Comprehensive fatigue test tool for scaling pod propeller davit

Abstract

The utility model relates to a comprehensive fatigue test tool for a scaling pod propeller davit, which is characterized in that a vertical plate of a fixed support member is fixedly connected with the scaling pod propeller davit through a fastener, a simulation connecting member is fixedly connected onto the scaling pod propeller davit, the simulation connecting member is connected with an adapter through a pin shaft, and the adapter is fixedly connected with the scaling pod propeller davit. And an MTS fatigue testing machine is connected through the adapter. According to the utility model, on the premise that a fatigue testing machine is not changed, the fatigue test of the davit sample piece in multiple modes can be realized by rotating the angles of the davit sample piece, the adapter and the simulation connecting component, and the actual stress condition of the davit of the pod propeller can be really simulated; the size of the load applied by the fatigue testing machine can be adjusted through the data of the strain gauges, so that the load value borne by each key part of the davit sample piece meets the test requirement, the fatigue testing machine does not need to be replaced, and if a fatigue life test under multi-mode superposition needs to be carried out, the davit sample piece and the adapter are rotated by a proper angle.

Description

Technical Field

[0001] The utility model relates to a comprehensive fatigue testing device for a pod propeller, in particular to a comprehensive fatigue testing tool for a scaled-down pod propeller sling. Background Art

[0002] With the continuous development of the shipbuilding industry, podded propulsion has been widely used in the shipbuilding field as a highly efficient propulsion device. Structurally, podded propulsion consists of a steering module and a propulsion module. The propulsion module extends outside the hull and is suspended on the steering module through a davit. A propulsion motor is arranged inside to directly drive the propeller to rotate. The performance and safety of podded propulsion are directly related to the overall performance and service life of the ship. To ensure its reliability, the podded propulsion davit must undergo rigorous fatigue testing. Existing fatigue testing tooling is mostly used for fatigue testing of general structural parts. For components with special structures and stress characteristics such as podded propulsion davits, existing technologies often cannot meet the needs of comprehensive fatigue testing. Abstract: Existing fatigue test tooling usually requires multi-directional and multi-dimensional loading methods. Its structure is complex, operation is difficult, and test accuracy is insufficient. At the same time, it is not universal for adapting to different fatigue test machines. When conducting comprehensive fatigue tests, it is necessary to design corresponding tooling and joints for different loading methods. There is currently no patent for fatigue test tooling for scaled-down pod propeller davits. Therefore, an effective and universal structure for comprehensive fatigue strength testing of scaled-down pod propeller davits is designed, and a new type of davit fatigue comprehensive fatigue strength testing system is proposed. This is of great significance for improving the fatigue strength measurement system of pod propeller davits and accurately obtaining the fatigue life of the davits. Summary of the Invention

[0003] In response to the problems existing in the prior art, the present invention aims to provide a comprehensive fatigue testing fixture for scaled-down pod propeller davits, compatible with MTS fatigue testing machines. This fixture simplifies the testing process, reduces testing costs, and improves testing efficiency and accuracy. By employing a simple connection method, the fixture allows for rapid assembly and disassembly while meeting the actual fatigue operating conditions of pod propeller davits, enabling fatigue testing to be completed under a single tensile force. This fixture supports accurate and efficient fatigue performance evaluation of scaled-down models in a laboratory environment.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a comprehensive fatigue testing tool for a scaled-down pod propeller sling, including a fixed support structure, a scaled-down pod propeller sling, a simulated connecting structure, and an adapter. The scaled-down pod propeller sling is fixedly connected to the vertical plate of the fixed support structure by fasteners, the scaled-down pod propeller sling is fixedly connected to the simulated connecting structure by fasteners, the simulated connecting structure is connected to the adapter through a pin shaft, and is connected to the MTS fatigue testing machine through the adapter.

[0005] Furthermore, the fixed support structure includes a vertical plate and a bottom plate that are perpendicular to each other, and the vertical plate and the bottom plate are connected into one by welding, wherein the bottom plate is connected to the ground or other structures by bolts to keep it fixed, and positioning holes are punched at corresponding positions on the connecting surface of the vertical plate for connection to the scaled pod thruster suspension column by bolts.

[0006] Furthermore, five ribs are provided between the vertical plate and the bottom plate. The ribs are connected to the vertical plate a and the bottom plate by welding, and avoid covering the positioning holes drilled on the upper plate surface.

[0007] Furthermore, the vertical plate of the fixed support member has a certain offset during the test, and the offset changes accordingly with the load applied by the fatigue testing machine, and the range of the offset is 0-0.5mm under the premise of not exceeding 150KN.

[0008] Furthermore, the simulated connecting component is composed of a flange and a U-shaped cylinder with a through hole. The flange is connected to the lower flange surface of the scaled-down pod thruster sling by bolts, and the U-shaped cylinder is welded between the flange and the adapter. The simulated connecting component is used to accurately simulate the actual force transmission and distribution of the sling.

[0009] Furthermore, when the simulated connecting component is connected to the lower flange surface of the scaled pod propeller sling, an avoidance space is formed at a position measured near the rounded corner transition at the upper end of the lower flange surface of the scaled pod propeller sling.

[0010] Furthermore, the adapter is a double-hole rectangular parallelepiped, one end of which is cut to form a matching gap, matching the mountain-shaped cylinder and connected by a pin.

[0011] Furthermore, the fixed support members and simulated connection members are made of Q235B material, and the adapters are made of 35# steel.

[0012] Furthermore, three strain gauges are affixed to the corresponding positions of the upper end of the lower flange surface of the scaled-down pod thruster sling near the rounded corner transition and the left and right rotation positions of the starting point of the sling sweeping the teardrop-shaped thin-walled body.

[0013] The beneficial effects of the utility model are:

[0014] 1. Through the optimized adapter design, comprehensive fatigue testing of the davit under single tension conditions is achieved, greatly simplifying the testing operation.

[0015] 2. The simplification of the structure significantly reduces the dependence on complex multi-dimensional detection equipment, reducing equipment and operating costs.

[0016] 3. Accurate simulation of the actual stress state of the suspender improves the accuracy and reliability of the test results.

[0017] 4. The utility model can realize multi-mode fatigue testing of the davit sample by rotating the angle of the davit sample, the adapter and the simulated connecting component without changing the fatigue testing machine, and can truly simulate the actual stress conditions of the pod thruster davit; the size of the load applied by the fatigue testing machine can be adjusted by the data of the strain gauge to ensure that the load values ​​borne by the key parts of the davit sample meet the test requirements. At the same time, this test device is simple to operate and there is no need to replace the fatigue testing machine. If a fatigue life test under multi-mode superposition is required, the davit sample and the adapter can be rotated at an appropriate angle.

[0018] In summary, the utility model provides an efficient and low-cost comprehensive fatigue testing solution for scaled-down podded propeller davits, which provides important technical support for reliability verification and fatigue performance testing of podded propeller davits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the fatigue test fixture in pure pulling mode of the present invention;

[0020] Figure 2 This is a schematic diagram of the fatigue test fixture in the tension-bending mode of the present invention;

[0021] Figure 3 is a schematic diagram of the supporting rib member;

[0022] Figure 4 This is a schematic diagram of the scaled-down pod thruster davit;

[0023] Figure 5 is a schematic diagram of simulated connection components;

[0024] Figure 6 This is a schematic diagram of the adapter;

[0025] Figure 7 This is a schematic diagram of the location of the strain gauges attached to the test davit;

[0026] In the figure: 1. Fixed support member, 1a. Upper plate, 1b. Support rib, 1c. Bottom plate, 2. Scaled pod thruster davit, 2a. Upper flange surface, 2b. Lower flange surface, 3. Simulated connection member, 3a. V-shaped cylinder, 3b. Flange plate, 4. Adapter, 5. Strain gauge. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the preferred embodiments cannot be used to limit the scope of protection of the present invention.

[0028] like Figures 1 to 7 As shown, the utility model provides a tool for comprehensive fatigue testing of a scaled-down pod thruster davit, comprising:

[0029] The vertical plate 1a and the bottom plate 1c are perpendicular to each other. One end of the vertical plate 1a will be bent and twisted. The hole on the top is a positioning hole. The bottom plate 1c is punched with holes and is connected to the ground groove by bolts. The upper flange surface 2a of the scaled pod thruster davit 2 is punched with positioning holes and is fixed to the vertical plate 1a by bolt connection method A.

[0030] Five supporting ribs 1b perpendicular to the vertical plate 1a and the bottom plate 1c are connected by welding (see Figure 3 ) is fixed to the plate, wherein the two smaller ribs are on the same side as the scaled pod propeller sling 2, and the three larger ribs are not on the same side as the scaled pod propeller sling 2.

[0031] The lower flange surface 2b of the scaled-down pod thruster davit 2 is connected to the flange surface 3b of the simulated connecting member 3 via bolt connection method B. Simultaneously, the U-shaped cylinder 3a is welded to the flange plate via method E. The U-shaped cylinder 3a is connected to the adapter 4 via pin connection method C. The other end of the adapter is connected to the joint of the fatigue testing machine.

[0032] like Figure 7 As shown, strain gauges 5 are attached to the upper end of the lower flange surface of the scaled-down podded thruster davit 2, near the arc transition. These strain gauges are connected to a signal acquisition device to calculate the stress magnitude at this location on the davit specimen 2. To prevent compression between the strain gauge 5 and the simulated connecting member 3 and to facilitate wiring of the strain gauge 5, the size of the flange 3b is controlled to create a certain clearance from the strain gauge 5.

[0033] In the above embodiment, the vertical plate 1a, the rib plate 1b, the bottom plate 1c, the gabled cylinder 3a, and the flange 3b are all made of Q235B material, and the adapter 4 is made of 35# steel.

[0034] During the use of the present invention, holes are punched on the bottom plate 1c and connected to the ground trough by bolts. The scaled-down pod thruster sling 2 being tested is aligned with the holes on the upper flange surface and the positioning holes on the upper plate surface, and then bolts of corresponding hole sizes are passed through them, and fastened with spring washers and nuts. The bolts and nuts are tightened to a predetermined preload. The lower flange surface 2b of the sling sample is connected to the flange plate 3b of the simulated connecting member by bolts, and the adapter is connected to the simulated connecting member and the MTS fatigue testing machine by means of a pin. In this case, the fatigue testing machine transfers the periodic load to the adapter through a pin, and the adapter transfers it to the simulated connecting member through a pin, and the simulated connecting member transfers it to the sling sample through bolts, while the vertical plate simulates the bottom plate of the ship. Figure 1 In the case shown, a tensile fatigue test can be performed on the suspender column. The strain data on the strain gauge 5 can be used to determine the force applied to the suspender column sample, thereby facilitating adjustment. Multiple sets of fatigue test result data can be used to draw the SN curve of the suspender column sample under tensile conditions.

Claims

1. A comprehensive fatigue test fixture for a scaled-down pod thruster davit, characterized by: It includes a fixed support structure, a scaled pod propeller sling, a simulated connection structure, and an adapter. The vertical plate of the fixed support structure is fixedly connected to the scaled pod propeller sling through fasteners. The scaled pod propeller sling is fixedly connected to the simulated connection structure through fasteners. The simulated connection structure is connected to the adapter through a pin shaft, and is connected to the MTS fatigue testing machine through the adapter.

2. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: The fixed support structure includes a vertical plate and a bottom plate that are perpendicular to each other. The vertical plate and the bottom plate are connected into one piece by welding, wherein the bottom plate is connected to the ground or other structures by bolts to keep it fixed. Positioning holes are punched at corresponding positions on the connecting surface of the vertical plate for connection to the scaled pod thruster suspension column by bolts.

3. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 2, characterized in that: There are five ribs between the vertical plate and the bottom plate. The ribs are connected to the vertical plate a and the bottom plate by welding, and avoid covering the positioning holes punched on the upper plate surface.

4. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 2, characterized in that: The vertical plate of the fixed support structure has a certain offset during the test. The offset changes accordingly with the load applied by the fatigue testing machine. The range of the offset is 0-0.5mm under the premise of not exceeding 150KN.

5. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: The simulated connecting component consists of a flange and a U-shaped cylinder with a through hole. The flange is connected to the lower flange surface of the scaled-down pod thruster sling by bolts. The U-shaped cylinder is welded between the flange and the adapter. The simulated connecting component is used to accurately simulate the actual force transmission and distribution of the sling.

6. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: When the simulated connecting component is connected to the lower flange surface of the scaled pod propeller sling, an avoidance space is formed at the position measured near the rounded corner transition at the upper end of the lower flange surface of the scaled pod propeller sling.

7. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: The adapter is a double-hole rectangular parallelepiped, one end of which is cut to form a matching gap, matching the mountain-shaped cylinder and connected by a pin.

8. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: Fixed support components and simulated connection components are made of Q235B material, and adapters are made of 35# steel.

9. The comprehensive fatigue testing tool for scaled-down pod propeller davit according to claim 1, characterized in that: Three strain gauges are attached to the corresponding positions on the upper end of the lower flange surface of the scaled-down pod thruster davit, near the rounded corner transition, and on the left and right sides of the starting point of the davit's swept teardrop-shaped thin-walled body.

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