Restraint-adjustable elastic plate water wave slamming experiment device

Abstract

The invention discloses an adjustable constraint elastic plate water wave slamming experiment device which comprises an experiment water tank, a slope structure, a bottom base, a bottom clamp, an elastic plate model, a top clamp, a top supporting structure, a tractor, a guide rail and an optical motion capturing system. The slope structure is installed at the bottom of the experiment water tank, the bottom base is arranged on the slope structure, the bottom clamp is installed on the bottom base in an angle-adjustable mode, the bottom clamp clamps the bottom of the elastic plate model, the top clamp clamps the top of the elastic plate model, and the top clamp is installed on the top supporting structure in an angle-adjustable mode. The top supporting structure is connected with the tractor, the guide rail is arranged on the upper portion of the experimental water tank, and the tractor is movably installed on the guide rail. The device is suitable for researching deformation response characteristics of the elastic plate under water wave slamming, and flexible and continuous regulation and control of end constraint conditions of an elastic plate model can be realized; the space pose of the elastic plate model can be flexibly adjusted and set, and a good platform is provided for research tests.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering hydrodynamic experiments, and in particular relates to an elastic plate water wave slamming experimental device with adjustable constraints. Background Art

[0002] Wave slamming refers to the violent collision of waves and structures at high speed, characterized by high loads and short durations. Numerous influencing factors and complex mechanisms pose challenges to research, and our current understanding of the phenomenon remains incomplete. Slamming of elastic structures, in particular, is often accompanied by significant hydroelastic effects, further complicating the slamming process. Specifically, elastic structures deform under wave slamming, and this deformation in turn affects wave propagation and the slamming force. To accurately predict the slamming loads on such structures, in-depth research is required into the structural deformation characteristics and their influencing mechanisms during the slamming process. Given the complexity of the slamming phenomenon, physical model experiments have become the most effective means of studying this phenomenon. Through physical model experiments, we can visually observe the interaction between waves and structures and obtain relevant physical parameters, providing a key basis for exploring the physical laws and mechanisms. Wave slamming experiments on fixed elastic structures require simultaneous monitoring of load variations and structural dynamic response, focusing on the influence of factors such as wave conditions, the type and strength of end restraints, and structural stiffness and inclination. Traditional experimental studies often focus on rigid models and ignore the effects of structural elasticity, or focus solely on the impact of a single factor during the slamming process, lacking systematic research on the combination of multiple factors. This leads to incomplete predictions of wave slamming loads, which in turn can affect the assessment of structural safety and reliability, as well as the rational formulation of slamming protection measures.

[0003] Patent document CN112798223A discloses an experimental device for studying the impact load and pressure distribution of breaking waves on cylinders. However, this experimental device only focuses on the impact experiment of rigid models. Its measurement system is only equipped with dynamic pressure sensors and force sensors for impact force measurement. It lacks deformation / strain sensing units and cannot obtain structural deformation response data. Secondly, the model adopts a cantilever beam rigid connection and lacks the ability to quickly adjust the constraint conditions at the end of the model. Therefore, it is difficult to study the influence of the change of constraint conditions on the vibration of the elastic model. Finally, its inclination adjustment mechanism based on T-bolts can only change the slope of the slope structure facing the wave, and the experimental model itself adopts a rigid vertical arrangement and does not have the function of adjusting the model inclination, which limits the flexibility and scalability of the experiment.

[0004] In summary, traditional water wave slamming devices have significant design limitations. Their research scope primarily focuses on rigid structures, enabling only structural stress monitoring but lacking the ability to observe structural deformation. More critically, these devices struggle to meet the requirements of elastic plate slamming experiments, such as analyzing the impact of plate end restraint strength and adjusting the model's position, and they are unable to achieve continuous, convenient, and precise adjustments.

[0005] Therefore, the present invention proposes an elastic plate water wave slamming experimental device with adjustable constraints to solve the above problems. Summary of the Invention

[0006] The present invention aims to address the shortcomings of existing technologies by providing an adjustable constraint elastic plate water wave impact test device. This device possesses multi-dimensional data acquisition capabilities, capable of acquiring not only impact load information but also structural deformation data during the impact process. This provides comprehensive data support for a comprehensive analysis of the mechanical response of elastic plates under water wave impact. Furthermore, the device enables continuous and rapid regulation of end constraint strength, simulating elastic plate slamming experiments under varying constraint strengths and facilitating in-depth exploration of the influence of plate end constraint strength on the dynamic deformation of the elastic plate. Furthermore, the device integrates a variety of practical features, including convenient model replacement, model position adjustment, and bottom slope angle adjustment, enabling flexible adaptation to diverse experimental scenarios and research needs, providing a more efficient and precise experimental platform for elastic plate water wave impact research.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: An elastic plate water wave slamming experimental device with adjustable constraints, comprising: an experimental water tank, a ramp structure, a bottom base, a bottom fixture, an elastic plate model, a top fixture, a top support structure, a tractor, a guide rail, and an optical motion capture system; The ramp structure is installed at the bottom of the experimental water tank, the bottom base is set on the ramp structure, the bottom clamp is installed on the bottom base with an adjustable angle, the bottom clamp clamps the bottom of the elastic plate model, the top clamp clamps the top of the elastic plate model, the top clamp is installed on the top support structure with an adjustable angle, the top support structure is connected to the tractor, the guide rail is set on the upper part of the experimental water tank and above the ramp structure, the tractor is installed on the guide rail, and the optical motion capture system is used to capture and record the motion trajectory of the elastic plate model.

[0008] Preferably, the bottom clamp includes a bottom bolt rod, a bottom spring, a bottom clip assembly and a bottom nut, the bottom clip assembly includes a bottom first clip and a bottom second clip, the bottom first clip and the bottom second clip respectively abut against the two sides of the bottom of the elastic plate model, the end of the bottom bolt rod passes through the bottom first clip, the elastic plate model, the bottom second clip and the bottom spring in sequence, the bottom nut is movably and adjustably installed at the end of the bottom bolt rod, and the bottom first clip or the bottom second clip is angle-adjustable installed on the bottom base; when the bottom clamp clamps the bottom of the elastic plate model, the bottom spring is in a compressed state, and has a force on the bottom second clip toward the bottom first clip, thereby clamping the bottom of the elastic plate model between the bottom first clip and the bottom second clip.

[0009] Preferably, the bottom clamp comprises a plurality of sets of bottom bolt rods, bottom springs and bottom nuts, so that the bottom of the elastic plate model is stably clamped between the bottom first clamping piece and the bottom second clamping piece.

[0010] Preferably, bottom washers are provided between the bottom nut and the bottom spring, and between the bottom bolt rod head and the bottom first clip.

[0011] Preferably, the bottom base includes a bottom plate, a bottom plate connecting hinge and a bottom connecting bolt. The bottom plate is installed on the slope structure through the bottom plate mounting bolts. A bottom connecting hinge is provided at the bottom of the bottom first clip or the bottom second clip. The bottom plate connecting hinge is fixed to the bottom plate. The bottom plate connecting hinge and the bottom connecting hinge are connected and fastened by the bottom connecting bolts. Bolt holes for the bottom connecting bolts to pass through are provided on the bottom plate connecting hinge and the bottom connecting hinge.

[0012] Preferably, a plurality of bottom connecting hinges are provided at the bottom of the first bottom clip or the second bottom clip, and a plurality of bottom plate connecting hinges are provided on the bottom plate in a one-to-one correspondence. The plurality of bottom connecting hinges and the plurality of bottom plate connecting hinges are connected and fastened in a one-to-one correspondence through a plurality of bottom connecting bolts.

[0013] Preferably, the top clamp includes a top bolt rod, a top spring, a top clip assembly and a top nut, the top clip assembly includes a top first clip and a top second clip, the top first clip and the top second clip are respectively abutted against the two sides of the top of the elastic plate model, the end of the top bolt rod passes through the top first clip, the elastic plate model, the top second clip and the top spring in sequence, the top nut is movably and adjustably installed at the end of the top bolt rod, and the top first clip or the top second clip is angle-adjustably installed on the top supporting structure; when the top clamp clamps the top of the elastic plate model, the top spring is in a compressed state, and has a force on the top second clip toward the top first clip, thereby clamping the top of the elastic plate model between the top first clip and the top second clip.

[0014] Preferably, the top supporting structure includes a top plate, a top plate connecting hinge and a top connecting bolt. The top plate is connected to the tractor. A top connecting hinge is provided on the top of the top first clip or the top second clip. The top plate connecting hinge is fixed to the top plate. The top plate connecting hinge and the top connecting hinge are fastened together by the top connecting bolts. Bolt holes for the top connecting bolts to pass through are provided on the top plate connecting hinge and the top connecting hinge.

[0015] Preferably, the slope structure includes a frame structure and a panel disposed on the frame structure, which is divided into a front slope, a slope top, and a rear slope, wherein the bottom base is disposed on the slope top, and the slopes of the front slope and the rear slope are adjustable. The frame structure is made of aluminum alloy, and the panel is made of organic glass.

[0016] Preferably, the optical motion capture system is arranged obliquely above the elastic plate model via a backing plate.

[0017] The elastic plate model and the slope structure are secured via a bottom base and a bottom fixture. During the experiment, a bottom base was first installed at the intended location of the elastic plate model on the aluminum alloy frame structure. This base was constructed of steel and required to prevent deformation during the experiment. The base plate of the base was rigidly connected to the aluminum alloy frame structure via base plate mounting bolts, allowing for easy relocation during the experiment as needed. Once the base plate was positioned, a plexiglass panel was placed on its upper surface, ensuring that the slope was flat throughout. During the experiment, the inclination angle of the elastic plate model was quickly adjusted to investigate its influence on structural deformation and slamming load during impact.

[0018] During the experimental preparation phase, the elastic plate model needs to be preprocessed as follows: threaded holes are opened on the surface of the elastic plate model for installing pressure sensors; strain gauges are arranged and protected with sealants or waterproof coatings to measure the impact response of the elastic specimen; in addition, monitoring points for the optical motion capture system need to be arranged on the surface of the elastic plate model and protected with waterproof tape to ensure that the structural deformation data during the impact process can be collected in real time and accurately.

[0019] The present invention also provides an experimental method for studying the impact load and structural dynamic response of a wave impacting an elastic plate model. The method is implemented based on the aforementioned experimental apparatus and is specifically as follows: First, the wave-making performance test of the empty water tank is carried out: the target incident wave is generated by starting the wave maker, and the wave surface parameters are monitored in real time using a wave height meter, and the wave-making performance of the experimental water tank is analyzed to ensure that the generated wave parameters meet the experimental design requirements.

[0020] Subsequently, a suitable experimental section was selected based on the wave propagation characteristics. The experimental apparatus, including a ramp structure, elastic plate model, tractor, and accessories, was installed in the selected experimental section. The ramp structure's purpose was to induce shallow-water deformation during wave propagation: increasing wave height and decreasing wave velocity and wavelength, thereby inducing wave breaking and slamming against the elastic plate.

[0021] During the experiment, strain gauges and pressure sensors placed on the surface of the elastic plate model were used to measure structural strain and impact pressure in real time. Simultaneously, an optical motion capture system monitored the deformation characteristics of the structure. Based on experimental requirements, the slope structure inclination, the inclination of the elastic plate model, the position of the elastic plate model on the slope structure, and the restraint strength at the ends of the elastic plate model were dynamically adjusted, and the wave generation and data recording operations were then repeated.

[0022] Finally, based on the experimental data, the typical slamming phenomena under different slamming conditions, the slamming load characteristics of the elastic plate model, and the structural dynamic response laws are analyzed.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) This experimental device has the function of quickly adjusting the plate end constraint strength. This function is achieved through a fixture with an integrated spring bolt. The fixture uses the synergistic effect of spring elastic deformation and bolt adjustment to accurately and continuously change the constraint force on the elastic plate end, thereby effectively adjusting the plate end constraint strength. (2) The experimental device is equipped with an optical motion capture system and strain gauges to measure the structural deformation during the slamming test, which can effectively solve the problem that traditional rigid structure slamming test devices do not have the ability to monitor structural deformation; (3) The entire experimental device is made of aluminum alloy connecting rods connected by bolts. This connection method is convenient for quick disassembly and can adjust the structural position and bottom slope angle. At the same time, the structural end clamps are fixed to the structural frame with connecting hinges. By rotating the connecting hinges, the tilt angle of the model can be adjusted. This enables the rapid disassembly and flexible adjustment of the experimental model posture and the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the elastic plate water wave slamming experimental device with adjustable constraints in a preferred embodiment of the present invention; Figure 2 A schematic diagram of the connection between the bottom clamp and the bottom base in a preferred embodiment of the present invention; Figure 3 A schematic diagram of the connection between the top clamp and the top supporting structure in a preferred embodiment of the present invention; Figure 4 This is a schematic structural diagram of a tractor in a preferred embodiment of the present invention; Figure 5 This is a schematic structural diagram of a slope structure in a preferred embodiment of the present invention; Figure 6 Graph showing the variation of the natural frequency of the elastic plate model with the constraint strength in a preferred embodiment of the present invention; Figure 7 Schematic diagram of structural deformation duration curves of elastic plate models with different constraint strengths under the same wave slamming conditions in a preferred embodiment of the present invention; Figure 8 1. A comparison diagram of the deformation amplitude of the elastic plate model under different constraint strengths as a function of wave slamming conditions in a preferred embodiment of the present invention; Figure 9 Comparison of the impact pressure duration curves of elastic and rigid plates.

[0025] in: 1. Frame structure, 1-1, front slope, 1-2, slope top, 1-3, rear slope, 2. Panel, 3. Elastic plate model, 4. Bottom clamp, 4-1. Bottom bolt rod, 4-2a / 4-2b. Bottom gasket, 4-3. Bottom spring, 4-4a. Bottom first clamp, 4-4b. Bottom second clamp, 4-5. Bottom connecting hinge, 4-6. Bottom nut, 5. Bottom base, 5-1. Bottom plate connecting hinge, 5-2. Bottom connecting bolt, 5-3. Bottom plate, 5-4. Bottom plate mounting bolt, 6. Top clamp, 6-1. Top bolt rod, 6-2a / 6-2b. Top gasket, 6-3. Top spring, 6-4a. Top first clamp, 6-4b. Top second clamp, 6-5. Top connecting hinge, 6-6. Top nut, 7. Top support structure, 7-1. Top plate connection hinge, 7-2. Top connection bolts, 7-3. Top plate, 7-4. Top support frame, 8. Tractor, 8-1. Electric motor, 8-2. Traction frame, 8-3. Slider, 9. Guide rails, 10. Optical motion capture system, 11. Pad, 12. Experimental water tank. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0028] The present invention will be further described below with reference to specific examples, but they are not intended to limit the present invention.

[0029] like Figures 1 to 5 As shown, an elastic plate water wave slamming experimental device with adjustable constraints includes: an experimental water tank 12, a slope structure, a bottom base 5, a bottom clamp 4, an elastic plate model 3, a top clamp 6, a top support structure 7, a tractor 8, a guide rail 9, an optical motion capture system 10 and a pad 11.

[0030] The ramp structure is installed at the bottom of the experimental water tank 12 and includes a frame structure 1 and a panel 2 installed on the frame structure 1. The frame structure 1 is made of aluminum alloy, and the panel 2 is made of organic glass. The bottom base 5 is set on the ramp structure, and the bottom clamp 4 is installed on the bottom base 5 with an adjustable angle. The bottom clamp 4 clamps the bottom of the elastic plate model 3, and the top clamp 6 clamps the top of the elastic plate model 3. The top clamp 6 is installed on the top support structure 7 with an adjustable angle. The angles of the bottom clamp 4 and the top clamp 6 are adjustable, that is, the angle of the elastic plate model 3 can be adjusted while clamping the elastic plate model 3. The top support structure 7 is connected to the tractor 8. The guide rail 9 is set on the upper part of the experimental water tank 12 and above the ramp structure. The tractor 8 is movably installed on the guide rail 9. The tractor 8 can move and stop on the guide rail 9 according to the experimental requirements. The optical motion capture system 10 is arranged obliquely above the elastic plate model 3 through a pad 11, and is used to capture and record the motion trajectory of the elastic plate model 3; in this embodiment, it is arranged on the rear side of the slope structure, and the pad 11 is arranged above the top guide rail 9 of the experimental water tank 12. It is made of a smooth solid wood horizontal board and can be firmly placed above the guide rail 9 during the experiment.

[0031] like Figure 2 As shown, the bottom clamp 4 includes a bottom bolt rod 4-1, a bottom spring 4-3, a bottom clip assembly and a bottom nut 4-6, and the bottom clip assembly includes a bottom first clip 4-4a and a bottom second clip 4-4b.

[0032] The first bottom clip 4-4a and the second bottom clip 4-4b are respectively abutted against the bottom sides of the elastic plate model 3. The end of the bottom bolt rod 4-1 passes through the first bottom clip 4-4a, the elastic plate model 3, the second bottom clip 4-4b, and the bottom spring 4-3 in sequence. The bottom nut 4-6 is movably and adjustably mounted on the end of the bottom bolt rod 4-1. In this embodiment, the first bottom clip 4-4a is L-shaped, with its short horizontal edge forming a bottom platform of the fixture, which is mounted on the bottom base 5 with an adjustable angle. The second bottom clip 4-4b is positioned on the upper surface of the short horizontal edge of the first bottom clip 4-4a and can slide along this platform. As a result, the spacing between the first bottom clip 4-4a and the second bottom clip 4-4b (i.e., the slot spacing for accommodating the elastic plate model 3) is adjustable to accommodate different model thicknesses. In order to ensure the stability of the bottom clamping of the elastic plate model 3, the bottom clamp 4 includes multiple sets of bottom bolt rods 4-1, bottom springs 4-3 and bottom nuts 4-6, so that the bottom of the elastic plate model 3 is stably clamped between the bottom first clamp 4-4a and the bottom second clamp 4-4b.

[0033] The lower vertical long side of the first bottom clip 4-4a, the second bottom clip 4-4b, and the lower portion of the elastic plate model 3 are all provided with correspondingly positioned and identically spaced through bolt holes. Furthermore, bottom washers 4-2a / 4-2b are provided between the bottom nut 4-6 and the bottom spring 4-3, and between the head of the bottom bolt rod 4-1 and the first bottom clip 4-4a. Multiple bottom bolt rods 4-1 sequentially penetrate the corresponding bolt holes of the following components: bottom washer 4-2a—bottom first clip 4-4a—elastic plate model 3—bottom second clip 4-4b—bottom spring 4-3—bottom washer 4-2b, and are tightened via the bottom nut 4-6. This connects the bottom of the bottom clip assembly to the elastic plate model 3.

[0034] When the bottom clamp 4 clamps the bottom of the elastic plate model 3, the bottom spring 4-3 is compressed, exerting a force on the bottom second clamp 4-4b toward the bottom first clamp 4-4a, clamping the bottom of the elastic plate model 3 between the bottom first clamp 4-4a and the bottom second clamp 4-4b. When the bottom nut 4-6 is tightened, the bottom nut 4-6 pushes the bottom washer 4-2b to compress the bottom spring 4-3. The reaction force of the bottom spring 4-3 pushes the bottom second clamp 4-4b forward. Simultaneously, the bottom bolt rod 4-1 tightens the bottom first clamp 4-4a and bottom washer 4-2a. This combined action causes the front and rear bottom first clamps 4-4a and bottom second clamp 4-4b to clamp the elastic plate model 3. When the bottom nut 4-6 is loosened, the compression of the bottom spring 4-3 decreases, reducing the clamping force. Therefore, by adjusting the tightening of the bottom nut 4-6 to change the compression of the bottom spring 4-3, the clamping strength of the clamp assembly on the bottom of the elastic plate model 3 can be controlled.

[0035] Meanwhile, the bottom base 5 includes a bottom plate 5-3, a bottom plate connecting hinge 5-1, and a bottom connecting bolt 5-2. The bottom plate 5-3 is mounted on the slope structure via bottom plate mounting bolts 5-4. A bottom connecting hinge 4-5 is provided at the bottom of the first bottom clip 4-4a. The bottom plate connecting hinge 5-1 is fixed to the bottom plate 5-3. The bottom plate connecting hinge 5-1 and the bottom connecting hinge 4-5 are connected and fastened via the bottom connecting bolt 5-2. Both the bottom plate connecting hinge 5-1 and the bottom connecting hinge 4-5 have bolt holes for the bottom connecting bolt 5-2 to pass through. The bottom connecting hinge 4-5 is a block connecting member with an arcuate edge (the lower end of the cross section is semicircular). Multiple bottom connecting hinges 4-5 are provided at the bottom of the first bottom clip 4-4a, each of which has a bolt hole extending through it at the center of its arcuate edge. A plurality of bottom plate connection hinges 5-1 are provided on the bottom plate 5-3 in a one-to-one correspondence. The bottom plate connection hinge 5-1 is also a block connection member with an arc-shaped edge (the upper end of the cross section is semicircular). A bolt hole is also provided at the center position of the circle edge of the bottom plate connection hinge 5-1. The plurality of bottom connection hinges 4-5 and the plurality of bottom plate connection hinges 5-1 are connected and fastened in a one-to-one correspondence through a plurality of bottom connection bolts 5-2.

[0036] During installation, the side of the bottom connecting hinge 4-5 is staggered and aligned with the side of the bottom plate connecting hinge 5-1 so that the through bolt holes at the center of the two circles coincide with each other and the axes are aligned, and then the bottom connecting bolt 5-2 is passed through the bolt hole to form a hinge structure that can rotate around the axis.

[0037] Angle Adjustment and Fixing: Loosen the bottom connecting bolts 5-2, and the bottom fixture 4 (together with the elastic plate model 3 attached thereto) can rotate about these bolts. After adjusting the elastic plate model 3 to the target tilt angle, tighten the bottom connecting bolts 5-2. The pressure generated by tightening the bottom connecting bolts 5-2 creates friction between the mating side surfaces, achieving friction locking, fixing the hinge angle and thus locking the position of the elastic plate model 3. Furthermore, the tilt angle of the elastic plate model 3 can be quickly changed by simply loosening the bottom connecting bolts 5-2, adjusting the angle, and re-tightening the bottom connecting bolts 5-2.

[0038] like Figure 3 As shown, the structure and function of the top clamp 6 correspond to those of the bottom clamp 4, including a top bolt rod 6-1, a top spring 6-3, a top clamp assembly and a top nut 6-6, and the top clamp assembly includes a top first clamp 6-4a and a top second clamp 6-4b.

[0039] The first and second top clamps 6-4a and 6-4b are respectively attached to the top sides of the elastic plate model 3. The end of the top bolt rod 6-1 passes through the first top clamp 6-4a, the elastic plate model 3, the second top clamp 6-4b, and the top spring 6-3. The top nut 6-6 is movably and adjustably mounted on the end of the top bolt rod 6-1. The first top clamp 6-4a is angularly adjustable and mounted on the top support structure 7. The first top clamp 6-4a has an inverted L-shaped cross-section, and its short horizontal side forms the top platform of the fixture. Multiple top connecting hinges 6-5 are welded to the surface of the platform for hinged connection with the top support structure 7. The second top clamp 6-4b is placed on the lower surface of the short horizontal side of the first top clamp 6-4a and can slide along this platform. As a result, the spacing (i.e., the slot spacing) between the front and rear first and second top clamps 6-4a and 6-4b is adjustable to accommodate variations in the thickness of the elastic plate model 3. In order to ensure the stability of the top clamping of the elastic plate model 3, the top clamp 6 includes multiple sets of top bolt rods 6-1, top springs 6-3 and top nuts 6-6, so that the top of the elastic plate model 3 is stably clamped between the top first clamp 6-4a and the top second clamp 6-4b.

[0040] Corresponding through-bolt holes are provided in the top first clamp 6-4a (vertical long side), the top second clamp 6-4b, and the upper portion of the elastic plate model 3. Top washers 6-2a / 6-2b are provided between the top nut 6-6 and the top spring 6-3, and between the head of the top bolt rod 6-1 and the top first clamp 6-4a. Multiple top bolt rods 6-1 sequentially pass through: top washer 6-2a, top first clamp 6-4a, elastic plate model 3, top second clamp 6-4b, top spring 6-3, and top washer 6-2b, with the ends being tightened via the top nut 6-6, thereby completing the connection between the elastic plate model 3 and the top clamp 6. When the top clamp 6 clamps the top of the elastic plate model 3, the top spring 6-3 is compressed, exerting a force on the top second clamp 6-4b toward the top first clamp 6-4a, clamping the top of the elastic plate model 3 between the top first clamp 6-4a and the top second clamp 6-4b.

[0041] When the top nut 6-6 is tightened, it pushes the top washer 6-2b to compress the top spring 6-3. The reaction force of the top spring 6-3 pushes the top second clamp 6-4b forward. Simultaneously, the top bolt rod 6-1 tightens the top first clamp 6-4a and the top washer 6-2a. This combined action causes the front and rear top first clamps 6-4a and top second clamps 6-4b to clamp the elastic plate model 3. When the nut is loosened, the compression of the top spring 6-3 decreases, reducing the clamping force. By adjusting the tightening degree of the top nut 6-6 to change the compression of the top spring 6-3, the strength of the top clamp assembly's constraint on the top of the elastic plate model 3 can be controlled.

[0042] At the same time, the top support structure 7 includes a top plate 7-3, a top plate connecting hinge 7-1, a top connecting bolt 7-2 and a top support frame 7-4. The top plate 7-3 is connected to the tractor 8 through the top support frame 7-4. In other embodiments, the top plate 7-3 can be directly connected to the tractor 8, or connected to the tractor 8 through other structures. A top connecting hinge 6-5 is provided on the top of the top first clamp 6-4a or the top second clamp 6-4b. The top plate connecting hinge 7-1 is fixed on the top plate 7-3. The top plate connecting hinge 7-1 and the top connecting hinge 6-5 are connected and fastened by the top connecting bolt 7-2. Bolt holes for the top connecting bolt 7-2 to pass through are provided on the top plate connecting hinge 7-1 and the top connecting hinge 6-5.

[0043] The top connecting hinge 6-5 is a block-shaped connecting member with an arcuate edge (the upper end of the cross section is semicircular). Multiple top connecting hinges 6-5 are provided on the top of the first top clip 6-4a. Each top connecting hinge 6-5 has a bolt hole extending through it at the center of its arcuate edge. The top plate 7-3 is provided with multiple corresponding top plate connecting hinges 7-1. These top plate connecting hinges 7-1 are also block-shaped connecting members with an arcuate edge (the lower end of the cross section is semicircular). Each of these top plate connecting hinges 7-1 has a bolt hole extending through it at the center of its edge. The multiple top connecting hinges 6-5 and the multiple top plate connecting hinges 7-1 are connected and secured to each other via multiple top connecting bolts 7-2.

[0044] During installation, the side of the top connecting hinge 6-5 is staggered and aligned with the side of the top plate connecting hinge 7-1 so that the through bolt holes at the center of the two circles coincide with each other and the axes are aligned, and then the top connecting bolt 7-2 is passed through the bolt hole to form a hinge structure that can rotate around the axis.

[0045] Angle Adjustment and Fixing: Loosen top connecting bolt 7-2, and top clamp 6 (together with the elastic plate model 3 underneath) can rotate about it. After adjusting the elastic plate model 3 to the target tilt angle, tighten top connecting bolt 7-2. The pressure generated by tightening top connecting bolt 7-2 creates friction between the mating side surfaces, achieving friction locking, fixing the hinge angle and thus locking the position of the elastic plate model 3. Furthermore, the tilt angle of the elastic plate model 3 can be quickly changed by simply loosening top connecting bolt 7-2, adjusting the angle, and re-tightening top connecting bolt 7-2.

[0046] like Figure 4The tractor 8 is driven by an electric motor 8-1, which is mounted on a traction frame 8-2. The traction frame 8-2 is provided with a slider 8-3. The electric motor 8-1 is rigidly fixed to the top of the traction frame 8-2, and the slider 8-3 is rigidly fixed to the bottom of the traction frame 8-2 and connected to the guide rail 9. Furthermore, a top support frame 7-4 is mounted on the top plate 7-3, and the bottom of the traction frame 8-2 is rigidly connected to the top plate 7-3 via the top support frame 7-4.

[0047] like Figure 5 The slope structure is divided into a front slope 1-1, a slope top 1-2, and a rear slope 1-3. The bottom base 5 is set on the slope top 1-2. The slopes of the front slope 1-1 and the rear slope 1-3 are adjustable. Specifically, the slope structure includes a frame structure 1 and a panel 2 set on the frame structure 1; the frame structure 1 is made of aluminum alloy straight rods connected by bolts. The length of the rods can be flexibly adjusted according to the test requirements, thereby changing the slope gradient; the panel 2 is a thin organic glass plate, connected to the frame structure 1 by bolts, and the length of the panel 2 can be adjusted at any time according to the experimental requirements. Based on the relative position of the slope and the elastic plate model 3, the slope structure can be further divided into three parts: the front slope 1-1, the slope top 1-2, and the rear slope 1-3. Each part contains part of the frame structure 1 and the panel 2. The elastic plate model 3, the bottom fixture 4, and the bottom base 5 are connected to the slope top 1-2 and can move along the slope top 1-2 according to the experimental requirements.

[0048] The following uses the data from an experiment on a water wave impacting an elastic plate model 3 as an example to further illustrate the effect of the plate end constraint on the deformation of the elastic plate during the impact process: The elastic plate model 3 used in the experiment is made of aluminum alloy, with a width of 800 mm, a height of 300 mm, and a thickness of 2 mm. The experiment uses a slope structure with a front slope 1-1 slope of 1:10 and a rear slope 1-3 slope of 1:1. The slope top 1-2 is 1000 mm long, and the elevation from the slope top 1-2 to the bottom of the pool is 250 mm. In the experiment, only the bottom of the elastic plate model 3 is constrained, while the top of the elastic plate model 3 is free. The overall experimental layout is the same as Figure 5 The incident wave type in the experiment is a solitary wave, and the still water depth from the bottom of the slope to the water surface is 0.27 m.

[0049] First, the influence of the plate end constraint strength and the natural frequency of the elastic plate model 3 is analyzed. The results are shown in Figure 6 The analysis process consists of the following four steps, the core of which is the modal superposition method in structural dynamics (which is an existing method in structural dynamics): Step 1: Experimental modal frequency measurement Under the preset plate end constraint conditions, hammering experiments were carried out, and the vibration response of the elastic plate was collected using an optical motion capture system (model: NDI Optotrak Certus, with an acquisition frequency of 500 Hz in the experiment). The first-order dry modal measured frequency of the elastic plate model 3 under each working condition was directly obtained by fast Fourier transform (FFT) and peak picking method. f exp .

[0050] Step 2: Build an equivalent mechanics model In view of the complex structure of the plate end constraint conditions in the actual experiment, in the mechanical modeling, the actual plate end constraint bottom fixture is equivalent to the spring support to simplify the calculation (the spring movement direction is perpendicular to the plate surface of the elastic plate model 3), and the stiffness density is used. k (N / m 3 ) is used as a quantitative indicator of support constraint strength. Its physical meaning is to make the unit area (1m 2 ) The normal pressure (N / m) required to produce a unit normal displacement (1m) 2 ).

[0051] Step 3: Parameter identification calculation: For each experimental constraint condition, an iterative identification process is performed: 1) ANSYS Mechanical Application (version: 2022 R1) was used to construct a parametric finite element model. The unit type of the model was SOLID186 solid unit. The material of the elastic plate model 3 was selected as aluminum alloy with an elastic modulus of E = 71 GPa, a density of ρ = 2770 kg / m3, and a Poisson's ratio of ν = 0.33. A single-degree-of-freedom spring constraint was applied within the constraint range of the lower edge of the elastic plate model 3, and the stiffness density k was a variable.

[0052] 2) Numerical model verification and modal solution, extracting the calculated value of the first-order dry modal frequency f num (k). First, optimization matching is performed and the Golden Section optimization algorithm (existing mathematical method) is used to solve the objective function min| f num (k)- f exp |, when| f num (k)- f exp When |≤0.1Hz, it is considered that the convergence condition is met. k It can be regarded as the equivalent stiffness density generated by the corresponding constraint conditions in the experiment k On this basis, further change the stiffness density kThe value of (the range is 10~10 9 N / m 3 ), and calculate the dry modal frequency of the numerical model at this time f num (k).

[0053] Step 4: Data association into graph All the data obtained ( k, f exp ) is plotted in a coordinate system represented by a logarithm of the horizontal axis, we can get Figure 6 .

[0054] from Figure 6 It can be seen that the plate end constraint has a significant effect on the vibration mode frequency of the elastic plate model 3. In particular, when the stiffness density k At 10 4 N / m 3 to 10 8 N / m 3 When the vibration mode frequency of elastic plate model 3 is within the range of , the vibration mode frequency of elastic plate model 3 is more sensitive to the plate end constraint strength. Under the same slamming conditions, as the plate end constraint strength increases k The deformation of the elastic plate model 3 will also change significantly as the plate end strength changes. This result can provide a theoretical basis for a deeper understanding of the influence of the plate end restraint strength on the deformation characteristics of the elastic plate model 3 during slamming.

[0055] Further, Figure 7 The incident wave height H =0.081m and the water depth before the slope D =0.27m under the specific working condition, the stiffness density k Take 2.3×10 6 N / m 3 and 4.4×10 6 N / m 3 The deformation time curve of the center point of the top plate 7-3 of the elastic plate model 3.

[0056] The data in the figure were obtained through the following experimental measurement process: (1) Dynamic deformation acquisition: An LED active luminous marker (NDIOptotrak Certus instrument dedicated marker) is installed at the top center point of the elastic plate model 3 to record the three-dimensional displacement coordinates of the marker in real time ( x , y , z ); Secondly, conduct experiments and collect data.

[0057] (2) Data processing: 1) Definition of deformation: Define the displacement component △ along the normal direction of the plate surface z (i.e. the displacement coordinate z at the current moment minus the displacement coordinate z at the initial moment初始 ) is the deformation, which is represented by the vertical coordinate dz in the figure; 2) Time reference alignment: the moment when the water wave is about to reach the plate surface in the experiment is taken as the time zero point t =0; In this figure, the horizontal axis t represents time (unit: s), and the vertical axis dz represents the normal dynamic deformation of the model (unit: mm). By comparing the two curves, we can see that when the stiffness density k From 2.3×10 6 N / m 3 Increased to 4.4×10 6 N / m 3 When , the maximum deformation of the elastic plate model 3 under the slamming load is significantly reduced, with a decrease of about 34.78%, which intuitively reflects the inhibitory effect of increasing the plate end constraint strength on the dynamic deformation amplitude of the elastic plate model 3.

[0058] Further, Figure 8 Revealing the depth of the water D = 0.27m, different wave heights H and constraint stiffness density k The change of the maximum deformation amplitude of the elastic plate model 3 under the condition of . The data analysis process is as follows: 1. Parametric Experimental Design: Fixed still water depth D = 0.27m; set 3 groups of gradient wave heights H = 0.081, 0.108, 0.135 m (covering H / D = 0.3 ~ 0.5); for two kinds of constraint stiffness density (k = 2.3×10 6 N / m 3 , 4.4×10 6 N / m 3 ) Repeat the experiment 2. Data collection and processing: 1) Same Figure 7 The data acquisition method was used. An infrared LED active luminous marker was installed at the top center of the elastic plate model 3, and an optical motion capture system (model: NDI Optotrak Certus, with a sampling rate of 500 Hz and a positioning accuracy of 0.1 mm) was used to continuously record the normal displacement Δ of the marker during the impact process. z ( t ); 2) Press Figure 7 The same process is used to align the time zero point and draw Δ z ( t )’s time history curve; 3) Extract the maximum value: for each Δ z ( t) time history curve, extract its peak data maxΔ z (Unit: mm) 3. Data Visualization: Dimensionless wave height H / D is the horizontal axis; the deformation peak value maxΔ z is the vertical axis; k Draw a point-line graph based on the grouped values.

[0059] Through Figure 8 From the analysis, we can see that as the plate end constraint strength k From 2.3×10 6 N / m 3 Increased to 4.4×10 6 N / m 3 , the deformation amplitude of the elastic plate model 3 decreases. Under the wave conditions shown in the figure ( H / D = 0.3~0.5, D=0.27m), the decrease is between 10%~50%.

[0060] To further illustrate the effect of water waves hitting the elastic plate, Figure 9 The elastic plate and the rigid plate under the same slamming condition ( H =0.081m, D =0.27m), pressure duration curve at the same plate surface pressure measuring point.

[0061] The main parameters and scale parameters of elastic plate model 3 are the same as those in the previous Figures 6-8 The middle model remains the same, with the bottom constraint stiffness density k =2.3×10 6 N / m 3 The dimensions of the rigid plate model were kept consistent with those of the elastic plate, and the deformation of the rigid model was ignored during the experiment. The pressure measurement point was located near the center of the plate surface, 40 mm from the bottom of the plate.

[0062] The data analysis method and process of this figure are as follows: 1. Data acquisition: The pressure history curve is captured using a point pressure sensor (model: Chengdu Shengying Technology CY302, accuracy 0.1% FS, overpressure 50% FS, range: -10kPa~10kPa, acquisition frequency 1~1000 Hz); the hydrostatic pressure value P when the pressure sensor is in still water is used as the reference value. static Zero the pressure sensor; 2. Data processing: 1) Pressure definition: the measured data of the point pressure sensor (i.e. the actual value of the pressure at the measuring point) P 实际 Subtract hydrostatic pressure P 静水The pressure obtained P ) as the vertical axis for drawing; 2) Time base alignment: the moment when the water wave is about to reach the plate surface in the experiment is taken as the time zero t=0; 3) Data filtering: FFT low-pass filtering method is used to eliminate high-frequency noise signals.

[0063] In the figure, the horizontal axis t (Unit: s) represents time, vertical axis P (unit: kPa) represents pressure. Comparative analysis shows that the peak slamming pressure of the rigid plate is higher than that of the elastic plate (see figure (a)), exceeding the peak pressure by approximately 11% in this example. After the peak pressure, the pressure signal of the elastic plate maintains small fluctuations for a period of time, with a maximum amplitude of approximately 0.2 kPa. Under the same water wave slamming conditions, the pressure signal of the rigid plate is relatively smooth and stable, with no significant fluctuations (see figure (b)).

[0064] This phenomenon indicates that during a slamming impact, the elastic deformation of the plate significantly influences the force-bearing process, leading to significant differences in the slamming force characteristics of elastic plates compared to rigid plates. Therefore, in-depth exploration of the deformation patterns of elastic structures during slamming and their resulting impacts is of theoretical and practical significance. Furthermore, while the results for the rigid and elastic plates shown in the figure differ, the differences are relatively limited. This is primarily due to the fact that the more extreme wave slamming conditions were not included in the experiment, given the current experimental instrument range limitations, model parameter settings, and the need to ensure instrument safety.

[0065] This example intuitively demonstrates the necessity of developing an experimental setup suitable for water wave slamming on an elastic straight plate, and thus of conducting scientific research on the problem of water wave slamming on an elastic plate. Furthermore, the model deformation amplitude in actual problems may be much larger than shown in this example, depending on various factors such as the strength of the plate end restraints and the model stiffness. In the specific experiment, the basic workflow of this setup is as follows: Step (1): Install the slope structure in the experimental water tank 12 and change the slope gradient by adjusting the length of the aluminum alloy straight rod; Step (2): Move the tractor 8 to a suitable position, and fix the bottom base 5 to the corresponding position of the aluminum alloy frame and fix it with bolts; preliminarily connect the elastic plate model 3 to the tractor 8 and the bottom base 5 through the top clamp 6 and the bottom clamp 4 respectively; Step (3): loosen the top connecting bolts 7-2 and the bottom connecting bolts 5-2 of the elastic plate model 3 respectively, adjust the inclination angle of the elastic plate model 3, and fine-tune the position of the tractor 8 at the same time, and then tighten the top connecting bolts 7-2 and the bottom connecting bolts 5-2 to ensure that the inclination angle of the elastic plate model 3 is stable; Step (4): adjusting the tightening degree of the top nut 6-6 and the bottom nut 4-6 to change the end restraint strength of the elastic plate model 3; Step (5): Install other necessary experimental measurement instruments, such as optical motion capture system, pressure sensor, strain gauge, etc. Step (6): Turn on the wave maker to generate waves and record relevant physical quantities to complete an experimental measurement process; Step (7): According to the experimental requirements, adjust the slope gradient, the position of the elastic plate model 3, the inclination angle of the elastic plate model 3, the constraint conditions of the elastic plate model 3, etc., and generate waves again to produce slamming, and record the relevant physical quantities.

[0066] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the present invention specification should be included in the protection scope of the present invention.

Claims

1. An elastic plate water wave slamming experimental device with adjustable constraints, characterized in that: include: experimental flume, ramp structure, bottom base, bottom fixture, elastic plate model, top fixture, top support structure, tractor, guide rails, and optical motion capture system; The ramp structure is installed at the bottom of the experimental water tank, the bottom base is set on the ramp structure, the bottom clamp is installed on the bottom base with an adjustable angle, the bottom clamp clamps the bottom of the elastic plate model, the top clamp clamps the top of the elastic plate model, the top clamp is installed on the top support structure with an adjustable angle, the top support structure is connected to the tractor, the guide rail is set on the upper part of the experimental water tank and above the ramp structure, the tractor is installed on the guide rail, and the optical motion capture system is used to capture and record the motion trajectory of the elastic plate model.

2. The adjustable constrained elastic plate water wave slamming experimental device according to claim 1, characterized in that: The bottom clamp includes a bottom bolt rod, a bottom spring, a bottom clip assembly and a bottom nut. The bottom clip assembly includes a bottom first clip and a bottom second clip. The bottom first clip and the bottom second clip are respectively abutted against two sides of the bottom of the elastic plate model. The end of the bottom bolt rod passes through the bottom first clip, the elastic plate model, the bottom second clip and the bottom spring in sequence. The bottom nut is movably and adjustably installed at the end of the bottom bolt rod. The bottom first clip or the bottom second clip is angle-adjustably installed on the bottom base. When the bottom clamp clamps the bottom of the elastic plate model, the bottom spring is in a compressed state, exerting a force on the bottom second clamp toward the bottom first clamp, clamping the bottom of the elastic plate model between the bottom first clamp and the bottom second clamp.

3. The adjustable constrained elastic plate water wave slamming experimental device according to claim 2, characterized in that: The bottom clamp comprises a plurality of bottom bolt rods, a bottom spring and a bottom nut, so that the bottom of the elastic plate model is stably clamped between the bottom first clamping piece and the bottom second clamping piece.

4. The adjustable constrained elastic plate water wave slamming experimental device according to claim 1, characterized in that: Bottom washers are provided between the bottom nut and the bottom spring, and between the bottom bolt rod head and the bottom first clamping piece.

5. The adjustable constrained elastic plate water wave slamming experimental device according to claim 2, characterized in that: The bottom base includes a bottom plate, a bottom plate connecting hinge and a bottom connecting bolt. The bottom plate is installed on the slope structure through the bottom plate mounting bolts. A bottom connecting hinge is provided at the bottom of the bottom first clamp or the bottom second clamp. The bottom plate connecting hinge is fixed to the bottom plate. The bottom plate connecting hinge and the bottom connecting hinge are connected and fastened by the bottom connecting bolts. Bolt holes for the bottom connecting bolts to pass through are provided on the bottom plate connecting hinge and the bottom connecting hinge.

6. The adjustable constrained elastic plate water wave slamming experimental device according to claim 5, characterized in that: The bottom of the first bottom clip or the second bottom clip is provided with multiple bottom connecting hinges, and the bottom plate is provided with multiple bottom plate connecting hinges one by one. The multiple bottom connecting hinges and the multiple bottom plate connecting hinges are connected and fastened one by one through multiple bottom connecting bolts.

7. The adjustable constrained elastic plate water wave slamming experimental device according to claim 1, characterized in that: The top clamp includes a top bolt rod, a top spring, a top clip assembly and a top nut. The top clip assembly includes a top first clip and a top second clip. The top first clip and the top second clip are respectively abutted against two sides of the top of the elastic plate model. The end of the top bolt rod passes through the top first clip, the elastic plate model, the top second clip and the top spring in sequence. The top nut is movably and adjustably installed at the end of the top bolt rod. The top first clip or the top second clip is installed on the top support structure with an adjustable angle. When the top clamp clamps the top of the elastic plate model, the top spring is in a compressed state, exerting a force on the top second clamp toward the top first clamp, clamping the top of the elastic plate model between the top first clamp and the top second clamp.

8. The adjustable constrained elastic plate water wave slamming experimental device according to claim 7, characterized in that: The top supporting structure includes a top plate, a top plate connecting hinge and a top connecting bolt. The top plate is connected to the tractor. A top connecting hinge is provided on the top of the top first clamp or the top second clamp. The top plate connecting hinge is fixed to the top plate. The top plate connecting hinge and the top connecting hinge are fastened by the top connecting bolts. Bolt holes for the top connecting bolts to pass through are provided on the top plate connecting hinge and the top connecting hinge.

9. The adjustable constrained elastic plate water wave slamming experimental device according to claim 1, characterized in that: The slope structure includes a frame structure and a panel arranged on the frame structure, which is divided into a front slope, a slope top and a rear slope. The bottom base is arranged on the slope top, and the slopes of the front slope and the rear slope are adjustable.

10. The adjustable constrained elastic plate water wave slamming experimental device according to claim 1, characterized in that: The optical motion capture system is arranged obliquely above the elastic plate model through a pad.

Images