Device and method for testing static stiffness of diaphragm assembly

Abstract

The invention belongs to the technical field of elastic assembly static test, and particularly relates to a diaphragm assembly static rigidity testing device and method.The axial rigidity testing device is composed of a diaphragm assembly mounting platform, an axial loading oil cylinder, an axial first end plate, a loading supporting plate, an axial second end plate, a displacement sensor and a force sensor, the loading supporting plate is connected with the axial loading oil cylinder and the diaphragm assembly, the displacement sensor measures axial displacement, the force sensor monitors loading force, the radial rigidity testing device comprises a radial loading rod and a loading mechanism, the loading rod is arranged in the horizontal direction, one end of the loading rod is fixed to the second axial end plate, and the other end of the loading rod is connected to the loading mechanism; and the radial loading mechanism applies a radial load to enable the axial second end plate to deflect around the central axis of the diaphragm assembly so as to measure the radial rigidity. Through the loading supporting structure, the displacement and force sensor for accurate measurement and the linkage type radial loading mechanism which are coaxially arranged, high precision, stability and adaptability of the test are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of static tests of elastic components. Specifically, it relates to a diaphragm component static stiffness test device and a test method. Background Art

[0002] In modern ship transmission systems, elastic couplings are important components connecting the main propulsion motor and the drive shaft system. One of their key components is the diaphragm component. The main function of the diaphragm component is to compensate for large axial and radial offsets of the ship drive shaft system, and at the same time play a vibration isolation role to reduce the transmission of the main propulsion motor vibration to the drive shaft system and ensure effective power transmission. Since both the axial and radial offset compensation capabilities and the vibration isolation performance are closely related to the stiffness index, the stiffness test of the diaphragm component is an important link in the design of elastic couplings, which can provide data support for its optimal design and be used to verify the static stiffness calculation results.

[0003] Currently, there are few test devices for the stiffness test of marine elastic couplings. Especially for the diaphragm component as an elastic structure, the accurate test of its axial and radial stiffness faces certain technical difficulties. When designing a special test device, it is necessary to reasonably eliminate the influence of the test device itself on the test data, and at the same time develop a high-precision test system to collect test data and perform calculation and analysis to obtain reliable stiffness data.

[0004] In the prior art, CN116698313A discloses a stiffness test bench with a torque load. This test bench can measure the axial and radial stiffness of the elastic coupling under load conditions and describes the specific structure of the test bench in detail. However, due to the large differences in the volume and interface structure between the diaphragm component and the elastic coupling, the elastic coupling consists of multiple diaphragm components, end plates, bolts, flanges, etc. Usually, as a complete component, it is connected to the drive shaft through a flange during installation and the coaxiality is ensured. Its stiffness characteristics are the coupling of axial, radial, and angular stiffness. While the diaphragm component is only a part of the elastic coupling, mainly composed of single or multiple thin metal diaphragms, and is usually fixed between the flanges at both ends of the coupling by clamping or bolts during installation. Its stiffness characteristics are that the axial and radial stiffnesses are relatively independent. And the tested elastic coupling is installed in the base of a rectangular frame, fixed at one end and loaded at the other end. The loading space of this device is restricted by the fixed positions of the axial loading cylinder and the radial loading cylinder, making it difficult to test the stiffness of the diaphragm component.

[0005] In addition, CN118583410A discloses a method for testing the angular stiffness and radial stiffness of a diaphragm coupling. The stiffness value is solved by combining the test data with the calculation models of the angular and radial stiffness of the diaphragm coupling. However, in this method, the thickness and length dimensions of the adapter connected to the diaphragm coupling are related to the thickness of the diaphragm group. Therefore, this test method is not applicable to the stiffness test of large-sized and complex-structured elastic couplings for ships. In addition, this method does not involve the test of axial stiffness and cannot meet the requirements of the ship transmission system for all-round stiffness testing.

[0006] In ship applications, elastic couplings are usually composed of multiple sets of circular diaphragm assemblies connected in series. Therefore, it is necessary to test the stiffness of a single set of diaphragm assemblies. This not only helps to obtain the basic stiffness data of the diaphragm assemblies but also enables the deduction of the overall stiffness parameters of the entire machine's elastic coupling through series-parallel relationships. However, the existing technical solutions cannot fully meet the requirements of the stiffness test of marine diaphragm assemblies. There is an urgent need to develop a stiffness test device suitable for marine diaphragm assemblies to improve the test accuracy and automation level and ensure the accuracy and reliability of the test data. Summary of the Invention

[0007] In view of the above problems, the present invention provides a static stiffness test device and method for diaphragm assemblies, which solve the technical problems in the prior art that the stiffness test device for diaphragm assemblies has insufficient accuracy and low automation level and is difficult to meet the requirements of the stiffness test of the ship transmission system. It can effectively measure the axial stiffness and radial stiffness of the diaphragm assemblies and evaluate their mechanical properties.

[0008] A static stiffness test device for diaphragm assemblies provided by the present invention, wherein the diaphragm assembly is composed of a plurality of elastic circular thin sheets combined in an axially juxtaposed manner. Each of the elastic circular sheets is provided with a first type of mounting through hole that penetrates and communicates with each other along the inner side of its outer edge. Each elastic circular sheet is provided with a coaxial central hole at its center position, and a second type of mounting hole for connecting with an external coupling is further opened at the edge part of the central hole; the static stiffness test device for diaphragm assemblies includes an axial stiffness test device and a radial stiffness test device.

[0009] The axial stiffness test mechanism includes a diaphragm assembly mounting platform, an axial loading oil cylinder, an axial first end plate, a loading support plate, an axial second end plate, a displacement sensor, and a force sensor; the axial stiffness test mechanism is used to measure the axial stiffness characteristics of the diaphragm assembly under controlled loading conditions to obtain the deformation response characteristics of the diaphragm assembly under axial force.

[0010] Among them, the axial first end plate, the loading support plate, and the axial second end plate are respectively provided with coaxial central holes penetrating along the central axis direction; the first side of the loading support plate is fixedly installed on the diaphragm assembly installation platform, and the axial loading oil cylinder is arranged in the middle of the first side of the loading support plate. The loading rod of the axial loading oil cylinder passes through the central hole of the loading support plate and realizes controllable telescopic movement along the axial direction to apply an axial loading force to the diaphragm assembly; the second side of the loading support plate is fixedly connected to the first type of installation through hole of the diaphragm assembly, so that the axial loading force is effectively transmitted to the measured diaphragm assembly through the structure of the loading support plate.

[0011] The axial second end plate and the axial first end plate are respectively arranged on both sides of the central hole of the diaphragm assembly and are fixedly connected to the first type of installation through hole of the diaphragm assembly; among them, the axial first end plate is arranged on the side close to the loading rod of the axial loading oil cylinder and is connected to the loading rod of the axial loading oil cylinder through a force sensor; the force sensor is fixedly installed at the central position of the axial first end plate and is coaxially arranged with the axial loading rod along the central axis direction to measure the axial load applied to the diaphragm assembly during the loading process of the axial loading oil cylinder.

[0012] The displacement sensor is fixedly installed on the outside of the axial second end plate, and its sensing end contacts the end face of the axial second end plate in the initial state and is used to detect the axial deformation amount of the diaphragm assembly under the axial loading during the axial stiffness test.

[0013] The radial stiffness test mechanism is arranged on the outside of the axial second end plate and includes a radial loading rod and a radial loading mechanism; among them, the radial loading rod is arranged horizontally and is coaxially arranged with the axis of the central hole of the diaphragm assembly; one end of the radial loading rod is fixedly connected to the axial second end plate, and the other end is connected to the radial loading mechanism; the radial loading mechanism is used to apply a predetermined radial load to the radial loading rod, so that the axial second end plate deflects around the central axis of the diaphragm assembly, and by measuring the mapping relationship between the deflection angle of the axial second end plate and the radial load, the radial stiffness characteristics of the diaphragm assembly are obtained.

[0014] In a preferred implementation manner, further, both the axial second end plate and the axial first end plate are constructed as disc parts with a stepped structure, and a coaxial through hole penetrating along the axial direction is provided in the central region for adapting to the installation requirements of the diaphragm assembly; among them, the stepped structure is formed by connecting a large-diameter disc and a small-diameter annular column, and the outer diameter size of the small-diameter annular column matches the inner diameter size of the diaphragm assembly and is nested and installed in the inner diameter of the diaphragm assembly by means of a transition fit.

[0015] In a preferred implementation manner, further, the loading support plate is composed of a diaphragm assembly connecting plate, a transition plate, and an axial backing plate stacked in sequence along the axial direction.

[0016] In a preferred implementation, further, in the configuration design of the loading support structure of the radial stiffness testing device, a radial end plate is used to replace the axial second end plate to optimize the force transmission path during the radial loading process; the radial end plate is assembled into an integrated structure by welding a loading rod, an end plate, and a sector-shaped rib plate; wherein, the loading rod is fixed to the end plate by welding, and the sector-shaped rib plate is arranged between the end plate and the loading rod; the end plate is arranged outside the central hole of the diaphragm assembly.

[0017] In a preferred implementation, further, the radial loading mechanism includes a sensor connection bracket, a spherical plain bearing, a radial loading cylinder sensor, an intermediate bolt, a radial loading cylinder, and an oil cylinder connection bracket; there are two spherical plain bearings, which respectively form a rotatable connection with the sensor connection bracket and the oil cylinder connection bracket; the radial loading cylinder sensor is fixed to the bottom of the sensor connection bracket and is used to measure in real time the radial load applied by the push rod of the radial loading cylinder to the diaphragm assembly; the top end of the push rod of the radial loading cylinder is connected to the radial loading cylinder sensor through the intermediate bolt.

[0018] In a preferred implementation, further, the displacement sensors are arranged in a dual-sensor symmetric configuration structure, and the number of them is two, which are respectively arranged on the inner sides of the upper and lower edges of the axial second end plate along the same vertical direction to construct a symmetric measurement reference; wherein, the measurement axes of the two displacement sensors are symmetrically arranged along the vertical direction and are evenly distributed relative to the central axis of the axial second end plate, so that when the diaphragm assembly is subjected to an axial load, the axial displacement data of the diaphragm assembly at different positions can be obtained synchronously.

[0019] In a preferred implementation, further, the diaphragm assembly mounting platform adopts a frame structure design, and its main frame is assembled into an integrated load-bearing structure by welding a plurality of rib plate members; the cross-sectional configuration of the rib plate adopts an H-shaped structure.

[0020] In a preferred implementation, further, it further includes a reverse measurement device for auxiliary testing and data calibration, and the reverse measurement device is fixedly installed on the diaphragm assembly mounting platform.

[0021] A testing method using the diaphragm assembly static stiffness testing device described in any one of the above, the testing method includes an axial stiffness testing method and a radial stiffness testing method; the axial stiffness testing method includes:

[0022] Step 1: Install the diaphragm assembly on the test bench, tighten the installation bolts according to the predetermined torque specification using a high-precision torque wrench, and record the pre-tightening force of each bolt.

[0023] Step 2: Arrange a force sensor in the central area of the diaphragm assembly, fix a sensor bracket inside the edge of the second axial end plate, make the end of the displacement sensor contact the surface of the second axial end plate, and connect the electrical signals of each sensor to the computer data acquisition system through a signal collector;

[0024] Step 3: Start the axial loading device, apply a small axial displacement to the diaphragm assembly to simulate the initial loading state, record the initial data of the axial load and axial displacement, calculate the initial axial stiffness, and judge whether there is an abnormality in the measured value of the initial data based on this calculated value; if the data deviates from the expected range, perform sensor calibration or loading system inspection;

[0025] Step 4: After the pre-test results show that the output load of the loading device, the axial displacement capacity of the diaphragm assembly, and the measured data of each sensor all meet the test requirements, stop the axial loading, remove all preloads, restore the diaphragm assembly to the initial zero position state, and perform zero calibration of the displacement sensor;

[0026] Step 5: Set the loading rate of the axial displacement load. In each test cycle, gradually reciprocally increase and decrease the loading force, continuously record the applied axial load and the measured axial displacement data, and calculate the axial stiffness based on the force-displacement relationship;

[0027] Step 6: Repeat the axial loading test at least three times, obtain the calculated values of the axial stiffness under different test cycles, perform statistical analysis on the test data, and evaluate the stability of the data based on the standard deviation;

[0028] Step 7: Calculate the percentage error between the obtained test data and the theoretical simulation data, and judge whether the axial stiffness of the diaphragm assembly meets the predetermined design standard based on the error range; when the error value is less than 5%, it is determined that the axial stiffness test result meets the design requirements;

[0029] The radial stiffness test method includes:

[0030] Step 1: Install the diaphragm assembly on the test bench, tighten the installation bolts with a high-precision torque wrench according to the set torque value, and record the pre-tightening force values of each bolt;

[0031] Step 2: Arrange a force sensor in the loading oil cylinder to ensure that its measurement axis is aligned with the radial loading direction, symmetrically arrange two displacement sensors above the radial end plate, and at the same time transmit all sensor signals to the computer data processing system through a signal collector;

[0032] Step 3: Start the radial loading device, apply a small radial load to the diaphragm assembly to simulate the actual test environment, record the measured values of the two displacement sensors and the radial loading force, and calculate the rotation angle of the diaphragm assembly based on the measurement data; if the calculation result deviates from the expected range, sensor adjustment or loading system inspection is required. Finally, numerically correct the calculated rotation angle value of the diaphragm assembly and use it as the control parameter for the formal test;

[0033] Step 4: After the pre-test results show that the output load of the loading device, the radial rotation angle of the diaphragm assembly, and the measurement data of each sensor all meet the experimental requirements, stop the radial loading, remove all preloads, restore the diaphragm assembly to the initial zero position state, and perform zero calibration of the displacement sensor;

[0034] Step 5: Set the loading rate of the radial displacement load. In each test cycle, gradually increase and decrease the radial loading force reciprocally, continuously record the applied radial load and the measured displacement change, calculate the angular displacement of the diaphragm assembly, and record the bending moment generated during the radial loading process. Calculate the radial stiffness of the diaphragm assembly through the bending moment-angular displacement relationship;

[0035] Step 6: Repeat the radial loading test at least three times, obtain the stiffness calculation values under different test cycles, and perform statistical analysis on the test data. Evaluate the stability of the test data based on the standard deviation;

[0036] Step 7: Calculate the percentage error between the obtained test data and the theoretical simulation data, and determine whether the radial stiffness of the diaphragm assembly meets the design requirements based on the error range; when the error value is less than 5%, it is determined that the radial stiffness test result meets the design standard.

[0037] In a preferred implementation, further, in step 3 of the radial stiffness test method, the rotation angle α of the diaphragm assembly is determined by the following formula:

[0038]

[0039] Where: h represents the height between the displacement sensor and the axis of the diaphragm assembly; Δx1 and Δx2 are the displacements measured by the two displacement sensors respectively.

[0040] The beneficial effects of the present invention are:

[0041] First, the present invention provides a diaphragm assembly static stiffness testing device with high precision, stable structure, and accurate measurement, which can effectively measure the axial stiffness and radial stiffness of the diaphragm assembly and evaluate its mechanical properties. The device adopts a modular design, and the axial stiffness testing device and the radial stiffness testing device can be used independently or in combination to ensure the adaptability and efficiency of the test. The coaxial arrangement of the loading support plate, the axial first end plate, and the axial second end plate ensures uniform load transfer, reduces test errors, and improves measurement accuracy. The axial loading rod of the axial loading cylinder moves along the direction of the central hole to ensure accurate force transfer. At the same time, the force sensor is coaxially arranged with the axial loading rod, which can accurately measure the axial load and improve the reliability of the data. The precise measurement of the displacement sensor ensures the high-precision recording of the axial displacement and optimizes the accuracy of the test results. The radial stiffness testing device adopts a linkage design of the radial loading rod and the radial loading mechanism to ensure that the deflection of the axial second end plate around the central axis of the diaphragm assembly is controlled. Combining the sensor data of the measured displacement and force, high-precision calculation of the radial stiffness is achieved. The device has strong overall rigidity and high measurement accuracy, is suitable for the stiffness testing of diaphragm assemblies of different specifications, provides reliable data support for the optimized design and engineering application of diaphragm assemblies, and improves the efficiency of product quality control and experimental testing.

[0042] Second, in the preferred implementation mode, the present invention adopts the axial first end plate and the axial second end plate with a stepped structure. Through the combined design of the large-diameter disc and the small-diameter annular column, precise support and centering positioning of the diaphragm assembly are achieved. The small-diameter annular column is nested in the inner ring of the diaphragm assembly by an interference fit method to ensure high coaxiality during installation, effectively reduce the eccentric error, and improve the uniformity of the force and the accuracy of the measurement during the loading process.

[0043] Third, in the preferred implementation mode, the present invention adopts a loading support plate formed by sequentially stacking a diaphragm assembly connecting plate, a transition plate, and an axial cushion plate. By optimizing the force transmission path through a multi-layer structure, the overall stiffness and anti-deformation ability are improved. The diaphragm assembly connecting plate provides a stable installation base, the transition plate ensures uniform load distribution, and the axial cushion plate further optimizes the force transmission, reduces local stress concentration, and improves the test accuracy. This design not only enhances the structural stability of the device but also effectively reduces the measurement error caused by support deformation, thereby improving the accuracy and repeatability of the axial stiffness test.

[0044] Fourth, in the preferred implementation mode, the present invention replaces the axial second end plate with a radial end plate as the loading support structure, optimizes the application method of the radial load, and improves the stability and accuracy of the test. The radial end plate is welded by a loading rod, an end plate, and a fan-shaped rib plate, which enhances the overall structural stiffness, enables the loading rod to transfer the radial load more evenly, and reduces the influence of local stress concentration and structural deformation on the test results.

[0045] Fifth, in the preferred implementation mode, the present invention adopts a modular radial loading mechanism. Through the reasonable combination of a sensor connection bracket, a spherical plain bearing, a radial loading cylinder sensor, an intermediate bolt, a radial loading cylinder, an oil cylinder connection bracket, and a radial loading cylinder bracket, efficient and stable radial load transmission is achieved. The double-point support design of the spherical plain bearing ensures uniform stress during the radial loading process and reduces the interference of lateral stress on the measurement accuracy. The radial loading cylinder bracket is fixed on the diaphragm assembly installation platform by a bolt connection method, ensuring the stability of the device. The direct installation of the oil cylinder connection bracket simplifies the structure and reduces the assembly error.

[0046] Sixth, in the preferred implementation mode, the present invention adopts two symmetrically arranged displacement sensors, which are distributed along the same vertical direction on the inner sides of the upper and lower edges of the axial second end plate or the radial end plate, and can accurately capture the rotational displacement of the end plate around the central axis of the diaphragm assembly, providing high-precision data support for calculating the axial stiffness and radial stiffness of the diaphragm assembly, thereby improving the reliability of the test.

[0047] Seventh, in the preferred implementation mode, the present invention adopts a diaphragm assembly installation platform with a frame structure, and its rib plates adopt an H-shaped cross-sectional structure, greatly improving the overall stiffness and bending strength of the platform.

[0048] Eighth, in the preferred implementation mode, the present invention further includes a reverse measurement device, which is fixedly installed on the diaphragm assembly installation platform and is used to monitor the deformation of the platform itself during the test in real time. This device can detect and compensate for the error caused by the deformation of the test bench under force to the test data, ensuring that the measured displacement change during the test only comes from the diaphragm assembly itself, thereby improving the accuracy and credibility of the test results.

[0049] Ninth, the test method of the diaphragm assembly static stiffness test device of the present invention covers axial stiffness test and radial stiffness test, ensuring the accuracy, repeatability, and data reliability of the test process. Through systematic steps such as bolt pre-tightening force recording, sensor arrangement, pre-testing, loading test, data calculation, and error analysis, the stability of the test results is ensured. Linear regression or curve fitting is used to calculate the axial stiffness, and segmented stiffness calculation can be performed when the data shows non-linearity to improve the measurement accuracy. In the radial stiffness test, the rotation angle of the diaphragm assembly is measured by a displacement sensor, and the bending moment is calculated in combination with the radial loading force to achieve high-precision bending moment-angular displacement calculation. In addition, this method ensures data stability by repeating the test multiple times and calculating the standard deviation, and compares the error with the theoretical simulation data. When the error is less than 5%, the test results are considered to meet the design requirements. This test method can not only accurately evaluate the mechanical properties of the diaphragm assembly, but also optimize the test process, improve the experimental efficiency, and provide a basis for highly reliable design verification, and is widely applicable to elastic couplings, engineering structure analysis, and related mechanical research. Brief Description of the Drawings

[0050] Figure 1 is a schematic diagram of the diaphragm assembly static stiffness test device according to an embodiment of the present invention;

[0051] Figure 2 is a schematic diagram of the first axial end plate according to an embodiment of the present invention;

[0052] Figure 3 is a schematic diagram of the axial stiffness test device according to an embodiment of the present invention;

[0053] Figure 4 is a schematic diagram of the diaphragm assembly mounting platform according to an embodiment of the present invention;

[0054] Figure 5 is a schematic diagram of the loading support plate and the axial loading oil cylinder according to an embodiment of the present invention;

[0055] Figure 6 is a schematic diagram of the radial loading mechanism according to an embodiment of the present invention;

[0056] Figure 7 is a schematic diagram for converting the rotation angle of the diaphragm assembly in the radial stiffness test of the test method of the diaphragm assembly static stiffness test device according to an embodiment of the present invention.

[0057] Wherein, 1 - diaphragm assembly mounting platform; 2 - reverse measuring device; 3 - axial loading oil cylinder; 4 - first axial end plate; 5 - loading support plate; 50 - diaphragm assembly connecting plate; 51 - transition plate; 52 - axial cushion plate; 6 - second axial end plate; 7 - displacement sensor; 8 - radial end plate; 9 - radial loading mechanism; 90 - sensor connection bracket; 91 - spherical plain bearing; 92 - radial loading oil cylinder sensor; 93 - intermediate bolt; 94 - radial loading oil cylinder; 95 - oil cylinder connection bracket; 10 - radial loading oil cylinder bracket; 11 - sensor rack; 12 - diaphragm assembly; 13 - bottom plate. Detailed Embodiments

[0058] In order to enable those skilled in the art to better understand the technical solutions of the present application, the following will further describe the present invention in detail with reference to the drawings and embodiments.

[0059] The orientation terms such as up, down, left, right, front, and back in the present application document are established based on the positional relationship shown in the drawings. If the drawings are different, the corresponding positional relationship may also change accordingly. Therefore, it should not be understood as a limitation of the protection scope.

[0060] In this application, terms such as "installation", "connection", "engagement", "attachment", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection or a connection that allows mutual communication, a direct connection, or an indirect connection through an intermediate medium. It can be the connection inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] The present invention aims to provide a static stiffness testing device and method for a diaphragm assembly. It adopts a modular design and is composed of an axial stiffness testing device and a radial stiffness testing device. The axial stiffness testing device applies an axial load to the diaphragm assembly by using an axial loading oil cylinder, measures the displacement through a displacement sensor, and combines with a force sensor to obtain a force-displacement curve, thereby calculating the axial stiffness. The radial stiffness testing device applies a bending moment through a radial loading mechanism to cause the diaphragm assembly to generate an angular displacement, and calculates the radial stiffness by measuring the torque-angular displacement relationship. It can accurately measure the static stiffness characteristics of the diaphragm assembly and compare the experimental results with the simulation calculation results to ensure the reliability and feasibility of the testing device. The device has a stable structure and high measurement accuracy, is applicable to the testing of diaphragm assemblies with different sizes and structures, and can provide accurate experimental basis for the design, optimization and engineering application of diaphragm assemblies.

[0062] Embodiment 1

[0063] Referring to the attached drawings of the specification Figure 1 , a static stiffness testing device for a diaphragm assembly is used to measure the axial stiffness and radial stiffness of the diaphragm assembly to evaluate its mechanical properties. The static stiffness testing device for the diaphragm assembly includes an axial stiffness testing device and a radial stiffness testing device. The axial stiffness testing device includes an axial second end plate 6, an axial first end plate 4, a diaphragm assembly mounting platform 1, a loading support plate 5, an axial loading oil cylinder 3, a displacement sensor 7 and a force sensor.

[0064] The loading support plate 5 serves as an intermediate support structure connecting the axial loading oil cylinder 3 and the diaphragm assembly 12 to ensure that the axial load is evenly applied to the diaphragm assembly 12. One side of the loading support plate 5 is fixed on the diaphragm assembly mounting platform 1, and the other side is connected to the inner edge of the diaphragm assembly 12 through a mounting hole. The axial second end plate 6 and the axial first end plate 4 are respectively installed on both sides of the central hole of the diaphragm assembly 12, and the axial first end plate 4 is close to one end of the loading support plate 5. The axial second end plate 6 and the axial first end plate 4 are used to support the inner ring of the diaphragm assembly, provide rigid support, and ensure the structural stability during the testing process.

[0065] In the implementation of this application, the diaphragm assembly mounting platform 1 is made of high-strength steel, and its bending stiffness is enhanced by various rib plates to reduce the influence of the deformation of the diaphragm assembly mounting platform 1 itself on the test results and ensure the structural stiffness and stability of the overall test device.

[0066] The loading support plate 5 is provided with a central hole, and the axial loading cylinder 3 is installed thereon. The axial loading cylinder 3 is used to generate axial tensile and compressive loads, and the force is applied to the diaphragm assembly 12 through its loading rod. In the implementation of this application, by controlling the axial displacement rate of the loading rod, the controllability of the test process and the data stability can be ensured. The axial loading cylinder 3 includes an axial loading rod, and the axial loading rod moves along the direction of the central hole, and the diameter of the loading rod is smaller than the central hole of the loading support plate 5, so that it can pass through freely. The central axis of the loading rod is coaxially aligned with the central axes of the diaphragm assembly 12, the axial first end plate 4, and the axial second end plate 6. The displacement sensor 7 is fixed on the end face side of the axial second end plate 6 through the sensor bracket 11, and its end contacts the end face of the axial second end plate 6 in the initial state (without pressure).

[0067] Further, there are 2 displacement sensors 7 symmetrically arranged. The end of each displacement sensor 7 corresponds to two measuring points on the axial second end plate 6, and is used to measure the displacement amount of the axial stiffness test of the diaphragm assembly 12 and the angular displacement of the radial stiffness test. In the implementation of this application, the 2 displacement sensors 7 are along the same vertical direction and are distributed inside the upper and lower edges of the axial second end plate 6.

[0068] The force sensor is located between the axial loading rod of the axial loading cylinder 3 and the first end plate 4, and its two sides are respectively fixed to the end face of the axial loading rod of the axial loading cylinder 3 and the center of the axial first end plate 4 through bolts. The force sensor is coaxially arranged with the axial loading rod to ensure the accurate transmission and measurement of the loading force. During the loading process, the axial loading cylinder 3 pushes the axial loading rod to apply a load to the first end plate 4, and the force sensor is clamped between the two to bear the pressure and detect the force applied by the axial loading rod in real time, and transmit the measurement signal to the data acquisition system. By applying an axial load to the first end plate 4 through the axial loading cylinder 3, the tensile and compressive forces are transmitted to the diaphragm assembly 12, and the axial displacement and axial displacement load of the diaphragm assembly 12 are measured through the displacement sensor 7 and the force sensor respectively, and the force-displacement relationship is calculated to obtain the axial stiffness.

[0069] The radial stiffness testing device is located on one side of the second axial end plate 6 and includes a radial loading rod and a radial loading mechanism. The radial loading rod is arranged horizontally and coaxially with the central hole of the diaphragm assembly 12. One end of it is fixed to the second axial end plate 6, and the other end is connected to the radial loading mechanism. The radial loading mechanism applies an upward force through an oil cylinder, causing one end of the loading rod to rise and the other end to drive the second axial end plate 6 to deflect around the central axis of the diaphragm assembly 12. The radial loading mechanism applies a bending moment to the second axial end plate 6, and this bending moment is transmitted to the diaphragm assembly 12 through the second axial end plate 6. The radial loading mechanism includes a force sensor. The radial displacement load is measured by the force sensor of the radial loading mechanism, and the angular displacement of the diaphragm assembly 12 is measured by the displacement sensor 7. The torque-angular displacement relationship is calculated to obtain the radial stiffness of the diaphragm assembly.

[0070] Furthermore, the static stiffness testing device of the diaphragm assembly also includes a bottom plate 13. The bottom plate 13 is the basic support structure of the device and is made of high-strength materials to ensure the stability and anti-vibration ability of the device during the testing process. The diaphragm assembly installation platform 1 is a frame structure, welded by various rib plates. Among them, the cross-section of the rib plates arranged circumferentially along the diaphragm assembly 12 is an H-shaped structure, effectively improving the stiffness and enhancing the bending resistance ability, thereby reducing the influence of the deformation of the platform itself on the test results. The bottom of the platform is fixedly connected to the bottom plate 13 by bolts to ensure the stability and structural stiffness during the testing process. The sensor rack 11 is also fixedly connected to the bottom plate 13 by bolts.

[0071] As shown in the instruction manual appendix Figure 2 , both the second axial end plate 6 and the first axial end plate 4 are stepped disks, and there are through holes in their centers to ensure the coaxiality of the installation of the diaphragm assembly 12. For this stepped structure, there is a coaxial small-diameter annular column on one side of the large-diameter disk, providing a stable transition fit, enabling the first axial end plate 4 and the second axial end plate 6 to achieve precise centering with the inner ring of the diaphragm assembly 12. The second axial end plate 6 and the first axial end plate 4 are processed from high-strength materials to ensure sufficient anti-deformation ability during the testing process. The small-diameter annular column is nested in the inner ring of the diaphragm assembly 12 in a transition fit manner to achieve precise positioning and ensure stable radial support. The large-diameter disk is connected to the diaphragm assembly 12 by no less than 8 high-strength bolts to ensure no loosening or displacement under axial and radial loads. The 8 high-strength bolts are arranged in a uniform distribution manner to ensure uniform distribution of force during the loading process and prevent local stress concentration.

[0072] The displacement sensor 7 transmits the collected axial displacement and radial displacement, and the force sensor transmits the collected force data to the signal acquisition system through voltage signals and is connected to a computer for data processing.

[0073] The diaphragm assembly static stiffness test device further includes a reverse measurement device 2. The reverse measurement device 2 is fixedly installed on the diaphragm assembly installation platform 1 and monitors the local deformation of the test bench in real time. By observing the deformation of the test bench itself during the test process, the accuracy of the experimental data is ensured. During the test, if the test bench deforms, the reverse measurement device can provide correction data to eliminate external influencing factors, avoid test errors, and ensure the accuracy of the test data.

[0074] The high-precision, stable and reliable diaphragm assembly static stiffness test device provided in this embodiment can effectively measure the axial stiffness and radial stiffness of the diaphragm assembly and evaluate its mechanical properties. The device adopts a high-rigidity frame structure, combined with the bottom plate, rib plate and transition fit design to ensure the stability and anti-vibration ability during the test process, thereby reducing the influence of the external environment on the test accuracy. The end plate and the support plate of the device are evenly connected through transition fit and high-strength bolts to ensure the coaxiality of the diaphragm assembly installation, prevent structural deformation during the test process, and improve the measurement accuracy. The axial loading oil cylinder cooperates with the loading support plate to evenly apply the load and ensure the accuracy of force transmission; the radial loading mechanism applies a bending moment load, and cooperates with the force sensor and the high-precision displacement sensor to achieve accurate measurement of stiffness. The signal acquisition system is used to collect and calculate the test data in real time to ensure the high precision and repeatability of the test results. In addition, the device integrates a reverse measurement device, which can monitor the deformation of the test bench in real time, provide correction data, and eliminate external interference, thereby ensuring the accuracy and reliability of the test data. This device is reasonably designed, accurately measured, and conveniently installed, can adapt to the test of diaphragm assemblies of different specifications, provides reliable data support for engineering optimization design, and is widely applicable to the stiffness test of elastic couplings and the research on mechanical structure optimization.

[0075] Embodiment 2

[0076] Refer to the attached drawings of the specification Figures 3 - 5 , this embodiment includes all the structures of Embodiment 1 and further optimizes the design of the loading support plate 5, making it composed of a diaphragm assembly connecting plate 50, a transition plate 51 and an axial cushion plate 52 to improve the rigidity and stability of the device.

[0077] The loading support plate 5 is formed by stacking the diaphragm assembly connecting plate 50, the transition plate 51, and the axial pad 52 in sequence, all of which are disc structures to ensure the coaxiality of the installation and optimize the force transmission path. The diaphragm assembly connecting plate 50 has a first surface and a second surface. The first surface is fixed to one side of the diaphragm assembly mounting platform 1 by screwing or welding, and is connected to the transition plate 51 and the axial pad 52 to form a complete loading support system, and the second surface is connected to the diaphragm assembly 12. Since the diaphragm assembly mounting platform 1 adopts a frame structure, its internal space can accommodate the axial loading cylinder 3, making the overall structure compact. The transition plate 51, the axial pad 52 and the axial loading cylinder 3 are coaxially installed in the frame structure of the diaphragm assembly mounting platform 1 in sequence, and are connected by no less than 6 high-strength bolts to ensure uniform force and improve the deformation resistance of the device.

[0078] The inner hole diameter of the diaphragm assembly connecting plate 50 is larger than the outer diameter of the axial first end plate 4, so that the axial first end plate 4 can be installed in the inner hole of the diaphragm assembly connecting plate 50. After installation, the axial first end plate 4 is completely accommodated in the central hole of the diaphragm assembly connecting plate 50, making the overall structure more compact, reducing the installation space, and improving the overall rigidity.

[0079] The composition structure of the loading support plate 5 of this embodiment improves the rigidity and stability of the device through the combination of the diaphragm assembly connecting plate 50, the transition plate 51, and the axial pad 52. At the same time, by optimizing the installation layout, the axial first end plate 4 is embedded in the diaphragm assembly connecting plate 50, making the overall structure more compact, enhancing the rigidity and force uniformity of the device, and improving the test accuracy and experimental reliability.

[0080] Example 3

[0081] In Example 1, the radial loading rod of the radial stiffness testing device may adopt an independent rod-shaped structure, one end of which is connected to the central hole of the axial second end plate 6, and the other end is connected to the radial loading mechanism to achieve the transmission of the radial loading force.

[0082] In this embodiment, the structure of the radial loading rod is optimized. On the basis of Embodiment 1, multiple reinforcing ribs are welded on the loading rod to improve the overall structural strength and stiffness. The shape of the reinforcing ribs can be selected according to the actual stress conditions, including trapezoidal or fan-shaped structures, such as Figure 1 The arrangement of the reinforcing ribs ensures that the loading rod has a higher bending resistance when subjected to radial loads, thereby reducing the deformation of the loading rod itself and improving the accuracy of the test.

[0083] In another implementation, the radial stiffness test device uses a radial end plate 8 to replace the axial second end plate 6 as the loading support structure to optimize the force loading path. The radial end plate 8 is welded by a loading rod of a certain length, an end plate, and fan-shaped rib plates to provide more stable support. The length of the loading rod is determined by the dimensions of the diaphragm assembly and the area of the loading cylinder. In this case, the length of the loading rod is set to 1 m to ensure the stability of force transmission during the loading process and optimize the accuracy of bending moment calculation.

[0084] With this structure, the radial stiffness test device can better adapt to the test requirements of diaphragm assemblies of different specifications, reduce test errors, and improve the reliability and repeatability of radial stiffness measurement.

[0085] Embodiment 4

[0086] Refer to the attached drawings of the specification Figure 1 and Figure 6 Based on Embodiment 1, the radial stiffness test device further includes a radial loading cylinder bracket 10, and an innovative design is made for the radial loading mechanism 9 to ensure the stable transmission of the radial load and improve the accuracy of stiffness testing. The mechanism includes a sensor connection bracket 90, a spherical plain bearing 91, a radial loading cylinder sensor 92, an intermediate bolt 93, a radial loading cylinder 94, and a cylinder connection bracket 95. Each component cooperates with each other to optimize the transmission path of the loading force and enhance the structural stability.

[0087] Both the sensor connection bracket 90 and the cylinder connection bracket 95 are welded by a horizontal plate, two vertical plates, and a circular tube. The two vertical plates are vertically arranged at intervals on the top surface of the horizontal plate to form a stable support structure. The circular tube is welded between the two vertical plates, and the spherical plain bearing 91 is sleeved on the circular tube to ensure the rotational freedom of the components during the radial loading process.

[0088] Furthermore, through holes communicating with the circular tube are provided on the vertical plates, and auxiliary support rotating shafts pass through the vertical plates and the circular tube and form a rotational connection with the spherical plain bearing 91 to ensure that the radial loading mechanism has a certain self-adaptive adjustment ability during the loading process and reduce the influence of lateral stress on the loading accuracy. Threaded holes are provided at the bottom of the horizontal plate of the sensor connection bracket 90 to facilitate the fixation of the radial loading cylinder sensor 92; the spherical plain bearing 91 on the cylinder connection bracket 95 is threadedly connected to the radial loading cylinder 94.

[0089] Furthermore, there are 2 spherical plain bearings 91, which are respectively sleeved on the circular tubes of the sensor connection bracket 90 and the cylinder connection bracket 95. They are used to provide rotational freedom, enabling the radial loading mechanism to adapt to small angular changes during operation, ensuring the consistency of the loading direction, and improving the test accuracy.

[0090] The top end of the push rod of the radial loading cylinder 94 is connected to the radial loading cylinder sensor 92 through an intermediate bolt 93 to achieve direct force transmission. The radial loading cylinder sensor 92 is fixed to the bottom of the horizontal plate of the sensor connection bracket 90 by bolts and is used to measure the load applied during the radial loading in real time to ensure the high precision and stability of data acquisition.

[0091] The radial loading cylinder bracket 10 is installed on the diaphragm assembly installation platform 1 by means of bolt connection to form a stable installation foundation to avoid structural offset during the test. The cylinder connection bracket 95 is directly installed on the top surface of the radial loading cylinder bracket 10, and through stable bolt connection, the stability of the radial loading cylinder 94 is ensured and the structural offset during the load application is reduced.

[0092] The radial loading mechanism of this embodiment enhances the rigidity and stability of the loading device by adding spherical plain bearings, stable connection brackets, and bolt connection schemes. At the same time, the test error is reduced, and the force transmission accuracy and measurement accuracy are improved. The modular connection between components makes the device applicable to the stiffness test of diaphragm assemblies of different specifications, ensuring the high precision, high stability, and repeatability of the experiment.

[0093] Embodiment 5

[0094] This embodiment illustrates the advantages of the present invention by comparing the prior art and the diaphragm assembly static stiffness test device of the present invention.

[0095]

[0096]

[0097] Embodiment 6

[0098] Combined with Embodiments 1-4, the present application also provides a test method for a diaphragm assembly static stiffness test device. The test method includes an axial stiffness test method and a radial stiffness test method. Specifically, the axial stiffness test method includes:

[0099] Step 1: Install the diaphragm assembly on the test bench, tighten the installation bolts according to the predetermined torque specification using a high-precision torque wrench, and record the pre-tightening force of each bolt.

[0100] Step 2: Arrange force sensors in the central area of the diaphragm assembly, fix a sensor bracket on the inner side of the edge of the second axial end plate, make the end of the displacement sensor contact the surface of the second axial end plate, and connect the electrical signals of each sensor to the computer data acquisition system through a signal acquisition instrument.

[0101] Step 3: Start the axial loading device, apply a small axial displacement to the diaphragm assembly to simulate the initial loading state, record the initial data of the axial load and axial displacement, calculate the initial axial stiffness, and based on this calculated value, determine whether there are any abnormalities in the measured values of the initial data; if the data deviates from the expected range, perform sensor calibration or loading system inspection.

[0102] The initial axial stiffness k pretest is determined by the following formula:

[0103]

[0104] where: F pretest represents the initial axial load; x pretest represents x pretest axial displacement.

[0105] In Step 3, the measured values of the initial data include the numerical values of the initial axial load and the initial axial displacement. Judging whether the measured values of the initial data are abnormal is through data consistency check and reasonableness judgment. The data consistency check is to check whether the readings of multiple sensors are within a reasonable range. For example, the changes in the axial load and the axial displacement should have a linear relationship, and a deviation from the expected curve shape may indicate sensor failure or system instability. The reasonableness judgment can be based on the initial calculated value of the axial stiffness, axial stiffness = axial load / axial displacement, and the initial calculated value of the axial stiffness should be consistent with the theoretical or expected axial stiffness value. If the preliminary calculated value is much lower or higher than the expected value, it may indicate measurement errors or equipment failures. If there is a significant deviation between the calculated axial stiffness and the known value in the design or specifications, and this difference cannot be explained by known operating conditions or device adjustments, then there is an abnormality. In addition, during the measurement process, the sensitivity and calibration of the sensors can be verified to ensure that they can accurately reflect the true response of the diaphragm assembly. If the measured values fluctuate abnormally and cannot be corrected through normal calibration procedures, the working state of the sensors should be considered.

[0106] Step 4: After the pre-test results show that the output load of the loading device, the axial displacement capacity of the diaphragm assembly, and the measurement data of each sensor all meet the test requirements, stop the axial loading, remove all preloads, restore the diaphragm assembly to the initial zero position state, and perform zero calibration of the displacement sensor.

[0107] It should be noted that the output load, the axial displacement capacity of the diaphragm assembly, and the measurements of each sensor are data obtained through verification and measurement during the pre-test process, which are used to confirm whether the system meets the test requirements and ensure that the behaviors of the loading device, the sensors, and the diaphragm assembly are within the expected range. At this time, the response data under the actual working state is measured to check whether it meets the design requirements and test specifications.

[0108] Specifically, the output load confirmation is to verify the range of the output load through preset test parameters and device functions before starting the loading device, ensuring that the actual working conditions can be simulated. A high-precision sensor is used for verification to ensure that the loading device operates within the rated range and does not exceed the bearing limit of the diaphragm assembly.

[0109] The axial displacement capacity confirmation is to record the axial displacement of the diaphragm assembly using a displacement sensor to ensure that the displacement of the diaphragm assembly does not exceed the design value during the loading process. Within the design range, the axial displacement should have good controllability without excessive deformation or non-linear response.

[0110] The sensor measurement verification is to monitor and compare the outputs of each sensor to ensure that the readings of the sensors are accurate, stable, and without abnormal drift during the test. At this time, multiple sensors can be used for redundant verification as needed to ensure the consistency of the measurement results.

[0111] The process of calibrating the zero point of the displacement sensor includes: The zero point calibration of the displacement sensor needs to be carried out after the diaphragm assembly returns to the initial state. Through a calibration tool or software, the zero point of the sensor is set to accurately reflect the starting position of the diaphragm assembly. At this time, a dedicated calibration device or reverse displacement operation (such as slightly adjusting the load or displacement) can be used to detect the accuracy of the displacement sensor to ensure that there is no deviation in the measurement results after zero point calibration.

[0112] Step 5: Set the loading rate of the axial displacement load. In each test cycle, gradually reciprocally increase and decrease the loading force, continuously record the applied axial load and the measured axial displacement data, and calculate the axial stiffness based on the force-displacement relationship.

[0113] It should be noted that according to the design and material properties of the diaphragm assembly, an appropriate loading rate is selected. The loading rate should ensure that the diaphragm assembly does not exhibit excessive non-linear response during the loading process. Generally speaking, the loading rate should not be too fast to avoid inertial effects and non-linear behavior of the system; at the same time, the rate should not be too slow to ensure a reasonable experimental time.

[0114] In the implementation mode of this application, the loading rate of the axial displacement load is set to 2 mm / min.

[0115] Specifically, the loading force is divided into multiple small steps and increased gradually. For example, starting from the initial load, a certain percentage of a predetermined force value is increased each time of loading. This can ensure that the system is in a controllable loading state and avoid affecting the test results due to sudden changes. The applied axial load (F) and the measured axial displacement (x) are recorded in real time through a data acquisition system to ensure the accuracy and integrity of the data. The recorded load (F) and displacement (x) data are sorted in order and plotted into a force-displacement curve. If there are fluctuations in the measured data, smoothing processing (such as using a moving average or filtering algorithm) can be performed to reduce the influence of noise on the results and ensure that the force-displacement curve reflects the true system behavior.

[0116] The calculation of axial stiffness includes the processing of linear relationships and non-linear behaviors. If the force-displacement curve shows a linear relationship, the curve is directly fitted by linear regression or the least squares method, and the slope is calculated as the axial stiffness. A linear relationship indicates that the stiffness of the system remains unchanged during this loading stage, so the slope of the curve can be directly used.

[0117] Calculate the axial stiffness k using linear regression or curve fitting axial The formula is:

[0118]

[0119] In the formula, ΔF represents the applied axial load (unit: N); Δx represents the axial displacement (unit: m).

[0120] Step 6: Repeat the axial loading test at least three times, obtain the calculated values of axial stiffness under different test cycles, and perform statistical analysis on the test data to evaluate the stability of the data based on the standard deviation.

[0121] Calculate the final test result:

[0122]

[0123] In the formula: k axial,1 、k axial,2 、k axial,3 respectively represent the axial stiffness calculated in the three tests.

[0124] Calculate the standard deviation to evaluate the data stability:

[0125]

[0126] In the formula: k axial,i represents the axial stiffness in each test; k axial,final represents the final axial stiffness (if the test is three times, it is the average of the three measurements); n represents the number of tests (3 in this example).

[0127] Standard deviation (σ k ) measures the degree of dispersion between each measured value and the final average value. The smaller the standard deviation, the smaller the fluctuation between the measured values and the more stable the data; the larger the standard deviation, the larger the fluctuation between the measured values and the less stable the data. To effectively judge the stability of the measured data, a permissible standard deviation range is set, and the stability of the data is evaluated according to this range. In the implementation manner of the present application, if σ k is less than the set threshold value (for example, within 2%), it can be considered that the test data is stable.

[0128] Step 7: Calculate the percentage error between the obtained test data and the theoretical simulation data, and judge whether the axial stiffness of the diaphragm assembly meets the predetermined design standard based on the error range; when the error value is less than 5%, it is determined that the axial stiffness test result meets the design requirements.

[0129] Calculate the error between the experimental data and the theoretical simulation data:

[0130]

[0131] In the formula: k axial,final represents the final axial stiffness obtained from the test (calculated from the actual test data); k simulated represents the axial stiffness predicted by the theoretical model; Error represents the percentage error, indicating the deviation between the experimental data and the theoretical model.

[0132] If the calculated error is less than 5%, it can be considered that the experimental result meets the design requirements, that is, the difference between the experimental data and the theoretical model data is within the allowable error range, and the axial stiffness test of the diaphragm assembly meets the design requirements.

[0133] Furthermore, the radial stiffness test method includes:

[0134] Step 1: Install the diaphragm assembly on the test bench, use a high-precision torque wrench to tighten the installation bolts according to the set torque value, and record the pre-tightening force values of each bolt.

[0135] Step 2: Arrange the force sensor on the loading cylinder to ensure that its measurement axis is aligned with the radial loading direction, symmetrically arrange two displacement sensors above the radial end plate, and transmit all sensor signals to the computer data processing system through the signal acquisition instrument.

[0136] Step 3: Start the radial loading device, apply a small radial load to the diaphragm assembly to simulate the actual test environment, record the measured values of the two displacement sensors and the radial loading force, and calculate the rotation angle of the diaphragm assembly based on the measurement data; if the calculation result deviates from the expected range, sensor adjustment or loading system inspection is required. Finally, numerically correct the calculated rotation angle value of the diaphragm assembly and use it as the control parameter for the formal test.

[0137] As shown in the attached Figure 7 , the displacements measured by the two displacement sensors are Δx1 and Δx2 respectively. Calculate the rotation angle α of the diaphragm assembly:

[0138]

[0139] Furthermore, it can be obtained that

[0140] In the formula: Δx1 and Δx2 represent the displacements measured by the two displacement sensors respectively; h represents the height of the displacement sensor from the axis position; Δh represents the height change of the axis position during the loading process.

[0141] Step 4: After the pre-test results show that the output load of the loading device, the radial rotation angle of the diaphragm assembly, and the measurement data of each sensor all meet the experimental requirements, stop the radial loading, remove all preloads, restore the diaphragm assembly to the initial zero position state, and perform zero calibration of the displacement sensor.

[0142] Specifically, for the verification of the output load of the loading device: Through the test of the loading device in the pre-test, it is confirmed that the output load should match the set expected load value and meet the design bearing capacity of the diaphragm assembly to avoid overloading or uneven loading.

[0143] Inspection of the radial rotation angle of the diaphragm assembly: Calculate the rotation angle from the displacement data recorded by the displacement sensor and compare it with the expected value. If the rotation angle is too large or too small, check the status of the loading device or the diaphragm assembly during the experiment.

[0144] Consistency of sensor measurements: Verify the stability of the data by comparing the measured values of multiple sensors and check for any abnormalities or drift in the sensors.

[0145] The process of calibrating the zero point of the displacement sensor is the same as step 4 of the axial loading test method and will not be elaborated here.

[0146] Step 5: Set the loading rate of the radial displacement load. In each test cycle, gradually reciprocally increase and decrease the radial loading force, continuously record the applied radial load and the measured displacement change, calculate the angular displacement of the diaphragm assembly, and record the bending moment generated during the radial loading process. Calculate the radial stiffness of the diaphragm assembly through the bending moment-angular displacement relationship.

[0147] In the implementation of this application, the loading rate of the radial displacement load is set to 2 mm / min.

[0148] The applied radial load is Fy, and the distance from the origin of the diaphragm assembly deformation to the loading point is L, and the bending moment M generated by the radial loading is obtained:

[0149] M = Fy × L

[0150] Calculate the radial stiffness:

[0151]

[0152] In the formula: ΔM represents the moment after removing the weight, with the unit of kN·mm; Δα represents the radian difference, with the unit of rad.

[0153] It should be noted that the calculation of the bending moment change ΔM and the rotation angle change Δα is based on the gradually increasing load and the measured rotation angle change.

[0154] Step 6: Repeat the radial loading test at least three times, obtain the stiffness calculation values under different test cycles, and conduct statistical analysis on the test data, and evaluate the stability of the test data based on the standard deviation.

[0155] Calculate the final test result:

[0156]

[0157] In the formula: k radial,1 、k radial,2 、k radial,3 respectively represent the radial stiffness calculated in the three tests.

[0158] Calculate the standard deviation to evaluate the data stability:

[0159]

[0160] In the formula: k radial,i represents the radial stiffness in each test; k radiall,final represents the final radial stiffness (if the test is three times, it is the average of the three measurements); n represents the number of tests (in this example, it is 3).

[0161] The standard deviation (σ k ) measures the degree of dispersion between each measured value and the final average value. The smaller the standard deviation, the smaller the fluctuation between the measured values, and the more stable the data; the larger the standard deviation, the larger the fluctuation between the measured values, and the data is unstable. In order to effectively judge the stability of the measurement data, a permissible standard deviation range is set, and the stability of the data is evaluated according to this range. In the implementation of this application, σ kIf it is less than the set threshold (e.g., within 2%), the test data can be considered stable.

[0162] Step 7: Calculate the percentage error between the obtained test data and the theoretically simulated data, and judge whether the radial stiffness of the diaphragm assembly meets the design requirements based on the error range; when the error value is less than 5%, it is determined that the radial stiffness test result meets the design standard.

[0163] Calculate the error between the experimental data and the theoretically simulated data:

[0164]

[0165] In the formula: k radiall,final represents the final radial stiffness obtained from the test (calculated from the actual test data); k simulated represents the radial stiffness predicted by the theoretical model; Error represents the percentage error, indicating the deviation between the experimental data and the theoretical model.

[0166] If the calculated error is less than 5%, it can be considered that the experimental results meet the design requirements, that is, the difference between the experimental data and the theoretical model data is within the allowable error range, and the radial stiffness test of the diaphragm assembly meets the design requirements.

[0167] The static stiffness test device and its test method for the diaphragm assembly of the present application can effectively measure the axial stiffness and radial stiffness of the diaphragm assembly and evaluate its mechanical properties. The device adopts a modular design, and the axial and radial stiffness test devices can be used independently or in combination to ensure test adaptability and efficiency. The stepped end plate and the support plate achieve precise alignment, and the multi-layer structure of the loading support plate optimizes the force transmission path, improves stiffness and reduces errors. The radial end plate replaces the end plate as the loading support structure, improves test stability, and the modular radial loading mechanism combined with the design of spherical plain bearings reduces lateral stress interference and improves measurement accuracy. The symmetrically arranged displacement sensors accurately capture the angular displacement, and the installation platform with an H-shaped rib plate structure enhances the stiffness. The reverse measurement device monitors the deformation of the test bench in real time to improve the credibility of the test data. The test method covers the measurement of axial stiffness and radial stiffness, uses a linear regression algorithm to optimize the calculation accuracy, and ensures data stability through multiple repeated tests with an error lower than 5%. The device and method are applicable to elastic couplings, engineering structure analysis and related mechanical research, providing highly reliable data support.

[0168] The above are only embodiments of the present invention, and common knowledge such as specific structures and characteristics known in the art are not described in detail herein. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A diaphragm assembly static stiffness test device, the diaphragm assembly is composed of a plurality of elastic circular sheets in an axially juxtaposed manner, each of the elastic circular sheets is provided with a first type of mounting through hole penetrating and interconnected along the inner side of its outer edge, each elastic circular sheet is provided with a coaxial center hole at the center position of its circle, and the edge of the center hole is further provided with a second type of mounting hole for connecting with an external coupling; the diaphragm assembly static stiffness test device includes an axial stiffness test device and a radial stiffness test device, characterized in that: The axial stiffness testing mechanism comprises a diaphragm assembly mounting platform (1), an axial loading cylinder (3), an axial first end plate (4), a loading support plate (5), an axial second end plate (6), a displacement sensor (7) and a force sensor; the axial stiffness testing mechanism is used to measure the axial stiffness characteristics of the diaphragm assembly (12) under controlled loading conditions, so as to obtain the deformation response characteristics of the diaphragm assembly (12) under an axial force state; The first axial end plate (4), the loading support plate (5) and the second axial end plate (6) are respectively provided with coaxial center holes penetrating along the center axis direction; the first side of the loading support plate (5) is fixedly mounted on the diaphragm assembly mounting platform (1), and the axial loading cylinder (3) is arranged in the middle of the first side of the loading support plate (5); the loading rod of the axial loading cylinder (3) is penetrated through the center hole of the loading support plate (5) and realizes controllable telescopic movement along the axial direction to apply an axial loading force to the diaphragm assembly; the second side of the loading support plate (5) is fixedly connected to the first type of mounting through hole of the diaphragm assembly (12), so that the axial loading force is effectively transmitted to the diaphragm assembly (12) to be measured through the structure of the loading support plate (5); The second axial end plate (6) and the first axial end plate (4) are respectively arranged on both sides of the center hole of the diaphragm assembly (12), and are fixedly connected to the first type of mounting through hole of the diaphragm assembly (12); wherein the first axial end plate (4) is arranged on a side close to the loading rod of the axial loading cylinder (3), and is connected to the loading rod of the axial loading cylinder (3) through a force sensor; the force sensor is fixedly installed at the center position of the first axial end plate (4), and is coaxially arranged with the axial loading rod along the center axis direction, so as to measure the axial load applied to the diaphragm assembly (12) during the loading process of the axial loading cylinder (3); The displacement sensor (7) is fixedly mounted on the outer side of the second axial end plate (6), and its sensing end is in contact with the end surface of the second axial end plate (6) in an initial state, and is used to detect the axial deformation of the diaphragm assembly (12) under axial loading during the axial stiffness test; The radial stiffness testing mechanism is arranged on the outer side of the axial second end plate (6), and comprises a radial loading rod and a radial loading mechanism; wherein the radial loading rod is arranged in a horizontal direction and is coaxially arranged with the central hole axis of the diaphragm assembly (12); one end of the radial loading rod is fixedly connected to the axial second end plate (6), and the other end is connected to the radial loading mechanism; the radial loading mechanism is used to apply a predetermined radial load to the radial loading rod so that the axial second end plate (6) deflects around the central axis of the diaphragm assembly (12), and the radial stiffness characteristics of the diaphragm assembly (12) are obtained by measuring the mapping relationship between the deflection angle of the axial second end plate (6) and the radial load.

2. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The second axial end plate (6) and the first axial end plate (4) are both constructed as discs with a stepped structure, and a coaxial through hole is provided in the central area thereof, which is used to adapt to the installation requirements of the diaphragm assembly; wherein the stepped structure is formed by interconnecting a large-diameter disc and a small-diameter annular column, the outer diameter size of the small-diameter annular column matches the inner ring size of the diaphragm assembly (12), and is nested and installed in the inner ring of the diaphragm assembly (12) in a transition fit manner.

3. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The loading support plate (5) is composed of a diaphragm assembly connecting plate (50), a transition plate (51) and an axial pad (52) which are stacked in sequence along the axial direction.

4. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The radial stiffness testing device adopts a radial end plate (8) to replace the axial second end plate (6) in the configuration design of the loading support structure, so as to optimize the force transmission path during radial loading; the radial end plate (8) is assembled into an integrated structure by a loading rod, an end plate and a fan-shaped rib plate through a welding process, and the length of the loading rod is determined by the size of the diaphragm assembly and the area of ​​the loading cylinder; wherein the loading rod and the end plate are fixed by welding, and the fan-shaped rib plate is arranged between the end plate and the loading rod; the end plate is arranged outside the center hole of the diaphragm assembly (12).

5. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The radial loading mechanism (9) comprises a sensor connecting bracket (90), a spherical bearing (91), a radial loading cylinder sensor (92), an intermediate bolt (93), a radial loading cylinder (94) and a cylinder connecting bracket (95); two spherical bearings (91) are provided, which are rotatably connected to the sensor connecting bracket (90) and the cylinder connecting bracket (95) respectively; the radial loading cylinder sensor (92) is fixed to the bottom of the sensor connecting bracket (90) and is used to measure in real time the radial load applied to the diaphragm assembly (12) by the push rod of the radial loading cylinder (94); the top end of the push rod of the radial loading cylinder (94) is connected to the radial loading cylinder sensor (92) via the intermediate bolt (93).

6. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The arrangement of the displacement sensors (7) adopts a dual-sensor symmetrical configuration structure, wherein two displacement sensors (7) are arranged along the same vertical direction on the inner sides of the upper and lower edges of the axial second end plate (6) to construct a symmetrical measurement reference; wherein the measurement axes of the two displacement sensors (7) are symmetrically arranged along the vertical direction and are evenly distributed relative to the central axis of the axial second end plate (6), so that when the diaphragm assembly (12) is subjected to a load, the displacement data of the diaphragm assembly (12) at different positions can be synchronously acquired.

7. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: The diaphragm assembly installation platform (1) adopts a frame-type structural design, and its main frame is composed of a plurality of rib plate components assembled through a welding process to form an integrated load-bearing structure; the cross-sectional configuration of the rib plate adopts an H-shaped structure.

8. The diaphragm assembly static stiffness testing device according to claim 1, characterized in that: It also comprises a reverse measuring device (2) for auxiliary testing and data calibration, wherein the reverse measuring device (2) is fixedly mounted on the diaphragm assembly mounting platform (1).

9. A testing method using the diaphragm assembly static stiffness testing device according to any one of claims 1 to 8, characterized in that: The test methods include axial stiffness test methods and radial stiffness test methods; the axial stiffness test methods include: Step 1: Install the diaphragm assembly to the test bench, tighten the mounting bolts according to the predetermined torque specification using a high-precision torque wrench, and record the preload force of each bolt; Step 2: Arrange the force sensor in the center area of ​​the diaphragm assembly, and fix the sensor holder on the inner side of the edge of the second axial end plate, so that the end of the displacement sensor contacts the surface of the second axial end plate, and connect the electrical signals of each sensor to the computer data acquisition system through a signal acquisition instrument; Step 3: Start the axial loading device, apply a small axial displacement to the diaphragm assembly to simulate the initial loading state, record the initial data of the axial load and axial displacement, calculate the initial axial stiffness, and determine whether the measured value of the initial data is abnormal based on the calculated value; if the data deviates from the expected range, perform sensor calibration or loading system inspection; Step 4: After the pre-test results show that the output load of the loading device, the axial displacement capacity of the diaphragm assembly and the measurement data of each sensor meet the test requirements, stop the axial loading, remove all preloads, restore the diaphragm assembly to the initial zero position, and perform zero point calibration of the displacement sensor; Step 5: Set the loading rate of the axial displacement load. In each test cycle, gradually increase and decrease the loading force, continuously record the applied axial load and the measured axial displacement data, and calculate the axial stiffness based on the force-displacement relationship; Step 6: Repeat the axial loading test at least three times to obtain the calculated values ​​of axial stiffness under different test cycles, and perform statistical analysis on the test data to evaluate the stability of the data based on the standard deviation; Step 7: Calculate the error percentage between the obtained test data and the theoretical simulation data, and determine whether the axial stiffness of the diaphragm assembly meets the predetermined design standard based on the error range; when the error value is less than 5%, it is determined that the axial stiffness test result meets the design requirements; Radial stiffness test methods include: Step 1: Install the diaphragm assembly on the test bench, use a high-precision torque wrench to tighten the mounting bolts according to the set torque value, and record the preload value of each bolt; Step 2: Arrange the force sensor on the loading cylinder, ensure that its measuring axis is aligned with the radial loading direction, and symmetrically arrange two displacement sensors above the radial end plate, and transmit all sensor signals to the computer data processing system through the signal acquisition instrument; Step 3: Start the radial loading device and apply a small radial load to the diaphragm assembly to simulate the actual test environment. Record the measured values ​​of the two displacement sensors and the radial loading force, and calculate the rotation angle of the diaphragm assembly based on the measured data. If the calculated result deviates from the expected range, the sensor needs to be adjusted or the loading system needs to be checked. Finally, the calculated rotation angle value of the diaphragm assembly is numerically corrected and used as the control parameter of the formal test. Step 4: After the pre-test results show that the output load of the loading device, the radial rotation angle of the diaphragm assembly and the measurement data of each sensor meet the experimental requirements, stop the radial loading, remove all preloads, restore the diaphragm assembly to the initial zero position state, and perform zero point calibration of the displacement sensor; Step 5: Set the loading rate of the radial displacement load. In each test cycle, gradually increase or decrease the radial loading force, continuously record the applied radial load and the measured displacement change, calculate the angular displacement of the diaphragm assembly, and record the bending moment generated during the radial loading process. Calculate the radial stiffness of the diaphragm assembly through the bending moment-angular displacement relationship; Step 6: Repeat the radial loading test at least three times to obtain the stiffness calculation values ​​under different test cycles, perform statistical analysis on the test data, and evaluate the stability of the test data based on the standard deviation; Step 7: Calculate the error percentage between the test data and the theoretical simulation data, and determine whether the radial stiffness of the diaphragm assembly meets the design requirements based on the error range; when the error value is less than 5%, it is determined that the radial stiffness test result meets the design standard.

10. The testing method of the diaphragm assembly static stiffness testing device according to claim 9, characterized in that: In step 3 of the radial stiffness test method, the rotation angle α of the diaphragm assembly is determined by the following formula: Where: h represents the height between the displacement sensor and the axis of the diaphragm assembly; Δx1 and Δx2 are the displacements measured by the two displacement sensors respectively.

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