A method for vibration analysis of spatial thin film structures under electrostatic discharge.

Abstract

This invention relates to the field of thin-film structure vibration analysis technology, specifically providing a method for analyzing the vibration of space thin-film structures under electrostatic discharge. Addressing the problems of existing technologies that neglect electrostatic discharge as a vibration source, the difficulty in establishing a potential-prestress coupling model, and inaccurate transient force simulation, this invention establishes a geometric model including the thin-film surface, electrode surface, and electrostatic field region. It uses triangular thin-film elements and tetrahedral electrostatic field elements for mesh generation, constructs a nonlinear coupled dynamic equation between the electrostatic field and the thin-film structure, and simulates the discharge transient through initial equilibrium state establishment, selected channel step discharge, and free vibration decay monitoring. By changing the initial voltage of the electrode surface, the second load step time, and the discharge channel position, the vibration law is quantitatively analyzed. This invention also reveals the key principle that voltage amplitude dominates vibration energy, while the discharge position has a weak influence, providing effective theoretical support for on-orbit vibration suppression of structures such as space thin-film antennas and solar sails.

Description

Technical Field

[0001] This invention relates to the field of thin film structure vibration analysis technology, and specifically to a method for analyzing the vibration of a spatial thin film structure under electrostatic discharge. Background Technology

[0002] With the gradual implementation of a series of major aerospace projects, such as manned lunar exploration, space-based observation, and lunar research stations, there is an urgent need to develop large-scale space thin-film structures such as spaceborne thin-film antennas, thin-film sunshades, and thin-film solar sails to meet the future development needs of aerospace technology. However, the vibration of thin-film structures during on-orbit applications is unavoidable due to various space environments, which seriously affects the performance of spacecraft. Although the establishment of nonlinear dynamic models and equivalent methods for thin-film structures has been extensively studied by scholars at home and abroad, and the influence of factors such as temperature and thin-film tension on the dynamic characteristics of thin-film structures has been noted, current research only considers the influence of the on-orbit thermal environment on the vibration of thin-film structures and has not yet considered electrostatic discharge as an on-orbit vibration source for thin-film structures.

[0003] In previous experimental studies of thin-film antennas, it was discovered that electrostatic discharge (ESD) can cause vibrations in the thin-film structure. On the one hand, there is a nonlinear coupling relationship between the on-orbit charging potential of the thin-film structure and the prestress of the thin-film reflector; on the other hand, ESD can cause transient forces to act on the thin-film reflector. Both of these factors affect the dynamic characteristics of the thin-film antenna. For the vibration analysis of space thin-film structures under ESD, existing technologies face the following technical challenges:

[0004] First, existing research has focused on the effects of factors such as temperature and film tension on the dynamic characteristics of thin film structures, but has not yet paid attention to the fact that electrostatic discharge is one of the vibration sources of space thin film structures.

[0005] Secondly, there is a nonlinear coupling relationship between the potential of the thin film structure and the prestress of the thin film structure. How to establish a nonlinear coupling dynamic model between the electrostatic field and the deformation field of the thin film structure is one of the existing technical challenges.

[0006] Furthermore, electrostatic discharge can cause thin film structures to be subjected to transient forces, and how to accurately establish a transient dynamic analysis model of thin film structures during electrostatic discharge is a current challenge.

[0007] Therefore, it is urgent to propose a vibration analysis method for space thin-film structures under electrostatic discharge to provide theoretical support for the prevention and control of on-orbit vibration of space thin-film structures. Summary of the Invention

[0008] To address the problems existing in the background art, the present invention provides a method for vibration analysis of a spatial thin film structure under electrostatic discharge, comprising the following steps:

[0009] S1. Establish a spatial thin film structure geometric model that includes the thin film surface, electrode surface, and electrostatic field region;

[0010] S2. Finite element meshing is performed on the thin film surface and electrostatic field region, and solution parameters are set to establish a nonlinear coupled dynamic analysis model of electrostatic field-space thin film structure.

[0011] S3. Simulate the stress state of a spatial thin-film structure during electrostatic discharge using transient voltage;

[0012] S4. Solve the transient analysis model of the nonlinear vibration of the spatial thin film structure and obtain the relationship curve between amplitude and time;

[0013] S5. Analyze the vibration law of the space thin film structure by changing the transient voltage amplitude, duration, or discharge voltage channel.

[0014] Preferably, S1 specifically includes:

[0015] S11. Construct a planar circular thin-film structure with its center at (0,0,0) and a radius of 2.5m;

[0016] S12. Construct a planar circular electrode surface with a center at (0,0,-0.05m) and a radius of 2.5m, and have 6 electrode channels;

[0017] S13. Construct a cylindrical surface based on the boundary lines of the thin film structure and electrode surface, and combine the thin film surface, electrode surface and cylindrical surface to generate a geometric model of the electrostatic field region.

[0018] Preferably, S2 specifically includes:

[0019] S21. The film surface is divided by triangular planar thin film units, the unit type is shell181, the thickness is 25μm, the elastic modulus is 2.17GPa, the Poisson's ratio is 0.34, and the mass density is 1432kg / m³.

[0020] S22. The electrostatic field region is divided using tetrahedral elements. The element type is solid227, the elastic modulus is 0 GPa, the Poisson's ratio is 0, and the mass density is 0 kg / m³.

[0021] S23. Establish a nonlinear coupled dynamics analysis model:

[0022] ;

[0023] in, The mass matrix of the thin film structure; The damping matrix of the thin film structure; Here is the stiffness matrix of the thin film structure; This is the equivalent stiffness matrix of the electrostatic field; , The coupling matrix between the thin film field and the electrostatic field; External load force for the thin film structure; It represents the amount of charge; For nodal acceleration; For node speed; For nodal displacement; It represents the electric potential.

[0024] Preferably, S3 specifically includes:

[0025] S31. Set the first load step: time 0.01s, disable time integration effect, enable stress stiffening and geometric nonlinearity effect, thin film surface voltage 0V, initial voltage of each channel on the electrode surface is 0V. ;

[0026] S32. Set the second load step: time When the time integration effect is activated, the voltage of the Nth channel on the electrode surface jumps to 0V, while the voltages of the other channels remain unchanged.

[0027] S33. Set the third load step: time 20s, maintain the load conditions of the second load step.

[0028] Preferably, S4 specifically includes:

[0029] S41. Set the solution parameters: the solution type is transient dynamic analysis, the mass damping coefficient is 0.05, the stiffness damping coefficient is 0.05, and the transient integral constant is 0.05;

[0030] S42. The complete method is used to solve the transient dynamics, and the SSOLVE command is used to solve for multiple load steps.

[0031] S43. Extract the displacement data of the center point of the thin film structure and plot the displacement-time curve using MATLAB.

[0032] Preferably, S5 specifically includes:

[0033] S51. Change the initial voltage of the electrode surface For 100V, 300V, and 500V, repeat S1-S4;

[0034] S52. Change the second load step time Repeat S1-S4 for intervals of 0.002s, 0.05s, and 0.1s.

[0035] S53. Step the voltage of the first, third, and fifth channels of the electrode surface to 0V respectively, and repeat S1-S4.

[0036] The beneficial effects achieved by this invention are as follows:

[0037] First, this invention is the first to incorporate electrostatic discharge as the core vibration source of space thin film structures into the analysis framework, breaking through the limitations of traditional research that only focuses on thermal environment or mechanical tension. By establishing the electrode-thin film spatial mapping relationship and a 6-channel discharge model, it successfully reveals the excitation mechanism of electrostatic discharge on thin film vibration, providing a new theoretical perspective for tracing the source of on-orbit vibration, enabling spacecraft designers to formulate targeted vibration prevention strategies.

[0038] Secondly, the electrostatic field-structure coupled dynamic model proposed in this invention effectively solves the modeling problem of nonlinear coupling between potential and prestress. This invention utilizes the field-structure coupling matrix to accurately characterize the interaction mechanism between charge distribution and thin film deformation. The zero-mass electrostatic field unit setting avoids inertial force interference, significantly improves the accuracy of electrostatic transient force simulation, and makes the vibration prediction results highly consistent with the real physical phenomena, laying a solid foundation for reliability analysis.

[0039] Third, the step voltage triggering mechanism and phased load step design of this invention overcome the technical bottleneck of electrostatic discharge transient force simulation. By separating the static balance establishment, discharge transient and vibration decay processes through three-stage load step, the instantaneous characteristics of microsecond-level discharge are accurately reproduced, while ensuring the computational stability of complex nonlinear problems. It also realizes the controllable adjustment of discharge parameters, including voltage amplitude, duration and position, providing a flexible technical means for vibration analysis in multiple scenarios.

[0040] Fourth, this invention utilizes parametric analysis to reveal the differentiated influence of the three elements of electrostatic discharge on vibration characteristics. Experiments demonstrate that voltage amplitude dominates vibration energy, while discharge location has almost no effect on the overall mode. The method can be extended to various space thin-film structures such as thin-film solar sails and sunshades, and the established universal analytical framework provides universal technical support for the on-orbit stability design of spacecraft. Attached Figure Description

[0041] Figure 1 This is an overall flowchart of the method for analyzing the vibration of a spatial thin film structure under electrostatic discharge according to the present invention.

[0042] Figure 2 This is a flowchart illustrating the geometric model of a spatial thin film structure with a thin film surface, an electrode surface, and an electrostatic field region, as described in this invention.

[0043] Figure 3 This is a flowchart of the nonlinear coupling dynamic analysis model of electrostatic field-space thin film structure established in this invention.

[0044] Figure 4 This is a flowchart illustrating the stress state of a spatial thin-film structure during the application of transient voltage to simulate electrostatic discharge, as described in this invention.

[0045] Figure 5This is a flowchart of the transient analysis model for solving the nonlinear vibration of a spatial thin film structure according to the present invention.

[0046] Figure 6 This is a flowchart illustrating the process of obtaining the vibration law of a spatial thin film structure during electrostatic discharge.

[0047] Figure 7 This is a geometric model diagram of the thin film structure of the present invention.

[0048] Figure 8 This is a voltage channel distribution diagram of the present invention.

[0049] Figure 9 This is a diagram illustrating the vibration law of the thin film structure under different initial voltage values ​​according to the present invention.

[0050] Figure 10 This is a diagram illustrating the vibration law of the thin film structure by altering the electrostatic discharge time according to the present invention.

[0051] Figure 11 This is a diagram illustrating the vibration law of the thin film structure that alters the electrostatic discharge voltage channel according to the present invention. Detailed Implementation

[0052] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] The following is in conjunction with the appendix Figures 1 to 11 The present invention will be further described below.

[0054] Example 1: The vibration analysis method for a spatial thin film structure under electrostatic discharge provided in Example 1 of this invention is as follows: Figure 1 As shown, it includes the following steps:

[0055] S1: Establish the geometric model of the spatial thin-film structure; such as... Figure 2 As shown, this step is implemented through the following sub-steps:

[0056] First, a planar circular thin-film structure with a center at coordinate point (0,0,0) and a radius of 2.5 meters is constructed. This structure serves as the basic geometric model for the space thin-film reflective surface. Second, a planar circular electrode surface with a center at (0,0,-0.05 meters) and a radius of 2.5 meters is constructed, and six uniformly distributed voltage channels are set (see...). Figure 8 ), Figure 8There are six circular rings, each representing a voltage channel, numbered from the inside out as channel 1, channel 2... channel 6, used to simulate multiple trigger points for electrostatic discharge. Finally, a closed cylindrical surface is constructed based on the boundary lines of the thin film structure and the electrode surface. The thin film surface, electrode surface, and cylindrical surface are combined to generate a three-dimensional geometric model of the electrostatic field region, ensuring that the spatial relationship between the electrostatic field's effective range and the thin film structure conforms to the actual physical scenario.

[0057] This invention establishes, for the first time, the spatial mapping relationship between electrodes and thin films. Through a 6-channel electrode design, it accurately simulates multi-point discharge scenarios in space, effectively solving the challenge of simulating multi-point triggering of electrostatic discharge. Furthermore, by employing a modeling method for a cylindrical, enclosed electrostatic field region, it successfully addresses the technical difficulty of accurately defining the boundary conditions of the electrostatic field.

[0058] S2: Establish a nonlinear coupled dynamics model; such as Figure 3 As shown, the specific implementation includes:

[0059] First, triangular planar thin film elements (Shell181) were used to divide the film surface, with a thickness of 25 micrometers, an elastic modulus of 2.17 gigapascals, a Poisson's ratio of 0.34, and a mass density of 1432 kg / m³, to accurately characterize the material properties of the polyimide film. Second, tetrahedral elements (Solid227) were used to divide the electrostatic field region, with an elastic modulus of 0 gigapascals, a Poisson's ratio of 0, and a mass density of 0 kg / m³, reflecting the massless nature of the electrostatic field. Finally, nonlinear coupled dynamic equations were established, as shown below:

[0060] ;

[0061] in, The mass matrix of the thin film structure; The damping matrix of the thin film structure; Here is the stiffness matrix of the thin film structure; This is the equivalent stiffness matrix of the electrostatic field; , The coupling matrix between the thin film field and the electrostatic field; External load force for the thin film structure; It represents the amount of charge; For nodal acceleration; For node speed; For nodal displacement; It represents the electric potential.

[0062] The zero-mass electrostatic field modeling method avoids inertial forces, significantly improving the accuracy of transient force simulation. The equations fully encompass inertial, damping, stiffness, and coupling terms, providing a complete mathematical foundation for transient dynamics analysis.

[0063] S3: Simulates transient forces during electrostatic discharge; such as... Figure 4 As shown, this is achieved through three load steps:

[0064] First, in the first load step (duration 0.01 seconds), the time integration effect is turned off, stress stiffening and geometric nonlinearity effects are enabled, and the thin film surface voltage is set to 0 volts and the initial voltage of each electrode channel is set to... First, establish the initial equilibrium state of the electrostatic field. Then, in the second load step (duration: ...), ... In this process, the time integration effect is activated, and the electrode is... The channel voltage steps to 0 volts to simulate a single-point discharge, while the voltages of the other channels remain constant. Finally, in the third load step (lasting 20 seconds), the conditions after discharge are maintained to capture the decay process of the film's free vibration.

[0065] This invention employs a step voltage triggering mechanism to accurately simulate the instantaneous nature of electrostatic discharge. The phased load step design successfully separates the static equilibrium establishment, discharge transients, and vibration decay processes, significantly improving computational stability. Furthermore, adjustable parameters... , , Achieve coverage of multiple discharge scenarios.

[0066] S4: Solve for the vibration response; such as Figure 5 As shown, the specific process is as follows:

[0067] First, the transient dynamic analysis parameters were set as follows: mass damping coefficient 0.05, stiffness damping coefficient 0.05, and transient integration constant 0.05, to ensure numerical convergence. Second, the Full Method combined with the LSSOLVE command was used to solve the multi-load step problem efficiently. Finally, the displacement data of the membrane center point was extracted, and displacement-time curves were plotted using MATLAB to quantify the vibration amplitude and attenuation characteristics.

[0068] The use of dual damping coefficients effectively suppresses numerical oscillations and significantly improves the smoothness of the vibration curve. Furthermore, center point displacement monitoring directly reflects the overall vibration modes of the thin film; relevant results can be found in [reference needed]. Figures 9-11 .

[0069] S5: Parametric vibration law analysis; such as Figure 6 As shown, the variation of three sets of parameters reveals the pattern: the three sets of parameters are the initial voltage (0-1000V), the discharge duration (0-0.1S), and the discharge channel.

[0070] First, change the initial voltage. (Respectively 100 volts, 300 volts, and 500 volts): For example Figure 9As shown, an increase in voltage leads to a significant increase in vibration amplitude (when...). At volts, the amplitude reaches (meters), proving the dominant role of electrostatic force in vibrational energy. Secondly, changing the discharge time... (0.002 seconds, 0.05 seconds, and 0.1 seconds respectively): For example Figure 10 As shown, The increase mainly caused a vibration phase shift, with an amplitude change of no more than 5%, revealing the mechanism by which discharge duration affects vibration frequency. Finally, the discharge channel was changed. (Channels 1, 3, and 5 respectively): For example Figure 11 As shown, the vibration waveforms are basically the same at different discharge locations. Figure 11 The image is displayed as a single line, indicating that the film vibration is insensitive to the location of the discharge point, thus simplifying the design of the vibration control strategy.

[0071] This invention quantifies the differentiated impact of the three elements of electrostatic discharge (voltage, time, and location) on vibration, breaking through the limitations of traditional methods that only consider the thermal environment. The parametric analysis results provide a clear theoretical basis for on-orbit vibration suppression, prioritizing the control of charging voltage rather than discharge location.

[0072] Example 2: This example is a vibration analysis experiment of a 5m diameter spatial thin film structure, which is carried out according to the following steps:

[0073] 1) Experimental model construction; using a typical space thin film structure as the verification object, a circular thin film model with a diameter of 5m was established, such as... Figure 7 As shown, the center of the thin film surface is located at coordinate point. It has a radius of 2.5 meters and a thickness of 25 micrometers. The material parameters are an elastic modulus of 2.17 gigapascals and a Poisson's ratio of 0.34, which precisely match the properties of polyimide film.

[0074] like Figure 8 As shown, the electrode surface is located 0.05 meters below the thin film, with the same radius as the thin film surface. Six voltage channels are evenly distributed on the edge of the electrode to simulate a multi-point discharge scenario.

[0075] The electrostatic field region is generated through the thin film boundary, electrode boundary, and closed cylindrical surface to ensure that the electric field distribution conforms to the actual space environment.

[0076] 2) Experimental parameter settings.

[0077] Initial voltage experiment, initial voltage on electrode surface The voltages are set to 100 volts, 300 volts, and 500 volts respectively.

[0078] Discharge time experiment, discharge time of the second load step Set them to 0.002 seconds, 0.05 seconds, and 0.1 seconds respectively.

[0079] The discharge position experiment triggered discharges in voltage channels 1, 3, and 5 respectively (while the remaining channels remained open). volt).

[0080] The dynamic solution parameters are set to 0.05 for both mass damping and stiffness damping, and 0.05 for transient integral constant to ensure numerical stability.

[0081] 3) The experimental results are as follows:

[0082] (1) The effect of voltage amplitude on vibration ( Figure 9 ).

[0083] when At volts, the maximum amplitude at the center point of the thin film is rice.

[0084] when At volts, the amplitude increases to The increase was 134% in meters.

[0085] when At volts, the amplitude jumps to Meters, a 243% increase compared to 100 volts.

[0086] Conclusion: The vibration amplitude induced by electrostatic discharge is strongly positively correlated with the initial voltage, proving that electrostatic force is the core excitation source.

[0087] (2) The effect of discharge time on vibration ( Figure 10 ).

[0088] exist Within the range of 0.1 seconds, the amplitude change was less than 5%, indicating that the discharge duration had a negligible effect on the vibration energy.

[0089] but When the duration increases from 0.002 seconds to 0.1 seconds, the vibration phase shift reaches 1 / 4 of the cycle, revealing that the discharge duration mainly changes the vibration frequency characteristics.

[0090] Vibration energy is dominated by voltage amplitude, while discharge time only modulates phase response, providing a basis for vibration frequency control.

[0091] (3) The effect of discharge location on vibration ( Figure 11 ).

[0092] During discharge in channels 1, 3, and 5, the waveform overlap of the displacement curves at the film center point exceeded 95%, and the maximum amplitude deviation was less than 3%. The vibration energy distribution was uniform, indicating that the overall modal response of the film was not affected by the location of partial discharge. The vibration characteristics were insensitive to the discharge location, simplifying the on-orbit vibration suppression strategy (no need to locate the discharge point).

[0093] In this embodiment, the geometric modeling parameters (coordinates, radius), material properties (elastic modulus, density), and element type (Shell181 / Solid227) are all publicly quantified. Equation parameters (mass matrix) Coupling stiffness matrix The load step time is automatically generated by the finite element software, requiring no manual intervention. (0.01 seconds / ...) The step voltage triggering mechanism ( / 20 seconds) is implemented through ANSYS command streams, with a clearly defined operation path. Result extraction uses the LSSOLVE command and MATLAB post-processing, and the process can be executed in batches.

[0094] This invention, for the first time, quantifies the differentiated effects of the three elements of electrostatic discharge (voltage, time, and location), solving the problem of difficulty in modeling electrostatic vibration sources and transient forces that are not considered. Coupling matrix This invention accurately characterizes the potential-prestress relationship, overcoming the challenge of nonlinear coupling modeling. It clarifies that voltage amplitude is a key factor in vibration control, superior to adjusting discharge position or duration, guiding the priority implementation of voltage suppression strategies in orbit. The controllability of vibration phase provides a new approach to active damping design, allowing for the regulation of vibration frequency through discharge timing. This invention is applicable to 5-meter aperture thin-film antennas, and the same process can be directly extended to structures such as thin-film solar sails and thin-film sunshades.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for analyzing the vibration of a spatial thin-film structure under electrostatic discharge, characterized in that, Includes the following steps: S1. Establish a spatial thin film structure geometric model that includes the thin film surface, electrode surface, and electrostatic field region; S2. Finite element meshing is performed on the thin film surface and electrostatic field region, and solution parameters are set to establish a nonlinear coupled dynamic analysis model of electrostatic field-space thin film structure. S3. Simulate the stress state of a spatial thin-film structure during electrostatic discharge using transient voltage; S4. Solve the nonlinear vibration transient analysis model of the spatial thin film structure and obtain the amplitude-time relationship curve; S5. Analyze the vibration law of the space thin film structure by changing the transient voltage amplitude, duration, or discharge voltage channel; S1 specifically includes: S11. Construct a planar circular thin-film structure with its center at (0,0,0) and a radius of 2.5m; S12. Construct a planar circular electrode surface with a center at (0,0,-0.05m) and a radius of 2.5m, and have 6 electrode channels; S13. Construct a cylindrical surface based on the boundary lines of the thin film structure and electrode surface, and combine the thin film surface, electrode surface and cylindrical surface to generate a geometric model of the electrostatic field region; S2 specifically includes: S21. The film surface is divided by triangular planar thin film units, the unit type is shell181, the thickness is 25μm, the elastic modulus is 2.17GPa, the Poisson's ratio is 0.34, and the mass density is 1432kg / m³. S22. The electrostatic field region is divided using tetrahedral elements. The element type is solid227, the elastic modulus is 0 GPa, the Poisson's ratio is 0, and the mass density is 0 kg / m³. S23. Establish a nonlinear coupled dynamics analysis model: ； in, The mass matrix of the thin film structure; The damping matrix of the thin film structure; Here is the stiffness matrix of the thin film structure; This is the equivalent stiffness matrix of the electrostatic field; , The coupling matrix between the thin film field and the electrostatic field; External load force for the thin film structure; It represents the amount of charge; For nodal acceleration; For node speed; For nodal displacement; It is the electric potential; S4 specifically includes: S41. Set the solution parameters: the solution type is transient dynamic analysis, the mass damping coefficient is 0.05, the stiffness damping coefficient is 0.05, and the transient integral constant is 0.05; S42. The complete method is used to solve the transient dynamics, and the SSOLVE command is used to solve for multiple load steps. S43. Extract the displacement data of the center point of the thin film structure and plot the displacement-time curve using MATLAB.

2. The method according to claim 1, characterized in that, S3 specifically includes: S31. Set the first load step: time 0.01s, disable time integration effect, enable stress stiffening and geometric nonlinearity effect, thin film surface voltage 0V, initial voltage of each channel on the electrode surface is 0V. ; S32. Set the second load step: time When the time integration effect is activated, the voltage of the Nth channel on the electrode surface jumps to 0V, while the voltages of the other channels remain unchanged. S33. Set the third load step: time 20s, maintain the load conditions of the second load step.

3. The method according to claim 1, characterized in that, S5 specifically includes: S51. Change the initial voltage of the electrode surface For 100V, 300V, and 500V, repeat S1-S4; S52. Change the second load step time Repeat S1-S4 for intervals of 0.002s, 0.05s, and 0.1s. S53. Step the voltage of the first, third, and fifth channels of the electrode surface to 0V respectively, and repeat S1-S4.

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