Comprehensive fatigue test tool for scaling pod propeller davit

Abstract

The invention 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, the scaling pod propeller davit is fixedly connected with a simulation connection member, the simulation connection 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 invention, 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 invention 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, pod thrusters, as a highly efficient propulsion device, have been widely used in the shipbuilding field. The pod thruster is structurally composed of a steering module and a propulsion module, wherein 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 the pod thruster are directly related to the overall performance and service life of the ship. To ensure its reliability, the pod thruster 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 pod thruster davits, existing technologies often cannot meet the needs of comprehensive fatigue testing. The existing fatigue test tooling usually requires multi-directional and multi-dimensional loading methods, and its structure is complex, the operation is difficult, the test accuracy is insufficient, and it is adapted to different fatigue test machines at the same time. The tooling is not universal. When conducting comprehensive fatigue tests, it is necessary to design corresponding tooling and joints for different loading methods. Currently, there is no patent for fatigue test tooling for scaled pod propeller davits. Therefore, an effective and universal structure for comprehensive fatigue strength testing of scaled pod propeller davits is designed, and a new type of davit fatigue comprehensive fatigue strength testing system is proposed, which 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 view of the problems existing in the prior art, the purpose of the present invention is to provide a comprehensive fatigue test fixture for a scaled-down pod thruster davit, which can be adapted to an MTS fatigue testing machine. The fixture can simplify the testing process, reduce testing costs, and improve the efficiency and accuracy of the test. By adopting a simple structural connection method, the fixture can be quickly assembled and disassembled, while meeting the actual fatigue working environment of the pod thruster davit, so that fatigue testing can be completed only under a single tension condition. Through this fixture, the scaled model can be supported to accurately and efficiently perform fatigue performance evaluation 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 member, a scaled-down pod propeller sling, a simulated connecting member, and an adapter. The scaled-down pod propeller sling is fixedly connected to the vertical plate of the fixed support member by fasteners, the scaled-down pod propeller sling is fixedly connected to the simulated connecting member by fasteners, the simulated connecting member 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 which 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 with the scaled pod thruster suspension column by bolts.

[0006] Furthermore, five rib plates are provided between the vertical plate and the bottom plate, and the rib plates 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. 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 member 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-through-hole cuboid, 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 attached to the upper end of the lower flange surface of the scaled-down pod thruster sling near the rounded corner transition and the corresponding positions on the left and right sides of the starting point of the sling sweeping the teardrop-shaped thin-walled body.

[0013] The beneficial effects of the present invention are:

[0014] 1. Through the optimized adapter design, the comprehensive fatigue test of the davit under a single tensile condition can be realized, which greatly simplifies the test operation.

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

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

[0017] 4. The present invention can realize fatigue testing of the column sample in multiple modes by rotating the column sample, the adapter and the angle of the simulated connecting component without changing the fatigue testing machine, and can truly simulate the actual stress condition of the pod thruster column; the size of the load applied by the fatigue testing machine can be adjusted through the data of the strain gauge to ensure that the load values ​​borne by the key parts of the column 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 column sample and the adapter can be rotated at an appropriate angle.

[0018] In summary, the present invention provides an efficient and low-cost comprehensive fatigue test solution for scaled-down pod thruster slings, which provides important technical support for reliability verification and fatigue performance testing of pod thruster slings. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0022] Figure 4 It 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 pasted on the test suspender;

[0026] In the figure: 1. Fixed support member, 1a. Upper plate, 1b. Support rib plate, 1c. Bottom plate, 2. Scaled pod thruster suspension column, 2a. Upper flange surface, 2b. Lower flange surface, 3. Simulated connection member, 3a. Mountain-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 protection scope of the present invention.

[0028] like Figures 1 to 7 As shown, the present invention 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, and one end of the vertical plate 1a will be bent and twisted, and the hole on the top is a positioning hole. The bottom plate 1c is punched with a hole and connected to the ground groove by bolts. The upper flange surface 2a of the scaled-down pod thruster suspender 2 is punched with a positioning hole and 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 D (see Figure 3 ) is fixed to the plate, wherein two smaller rib plates are on the same side as the scaled pod propeller sling 2, and three larger rib plates 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 connection member 3 by bolt connection method B, and the U-shaped cylinder 3a is connected to the flange plate by welding method E, and the U-shaped cylinder 3a is connected to the adapter 4 by pin method C, and 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 pod thruster davit 2 near the arc transition. These strain gauges are then connected to the signal acquisition device to calculate the stress magnitude of the davit sample 2 at this location. In order to avoid the strain gauge 5 and the simulated connecting member 3 from being squeezed, and also to facilitate the wiring of the strain gauge 5, the size of the flange 3b is controlled to form a certain distance of avoidance space from the strain gauge 5.

[0033] In the above implementation, the vertical plate 1a, the rib plate 1b, the bottom plate 1c, the mountain-shaped 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 groove by bolts. The scaled-down pod thruster sling 2 being tested is made by aligning the holes on the upper flange surface with the positioning holes on the upper plate surface, and then passing bolts of corresponding hole sizes through them, and fastening them 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 shaft. 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, the sling can be subjected to a tensile fatigue test, and the stress magnitude of the sling sample can be obtained through the strain data on the strain gauge 5, thereby facilitating adjustment. In this way, multiple sets of fatigue test result data can be used to draw the SN curve of the sling sample under tensile conditions.

Claims

1. A comprehensive fatigue test tool for a scaled-down pod thruster davit, characterized in that: It includes a fixed supporting member, a scaled pod propeller sling, a simulated connecting member, and an adapter. The vertical plate of the fixed supporting member is fixedly connected to the scaled pod propeller sling by fasteners, the scaled pod propeller sling is fixedly connected to the simulated connecting member by fasteners, the simulated connecting member 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 the scaled-down pod thruster davit according to claim 1 is characterized by: The fixed support structure includes a vertical plate and a bottom plate which are perpendicular to each other. 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 with the scaled pod thruster suspension column by bolts.

3. The comprehensive fatigue test fixture for the scaled-down pod thruster davit according to claim 2 is characterized in that: Five rib plates are arranged between the vertical plate and the bottom plate. The rib plates 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.

4. The comprehensive fatigue testing tool for the scaled-down pod thruster davit according to claim 2 is characterized by: The vertical plate of the fixed support member 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 the scaled-down pod thruster 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 the scaled-down pod thruster davit according to claim 1, characterized in that: When the simulated connecting component is connected to the lower flange surface of the scaled pod thruster sling, an avoidance space is formed at the measured position near the rounded corner transition at the upper end of the lower flange surface of the scaled pod thruster sling.

7. The comprehensive fatigue testing tool for the scaled-down pod thruster davit according to claim 1, characterized in that: The adapter is a double-through-hole cuboid, 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 the scaled-down pod propeller davit according to claim 1 is characterized by: 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 the scaled-down pod thruster davit according to claim 1, characterized in that: Three strain gauges are attached to the upper end of the lower flange surface of the scaled-down pod thruster sling near the rounded corner transition and the corresponding positions on the left and right sides of the starting point of the sling sweeping the teardrop-shaped thin-walled body.

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