Resonance analysis method, system and equipment for metal oil pan and medium
By establishing a fluid-structure interaction finite element model for wet modal analysis, the problem of inaccurate prediction of oil pan resonance was solved, achieving efficient resonance frequency identification and structural optimization, shortening the development cycle and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-04-07
AI Technical Summary
Existing technologies fail to effectively consider the additional mass effect of lubricating oil in oil pan resonance analysis, resulting in inaccurate modal frequency prediction, prolonged product development cycle and increased manufacturing costs.
A fluid-structure interaction finite element model is established, wet modal analysis is performed, the additional mass effect of lubricating oil is considered, the vibration excitation spectrum is obtained through experimental measurement or engine dynamics simulation, frequency response analysis is performed, and resonance frequency points and high stress regions are identified.
It significantly improves the accuracy of resonant frequency prediction, identifies resonant risks in advance, shortens the development cycle, reduces design change costs, and provides a basis for structural optimization.
Smart Images
Figure CN121809150A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of engine vibration and noise analysis and control technology, specifically to a resonance analysis method, system, equipment, and medium for a metal oil pan. Background Technology
[0002] The oil pan is a crucial component of the engine lubrication system, typically made of stamped sheet metal or die-cast aluminum alloy. It is mounted to the bottom of the engine block using bolts and gaskets. During engine operation, moving parts such as the piston, connecting rod, and crankshaft generate complex, wide-bandwidth vibrations. These vibrations are transmitted to the oil pan through the mounting points, easily causing severe vibrations or even resonance. Resonance can lead to excessive dynamic stress on the oil pan, potentially causing weld cracking, seal failure, and oil leaks. It also generates strong radiated noise, negatively impacting the overall NVH (noise, vibration, and harshness) performance of the vehicle.
[0003] Traditional oil pan designs rely heavily on engineers' experience and analogical design, often resulting in resonance issues being discovered after the physical prototype is manufactured and bench tested. Once a problem is identified, modifications are typically made through trial and error, such as adding reinforcing ribs or changing local thicknesses. This not only prolongs the product development cycle but also increases manufacturing costs.
[0004] While existing computer-aided engineering (CAE) analysis techniques can be used for structural modal analysis, conventional "dry modal" analysis (i.e., ignoring the influence of internal lubricating oil) has significant limitations. The oil pan contains a large amount of lubricating oil, which exerts a significant "added mass" effect on the structure's vibration characteristics, resulting in a large difference between wet and dry modal frequencies. Therefore, analysis results that ignore fluid effects deviate significantly from actual operating conditions and cannot accurately predict resonance risks. Summary of the Invention
[0005] The purpose of this invention is to provide a resonance analysis method, system, device, and medium for metal oil pans. By establishing a fluid-structure interaction model and performing wet modal analysis, the additional mass effect of lubricating oil is fully considered, making the modal prediction results closer to the actual working state of the oil pan and significantly improving the accuracy of resonance frequency prediction.
[0006] To achieve the above objectives, embodiments of the present invention provide a resonance analysis method for a metal oil pan, comprising: A fluid-structure interaction finite element model was established, which included the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block. Modal analysis was performed on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under fluid coupling. The vibration excitation spectrum acting on the oil pan mounting point is obtained through experimental measurement or engine dynamics simulation. The vibration excitation spectrum is used as a load condition and applied to the corresponding mounting points of the fluid-structure interaction finite element model. Frequency response analysis is performed to calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum. Based on the comparison results of dynamic stress and vibration response with natural frequency and mode shape, the resonant frequency point and high stress area of the oil pan are identified, and the risk of structural fatigue failure or abnormal noise generation of the oil pan is assessed.
[0007] Optionally, in the fluid-structure interaction finite element model, the metal oil pan structure is discretized using shell elements or solid elements; The internal lubricating oil fluid domain is modeled using acoustic fluid elements or Euler fluid elements; The interaction between shell elements or solid structural elements and acoustic fluid elements or Eulerian fluid elements is defined through the fluid-structure interaction interface.
[0008] Optionally, the connection boundary conditions between the oil pan and the engine block include: The preload constraint on the bolts connecting the oil pan and the engine block, and the mechanical effect of the rubber gasket at the installation joint surface simulated by using a spring unit.
[0009] Optionally, the process of constructing the fluid-structure interaction finite element model includes: The three-dimensional geometric model of the metal oil pan is imported into the finite element preprocessing software. Shell elements or solid elements are used to mesh the oil pan structure, and its material properties, including elastic modulus, Poisson's ratio and density, are defined. Based on the internal cavity of the oil pan, a geometric model of the fluid domain of the lubricating oil is created. The fluid domain is meshed using acoustic fluid elements or Euler fluid elements, and the density and bulk modulus of the lubricating oil are defined. At the mounting holes of the oil pan and the engine block, a constraint relationship is established to simulate the bolt connection, and a preset bolt preload is applied; between the mating surfaces of the oil pan and the engine block, a spring unit is established to simulate the stiffness and damping characteristics of the rubber gasket. The unit surface that comes into contact with the lubricating oil fluid domain on the inner wall of the oil pan structure is defined as the fluid-structure interaction interface to achieve bidirectional coupling and transmission between fluid pressure load and structural deformation.
[0010] Optionally, the vibration excitation spectrum acting on the oil pan mounting point can be obtained through experimental measurements or engine dynamics simulation, including: On a test platform for a complete machine or vehicle equipped with the engine, an acceleration sensor is arranged at the connection and mounting point between the oil pan and the engine block. Based on the aforementioned accelerometer, the vibration acceleration time-domain signal at the mounting point is acquired when the engine is running under target conditions. The vibration acceleration time-domain signal is then subjected to frequency domain transformation and statistical analysis to generate an acceleration power spectral density curve as the vibration excitation spectrum; or... Establish a multibody dynamics simulation model that includes the engine crankshaft and connecting rod mechanism, valve train mechanism and engine block structure; and define the gas pressure in the cylinder, the inertial force of moving parts and the impact load of the valve system in the multibody dynamics simulation model; Through dynamic calculations, the time-domain history of the dynamic support reaction force or vibration acceleration at the oil pan mounting point is output; and the time-domain history is converted into a power spectral density function in the frequency domain as the vibration excitation spectrum.
[0011] Optionally, based on the dynamic stress and vibration response results, the resonant frequency points and high-stress areas of the oil pan are identified, and the risk of structural fatigue failure or abnormal noise generation is assessed, including: In the frequency response analysis results, vibration response data from multiple feature monitoring points on the oil pan are extracted, and frequency-response amplitude curves are plotted based on the vibration response data. Identify the frequency point corresponding to the response peak in the frequency-response amplitude curve, and compare the frequency point with the natural frequency of the oil pan under the action of liquid coupling. The frequency points that are consistent or similar to the two are determined as the resonant frequency of the oil pan. Based on the dynamic stress distribution of the oil pan under the vibration excitation spectrum, a dynamic stress cloud map of the oil pan structure at the resonant frequency is generated; and regions in the dynamic stress cloud map where the dynamic stress value exceeds a preset threshold are identified as high-risk areas for structural fatigue; at the same time, a vibration velocity or acceleration cloud map of the oil pan at the resonant frequency is generated, and regions where the vibration amplitude is higher than the average level are identified and defined as high-risk areas for radiated noise. The resonance frequency is compared with the energy concentration frequency band in the vibration excitation spectrum acting on the oil pan mounting point. If the resonance frequency falls within the excitation frequency band, the resonance risk level is determined to be high; otherwise, the risk level is determined to be low.
[0012] Optionally, the resonance analysis method for the metal oil pan further includes: Based on the risk assessment results of resonance risk of structural fatigue failure or abnormal noise in the oil pan, the structural design of the oil pan is optimized; and the above steps are repeated to model and analyze the optimized structural design of the oil pan until the resonance risk of the oil pan meets the preset design target. The optimization of the structural design of the oil pan includes adjusting the wall thickness of the oil pan, adding or modifying the layout and shape of the reinforcing ribs, and changing one or more of the local curvature.
[0013] Secondly, the present invention also provides a resonance analysis system for a metal oil pan, comprising: The model building module is used to establish a fluid-structure interaction finite element model that includes the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block. The modal analysis module is used to perform modal analysis on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under the action of fluid coupling. The excitation spectrum acquisition module is used to acquire the vibration excitation spectrum acting on the oil pan mounting point through experimental measurement or engine dynamics simulation. The dynamic response module is used to apply the vibration excitation spectrum as a load condition to the corresponding mounting points of the fluid-structure interaction finite element model, perform frequency response analysis, and calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum. The risk assessment module is used to identify the resonant frequency points and high-stress areas of the oil pan based on the comparison results of dynamic stress and vibration response with natural frequencies and mode shapes, and to assess the risk of structural fatigue failure or abnormal noise generation of the oil pan.
[0014] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the resonance analysis method for the metal oil pan described above.
[0015] Fourthly, the present invention also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the resonance analysis method for the metal oil pan described above.
[0016] By establishing a fluid-structure interaction model and performing wet modal analysis, the above technical solution fully considers the additional mass effect of lubricating oil, making the modal prediction results closer to the actual working state of the oil pan and significantly improving the accuracy of resonant frequency prediction.
[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description
[0018] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a resonance analysis method for a metal oil pan provided in an embodiment of the present invention; Figure 2(a) is a model of a metal oil pan before optimization provided in an embodiment of the present invention; Figure 2 (b) An optimized model of a metal oil pan provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a fluid-structure interaction finite element model provided in an embodiment of the present invention; Figure 4 This is a wet modal shape diagram obtained by wet modal analysis before and after optimization, provided by an embodiment of the present invention; Figure 5 (a) A vibration excitation spectrum of an installation point in the X-space direction provided by an embodiment of the present invention; Figure 5 (b) A vibration excitation spectrum of an installation point in the Y-space direction provided by an embodiment of the present invention; Figure 5 (c) A vibration excitation spectrum of an installation point in the Z-space direction provided by an embodiment of the present invention; Figure 6 This is a dynamic stress distribution cloud map on the surface of an oil pan obtained by frequency response analysis, provided in an embodiment of the present invention. Figure 7 This invention provides an embodiment of the noise spectrum before and after engine oil pan improvement through actual measurement; Figure 8 This is a schematic diagram of the structure of a resonance analysis system for a metal oil pan provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation
[0019] Various embodiments of this disclosure will be described more fully in the following detailed description. This disclosure may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this disclosure to the specific embodiments disclosed herein, but rather this disclosure should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this disclosure.
[0020] In the following, the terms “comprising” or “may include”, which may be used in various embodiments of this disclosure, indicate the presence of the disclosed functions or operations and do not limit the addition of one or more functions or operations. Furthermore, as used in various embodiments of this disclosure, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, or combination of the foregoing and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, or combinations of the foregoing, or the possibility of adding one or more features, numbers, steps, operations, or combinations of the foregoing.
[0021] In various embodiments of this disclosure, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.
[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] See Figure 1 The diagram shows a flowchart of a resonance analysis method for a metal oil pan in a specific embodiment, including the following steps: Step 100: Establish a fluid-structure interaction finite element model that includes the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block.
[0024] Specifically, in the fluid-structure interaction finite element model, the metal oil pan structure is discretized using shell elements or solid elements; the internal lubricating oil fluid domain is modeled using acoustic fluid elements or Eulerian fluid elements; and the interaction between the shell elements or solid structural elements and the acoustic fluid elements or Eulerian fluid elements is defined through the fluid-structure interaction interface.
[0025] Preferably, the boundary conditions for the connection between the oil pan and the engine block include: preload constraint on the bolts connecting the oil pan and the engine block, and the mechanical effect of the rubber sealing gasket at the installation mating surface is simulated by using a spring unit.
[0026] In one specific implementation, when performing step 100, the following steps may be specifically performed: S1000: Import the three-dimensional geometric model of the metal oil pan into the finite element preprocessing software, mesh the oil pan structure using shell elements or solid elements, and define its material properties, including elastic modulus, Poisson's ratio, and density.
[0027] For example, taking the stamped oil pan of an inline six-cylinder diesel engine as an example, the method of this invention is applied to perform resonance analysis. A digital model of the oil pan is obtained using 3D software; see [link to documentation]. Figure 2 Before optimization of the metal oil pan established in the implementation case ( Figure 2 (a) Optimized ( Figure 2(b) The model was imported into finite element preprocessing software (such as ANSYS or Abaqus). Tetrahedral solid elements were used to mesh the oil pan. The material properties were defined as DC06, and its elastic modulus, Poisson's ratio, and density were set.
[0028] S1001: Based on the internal cavity of the oil pan, create a geometric model of the fluid domain of the lubricating oil, mesh the fluid domain using acoustic fluid elements or Euler fluid elements, and define the density and bulk modulus of the lubricating oil.
[0029] S1002: Establish a constraint relationship to simulate bolt connection at the mounting hole position of the oil pan and engine block, and apply a preset bolt preload; establish a spring unit between the mating surfaces of the oil pan and engine block to simulate the stiffness and damping characteristics of the rubber gasket.
[0030] S1003: The unit surface in contact with the lubricating oil fluid domain on the inner wall of the oil pan structure is defined as the fluid-structure interaction interface to realize the bidirectional coupling transmission between fluid pressure load and structural deformation.
[0031] For example, the constructed fluid-structure interaction finite element model is as follows: Figure 3 As shown.
[0032] Step 101: Perform modal analysis on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under fluid coupling.
[0033] In one specific implementation, see [reference] Figure 4 The figure shows the wet modal shape diagrams obtained by wet modal analysis before and after optimization in this embodiment of the invention. A finite element solver was used to perform modal analysis on the above fluid-structure interaction finite element model. The analysis type was selected as either "wet modal" or "fluid-structure interaction modal analysis". After solving, the first 5 natural frequencies and mode shapes were extracted. The results show that the second wet modal frequency is 103.1 Hz, and the mode shape is a large-area up-and-down vibration of the bottom surface of the small end of the oil pan. Before optimization, the frequencies were 39.0 Hz, 103.1 Hz, 122.9 Hz, 142.8 Hz, 168.3 Hz, and 200.1 Hz, showing a total of 6 modes. After optimization, the frequencies were 48.3 Hz, 120.3 Hz, 131.4 Hz, 149.3 Hz, and 191.4 Hz, showing a total of 5 modes.
[0034] One of the core objectives of this invention is to solve the resonance problem (second-order wet mode) of the oil pan around 103.1 Hz. Before optimization, the second-order frequency was 103.1 Hz. This vibration mode is characterized by a large-area vertical vibration on the bottom surface of the small end of the oil pan. Frequency response analysis revealed a peak around 130 Hz, which coincides with the wet mode frequency, confirming a resonance risk and causing abnormal noise. After structural optimization based on the analysis results (such as adding reinforcing ribs), the second-order mode frequency was significantly increased to 120.3 Hz, an increase of approximately 17.2 Hz. This optimization eliminated the large-area vertical vibration on the bottom surface of the small end of the oil pan, avoiding the main excitation frequency and eliminating the measured noise resonance risk. Furthermore, other frequencies were also generally improved, indicating that the optimization measures enhanced the overall structural stiffness of the oil pan.
[0035] Step 102: Obtain the vibration excitation spectrum acting on the oil pan mounting point through experimental measurement or engine dynamics simulation.
[0036] Specifically, when executing step 102, the following steps can be performed: S1020: On a test platform for a complete machine or vehicle equipped with the engine, an acceleration sensor is arranged at the connection point between the oil pan and the engine block.
[0037] S1021: Based on the aforementioned accelerometer, acquire the vibration acceleration time-domain signal of the mounting point when the engine is running under the target operating condition, and perform frequency domain transformation and statistical analysis on the vibration acceleration time-domain signal to generate an acceleration power spectral density curve as the vibration excitation spectrum; or, S1022: Establish a multibody dynamics simulation model that includes the engine crankshaft and connecting rod mechanism, valve train mechanism and engine block structure; and define the gas pressure in the cylinder, the inertial force of moving parts and the valve system impact load in the multibody dynamics simulation model.
[0038] S1023: Through dynamic calculation, output the time-domain history of the dynamic support reaction force or vibration acceleration at the oil pan mounting point; and convert the time-domain history into a power spectral density function in the frequency domain as the vibration excitation spectrum.
[0039] For example, by measuring the vibration acceleration excitation spectrum at the engine oil pan mounting point (see... Figure 5 (as shown) Figure 5 (a), 5(b), and 5(c) correspond to the vibrations of the installation point in the X, Y, and Z spatial directions, respectively. Figure 5The curve should show several energy concentration peaks or frequency bands. These peaks correspond to the main excitation sources at different frequencies of multiple engines (X_A engine, X_B engine, X_C engine, X_D engine, X_E engine, X_F engine). These data are integrated to form the maximum outer envelope, and then the data is amplified by multiple factors (including 1.5x, 1.2x, and 2x) and used as input to the simulation model. Figure 5 The high-energy frequency bands displayed provide a direct comparative benchmark for resonance risk assessment. Determining the wet modal frequency of the oil pan ( Figure 4 Whether it is dangerous depends on whether the wet modal frequency falls within a certain range. Figure 5 Within these high-energy excitation frequency bands shown, falling into them poses a high risk of resonance, while avoiding them reduces the risk. This transforms risk assessment from a qualitative judgment to a quantitative comparison based on data.
[0040] Step 103: Apply the vibration excitation spectrum as a load condition to the corresponding mounting point of the fluid-structure interaction finite element model, perform frequency response analysis, and calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum.
[0041] Step 104: Based on the comparison results of dynamic stress and vibration response with natural frequency and mode shape, identify the resonant frequency point and high stress area of the oil pan, and assess the risk of structural fatigue failure or abnormal noise generation of the oil pan.
[0042] Specifically, when executing step 104, the following steps can be performed: S1040: In the frequency response analysis results, extract the vibration response data of multiple feature monitoring points on the oil pan, and plot the frequency-response amplitude curve based on the vibration response data.
[0043] S1041: Identify the frequency point corresponding to the response peak in the frequency-response amplitude curve, and compare the frequency point with the natural frequency of the oil pan under the action of liquid coupling. The frequency points that are consistent or similar to the two are determined as the resonant frequency of the oil pan.
[0044] S1042: Based on the dynamic stress distribution results of the oil pan under the vibration excitation spectrum, generate a dynamic stress cloud map of the oil pan structure at the resonant frequency; identify areas in the dynamic stress cloud map where the dynamic stress value exceeds a preset threshold, and designate them as high-risk areas for structural fatigue; at the same time, generate a vibration velocity or acceleration cloud map of the oil pan at the resonant frequency, identify areas where the vibration amplitude is higher than the average level, and define them as high-risk areas for radiated noise.
[0045] For example, see Figure 5The frequency response function curves plotted for a specific point on the oil pan revealed a significant peak around 130Hz, which coincides with the obtained wet modal frequencies, identifying it as a resonance point. Refer to the dynamic stress distribution cloud map on the oil pan surface obtained from the frequency response analysis. Figure 6 As shown, the color bars in the graph indicate the stress range. The maximum stress value (red area in the graph) is approximately 19.1 MPa. The stress gradually changes from blue (low) to red (high), visually indicating the stress concentration. The high-stress areas (red and yellow) are not uniformly distributed but highly concentrated on the lower wall of the small end of the oil pan. Although the maximum stress value does not exceed the fatigue limit of the material, noise resonance was observed at the small end of the engine oil pan in actual measurements (see...). Figure 7 As shown), in Figure 4 The analysis determined that the resonance frequency point was around 130Hz. Before optimization, there was a significant peak in the noise spectrum. After optimization, this peak should have been significantly reduced or basically disappeared. This indicates that the optimization eliminated the large-area vertical vibration mode of the bottom surface of the small head of the oil pan, avoided the main excitation frequency, and eliminated the risk of noise resonance in the actual measurement.
[0046] S1043: Compare the resonant frequency with the excitation frequency band where energy is concentrated in the vibration excitation spectrum acting on the oil pan mounting point. If the resonant frequency falls within the excitation frequency band, the resonance risk level is determined to be high; otherwise, the risk level is determined to be low.
[0047] In one specific embodiment, the resonance analysis method for the metal oil pan further includes: optimizing the structural design of the oil pan based on the risk assessment results of structural fatigue failure or abnormal noise generation of the oil pan; and repeating the above steps 100-104 to model and analyze the optimized structural design of the oil pan until the resonance risk of the oil pan meets the preset design target. The optimization of the structural design of the oil pan includes adjusting the wall thickness of the oil pan, adding or modifying the layout and shape of the reinforcing ribs, and changing one or more of the local curvature.
[0048] In this embodiment, the digital model of the oil pan is optimized based on the mode shape distribution obtained from modal analysis, such as by adding reinforcing ribs to the bottom surface of the small end. Steps 100 to 104 are repeated to analyze the optimized model. The results are shown (see...). Figure 4 The original second-order wet modal frequency was 103.1 Hz. The large-area vertical vibration mode on the bottom surface of the small end of the oil pan disappeared, and the second-order wet modal frequency increased to 120.3 Hz. The bottom surface of the small end of the oil pan avoided the main excitation frequency, and the maximum vibration amplitude of other orders at this location also decreased significantly. Furthermore, the noise risk at this location was eliminated through actual measurement. In summary, this invention predicted and solved the resonance problem of the oil pan during the design phase, proving the effectiveness and engineering application value of the method.
[0049] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
[0050] The technical effects achieved by this application are as follows: 1. By establishing a fluid-structure interaction model and performing wet modal analysis, the additional mass effect of lubricating oil is fully considered, making the modal prediction results closer to the actual working state of the oil pan and significantly improving the accuracy of resonant frequency prediction.
[0051] 2. It can be carried out in the design stage without a physical prototype, so as to identify resonance risks in advance, achieve "front-end prevention", and avoid the cost of expensive design changes and prototype modifications in the later stage.
[0052] 3. The analysis results can clearly indicate the resonant frequency and stress concentration area, providing engineers with clear and quantitative basis for targeted structural optimization (such as stiffener layout and wall thickness adjustment), thus shortening the development cycle.
[0053] 4. By integrating modeling, modal analysis, stimulus acquisition, dynamic response calculation, and risk assessment into a complete process, a systematic and standardized solution is formed, which is easy to promote and apply within an enterprise.
[0054] like Figure 8 As shown, the following are embodiments of the resonance analysis system for metal oil pans provided in this disclosure. The system belongs to the same inventive concept as the resonance analysis methods for metal oil pans in the above embodiments. For details not described in detail in the embodiments of the resonance analysis system for metal oil pans, please refer to the embodiments of the resonance analysis methods for metal oil pans described above.
[0055] The resonance analysis system for metal oil pans includes: The model building module is used to establish a fluid-structure interaction finite element model that includes the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block. The modal analysis module is used to perform modal analysis on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under the action of fluid coupling. The excitation spectrum acquisition module is used to acquire the vibration excitation spectrum acting on the oil pan mounting point through experimental measurement or engine dynamics simulation. The dynamic response module is used to apply the vibration excitation spectrum as a load condition to the corresponding mounting points of the fluid-structure interaction finite element model, perform frequency response analysis, and calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum. The risk assessment module is used to identify the resonant frequency points and high-stress areas of the oil pan based on dynamic stress and vibration response results, and to assess the risk of structural fatigue failure or abnormal noise generation of the oil pan.
[0056] Figure 9 This is a schematic diagram of the hardware structure of an electronic device that implements various embodiments of the present invention.
[0057] The resonance analysis method for metal oil pans provided in this application can be applied to electronic devices. Those skilled in the art will understand that the electronic device structures involved in the embodiments of this invention do not constitute a limitation on the electronic device. An electronic device may include more or fewer components than illustrated, or combine certain components, or have different component arrangements. In the embodiments of this invention, electronic devices include, but are not limited to, laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the embodiments of this application described and / or claimed herein.
[0058] Electronic devices may include processors, external memory interfaces, internal memory, universal serial bus (USB) interfaces, charging management modules, power management modules, batteries, wireless communication modules, audio modules, speakers, microphones, sensor modules, buttons, cameras, displays, and SIM card interfaces, etc.
[0059] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device. In other embodiments of this application, the electronic device may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.
[0060] A processor may include one or more processing units, such as: a central processing unit (CPU), an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.
[0061] The processor can serve as the nerve center and command center of an electronic device. The controller can generate operation control signals based on the instruction opcode and timing signals to control the fetching and execution of instructions.
[0062] The processor may also include memory for storing instructions and data. In some embodiments, the memory in the processor is a cache memory. This memory can store instructions or data that the processor has just used or that are used repeatedly. If the processor needs to use the instruction or data again, it can retrieve it directly from this memory. This avoids repeated accesses, reduces processor latency, and thus improves system efficiency.
[0063] An external storage interface (ESI) can be used to connect external memory cards, such as microSD cards, to expand the storage capacity of electronic devices. The external memory card communicates with the processor through the ESI to perform data storage functions, such as saving music and video files on the external memory card.
[0064] Internal memory can be used to store computer executable program code, which includes instructions. The processor executes various functional applications and data processing of electronic devices by running the instructions stored in internal memory. Internal memory can include a program storage area and a data storage area. Internal memory can include high-speed random access memory, and can also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.
[0065] Wireless communication functionality in electronic devices can be achieved through antennas, wireless communication modules, modem processors, and baseband processors.
[0066] Wireless communication modules can provide solutions for wireless communication applications in electronic devices, including wireless local area networks (WLANs) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies.
[0067] Electronic devices can implement audio functions through audio modules, speakers, receivers, microphones, headphone jacks, and application processors.
[0068] Electronic devices can achieve shooting functions through ISPs, cameras, video codecs, GPUs, displays, and application processors.
[0069] Electronic devices can achieve display functions through GPUs, displays, and application processors.
[0070] A GPU is a microprocessor for image processing, connected to the display screen and application processor. GPUs are used to perform mathematical and geometric calculations for graphics rendering. A processor may include one or more GPUs, which execute program instructions to generate or modify display information.
[0071] A display screen is used to display images, videos, etc. A display screen includes a display panel.
[0072] The storage medium provided in this application stores a program product capable of implementing a resonance analysis method for metal oil pans.
[0073] The resonance analysis method for a metal oil pan includes: establishing a fluid-structure interaction (FSI) finite element model that includes the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan to the engine block; performing modal analysis on the FSI finite element model to obtain the natural frequencies and mode shapes of the oil pan under fluid coupling; obtaining the vibration excitation spectrum acting on the mounting point of the oil pan through experimental measurements or engine dynamics simulation; applying the vibration excitation spectrum as a load condition to the corresponding mounting point of the FSI finite element model, performing frequency response analysis, and calculating the dynamic stress and vibration response of the oil pan under the vibration excitation spectrum; and identifying the resonance frequency points and high-stress regions of the oil pan based on the comparison results of the dynamic stress and vibration response with the natural frequencies and mode shapes, and assessing the risk of structural fatigue failure or abnormal noise generation of the oil pan.
[0074] In some possible implementations, the subject matter of this disclosure, namely, the resonance analysis method and system for metal oil pans, can be implemented as a program product comprising program code that, when run on a terminal device, causes the terminal device to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure.
[0075] The storage medium disclosed herein may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.
[0076] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A resonance analysis method for a metal oil pan, characterized in that, include: A fluid-structure interaction finite element model was established, which included the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block. Modal analysis was performed on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under fluid coupling. The vibration excitation spectrum acting on the oil pan mounting point is obtained through experimental measurement or engine dynamics simulation. The vibration excitation spectrum is used as a load condition and applied to the corresponding mounting points of the fluid-structure interaction finite element model. Frequency response analysis is performed to calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum. Based on the comparison results of dynamic stress and vibration response with natural frequency and mode shape, the resonant frequency point and high stress area of the oil pan are identified, and the risk of structural fatigue failure or abnormal noise generation of the oil pan is assessed.
2. The resonance analysis method for a metal oil pan according to claim 1, characterized in that, In the fluid-structure interaction finite element model, the metal oil pan structure is discretized using shell elements or solid elements; The internal lubricating oil fluid domain is modeled using acoustic fluid elements or Euler fluid elements; The interaction between shell elements or solid structural elements and acoustic fluid elements or Eulerian fluid elements is defined through the fluid-structure interaction interface.
3. The resonance analysis method for a metal oil pan according to claim 2, characterized in that, The connection boundary conditions between the oil pan and the engine block include: The preload constraint on the bolts connecting the oil pan and the engine block, and the mechanical effect of the rubber gasket at the installation joint surface simulated by using a spring unit.
4. The resonance analysis method for a metal oil pan according to claim 3, characterized in that, The construction process of the fluid-structure interaction finite element model includes: The three-dimensional geometric model of the metal oil pan is imported into the finite element preprocessing software. Shell elements or solid elements are used to mesh the oil pan structure, and its material properties, including elastic modulus, Poisson's ratio and density, are defined. Based on the internal cavity of the oil pan, a geometric model of the fluid domain of the lubricating oil is created. The fluid domain is meshed using acoustic fluid elements or Euler fluid elements, and the density and bulk modulus of the lubricating oil are defined. At the mounting holes of the oil pan and the engine block, a constraint relationship is established to simulate the bolt connection, and a preset bolt preload is applied; between the mating surfaces of the oil pan and the engine block, a spring unit is established to simulate the stiffness and damping characteristics of the rubber gasket. The unit surface that comes into contact with the lubricating oil fluid domain on the inner wall of the oil pan structure is defined as the fluid-structure interaction interface to achieve bidirectional coupling and transmission between fluid pressure load and structural deformation.
5. The resonance analysis method for a metal oil pan according to claim 1, characterized in that, The vibration excitation spectrum acting on the oil pan mounting point is obtained through experimental measurements or engine dynamics simulation, including: On a test platform for a complete machine or vehicle equipped with the engine, an acceleration sensor is arranged at the connection and mounting point between the oil pan and the engine block. Based on the aforementioned accelerometer, the vibration acceleration time-domain signal at the mounting point is acquired when the engine is running under target conditions. The vibration acceleration time-domain signal is then subjected to frequency domain transformation and statistical analysis to generate an acceleration power spectral density curve as the vibration excitation spectrum; or... Establish a multibody dynamics simulation model that includes the engine crankshaft and connecting rod mechanism, valve train mechanism and engine block structure; and define the gas pressure in the cylinder, the inertial force of moving parts and the impact load of the valve system in the multibody dynamics simulation model; Through dynamic calculations, the time-domain history of the dynamic support reaction force or vibration acceleration at the oil pan mounting point is output; and the time-domain history is converted into a power spectral density function in the frequency domain as the vibration excitation spectrum.
6. The resonance analysis method for a metal oil pan according to claim 1, characterized in that, Based on the dynamic stress and vibration response results, the resonant frequency points and high-stress areas of the oil pan are identified, and the risk of structural fatigue failure or abnormal noise generation is assessed, including: In the frequency response analysis results, vibration response data from multiple feature monitoring points on the oil pan are extracted, and frequency-response amplitude curves are plotted based on the vibration response data. Identify the frequency point corresponding to the response peak in the frequency-response amplitude curve, and compare the frequency point with the natural frequency of the oil pan under the action of liquid coupling. The frequency points that are consistent or similar to the two are determined as the resonant frequency of the oil pan. Based on the dynamic stress distribution of the oil pan under the vibration excitation spectrum, a dynamic stress cloud map of the oil pan structure at the resonant frequency is generated; and regions in the dynamic stress cloud map where the dynamic stress value exceeds a preset threshold are identified as high-risk areas for structural fatigue; at the same time, a vibration velocity or acceleration cloud map of the oil pan at the resonant frequency is generated, and regions where the vibration amplitude is higher than the average level are identified and defined as high-risk areas for radiated noise. The resonance frequency is compared with the energy concentration frequency band in the vibration excitation spectrum acting on the oil pan mounting point. If the resonance frequency falls within the excitation frequency band, the resonance risk level is determined to be high; otherwise, the risk level is determined to be low.
7. The resonance analysis method for a metal oil pan according to claim 1, characterized in that, The resonance analysis method for the metal oil pan also includes: Based on the risk assessment results of resonance caused by structural fatigue failure or abnormal noise in the oil pan, the structural design of the oil pan is optimized; and the steps in claim 1 are repeated to model and analyze the optimized structural design of the oil pan until the resonance risk of the oil pan meets the preset design target. The optimization of the structural design of the oil pan includes adjusting the wall thickness of the oil pan, adding or modifying the layout and shape of the reinforcing ribs, and changing one or more of the following:
8. A resonance analysis system for a metal oil pan, characterized in that, include: The model building module is used to establish a fluid-structure interaction finite element model that includes the metal oil pan structure, the internal lubricating oil fluid domain, and the boundary conditions connecting the oil pan and the engine block. The modal analysis module is used to perform modal analysis on the fluid-structure interaction finite element model to obtain the natural frequencies and mode shapes of the oil pan under the action of fluid coupling. The excitation spectrum acquisition module is used to acquire the vibration excitation spectrum acting on the oil pan mounting point through experimental measurement or engine dynamics simulation. The dynamic response module is used to apply the vibration excitation spectrum as a load condition to the corresponding mounting points of the fluid-structure interaction finite element model, perform frequency response analysis, and calculate the dynamic stress and vibration response of the oil pan under the action of the vibration excitation spectrum. The risk assessment module is used to identify the resonant frequency points and high-stress areas of the oil pan based on the comparison results of dynamic stress and vibration response with natural frequencies and mode shapes, and to assess the risk of structural fatigue failure or abnormal noise generation of the oil pan.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the resonance analysis method for the metal oil pan as described in any one of claims 1 to 7.
10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the resonance analysis method for the metal oil pan as described in any one of claims 1 to 7.