Complex dynamic loading test device for offshore structure

Abstract

The invention relates to a complex dynamic loading test device for an offshore structure, and is suitable for the technical field of test equipment for ocean engineering, hydraulic engineering and civil engineering. The test device comprises a model box used for loading a soil sample; the axial loader is mounted on the rack and can be used for applying an axial load to a sample inserted into the soil sample in the model box; the radial loader is mounted on the rack and can be used for applying a radial load to a sample inserted into the soil sample in the model box; the torque loader is mounted on the rack and can be used for applying torque to a sample inserted into the soil sample in the model box; the torque loader comprises a loading arm, the axis direction of which is perpendicular to the axis direction of a sample, the first end of which is provided with a mounting hole, and the second end of which is connected with a rotation driving assembly and a guide assembly; the loading head is provided with a clamping groove and a mounting part, the mounting part can be matched with the mounting hole in the loading arm to realize connection, and the clamping groove can be matched with a clamping part on the sample.

Description

Technical Field

[0001] The present invention relates to a complex dynamic loading test device for offshore structures, particularly suitable for testing and simulating offshore pile foundation structures under combined axial, radial, and torque loads. The device belongs to the technical field of testing equipment for offshore engineering, hydraulic engineering, and civil engineering. Background Art

[0002] With the acceleration of urbanization, the increase in the scale of engineering projects and the continuous improvement of technical requirements, the research on mechanical analysis and deformation characteristics of engineering structures has become increasingly critical. However, in-depth research on these issues requires advanced testing equipment and high-precision detection technology.

[0003] In recent years, testing instrumentation and technology in the marine sector have developed rapidly, leading to an increasing demand for complex load simulation technologies that meet actual stress conditions. Buildings and structures in diverse fields, such as geotechnical engineering, earthquake engineering, hydraulic engineering, and marine engineering, are subject to the coupled effects of multiple dynamic loads during operation and maintenance, including earthquakes, wind, waves, ocean currents, and overhead loads. These dynamic loads involve multi-dimensional stress factors such as axial stress, radial stress, and lateral torque. Especially in complex environments such as high winds and extreme sea conditions, the loads borne by structures exhibit significant asymmetry and randomness. For example, during windy periods, offshore pile foundations must simultaneously cope with the axial impact of random waves, the lateral scouring of ocean currents, and the resulting dynamic torque coupling effects. The time-varying characteristics and spatially asymmetric distribution of these loads (such as the continuous change in torque direction with ocean current deflection) make it difficult for traditional testing equipment to accurately simulate actual operating conditions.

[0004] Existing technologies suffer from the following limitations: Inherent limitations of single-dimensional static loading: Conventional testing devices can only apply static or simple cyclic loads in a single direction (such as axial or radial), failing to replicate the asymmetric dynamic loading characteristics of wave-current coupling. Lack of dynamic coupling mechanisms: Existing technologies lack the ability to dynamically control the coordinated effects of multi-degree-of-freedom loads (axial, radial, and torque). For example, key parameters such as the temporal coupling effect (phase difference Δθ) between wave load peaks and current torque valleys, as well as the non-integer multiple relationship between load frequencies, cannot be accurately simulated, resulting in a significant deviation from the actual progressive damage process of pile foundations. Distorted boundary conditions and mismatched spatial posture: Traditional fixed loading devices struggle to dynamically adjust the spatial posture of the load. For example, with continuous deflection of the current direction (0°-180°), existing technologies can only apply loads at discrete angles (e.g., 30° intervals), resulting in distorted torque distribution and simulated errors exceeding 25% in eccentric pile loading. Furthermore, rigid fixture constraints cause the specimen loading path to be inconsistent with the actual free boundary conditions, further distorting the test results. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in view of the defect that the existing technology cannot realize multi-degree-of-freedom coupled loading, the present invention innovatively proposes a three-degree-of-freedom collaborative loading system, and provides a complex dynamic loading test device for offshore structures that can realize multi-degree-of-freedom coupled load loading, so that the load energy of the specimen in the marine engineering simulation test loading can be more in line with the actual working conditions.

[0006] The technical solution adopted by this invention is: a complex dynamic loading test device, which uses an adjustable loading structure to construct a three-degree-of-freedom coupled loading system in the axial (Z direction), radial (X / Y direction), and rotational (θ direction) directions through axial loaders, radial loaders, and torque loaders, thereby realizing dynamic coupling of multi-dimensional loads. The test device includes: Model box, used to load soil samples; an axial loader, mounted on the frame, capable of applying an axial load to a specimen inserted into the soil sample in the model box; The radial loader is mounted on the frame and can be used to apply radial load to the specimen inserted into the soil sample in the model box; The torque loader is mounted on the frame and can be used to apply torque to the specimen inserted into the soil sample in the model box; The torque loader comprises: The loading arm has an axis perpendicular to the axis of the sample, a first end of the loading arm is provided with a mounting hole, and a second end of the loading arm is connected to the rotation drive assembly and the guide assembly; The loading head has a clamping groove and a mounting piece, wherein the mounting piece can cooperate with the mounting hole on the loading arm to achieve connection, and the clamping groove can cooperate with the clamping part on the sample.

[0007] The torque loader has two upper and lower loading arms, the second ends of the two loading arms are connected by a connecting piece, the mounting hole is a hexagonal hole, and a support plate is provided below the mounting hole of the lower loading arm; The loading head has a hexagonal vertical through hole in it. A hexagonal column-shaped latch is provided in the hexagonal vertical through hole. The latch is adapted to the mounting hole on the loading arm.

[0008] The guide assembly comprises an arc-shaped guide rail and a pulley adapted to the arc-shaped guide rail, and the pulley is installed at the second end of the loading arm.

[0009] The rotary drive assembly has a hydraulic mechanism driven by a hydraulic pump, and the hydraulic mechanism can drive the second end of the loading arm to move along the arc-shaped guide rail.

[0010] The axial loader is installed on the first beam on the frame via the first mounting seat, wherein the first mounting seat can fix the axial loader at any axial position of the first beam, and the first beam can be installed on the frame to move back and forth along a direction perpendicular to its own axis.

[0011] The radial loader is mounted on the second beam on the frame via a second mounting seat, wherein the second mounting seat can fix the radial loader at any axial position of the second beam, and the second beam can be mounted on the frame so as to move back and forth in a direction perpendicular to its own axis.

[0012] The torque loader is mounted on the third beam on the frame via the third mounting seat, wherein the third mounting seat can fix the torque loader at any axial position of the third beam, and the third beam can be mounted on the frame so as to move back and forth in a direction perpendicular to its own axis.

[0013] The axial loader includes a hydraulic jack.

[0014] A limiting ring is provided between the top surface of the sample and the loading surface of the axial loader; The limiting ring is a ring-shaped metal part, the inner diameter of which is slightly larger than the outer diameter of the sample, and has a buffer material inside; The limiting ring is sleeved on the top of the sample, and the upper end of the limiting ring contacts the loading surface of the axial loader.

[0015] The four corners of the model box are provided with slot angle steels, the middle of each side wall of the model box is provided with a slot I-steel, a plurality of wooden templates are provided between the slot I-steel and the slot angle steels, and the two ends of the wooden templates are clamped into the slots.

[0016] The beneficial effects of the present invention are as follows: by providing an axial loader, a radial loader, and a torque loader, the present invention constructs a three-degree-of-freedom collaborative loading system of axial (Z direction), radial (X / Y direction), and rotational (θ direction), thereby achieving high-precision simulation of asymmetric dynamic coupling loads, especially the three-degree-of-freedom collaborative loading of axial impact, lateral shear, and rotational torque under the action of wave-current coupling; a phase difference adjustable mechanism is established to accurately control the timing matching of axial load and torque, and reproduce the dynamic coupling characteristics of wave crests and torque troughs; and adaptive boundary conditions are designed to support continuous deflection of the loading head from 0° to 180°, eliminating the posture mismatch problem caused by discrete angle loading.

[0017] This invention utilizes hexagonal pins that mate with mounting holes to enable rapid assembly and disassembly of the loading head, improving efficiency. The curved track provides a precise sliding path for the torque loader, ensuring smooth and accurate torque loading. The curved track is constructed from high-strength steel to ensure stability under high loads.

[0018] The curved track provides a precise sliding path for the torque loader, guiding it along a defined trajectory. This ensures that the application end can cover different locations on the specimen, thereby simulating the forces acting on the structure in different directions and angles. During the torque application process, the pulley system transmits the applied force to the specimen with minimal friction loss. The curved track's circular arc design ensures the pulley is always in the optimal position, thereby improving loading accuracy. The mixed pulley design ensures smooth sliding within the curved track groove, avoiding uneven load transfer.

[0019] In the present invention, the crossbeam cooperates with the mounting seat to move the axial loader, radial loader and torque loader to any position within the model box, thereby ensuring that the axial loader, radial loader and torque loader can match the sample at any position within the model box.

[0020] The loading head of this invention features a recessed slot with a recessed design to ensure alignment with the specimen's geometric center and avoid eccentric forces. The loading head is designed to be interchangeable to accommodate varying specimen specifications and material properties. The loading head's contact surface utilizes a zigzag contact structure, allowing for relative slippage with the specimen.

[0021] Compared with fixed model test boxes, the present invention uses customized steel components as model box corners and prefabricated I-beams as connectors in the middle, so that the volume of the model box can be adjusted arbitrarily, and the scale of the model test can be adjusted according to different test schemes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of the embodiment.

[0023] Figure 2 Schematic diagram of the structure of the axial loader in the embodiment.

[0024] Figure 3 Schematic diagram of the structure of the radial loader in the embodiment.

[0025] Figure 4 Schematic diagram of the structure of the torque loader in the embodiment.

[0026] 100, model box; 110, slot angle steel; 120, connecting steel plate; 130, limit steel foot; 140, slot I-beam; 150, wooden formwork; 200, rack; 210, upper longitudinal beam; 220, lower longitudinal beam; 230, first cross beam; 240, second cross beam; 250, third cross beam; 300, axial loader; 400, U-shaped fastener; 500, mounting plate; 600, bolt plate; 700, radial loader; 800, torque loader; 810, loading arm; 811, mounting hole; 820, connecting piece; 830, arc guide rail; 840, loading head; 841, latch; 842, snap-in slot. DETAILED DESCRIPTION

[0027] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0028] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0030] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0031] This embodiment is a complex dynamic loading test device for offshore structures, including a model box, a frame, an axial loader, a radial loader, a torque loader, and the like.

[0032] In this embodiment, the model box is a rectangular structure used to load soil samples for the test. The four corners of the model box are made of prefabricated slot angle steels made of steel sections. The bottom of the slot angle steels is connected to the ground with a connecting steel plate and fixed by bolts driven into the ground. Limiting steel feet are set between the connecting steel plate and the side of the slot angle steel to constrain the slot angle steel and prevent sliding displacement. A slot I-beam is set in the middle of the side of the model box. A wooden formwork is used between the slot I-beam and the slot angle steel as an enclosure structure to enclose the test environment. The size and quantity of the structure can be configured according to the size of the environment required by the test model.

[0033] In this example, the frame has reaction frames respectively arranged at both ends of the model box in the width direction, and a first crossbeam, a second crossbeam and a third crossbeam arranged on the two reaction frames.

[0034] In this embodiment, the reaction frames on both sides of the model box are arranged along the length direction of the model box. The reaction frames are provided with an upper longitudinal beam and a lower longitudinal beam located below the upper longitudinal beam. The upper longitudinal beam and the lower longitudinal beam are arranged parallel to the length direction of the model box. The upper longitudinal beam is provided with a track arranged along the axis of the upper longitudinal beam, and the upper surface of the lower longitudinal beam is provided with a row of bolt holes arranged along the axis of the lower longitudinal beam.

[0035] In this embodiment, the first crossbeam is arranged parallel to the width direction of the model box. The two ends of the first crossbeam are installed on the upper longitudinal beams of the reaction frames on both sides of the model box through pulleys, and cooperate with the tracks of the upper longitudinal beams. The first crossbeam can move back and forth on the reaction frame along the direction perpendicular to its own axis through the pulley. A limiter is set corresponding to the pulley to ensure that the gantry can be fixed after sliding to the specified position without slipping, thereby ensuring the stability and accuracy of loading.

[0036] In this example, the second crossbeam is arranged parallel to the width direction of the model box. The two ends of the second crossbeam are fixed to the lower longitudinal beams of the reaction frames on both sides of the model box by bolts, and the connection is achieved by cooperating with the bolt holes at the corresponding positions. The position of the second crossbeam can be adjusted by loosening the bolts and moving back and forth in a direction perpendicular to its own axis, and the second crossbeam can be fixed at any position in the length direction of the model box by cooperating with any bolt hole.

[0037] In this embodiment, the third crossbeam is arranged parallel to the width direction of the model box. The two ends of the third crossbeam are fixed to the lower longitudinal beams of the reaction frames on both sides of the model box by bolts, and the connection is achieved by cooperating with the bolt holes at corresponding positions. The position of the third crossbeam can be adjusted by loosening the bolts and moving back and forth in a direction perpendicular to its own axis, and the third crossbeam can be fixed at any position in the length direction of the model box by cooperating with any bolt hole.

[0038] In this embodiment, the axial loader utilizes a hydraulic jack, which is used to apply an axial load to a specimen inserted into a soil sample within the model box. The hydraulic jack is arranged vertically, with its upper end mounted on the first beam via a first mounting base. The first mounting base comprises a mounting plate, a U-shaped fastener, and a bolt plate. The mounting plate is secured to the upper end of the hydraulic jack and contacts the lower surface of the first beam. The mounting plate is secured to the first beam via the U-shaped fastener and the bolt plate. Adjustment of the U-shaped fastener and the bolt plate allows the mounting plate to be adjusted along the axis of the first beam.

[0039] In this example, the radial loader uses a radial vibrator, which is arranged horizontally. One end of the radial vibrator is mounted on the second beam via a second mounting base. The second mounting base includes a mounting plate, a U-shaped fastener, and a bolt plate. The mounting plate is fixed to the radial loader and placed on the upper surface of the second beam. The mounting plate is secured to the first beam via the U-shaped fastener and the bolt plate. The position of the stopper can be adjusted along the axis of the first beam by adjusting the U-shaped fastener and the bolt plate.

[0040] In this embodiment, the torque loader comprises a loading arm, a loading head, a rotary drive assembly and a guide assembly, wherein there are two loading arms, which are arranged in parallel and horizontally up and down. The first end of each loading arm is provided with a mounting hole, and the two mounting holes correspond to each other up and down. The lower end of the corresponding mounting hole on the lower loading arm is connected to a support plate, and the second ends of the two loading arms are connected to a connecting piece.

[0041] In this embodiment, the guide assembly comprises a curved rail and a pulley adapted for the curved rail. The pulley is mounted at the lower end of the connector, and the curved rail is removably mounted on the third crossbeam. The curved rail is secured to the third crossbeam using L-shaped fasteners and bolts, allowing for adjustment along the crossbeam's axis to accommodate various experimental configurations.

[0042] In this example, the rotary drive assembly has a hydraulic mechanism driven by a hydraulic pump, which can drive the second end of the loading arm to move along the arc guide rail. In the hydraulic mechanism structure of the rotary drive assembly, the hydraulic power unit is powered by a hydraulic pump station (including a motor, an oil tank, and a pressure valve group), and the pump station is connected to the actuator through a high-pressure oil pipe. A proportional servo hydraulic system is used, integrating high-precision pressure sensors and displacement sensors to achieve closed-loop control. Double-acting hydraulic cylinder: The main body is fixed to the mounting base at the end of the third crossbeam through an articulated support. The end of the piston rod is hinged to the drive ear plate on the side of the loading arm connector (820) through a universal joint, forming a flexible connection that can adapt to arc movement. The loading head (840) is preloaded with a pressure sensor on the contact surface with the specimen to provide real-time feedback on the torque value and adjust the hydraulic pressure. After the hydraulic pump is started, the oil flow direction is adjusted according to the control signal; the hydraulic cylinder pushes the loading arm connector to slide along the arc guide rail, and the pulley group constrains the motion trajectory; the loading head transmits the rotation torque to the sample through the hexagonal prism pin (841); the displacement sensor monitors the loading arm rotation angle in real time, and the pressure sensor detects the torque value, forming a closed-loop control.

[0043] In this example, the loading head has a clamping groove and a mounting part, wherein the mounting part can cooperate with the mounting hole on the loading arm to achieve connection, and the clamping groove can cooperate with the clamping part fixed on the sample, and the torque is transmitted to the sample through the clamping groove and the clamping part.

[0044] In this example, the mounting hole is a hexagonal hole, the mounting piece has a hexagonal column-shaped pin that matches the hexagonal hole, and the loading head has a vertical hexagonal through hole inside, which is inserted into the hexagonal vertical through hole.

[0045] In this embodiment, when installing the loading head, the loading head (excluding the latch) can be first installed between the upper and lower loading arms, and the hexagonal vertical through-holes on the loading head can be aligned with the mounting holes on the loading arms. Then, the latches are inserted into the upper and lower mounting holes and the middle hexagonal vertical through-hole to connect the loading head to the loading arms. The lower end of the latch is supported on the support plate below.

[0046] In this example, the center of the arc-shaped guide rail substantially corresponds to the axis position of the clamping slot of the loading head mounted on the loading arm.

[0047] In this embodiment, an acquisition box and a computer are provided outside the device, and the acquisition box and the computer are connected via a data cable. A servo electrical box is also provided outside the device, and the servo electrical box is connected to the axial loader, radial loader, and torque loader respectively via data cables. The servo electrical box controls the servo motors provided inside the axial loader, radial loader, and torque loader, thereby achieving precise control of parameters such as the speed, direction, position, and torque of the servo motors.

[0048] The axial loader, radial loader and torque loader are connected to the acquisition box via data cables. The parameters of the servo motors are transmitted to the acquisition box and processed by a computer to simulate the multidimensionality and randomness of the load.

[0049] In this embodiment, the axial sensor, radial displacement sensor and lateral displacement sensor are respectively attached to the component at the pickup points, and are all connected to the acquisition box through data lines. The parameters monitored by each sensor are transmitted to the acquisition box, and then the data is processed and analyzed by a computer to monitor the displacement of each part of the component, thereby obtaining the actual deformation of the component.

Claims

1. A complex dynamic loading test device for offshore structures, characterized in that: include: The three-degree-of-freedom collaborative loading system consists of an axial loading subsystem, a radial loading subsystem, and a torque loading subsystem; Model box, used to construct soil-structure interaction test environment; An axial loader, mounted on the frame, capable of dynamically loading the sample inserted into the soil sample in the model box in the Z-axis direction; The radial loader is mounted on the frame and can be used to dynamically load the specimen in the X / Y axis direction inserted into the soil sample in the model box; The torque loader is installed on the frame and can be used to realize the θ-axis rotation torque for the sample inserted in the soil sample in the model box; The torque loader comprises: The loading arm has an axis perpendicular to the axis of the sample, a first end of the loading arm is provided with a mounting hole, and a second end of the loading arm is connected to the rotation drive assembly and the guide assembly; A loading head having a snap-in slot and a mounting member, wherein the mounting member can cooperate with the mounting hole on the loading arm to achieve connection, and the snap-in slot can cooperate with the snap-in portion on the specimen; Dynamic torque transmission assembly, with hexagonal pins embedded in the loading head forming a gapless fit with the mounting holes; The hydraulic servo drive module achieves precise torque loading within the angular range through the curved guide rail.

2. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The torque loader has two upper and lower loading arms, the second ends of the two loading arms are connected by a connecting piece, the mounting hole is a hexagonal hole, and a support plate is provided below the mounting hole of the lower loading arm; The loading head has a hexagonal vertical through hole in it. A hexagonal column-shaped latch is provided in the hexagonal vertical through hole. The latch is adapted to the mounting hole on the loading arm.

3. The offshore structure complex dynamic loading test device according to claim 1 or 2, characterized in that: The guide assembly comprises an arc-shaped guide rail and a pulley adapted to the arc-shaped guide rail, and the pulley is installed at the second end of the loading arm.

4. The offshore structure complex dynamic loading test device according to claim 3, characterized in that: The rotary drive assembly has a hydraulic mechanism driven by a hydraulic pump, and the hydraulic mechanism can drive the second end of the loading arm to move along the arc-shaped guide rail.

5. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The axial loader is installed on the first beam on the frame via the first mounting seat, wherein the first mounting seat can fix the axial loader at any axial position of the first beam, and the first beam can be installed on the frame to move back and forth along a direction perpendicular to its own axis.

6. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The radial loader is mounted on the second beam on the frame via a second mounting seat, wherein the second mounting seat can fix the radial loader at any axial position of the second beam, and the second beam can be mounted on the frame so as to move back and forth in a direction perpendicular to its own axis.

7. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The torque loader is mounted on the third beam on the frame via the third mounting seat, wherein the third mounting seat can fix the torque loader at any axial position of the third beam, and the third beam can be mounted on the frame so as to move back and forth in a direction perpendicular to its own axis.

8. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The axial loader includes a hydraulic jack.

9. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: A limiting ring is provided between the top surface of the sample and the loading surface of the axial loader; The limiting ring is a ring-shaped metal part, the inner diameter of which is slightly larger than the outer diameter of the sample, and has a buffer material inside; The limiting ring is sleeved on the top of the sample, and the upper end of the limiting ring contacts the loading surface of the axial loader.

10. The offshore structure complex dynamic loading test device according to claim 1, characterized in that: The four corners of the model box are provided with slot angle steels, the middle of each side wall of the model box is provided with a slot I-steel, a plurality of wooden templates are provided between the slot I-steel and the slot angle steels, and the two ends of the wooden templates are clamped into the slots.

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