A nonlinear fender simulation device

Abstract

The application provides a nonlinear fender simulation device, which comprises a base plate, a crossbeam assembly arranged on the top of one side of the base plate, a collision block assembly movably connected to the crossbeam assembly, a first spring assembly connected to the collision block assembly through a first connecting rope, a counterweight block assembly arranged on the side of the base plate away from the crossbeam assembly and connected to the first spring assembly through a second connecting rope, a tension sensor arranged between the first spring assembly and the counterweight block assembly and mounted on the second connecting rope, and the counterweight block assembly comprising a counterweight block connected to the second connecting rope and a shell arranged directly below the counterweight block, wherein a second spring assembly is arranged in the shell and connected to the counterweight block through a third connecting rope. The application has the following advantages: the application can simulate the nonlinear characteristics of actual fenders, and has the advantages of simple structure, simple calibration, high speed, high precision and the like.

Description

Technical Field

[0001] This invention relates to the field of fender simulation technology, and in particular to a nonlinear fender simulation device. Background Technology

[0002] In marine engineering pool tests of ship mooring models, hull motion amplitude, maximum cable tension, and fender reaction force are the key metrics for determining a ship's safe berthing capability. While hull motion measurement and cable mechanical performance simulation are mature technologies, fender mechanical performance simulation and reaction force testing present greater challenges compared to motion measurement, cable performance simulation, and tension measurement. In practical engineering, fenders are primarily made of rubber, and the typical reaction force exhibits a non-monotonic relationship with the deformation rate. Figure 1 As shown, the curve consists of three parts: 1) In the stage where the fender deformation rate is 0% to 25%, the fender reaction force and deformation are approximately linearly related; 2) In the stage where the fender deformation rate is 25% to 50%, the fender only deforms and does not continue to provide excess reaction force; 3) In the stage where the fender deformation rate exceeds 50%, the fender reaction force and deformation are approximately linearly related. When conducting ship dock mooring model tests in marine engineering pools, the actual shape of the fender is usually not simulated. Different types of devices are used to simulate the mechanical properties of the fender and measure the fender reaction force. In the field of ship and marine engineering model testing, the commonly used fender simulation devices have limitations. They are not only complex in structure, but can only realize the simulation of monotonically increasing nonlinear stiffness. Therefore, in terms of simulating the non-monotonic increasing nonlinear characteristics of actual rubber fenders, there has never been a simulation device with good performance. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a nonlinear fender simulation device to solve the problem that the fender simulation devices commonly used in the prior art have limitations, such as complex structure and the inability to simulate only monotonically increasing nonlinear stiffness.

[0004] To achieve the above and other related objectives, the present invention provides the following technical solution:

[0005] A nonlinear fender simulation device includes a base plate, a crossbeam assembly on the top of one side of the base plate, a bumper assembly movably connected to the crossbeam assembly, a first spring assembly connected to the bumper assembly via a first connecting rope, and a counterweight assembly located on the side of the base plate away from the crossbeam assembly connected to the first spring assembly via a second connecting rope. A tension sensor is installed on the second connecting rope between the first spring assembly and the counterweight assembly. The counterweight assembly includes a counterweight connected to the second connecting rope and a housing located directly below the counterweight. A second spring assembly connected to the counterweight via a third connecting rope is disposed within the housing.

[0006] In one embodiment of the present invention, the crossbeam assembly includes two first supports mounted on the top of one side of the base plate and a crossbeam mounted between the two first supports and located above the base plate.

[0007] In one embodiment of the present invention, the contact block assembly includes a rocker arm movably connected to the crossbeam and a contact block mounted on the rocker arm. The base plate has an opening, one end of the rocker arm passes through the opening and is connected to the contact block, and the end of the rocker arm away from the contact block is connected to the first connecting rope. This technical solution allows the rocker arm to rotate on the crossbeam by touching the contact block, thereby pulling the first connecting rope to move.

[0008] In one embodiment of the present invention, the first spring assembly includes a first connecting post connected to the first connecting rope, a second connecting post connected to the second connecting rope, and a first spring installed between the first connecting post and the second connecting post, wherein a limiting rope is provided inside the first spring.

[0009] In one embodiment of the present invention, the second spring assembly includes a third connecting post connected to the third connecting rope, a fourth connecting post installed in the housing, and a second spring installed between the third connecting post and the fourth connecting post.

[0010] In one embodiment of the present invention, a support assembly located between the crossbeam assembly and the counterweight assembly is installed on the top of the base plate on the side away from the crossbeam assembly. The support assembly includes a second bracket installed on the base plate and a fixed pulley movably connected to the second bracket. The fixed pulley is slidably connected to the second connecting rope. In this technical solution, the fixed pulley can ensure the stability of the counterweight moving up and down.

[0011] As described above, the nonlinear fender simulation device of the present invention has the following beneficial effects:

[0012] This invention utilizes the collision between the hull and the collision block to cause the rocker arm to rotate, thereby pulling the first, second, and third connecting ropes. This causes the first spring in the first spring assembly and the second spring in the second spring assembly to elastically extend, while simultaneously causing the limiting rope to extend and the counterweight to move upward. At this time, the tension sensor measures the reaction force of the fender during the test, thus simulating the non-monotonic increasing nonlinear characteristics of the actual fender. Moreover, this invention not only has a simple structure but also has significant advantages such as easy and fast calibration and high accuracy. Attached Figure Description

[0013] Figure 1 The diagram shows a typical reaction force versus deformation rate curve for actual rubber fenders.

[0014] Figure 2The diagram shows the overall structure of the nonlinear fender simulation device disclosed in this embodiment of the invention.

[0015] Figure 3 The diagram shown is a schematic diagram of the first stage test of the nonlinear fender simulation device disclosed in this embodiment of the invention, showing the fender reaction force and deformation rate curves.

[0016] Figure 4 The diagram shown is a schematic diagram of the second-stage test of the nonlinear fender simulation device disclosed in this embodiment of the invention, which shows the fender reaction force and deformation rate curves.

[0017] Figure 5 The diagram shown is a schematic diagram of the third stage test of the fender reaction force and deformation rate curve of the nonlinear fender simulation device disclosed in this embodiment of the invention.

[0018] Component designation explanation

[0019] 1. Base plate; 2. Crossbeam assembly; 201. First bracket; 202. Crossbeam; 3. Block assembly; 301. Block; 302. Rocker arm; 4. First connecting rope; 5. First spring assembly; 501. First connecting column; 502. Second connecting column; 503. First spring; 504. Limiting rope; 6. Tension sensor; 7. Support assembly; 701. Fixed pulley; 702. Second bracket; 8. Counterweight; 9. Third connecting rope; 10. Housing; 11. Second spring assembly; 1101. Third connecting column; 1102. Fourth connecting column; 1103. Second spring; 12. Through port; 13. Second connecting rope. Detailed Implementation

[0020] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0021] Please see Figure 2This invention provides a nonlinear fender simulation device, including a base plate 1. The base plate 1 has multiple threaded holes. The base plate 1 is used to fix the entire simulation device to the plane of a dock model. A crossbeam assembly 2 is provided on the top of one side of the base plate 1. The crossbeam assembly 2 includes two first supports 201 installed on the top of one side of the base plate 1 and a crossbeam 202 installed between the two first supports 201 and located above the base plate 1. A stop block assembly 3 is movably connected to the crossbeam assembly 2. The stop block assembly 3 includes components movably connected to the crossbeam 202. The rocker arm 302 and the contact block 301 mounted on the rocker arm 302 are provided. The rocker arm 302 has a first through hole for the crossbeam 202 to pass through. The base plate 1 has a through opening 12. One end of the rocker arm 302 passes through the through opening 12 and is connected to the contact block 301. The end of the rocker arm 302 away from the contact block 301 is connected to the first connecting rope 4. The contact block 301 is the force contact surface between the simulation device and the moored ship. The length of the contact block 301 is made according to the actual fender thickness according to the test scale ratio. The rocker arm 302 can rotate freely around the crossbeam 202 on the support.

[0022] A first spring assembly 5 is connected to the bumper assembly 3 via a first connecting rope 4. The first spring assembly 5 is connected to a counterweight assembly located on the side of the base plate 1 away from the crossbeam assembly 2 via a second connecting rope 13. A tension sensor 6 is installed on the second connecting rope 13 between the first spring assembly 5 and the counterweight assembly. The tension sensor 6 is used to measure the reaction force of the fender during the test. The first spring assembly 5 includes a first connecting post 501 connected to the first connecting rope 4, a second connecting post 502 connected to the second connecting rope 13, and a first spring 503 installed between the first connecting post 501 and the second connecting post 502. The stiffness of the first spring 503 is... Figure 1 The stiffness of the first stage of the reaction force and deformation rate curve of the middle fender is the same. A limiting rope 504 is provided inside the first spring 503. The limiting rope 504 passes through the first spring 503, and one end of the limiting rope 504 is connected to the first connecting post 501, and the other end of the limiting rope 504 is connected to the second connecting post 502. The limiting rope 504 is also a rigid rope, and its length corresponds to... Figure 1 The length of the fender with a deformation rate of 25% is the sum of the initial length of the first spring 503.

[0023] The counterweight assembly includes a counterweight 8 connected to a second connecting rope 13 and a housing 10 located directly below the counterweight 8. The weight of the counterweight 8 is equal to the reaction force value corresponding to the fender deformation rate in the range of 25% to 50%. The housing 10 is rigidly connected to the dock plane by bottom bolts. A second spring assembly 11 is provided inside the housing 10 and connected to the counterweight 8 by a third connecting rope 9. The top of the housing 10 has a second through hole for the third connecting rope 9 to pass through, and the length of the third connecting rope 9 corresponds to... Figure 1The deformation amount in the 25% to 50% stage of the fender reaction force and deformation rate curve, as well as the fact that the first connecting rope 4, the second connecting rope 13, and the third connecting rope 9 are all rigid ropes, will not elongate or deform under force. The second spring assembly 11 includes a third connecting post 1101 connected to the third connecting rope 9, a fourth connecting post 1102 installed inside the housing 10, and a second spring 1103 installed between the third connecting post 1101 and the fourth connecting post 1102. The stiffness of the second spring 1103 is... Figure 1 The stiffness of the third stage of the reaction force and deformation rate curve of the middle fender is the same. Among them, the first connecting column 501 to the fourth connecting column 1102 are all rigid organic glass sheets. On the top of the base plate 1 on the side away from the crossbeam assembly 2, a support assembly 7 is installed between the crossbeam assembly 2 and the counterweight assembly. The support assembly 7 includes a second bracket 702 installed on the base plate 1 and a fixed pulley 701 movably connected to the second bracket 702. The fixed pulley 701 is slidably connected to the second connecting rope 13. The fixed pulley can ensure the stability of the counterweight moving up and down.

[0024] Specifically, during ship dock mooring trials, in Figure 1 The reaction force versus deformation rate curve shown is for the first stage, as follows: Figure 3 As shown, when the hull collides with the collision block 301, the nonlinear fender simulation device is subjected to force, the rocker arm 302 rotates, the first spring 503 extends and deforms, the limiting rope 504 is in a relaxed state and will not affect the extension of the first spring 503, and the tension measured by the tension sensor 6 is equal to the reaction force of the nonlinear fender simulation device on the hull.

[0025] exist Figure 1 The second stage of the reaction force versus deformation rate curve is shown below. Figure 4 As shown, when the hull collides with the collision block 301, and the reaction force of the nonlinear fender simulation device is greater than the reaction force corresponding to a deformation rate of 25%, the limiting rope 504 in the first spring 503 straightens, the first spring 503 no longer elongates and deforms, and at the same time, the counterweight 8 is pulled away from its initial position. Figure 1 During the stage of 25%-50% fender deformation rate, the third connecting rope 9 is in a slack state. The tension measured by the tension sensor 6 and the reaction force of the nonlinear fender simulation device on the hull are both equal to the weight of the counterweight 8. During this stage, the fender simulator only deforms and does not provide any extra reaction force.

[0026] exist Figure 1 In the third stage of the reaction force versus deformation rate curve shown, when the reaction force of the nonlinear fender simulation device is greater than the reaction force corresponding to 50% of the deformation rate, such as... Figure 5 As shown, the third connecting rope 9 is straightened, the second spring 1103 is stretched and deformed, and the tension measured by the tension sensor 6 and the reaction force of the nonlinear fender simulation device on the hull are equal to the sum of the weight of the counterweight 8 and the tension of the second spring 1103.

[0027] This invention utilizes the collision between the hull and the collision block 301 to rotate the rocker arm 302, thereby pulling the first connecting rope 4, the second connecting rope 13, and the third connecting rope 9. This causes the first spring 503 in the first spring assembly 5 and the second spring 1103 in the second spring assembly 11 to elastically extend, simultaneously causing the limiting rope 504 to extend and the counterweight 8 to move upward. At this time, the tension sensor 6 measures the reaction force of the fender during the test, thus simulating the non-monotonic increasing nonlinear characteristics of the actual fender. Furthermore, this invention has a simple structure, and the specific form of the device can be adjusted according to the actual situation of the dock and the berthed ship model, making it convenient for workers to install and disassemble. Moreover, this invention uses the tension sensor 6 to measure pressure: the experimental nonlinear fender simulation device changes the traditional method of using pressure sensors to measure the reaction force of the fender. Before the device is used, it is not necessary to calibrate the entire device, but only the tension sensor 6, which has the significant advantages of simple, fast, and high-precision calibration.

[0028] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A nonlinear fender simulation device, comprising a base plate (1), characterized in that: A crossbeam assembly (2) is provided on the top of one side of the base plate (1). A bumper assembly (3) is movably connected to the crossbeam assembly (2). A first spring assembly (5) is connected to the bumper assembly (3) via a first connecting rope (4). The first spring assembly (5) is connected to a counterweight assembly located on the side of the base plate (1) away from the crossbeam assembly (2) via a second connecting rope (13). A tension sensor (6) is installed on the second connecting rope (13) between the first spring assembly (5) and the counterweight assembly. The counterweight assembly includes a counterweight (8) connected to the second connecting rope (13) and a housing (10) located directly below the counterweight (8). A second spring assembly (11) is provided inside the housing (10) and connected to the counterweight (8) via a third connecting rope (9).

2. The nonlinear fender simulation device according to claim 1, characterized in that: The crossbeam assembly (2) includes two first supports (201) mounted on the top of one side of the base plate (1) and a crossbeam (202) mounted between the two first supports (201) and located above the base plate (1).

3. The nonlinear fender simulation device according to claim 2, characterized in that: The contact block assembly (3) includes a rocker arm (302) movably connected to the crossbeam (202) and a contact block (301) mounted on the rocker arm (302). The base plate (1) has an opening (12). One end of the rocker arm (302) passes through the opening (12) and is connected to the contact block (301). The end of the rocker arm (302) away from the contact block (301) is connected to the first connecting rope (4).

4. The nonlinear fender simulation device according to claim 1, characterized in that: The first spring assembly (5) includes a first connecting post (501) connected to the first connecting rope (4), a second connecting post (502) connected to the second connecting rope (13), and a first spring (503) installed between the first connecting post (501) and the second connecting post (502). A limiting rope (504) is provided inside the first spring (503).

5. The nonlinear fender simulation device according to claim 1, characterized in that: The second spring assembly (11) includes a third connecting post (1101) connected to the third connecting rope (9), a fourth connecting post (1102) installed in the housing (10), and a second spring (1103) installed between the third connecting post (1101) and the fourth connecting post (1102).

6. The nonlinear fender simulation device according to claim 1, characterized in that: A support assembly (7) is installed on the top of the base plate (1) on the side away from the crossbeam assembly (2), located between the crossbeam assembly (2) and the counterweight assembly. The support assembly (7) includes a second bracket (702) mounted on the base plate (1) and a fixed pulley (701) movably connected to the second bracket (702). The fixed pulley (701) is slidably connected to the second connecting rope (13).

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