Testing device for dynamic stability of simply supported beam

Abstract

A test device for the dynamic stability of a simply supported beam comprises a base, two ends of the base are respectively provided with a fixed hinge support and a sliding hinge support, the simply supported beam is connected between the upper parts of the fixed hinge support and the sliding hinge support, one end of the sliding hinge support is connected with a transition part, and the other end of the sliding hinge support is connected with a bearing. The transition part is sequentially connected with the force sensor and the vibration exciter through the screw rod; the vibration exciter applies an external force to the end of the sliding hinged support, the force acts on the sliding hinged support through the force sensor and the transition part, the sliding hinged support slides on the sliding rail, the steel column rotates through the bearing, the beam is bent, and then the actual dynamic stability condition of the simply supported beam in engineering is simulated. The sliding block and the sliding rail are additionally arranged on the hinged support at one end, so that the hinged support at one end is changed into a support capable of freely sliding, the characteristics of a simply supported beam movable support are perfectly simulated, and the device has the technical effect that result data of a simulation experiment are more suitable for actual engineering conditions.

Description

Technical Field

[0001] The utility model belongs to the technical field of simply supported beams, and particularly relates to a testing device for the dynamic stability of simply supported beams. Background Art

[0002] Structural dynamic instability is a common engineering phenomenon. Dynamic instability is extremely harmful and may lead to structural damage. It is necessary to avoid this situation in engineering structure design. In order to fully understand the physical phenomenon of structural dynamic instability, it is necessary to provide a test device for structural dynamic instability to meet the needs of engineering structure teaching, design and scientific research. The dynamic instability of a simply supported beam is a typical example of engineering dynamic instability. At present, no relevant engineering teaching test device has been found. The specific details of the dynamic instability test device of a simply supported beam involved in relevant scientific research are unknown. The existing load loading method is to directly load the axial direction of the simply supported beam. Since the loading direction is generally difficult to be consistent with the axis of the beam, it is easy to produce eccentricity, thereby generating additional bending moment, interfering with the test results, and it is difficult to accurately simulate the dynamic instability of the structure. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the utility model is to provide a test device for the dynamic stability of a simply supported beam. By arranging sliders and slide rails on the two fixed hinge supports of the traditional simply supported beam model, the hinge support at one end is transformed into a freely sliding support, which perfectly simulates the characteristics of the dynamic support of the simply supported beam to meet the needs of actual engineering structure teaching, design and research. The utility model has the technical effect of making the result data of the simulation experiment more in line with the actual engineering situation.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A test device for the dynamic stability of a simply supported beam comprises a base 9, with a fixed hinge support 4 and a sliding hinge support 6 respectively mounted at both ends of the base 9, a simply supported beam 1 is connected between the upper parts of the fixed hinge support 4 and the sliding hinge support 6, one end of the sliding hinge support 6 is connected to a transition component 5, and the transition component 5 is connected to a force sensor 8 and an exciter 7 in sequence through a screw.

[0006] The sliding hinge support 6 includes a sliding hinge support pad 61, a sliding rail 62 is installed above the sliding hinge support pad 61, a slider 63 matching the sliding rail 62 is installed above the sliding rail 62, and two parallel arranged first convex steel block assemblies 64 are installed above the slider 64. The first convex steel block assembly 64 is connected to one end of the simply supported beam 1.

[0007] The fixed hinge support 4 includes a fixed hinge support cushion block 41 , on which two second convex steel block assemblies 42 arranged in parallel are arranged, and the second convex steel block assemblies 42 are connected to the other end of the simply supported beam 1 .

[0008] The transition component 5 is a rectangular steel member, with holes formed on both sides and the middle of the transition component 5. The holes on both sides of the transition component 5 are connected to one side of the first convex steel block assembly 64 through bolts, and the middle hole of the transition component 5 is connected to the force sensor 8 and the exciter 7 in sequence through a screw.

[0009] The first convex steel block assembly 64 and the second convex steel block assembly 42 are both provided with holes at the upper center, and miniature bearings are installed in the holes. The two first convex steel block assemblies 64 and the two second convex steel block assemblies 42 are connected to the steel column 2 through miniature bearings, and the steel column 2 is respectively connected to the two ends of the simply supported beam 1.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] 1) Due to the addition of the slider 63 and the slide rail 62, the hinge support at one end of the utility model is transformed into a freely slidable sliding hinge support 6, which perfectly simulates the characteristics of the dynamic support of the simply supported beam.

[0012] 2) The utility model adopts standard micro bearings to connect the supports at both ends of the simply supported beam 1, so that both ends of the simply supported beam 1 structure can rotate freely, perfectly simulating the hinge support characteristics of the structure.

[0013] 3) In the present invention, a rigid slider 63 is used to connect the test beam model and the vibrator 7. The vibrator 7 directly pushes the slider 63 to run on the slide rail 62, thereby ensuring the linear motion of the slider 63. As long as the position elevation of the hinge support is kept consistent during machining, the loading direction can be guaranteed to be consistent with the axis of the simply supported beam, thereby avoiding the interference of additional bending moment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a front view of the test device of the utility model.

[0015] Figure 2 It is a top view of the test device of the utility model.

[0016] Figure 3 Schematic diagram of the simply supported beam model structure.

[0017] Figure 4 Schematic diagram of the structure of the second convex steel block assembly 42 / the first convex steel block assembly 64; wherein, Figure 4 (a) is the front view, Figure 4 (b) is a side view, Figure 4 (c) is a top view.

[0018] Figure 5 It is a structural diagram of a fixed hinge support pad 41; wherein, Figure 5 (a) is the front view, Figure 5 (b) is a side view, Figure 5 (c) is a top view.

[0019] Figure 6 is a schematic diagram of the structure of the transition component 5; wherein, Figure 6 (a) is the front view, Figure 6 (b) is a side view, Figure 6 (c) is a top view.

[0020] Figure 7 It is a structural schematic diagram of the sliding hinge support pad 61; wherein, Figure 7 (a) is the front view, Figure 7 (b) is a side view, Figure 7 (c) is a top view.

[0021] Among them, 1. simply supported beam; 2. steel column; 4. fixed hinge support; 41. fixed hinge support pad; 42. second convex steel block assembly; 5. transition component; 6. sliding hinge support; 61. sliding hinge support pad; 62. slide rail; 63. slider; 64. first convex steel block assembly; 7. exciter; 8. force sensor; 9. base. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0023] like Figure 1 , Figure 2 As shown, a test device for the dynamic stability of a simply supported beam includes a base 9, with a fixed hinge support 4 and a sliding hinge support 6 respectively installed at both ends of the base 9, a simply supported beam 1 is connected between the upper parts of the fixed hinge support 4 and the sliding hinge support 6, one end of the sliding hinge support 6 is connected to a vibration exciter 7, and a force sensor 8 is arranged between the vibration exciter 7 and the sliding hinge support 6.

[0024] Due to the need for real-time monitoring of the experiment, a force sensor 8 is added between the transition component 5 and the exciter 7. The specific connection structure is: a screw fixed on the transition component 5 is connected to one end of the force sensor 8, and the other end of the force sensor 8 is connected to the exciter 7 through the screw. In this way, the exciter 7 can load the simply supported beam 1 in a way that does not deviate from the center of mass direction, thereby more accurately simulating the actual engineering situation.

[0025] The fixed hinge support 4 includes two second convex steel block assemblies 42 arranged in parallel, both of which are fixed on the fixed hinge support pad 41. A standard miniature bearing is installed in the second convex steel block assembly 42. The inner hole of the miniature bearing is connected to one end of the simply supported beam 1 through the steel column 2 (connected by transition fit); the sliding hinge support 6 is similar to the fixed hinge support 4. The sliding hinge support 6 is fixed on the sliding hinge support pad 61, but a standard guide rail 62 is installed on the sliding hinge support pad 61, and a slider 63 is installed above the guide rail 62. Two first convex steel block assemblies 64 are installed above the slider 64. Transition components 5 are installed on the two first convex steel block assemblies 64 for connecting with the vibrator 7. A force sensor 8 is installed between the transition component 5 and the vibrator 7. Finally, the fixed hinge support pad 41, the sliding hinge support pad 61 and the vibrator 7 are installed on the base 9.

[0026] The sliding hinge support pad 61 is convex (for details, see Figure 7 ), the convex surface size of the sliding hinge support pad 61 matches the size of the slide rail 62, which just fixes the slide rail 62 on the sliding hinge support pad 61, and is also used to fix the transition component 5.

[0027] The simply supported beam 1 of the utility model adopts an elastic rectangular steel sheet with a length of 500 mm, a width of 10 mm and a thickness of 0.5-0.7 mm, and the diameter of two steel columns 2 used for connecting the two ends of the rectangular steel sheet is 5 mm.

[0028] The fixed hinge support pad 41 is the basis of the fixed hinge support 4 and is placed on the base 9 .

[0029] The sliding hinge support pad 61 is the basis of the sliding hinge support 6 and is placed on the base 9 .

[0030] The force sensor 8 transmits the experimental related data to the computer for visualization.

[0031] The exciter 7 is an important component of the dynamic stability test and provides vibrations of different frequencies.

[0032] The base 9 is made of a steel plate and is mainly used to fix the metal pedestal and is the fixed foundation of the test device.

[0033] like Figure 3 As shown, it is a simply supported beam model, which can respond to vibrations at different frequencies in the dynamic stability test and show vibration modes. The simply supported beam end shaft (steel column 2) is connected, with a diameter of 5mm. The two ends of the steel column 2 are double-sided welded with elastic rectangular steel sheets and matched with the micro bearing transition.

[0034] like Figure 4The three views of the convex steel block assembly are shown in FIG. The convex steel block assembly has a central hole with a hole diameter of 9-12 mm, which is transitionally matched with the miniature bearing and has double holes drilled at the bottom. The component is mainly used to fix the simply supported beam model.

[0035] like Figure 5 As shown, it is a front view and a side view of the metal pedestal at the end of the fixed hinge support pad 41. The top and bottom of the metal pedestal are opened, the top hole is used to fix the second convex steel block assembly 42, and the bottom hole is used to fix it on the base 9.

[0036] like Figure 6 The figure shows a three-view diagram of the transition component 5. Double holes are provided at both ends for connecting the sliding hinge support 6. A hole is provided in the center of the side for connecting the exciter 7 via a screw.

[0037] like Figure 7 , which is a schematic structural diagram of a sliding hinge support pad 61 , which is used to fix a slide rail 62 so that the sliding hinge support 6 can slide on the slide rail 62 .

[0038] The working principle of the utility model is:

[0039] The exciter 7 applies an external force to the end of the sliding hinge support 6, and the force acts on the sliding hinge support 6 through the force sensor 7 and the transition component 5. At this time, the sliding hinge support 6 will slip on the slide rail 62, and the steel column 2 at the hinge support end will rotate through the bearing, causing the beam to bend, thereby simulating the actual dynamic stability of the simply supported beam in engineering.

[0040] The force sensor 8 records the magnitude of the loading force in real time. The exciter 7 can be driven by a signal generator and a power amplifier to generate a periodic exciting force to axially push the simply supported beam 1. By adjusting the frequency of the signal generator and the strength of the signal, the simply supported beam 1 can be caused to undergo dynamic instability (a strong lateral vibration). This vibration can be measured by a peripheral laser displacement sensor. By observing and studying the amplitude and frequency of the applied axial force, as well as the properties of the dynamic instability response of the simply supported beam, the nature of the dynamic instability of the structure can be understood.

[0041] The embodiments disclosed in the present utility model are preferred embodiments, but are not limited to them. Ordinary technicians in this field can easily understand the spirit of the present utility model based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present utility model, they are all within the protection scope of the present utility model.

Claims

1. A test device for the dynamic stability of a simply supported beam, comprising a base (9), characterized in that: A fixed hinge support (4) and a sliding hinge support (6) are respectively installed at both ends of the base (9); a simply supported beam (1) is connected between the upper parts of the fixed hinge support (4) and the sliding hinge support (6); one end of the sliding hinge support (6) is connected to a transition component (5); and the transition component (5) is connected to a force sensor (8) and an exciter (7) in sequence through a screw rod.

2. A test device for dynamic stability of simply supported beams according to claim 1, characterized in that: The sliding hinge support (6) includes a sliding hinge support pad (61), a slide rail (62) is installed above the sliding hinge support pad (61), a slider (63) matching the slide rail (62) is installed above the slide rail (62), and two first convex steel block assemblies (64) arranged in parallel are installed above the slider (63), and the first convex steel block assembly (64) is connected to one end of the simply supported beam (1).

3. A test device for dynamic stability of simply supported beams according to claim 2, characterized in that: The fixed hinge support (4) comprises a fixed hinge support cushion block (41), on which two second convex steel block assemblies (42) arranged in parallel are arranged, and the second convex steel block assemblies (42) are connected to the other end of the simply supported beam (1).

4. A test device for dynamic stability of simply supported beams according to claim 1 or 2, characterized in that: The transition component (5) is a rectangular steel member, and holes are provided on both sides and in the middle of the transition component (5). The holes on both sides of the transition component (5) are connected to one side of the first convex steel block assembly (64) through bolts, and the middle hole of the transition component (5) is connected to the force sensor (8) and the exciter (7) in sequence through a screw.

5. The test device for dynamic stability of simply supported beams according to claim 3, characterized in that: The first convex steel block assembly (64) and the second convex steel block assembly (42) are both provided with holes at their upper centers, and miniature bearings are installed in the holes. The two first convex steel block assemblies (64) and the two second convex steel block assemblies (42) are connected to the steel column (2) via the miniature bearings, and the steel column (2) is respectively connected to the two ends of the simply supported beam (1).

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