition instrument and computer connected to the axial force sensor 11 monitor the axial force value. After reaching the predetermined axial force value, maintain the oil pressure so that the axial force remains relatively stable;

[0051] Step 4: Check whether the high-strength bolt 7 is loose. If it is loose, tighten it with a wrench. After confirming that the acquisition equipment is working normally, perform the impact test.

[0052] Working principle: Test system and method for simulating lateral impact of four-sided simply supported members, such as Figure 1 As shown, in order to simulate the actual working condition of a four-sided simply supported member bearing vertical load, an oil hydraulic jack 14 is used to apply axial pressure to the member 4. In order to prevent the member 4 from axially shortening under lateral impact and causing excessive unloading of the axial force, a disc spring sheet 12 is arranged between the jack and the member 4. When axial deformation occurs, the disc spring sheet 12 releases elastic potential energy to continuously provide axial pressure to the member 4. In order to ensure that the axial force is evenly applied to the member 4, a rigid distribution beam 10 is arranged between the disc spring sheet 12 and the member 4. At the same time, in order to ensure that the axial force action line coincides with the centroid of the member, the axial force sensor 11 is placed in the shallow circular groove 18 at the centroid of the flange of the distribution beam. The axial force sensor 11 is connected to an external dynamic acquisition instrument and a computer, and the axial pressure loading value can be monitored in real time. When the axial force reaches a predetermined value and remains stable, the four-sided simply supported member is tested under the coupling of axial load and impact.

[0053] The impact test device includes a vertical guide rail 3 and a drop hammer that falls along the guide rail. The drop hammer consists of a hammer body (counterweight 1) with variable mass, a hemispherical hammer head 2, and an impact force sensor. The counterweight 1 is connected to the hemispherical hammer head 2 by a precision-machined thread, and different-shaped hammer heads can also be replaced according to test requirements. The impact force sensor is located in the upper-middle part of the hammer head and is a strain-type force sensor made based on the Wheatstone bridge principle. There is a certain gap between the drop hammer and the guide rail, and the guide rail is coated with lubricating oil to ensure that the frictional energy consumption during the fall of the drop hammer is small enough, and the impact energy loss of the drop hammer is within a reasonable range. Before the impact occurs, the drop hammer is fixed at a certain height by an electromagnetic device. The impact force sensor on the hammer head is externally connected to a dynamic acquisition instrument and a computer. The dynamic acquisition instrument has a high sampling frequency and can accurately collect the time history curve of the impact force between the drop hammer and the component.

[0054] After checking that the support device and the axial force loading device are in normal working conditions, start the impact test device to simulate the actual situation of a four-sided simply supported component suffering from accidental load impact under a loaded state.

[0055] Determine the component 4 to be tested, check the number of component 4 and attach strain gauges, place component 4 between the upper steel frame and the lower steel frame, adjust the position of component 4 and the "square" steel frame 8 so that the impacted part of component 4 is at the mid-span position 17 of the component, and then pass high-strength bolts 7 through the high-strength bolt holes 16 around the "square" steel frame 8 and the round holes 6 reserved in the component, and then fix component 4 to the "square" steel frame 8 and the rigid foundation platform 9 to ensure that the support does not displace during the test. Four smooth round steel bars 5 are welded on each "square" steel frame 8. Component 4 can rotate around the axis under axial force-impact load to achieve the boundary conditions of four-sided simple support. After the boundary supports are installed, install the dynamic displacement gauge under component 4, and connect the strain gauge wires and the displacement gauge wires to the dynamic strain acquisition instrument.

[0056] As Figure 2 shown, the two ends of component 4 where the axial force is applied must extend out of the steel frame 8 to ensure that the axial force does not act on the "square" steel frame 8. The uniform loading of the axial force is achieved through a distribution beam 10 with a length not less than the length of the component, and the thickness of the shallow circular groove processed on the distribution beam 10 is 1 / 3 of the flange thickness of the distribution beam. The axial force sensor 11 placed in the groove is aligned horizontally with the spring disc 12 and the oil jack 14 on the rigid support 13. Install the axial force sensor 11 between the disc spring 12 and the distribution beam 10, and connect the axial force sensor wires to the dynamic strain acquisition instrument. Slowly adjust the axial loading device, and the horizontal axial force gradually increases. After the axial force is loaded to the predetermined value, adjust the oil pressure to maintain the stability of the axial force.

[0057] Lift the drop hammer to the specified height, check whether the test acquisition instrument and test signal are normal, place the high-speed camera in front of the component, and adjust the instrument so that it can clearly observe the entire impact system. Check whether the acquisition channel of the dynamic strain collector is working properly. Finally, release the drop hammer, and the drop hammer slides down along the track to complete the impact. Unload the axial force and replace the component. Extract data from the dynamic strain collector and high-speed camera and perform data processing.

[0058] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A test system for simulating a four-side simply supported member subjected to a lateral impact, characterized in that: It includes a guide rail type drop hammer device for simulating the lateral impact on components, a support device for realizing the four-sided simply supported boundary condition, an axial force loading device for applying uniform axial force, and a rigid foundation platform (9). Reaction frames (15) are fixedly connected to both ends at the top of the rigid foundation platform (9). The guide rail type drop hammer device consists of a vertical guide rail (3) and a drop hammer, with a gap between the vertical guide rail (3) and the drop hammer; the drop hammer is composed of a counterweight (1) and a hemispherical hammer head (2), and a strain type force sensor is arranged above the impact surface of the hammer head (2), and the strain type force sensor is connected to a dynamic acquisition instrument for measuring the contact force between the impact surface of the drop hammer and the component (4). The support device is composed of a smooth round steel bar (5), a high-strength bolt (7), and a "mouth"-shaped steel frame (8). The "mouth"-shaped steel frame (8) is composed of an upper steel frame and a lower steel frame. The upper steel frame and the lower steel frame are fixed on the rigid foundation platform (9) through high-strength bolts (7). A component (4) is placed between the upper steel frame and the lower steel frame. The two ends of the component (4) bearing the axial compression load extend out of the "mouth"-shaped steel frame (8) and round holes (6) are opened at the positions where the high-strength bolts (7) pass through. Smooth round steel bars (5) are welded around the contact surfaces of the upper steel frame and the lower steel frame with the component (4) respectively to ensure that the component (4) can rotate around the axis (5) under the lateral impact load. The "mouth"-shaped steel frame (8), the component (4) with reserved holes, and the rigid foundation platform (9) are connected together through high-strength bolts (7). The axial force loading device includes a distribution beam (10), an axial force sensor (11), a disc spring piece (12), a rigid support (13), an oil pressure jack (14), and a reaction frame (15). The oil pressure jack (14) is installed on the reaction frame (15) through bolts. The distribution beam (10) is reinforced with stiffeners, and a shallow circular groove (18) is arranged on one side of the flange of the distribution beam (10). One end of the axial force sensor (11) abuts against the groove (18) on one side of the flange of the distribution beam (10), and the other end of the axial force sensor (11) contacts the flange on the rigid support (13), and the gap between the disc spring piece (12), the flange, and the axial force sensor (11) on the rigid support (13) is reduced through the oil pressure jack (14).

2. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The hemispherical hammer head (2) is processed from a rigid material. The hemispherical hammer head (2) and the counterweight (1) are connected by threads, and an electromagnetic device is installed at the top of the vertical guide rail (3).

3. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The center lines of the oil pressure jack (14), the disc spring piece (12), the axial force sensor (11), and the distribution beam (10) coincide with the centroid of the side surface of the component (4).

4. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The diameter of the round holes (6) reserved on the component (4) is not less than 2 times the diameter of the high-strength screw holes (16), and the diameter of the smooth round steel bars (5) on the "mouth"-shaped steel frame (8) is 15 mm to 25 mm.

5. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The length of the distribution beam (10) is not less than the side length of the axial force loading end of the component (4), the thickness of the shallow circular groove (18) processed on the distribution beam (10) is 1 / 3 of the thickness of the distribution beam flange, and the length of the component (4) along the axial force direction is greater than the length of the "U"-shaped steel frame (8).

6. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The component (4) comprises a reinforced concrete wall panel, a steel-concrete composite wall panel or an ECC double steel plate concrete mixed structure wall panel.

7. The test system for simulating lateral impact of a four-side simply supported member according to claim 1, characterized in that: The component (4) passes through the vertical guide rail (3) and the drop weight at the top of the vertical guide rail (3) is on the same vertical line as the component mid-span position (17) on the component (4).

8. A test method for simulating a lateral impact on a four-side simply supported member, characterized in that: The test system according to any one of claims 1 to 7 is used for implementation, and the specific steps are as follows: Step 1: Place the component (4) above the lower steel frame, adjust the position of the component (4) so ​​that the high-strength bolts (7) pass through the circular holes (6) reserved on the component (4), press the upper steel frame onto the component (4) and tighten the high-strength bolts (7); Step 2: Raise the drop hammer along the vertical guide rail (3) to a predetermined height above the component (4), and the drop hammer impact position is the mid-span of the component (17); Step 3: applying an axial pressure load through the hydraulic jack (14), the disc spring sheet (12) is gradually compressed, and the axial force on the component (4) is gradually increased. The dynamic data acquisition instrument and computer connected to the axial force sensor (11) monitor the axial force value. After reaching the predetermined axial force value, the oil pressure is maintained so that the axial force remains relatively stable; Step 4: Check whether the high-strength bolts (7) are loose. If they are loose, tighten them with a wrench. After ensuring that the acquisition equipment is working properly, perform the impact test.

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