A method for designing equivalent stiffness of a containment test device for a casing

Abstract

The application belongs to the field of aero-engine design and manufacturing, and particularly relates to a casing containment test device equivalent stiffness design method, which comprises the following steps: extracting shafting components related to the casing containment test of an aero-engine; establishing a three-dimensional simulation model of the shafting components; performing quasi-static analysis on the three-dimensional simulation model, and applying unbalanced forces generated by blade loss; obtaining stress and displacement values of each part of the three-dimensional simulation model under the action of the unbalanced forces; based on the stress, the displacement values and the real shape of the shafting components, initially designing a rotor assembly protection device and an adapter shaft; taking the displacement values of the shafting components of the real engine as constraint conditions, and taking the combined displacement of the rotor assembly protection device and the adapter shaft as an optimization target; performing optimization iteration until the deviation between the combined displacement and the displacement of the shafting components of the real engine is less than a preset value, so that the shafting stiffness of the containment test is close to the shafting stiffness of the whole machine test.

Description

Technical Field

[0001] This application belongs to the field of aero-engine design and manufacturing, and specifically relates to an equivalent stiffness design method for a casing containment test device. Background Technology

[0002] Casing containment testing is a crucial component of aero-engine structural integrity testing. Various airworthiness regulations specify clear requirements for the containment design of the casing: the casing must possess sufficient strength to contain a broken or detached blade at maximum operating speed. Typically, component-level containment testing is conducted before the overall engine containment test to assess the casing's containment performance. Component-level tests are performed on a rotor tester, where the test casing and rotor are mounted and connected to the tester's drive shaft via an adapter shaft.

[0003] Current containment test equipment, when designing the protective devices for the transition shaft and rotor assembly (including the rotor assembly protection device for the transition shaft and the rotor itself), rarely considers the need for the equivalent stiffness of the rotor assembly to be comparable to the engine shaft system. This leads to a significant deviation between the dynamic characteristics of the rotor components and the actual engine conditions after blade loss, affecting the containment test results. Existing technology involves setting limiting structures on the periphery of the rotor assembly and the inner side of the casing to resist the unbalanced force generated by the rotor disk after blade loss. The clearance between the limiting structure and the rotor component is set based on the maximum vibration value at the corresponding location during engine testing. That is, first, a displacement sensor is used to measure the vibration value near the bearing support point during engine operation, and then a protective device is designed at the same location in the component test, using the maximum vibration value for limiting.

[0004] Firstly, regarding the technical aspects, the bearing support vibration displacement measured using displacement sensors represents the value of the aero-engine under normal test conditions, not the vibration displacement during the whole-engine containment test. In the whole-engine containment test, blade breakage generates enormous unbalanced forces, causing engine vibration measurements to far exceed those under normal test conditions. However, component-level containment tests are prerequisites for whole-engine testing; therefore, vibration displacement data from the whole-engine test cannot be applied during this test. This inherently introduces a flaw in the design of the equivalent stiffness of the containment test device in the existing technical solution.

[0005] Secondly, there's the cost aspect. Whole-engine testing of aircraft engines is extremely resource-intensive, requiring significant manpower and resources for installation, debugging, and testing. Furthermore, installing sensors within the actual engine structure is challenging, further increasing data acquisition costs. Therefore, obtaining test parameters through whole-engine testing is not economically viable.

[0006] Finally, regarding efficiency. Obtaining whole-machine test data first, and then designing component protection devices, results in a lengthy design cycle. Obtaining vibration displacement parameters from the whole-machine test requires the engine to reach its maximum speed, which necessitates sampling during multiple test runs, further increasing the time required and making it relatively inefficient. Summary of the Invention

[0007] In view of the technical shortcomings of current containment test devices in terms of equivalent stiffness design, this invention aims to solve the problems of rationality, low cost, and high efficiency.

[0008] In terms of rationality, this invention extracts the shafting components related to the casing containment test in an aero-engine and applies the unbalanced force generated by blade slippage to calculate the stress and displacement of various parts of the actual engine shafting. Based on the extracted shafting structure, a casing containment test device similar to the actual shafting is initially designed, such as the transition shaft and rotor assembly protection device. Then, through simulation and iterative optimization, the clearance values ​​between the rotor assembly and the protection device are gradually adjusted, ultimately achieving a combined displacement of the rotor assembly protection device and the transition shaft consistent with the engine shafting under the unbalanced load generated by blade slippage. This maximizes the consistency of the equivalent stiffness state between component-level testing and whole-engine testing.

[0009] In terms of cost and efficiency, this invention avoids displacement measurement in the state of the entire engine, eliminating steps such as sensor installation and debugging, and engine testing, thus greatly saving testing costs. Simultaneously, the adjustment of the rotor assembly's protective device and the stiffness of the transition shaft is achieved through simulation, avoiding the need for additional machining of the actual workpiece. This allows the casing enclosure test device to be accurately designed during the design phase, avoiding repeated machining processes and greatly improving design efficiency.

[0010] The method described in this application specifically includes:

[0011] Step S1: Extract the shafting components related to the casing containment test in the aero-engine; establish a three-dimensional simulation model of the shafting components;

[0012] Step S2: Perform quasi-static analysis on the three-dimensional simulation model and apply the unbalanced force generated by the blade flight failure;

[0013] Step S3: Obtain the stress and displacement values ​​of each part of the three-dimensional simulation model under the action of the unbalanced force;

[0014] Step S4: Based on the stress, the displacement value, and the actual shape of the shaft system components, a preliminary design of the rotor assembly protection device and the adapter shaft is made;

[0015] Step S5: Using the displacement values ​​of the shaft system components of the actual engine as constraints, and the combined displacement of the rotor assembly protection device and the adapter shaft as the optimization target; perform optimization iterations until the deviation between the combined displacement and the displacement of the shaft system components of the actual engine is less than the preset value.

[0016] Preferably, before step S5, an unbalanced force caused by blade slippage is applied to the rotor assembly protection device and the adapter shaft, with the goal of ensuring that the stress values ​​of the rotor assembly protection device and the adapter shaft meet the preset strength requirements, and the rotor assembly protection device and the adapter shaft are checked.

[0017] Preferably, after step S5, the rotor assembly protection device and the adapter shaft are checked again with the goal of ensuring that the stress values ​​of the rotor assembly protection device and the adapter shaft meet the preset strength requirements.

[0018] Preferably, the magnitude of the unbalanced force generated by the blade slippage is 1.5 times the statically calculated value.

[0019] Preferably, the preset value described in step S5 is 2%.

[0020] The advantages of this application include:

[0021] 1. The design method described in this invention can more accurately simulate the overall enclosure test conditions of an aero-engine under test conditions. By comparing and iterating the equivalent stiffness of the actual shaft system, rotor assembly protection structure, and transition shaft assembly structure, the equivalent stiffness state of the component-level test and the overall test is made consistent, thereby more accurately evaluating the results of the actual engine casing enclosure test;

[0022] 2. The design method described in this invention can obtain the device design parameters for component-level casing containment testing more efficiently and at a lower cost. Through 3D model reconstruction, numerical simulation, and iterative optimization, reliable design parameters can be obtained before the test device is put into production, avoiding the cumbersome steps of obtaining parameters through whole-machine testing and repeated processing, thus greatly saving test resources and test time. Attached Figure Description

[0023] Figure 1 This is a flowchart of the equivalent stiffness design method for a casing containment test device according to a preferred embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown: The equivalent stiffness design method for the casing containment test device of this application specifically includes:

[0026] Step S1: Extract the shafting components related to the casing containment test from the shafting system of the aero-engine; and establish a three-dimensional simulation model for the shafting components; the three-dimensional simulation model refers to a realistic three-dimensional model generated using computer technology, and the structure of the model is changed by changing various parameters on the desktop, or virtual influence factors, including temperature, load, etc., are applied to the three-dimensional model to obtain the required numerical feedback, including deformation, stress, and thermal conductivity.

[0027] Step S2: Perform quasi-static analysis on the three-dimensional simulation model and apply the unbalanced force caused by blade fly-off. Specifically, after applying the unbalanced force to the shaft, the shaft components will oscillate and displace. Blade fly-off means blade breakage and loss.

[0028] Step S3: Obtain the stress and displacement values ​​of each part of the three-dimensional simulation model under the action of the unbalanced force;

[0029] Step S4: Based on the stress, the displacement value and the actual shape of the shaft system components, a preliminary design of the rotor assembly protection device and the adapter shaft is made. The rotor assembly protection device is a limiting structure set on the periphery of the rotor assembly and the inner side of the casing to resist the unbalanced force generated by the wheel disk after the blades fly away.

[0030] Step S5: Using the displacement values ​​of the shaft system components of the actual engine as constraints, and the combined displacement of the rotor assembly protection device and the adapter shaft as the optimization target; perform optimization iterations until the deviation between the combined displacement and the displacement of the shaft system components of the actual engine is less than the preset value.

[0031] Preferably, before step S5, an unbalanced force caused by blade slippage is applied to the rotor assembly protection device and the adapter shaft, with the goal of ensuring that the stress values ​​of the rotor assembly protection device and the adapter shaft meet the preset strength requirements, and the rotor assembly protection device and the adapter shaft are checked.

[0032] Preferably, after step S5, the rotor assembly protection device and the adapter shaft are checked again with the goal of ensuring that the stress values ​​of the rotor assembly protection device and the adapter shaft meet the preset strength requirements.

[0033] Preferably, the magnitude of the unbalanced force generated by the blade slippage is 1.5 times the statically calculated value.

[0034] Preferably, the preset value described in step S5 is 2%.

[0035] The advantages of this application include:

[0036] 1. The design method described in this invention can more accurately simulate the overall enclosure test conditions of an aero-engine under test conditions. By comparing and iterating the equivalent stiffness of the actual shaft system, rotor assembly protection structure, and transition shaft assembly structure, the equivalent stiffness state of the component-level test and the overall test is made consistent, thereby more accurately evaluating the results of the actual engine casing enclosure test;

[0037] 2. The design method described in this invention can obtain the device design parameters for component-level casing containment testing more efficiently and at a lower cost. Through 3D model reconstruction, numerical simulation, and iterative optimization, reliable design parameters can be obtained before the test device is put into production, avoiding the cumbersome steps of obtaining parameters through whole-machine testing and repeated processing, thus greatly saving test resources and test time.

[0038] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for designing the equivalent stiffness of a casing containment test device, characterized in that, Step S1: Extract the shafting components related to the casing containment test in the aero-engine; establish a three-dimensional simulation model of the shafting components; Step S2: Perform quasi-static analysis on the three-dimensional simulation model and apply the unbalanced force generated by the blade flight failure; Step S3: Obtain the stress and displacement values ​​of each part of the three-dimensional simulation model under the action of the unbalanced force; Step S4: Based on the stress, the displacement value, and the actual shape of the shaft system components, a preliminary design of the rotor assembly protection device and the adapter shaft is made; Step S5: Using the displacement values ​​of the shaft components of the actual engine as constraints, and the combined displacement of the rotor assembly protection device and the adapter shaft as the optimization target; The optimization process continues until the deviation between the combined displacement and the actual displacement of the shaft components of the engine is less than a preset value.

2. The equivalent stiffness design method for the casing containment test device as described in claim 1, characterized in that, Before step S5, an unbalanced force caused by blade slippage is applied to the rotor assembly protection device and the adapter shaft. The rotor assembly protection device and the adapter shaft are checked with the goal of meeting the preset strength requirements for stress values.

3. The equivalent stiffness design method for the casing containment test device as described in claim 2, characterized in that, After step S5, the rotor assembly protection device and the adapter shaft are checked again with the goal of ensuring that the stress values ​​of the rotor assembly protection device and the adapter shaft meet the preset strength requirements.

4. The equivalent stiffness design method for the casing containment test device as described in claim 1, characterized in that, The magnitude of the unbalanced force generated by the blade slippage is 1.5 times the statically calculated value.

5. The equivalent stiffness design method for the casing containment test device as described in claim 1, characterized in that, The preset value mentioned in step S5 is 2%.

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