Electronic equipment impact function failure evaluation method based on pseudo velocity spectrum

Abstract

The invention discloses an electronic equipment impact function failure evaluation method based on a pseudo-velocity spectrum, and belongs to the field of electronic equipment function failure evaluation in an impact environment. The implementation method comprises the following steps: establishing a nonlinear structure impact dynamic model with viscous damping according to geometric and functional characteristics of electronic equipment; and setting a function failure criterion, determining the dominant frequency of the equipment by a numerical method, enabling the equipment to be equivalent to a single-degree-of-freedom structure, calculating equal failure reference parameters by a critical static load, and drawing a function failure reference boundary. According to the impact environment, selecting an impact waveform coefficient, and calculating the critical impact load of the equipment impact function failure under different impact waveforms and different signal frequencies. And analyzing pseudo velocity spectrum characteristics of all critical impact loads, correcting equivalent failure reference parameters, and establishing an equipment impact function failure boundary containing upper and lower boundaries. And according to the impact function failure boundary of the electronic equipment, realizing impact function failure evaluation of the electronic equipment. The method has the advantages of low cost, high precision, high speed and the like.

Description

Technical Field

[0001] The present invention belongs to the field of electronic equipment function failure assessment under shock environment, and relates to an electronic equipment shock function failure assessment method based on pseudo velocity spectrum. Background Art

[0002] With the rapid advancement of science and technology, various electronic devices, such as gyroscopes, relays, circuit breakers, solenoid valves, and various sensors, are widely used in various military and civilian fields, including aviation, aerospace, shipbuilding, and automotive. These devices offer superior stability compared to digital circuit control and play a vital role in system functionality and reliability. However, when performing complex tasks or encountering unexpected operating conditions, these devices often face extremely harsh operating environments, such as high-speed impact or explosions from explosive devices, underwater submarine explosions, bird strikes on aviation equipment, and violent collisions with vehicles. In these scenarios, the mechanical loads are extremely severe, characterized by high intensity and transient impact, which can easily lead to shock-induced functional failure in electronic equipment. Shock-induced functional failure in electronic equipment can lead to the failure of the entire project and even cause immeasurable economic losses. Therefore, it is particularly important to develop methods to evaluate the functional reliability of various electronic devices under shock conditions.

[0003] However, existing impact function failure assessment methods have essential flaws. Traditional technologies are based on simple harmonic vibration theory and define safety boundaries by establishing a relationship between the frequency of the impact signal and the critical acceleration threshold. Although this method can reflect the failure characteristics under steady-state vibration, it cannot effectively characterize the transient broadband characteristics of real impact loads. As a result, traditional acceleration-frequency boundaries often have conservative designs or missed judgment risks in engineering applications, making it difficult to meet high-precision assessment requirements.

[0004] In contrast, the shock response spectrum theory can fully capture the multi-frequency energy distribution and transient waveform characteristics of the shock environment through joint analysis in the time domain and frequency domain, and can more accurately establish the correlation mechanism between shock loads and functional failure of electronic equipment. This is the core advantage that the traditional acceleration-frequency method cannot achieve.

[0005] The failure behavior of most electronic devices under shock conditions can be attributed to the failure behavior of a single-degree-of-freedom structural model under shock conditions. Currently, in the field of structural impact damage failure, the single-degree-of-freedom structural impact damage boundary based on pseudo-velocity spectrum has been successfully developed and extended to the field of impact damage assessment of continuous structures, playing an important role in the impact damage assessment of ships and aerospace equipment. If this theory can be applied to the field of electronic equipment shock functional failure, it will be able to more quickly and accurately describe the failure behavior of electronic equipment under shock conditions, which can provide theoretical guidance for the shock assessment test and optimization design of various electronic equipment. Therefore, the study of the shock functional failure boundary of electronic equipment based on pseudo-velocity spectrum is of great significance. Summary of the Invention

[0006] The main purpose of this invention is to provide a method for assessing electronic device failure under shock conditions based on pseudo-velocity spectra, addressing the difficulty in determining the failure boundary of electronic devices under shock conditions. This method allows for rapid and accurate assessment of electronic device failure behavior under shock conditions, offering advantages such as low cost, high accuracy, and high speed.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The present invention discloses a method for evaluating the impact functional failure of electronic equipment based on pseudo-velocity spectrum. According to the geometric and functional characteristics of the electronic equipment, a nonlinear structural impact dynamics model with viscous damping is established. The functional failure criterion is set, the dominant frequency of the equipment is determined by numerical methods, the equipment is equivalent to a single-degree-of-freedom structure, the equal failure reference parameters are calculated with the critical static load, and the functional failure reference boundary is drawn. According to the actual impact environment, the impact waveform parameters are selected, and the critical impact load of the equipment impact functional failure under different impact waveforms and different signal frequencies is calculated. The pseudo-velocity spectrum characteristics of all critical impact loads are analyzed, the equal failure reference parameters are corrected, and the equipment impact functional failure boundary containing upper and lower limits is established. According to the impact functional failure boundary of the electronic equipment, the impact functional failure evaluation of the electronic equipment is realized.

[0009] The present invention discloses a method for evaluating electronic device impact failure based on pseudo-velocity spectrum, comprising the following steps:

[0010] Step 1: Establish a system impact dynamics model with viscous damping and construct a numerical method to solve the dynamic response of the equipment.

[0011] A parametric model is established based on the geometric and functional characteristics of the electronic device. Through impact load path analysis, the parametric model is simplified into a mechanically equivalent combination of beams, plates, and shell structures that can characterize the impact characteristics of the device, resulting in a simplified model. The corresponding material constitutive, boundary conditions, and interaction relationships are applied to the simplified model to establish an impact dynamics model:

[0012]

[0013] Among them, M is the mass coefficient matrix, C is the viscous damping coefficient matrix, K is the stiffness coefficient matrix, and F(t) is the time-varying impact load vector to be input.

[0014] The impact dynamics model shown in equation (1) is solved using explicit numerical calculation methods to obtain the dynamic response x of the equipment.

[0015] Step 2: Calibrate the critical area of electronic equipment failure based on the maximum relative displacement D of the critical area of functional failure max , maximum pseudo speed V max Or maximum acceleration response A max Based on the relationship with equipment function failure, establish the equipment function failure criterion P.

[0016] Analyze the geometric weak points and functional sensitive areas of the equipment to identify the key areas where the equipment is most likely to fail in an impact environment. These areas usually include the connection points, sensitive components, and supporting structures of the equipment. Determine the relationship between the response and functional failure based on the dynamic response characteristics of the key areas of functional failure. Based on the maximum relative displacement (D max ), maximum pseudo speed (V max ) or maximum acceleration response (A max ), establish the functional failure criterion P of the equipment:

[0017]

[0018] Among them, R i is the dynamic response parameter of the key area, R critic is the critical threshold. Based on the functional characteristics of the device, select a single parameter criterion or a multi-parameter joint criterion:

[0019] R critic =α·D max +β·V max +γ·A max (3)

[0020] Among them, α, β, and γ are all proportional coefficients greater than zero.

[0021] Step 3: Apply a constant acceleration load to the device and calculate the dynamic response of the device according to the numerical method in step 1. Use the functional failure criterion P in step 2 to determine whether the device function fails under the constant acceleration load. If not, adjust the constant acceleration load amplitude and repeat the load failure judgment operation. If it fails, the constant acceleration load at this time is the critical failure static load. The static load amplitude is A D .

[0022] For a device under a given impact load, when the frequency of the low-frequency impact is low enough, the absolute acceleration response at any position is equal to the acceleration corresponding to the impact load applied to the device.

[0023] Apply a constant acceleration load to the device and calculate the dynamic response of the device according to the method in step 1. Determine the failure of the device under the constant acceleration load according to the functional failure criterion P in step 2. By adjusting the amplitude of the constant acceleration load, the critical failure static load is obtained. The static load amplitude is A D .

[0024] Step 4: Extract critical failure static load a D (t) The response signal x(t) of the critical area of functional failure after release is converted into a frequency domain signal X(f) through Fourier transform. The dominant frequency f0 of the device can be obtained by analyzing the frequency domain signal X(f). The device is equivalent to a single-degree-of-freedom structure with a natural frequency of f0.

[0025] Step 5: For the equivalent single-degree-of-freedom structure in step 4, according to the functional failure behavior characteristics of the single-degree-of-freedom system in the impact environment, the critical failure static load amplitude A obtained in step 3 is obtained. D The equal failure reference parameter of the single degree of freedom structure is obtained by converting Equation (4a, 4b), which is the equal failure displacement reference D c , equal failure acceleration benchmark A c and equal failure pseudo speed reference V c .

[0026] After the electronic device is equivalent to a single-degree-of-freedom structure with a known natural frequency, the three equal-failure reference parameters are converted using formula (4) while considering damping:

[0027] A c =A D (4a)

[0028]

[0029] Step 6: Determine the impact function failure reference boundary of the electronic device based on the three equal failure reference parameters in step 5.

[0030] The three equal failure benchmark parameters (D c 、A c 、V c ) is drawn on the same four-axis pseudo velocity spectrum, and three line segments are obtained, which intersect at one point. The vertical coordinate of the intersection point corresponds to the equal failure pseudo velocity reference V cThe horizontal axis corresponds to the natural frequency f0 of the single-degree-of-freedom structure, and the combination of the three line segments is the impact function failure reference boundary of the electronic equipment.

[0031] Step 7: Decompose the real shock environment into a finite number of arbitrary shock waveforms as shown in formula (5). According to the actual working conditions of the electronic equipment, select the shock waveform coefficient range χ i ∈[χ min ,χ max ].

[0032] The true shock waveform is characterized by the following formula:

[0033]

[0034] Where A0 is the amplitude, t is the time variable, θ is the phase (taken as zero), ξ P is the exponential damping ratio, ω p =2πf p is the angular frequency, f p is the shock frequency, χ is the shock waveform coefficient, and the waveform coefficient range is selected according to the actual shock environment of the equipment. i ∈[χ min ,χ mac ].

[0035] Step 8: For any shock waveform coefficient χ in step 7 i , set the impulse signal frequency range f j ∈[f min ,f max ], for any frequency f j The corresponding impulse signal a ij (t), repeat the operation of calculating the critical load in step 3 to obtain the corresponding critical impact load Adjust the impact load frequency and impact waveform coefficient, repeat the critical impact load calculation operation, and obtain all critical impact loads In step six, the impact response spectra of all critical impact loads are plotted on the functional failure reference boundary diagram, and the characteristics of the impact response spectrum are analyzed to obtain the correction coefficient η. The failure boundary control parameter is selected, and the functional failure reference boundary is corrected by the correction coefficient η to obtain the upper and lower limits of the functional failure boundary of the equipment. That is, the impact functional failure assessment of the electronic equipment is realized based on the pseudo-velocity spectrum.

[0036] For any shock waveform coefficient χ i ∈[χ min ,χ max ] at any frequency f j ∈[f min ,f max ], there is a corresponding impulse signal a ij(t), the critical impact load can be obtained by repeating the operation in step 3 By adjusting the shock wave coefficient and impulse signal frequency, all critical shock loads can be obtained. Plot all critical impact loads on a four-axis pseudo-velocity spectrum Analyze the boundary characteristics of the impact functional failure spectrum to obtain the correction coefficient η, select the failure boundary control parameter, and correct the functional failure reference boundary in step 6 according to formula (6).

[0037]

[0038] Among them, A C ,V C ,D C are equal failure benchmark parameters, representing equal failure displacement benchmark, equal failure acceleration benchmark and equal failure pseudo velocity benchmark, η L is the lower limit correction coefficient (0<η L ≤1), used to determine the lower limit of the equal failure boundary, η U is the upper limit correction coefficient (η U >1), used to determine the upper limit of the equal failure boundary, A L ,V l ,D L For the L The revised failure boundary lower limit control parameter, A U ,V U ,D U For the U Modified upper limit control parameter of failure boundary.

[0039] According to formula (6), the functional failure boundary of the equipment can be constructed in the four-coordinate pseudo-velocity spectrum. The boundary consists of two upper and lower broken lines. Each broken line consists of two to three line segments. The lower broken line segment is the lower limit of the functional failure boundary of the equipment, corresponding to the selected lower limit control parameter of the failure boundary (A L ,V L ,D L ); the upper broken line segment is the upper limit of the equipment function failure boundary, corresponding to the selected failure boundary upper limit control parameter (A U ,V U ,D U ).

[0040] When the peak value of the pseudo-velocity spectrum of a given shock waveform is higher than the given upper limit of the shock functional failure boundary, the shock load will cause the electronic equipment to fail; when the peak value of the pseudo-velocity spectrum of a given shock waveform is lower than the given lower limit of the shock functional failure boundary, the shock load will not cause the electronic equipment to fail.

[0041] The method also includes step nine: implementing an impact functional failure evaluation of the electronic equipment according to steps one to eight, combining the upper and lower limits of the impact functional failure boundaries of the electronic equipment output in step eight, analyzing the impact functional failure mechanism of the electronic equipment being evaluated, quickly and efficiently evaluating the functional failure behavior of the electronic equipment under any impact environment, reducing the trial and error cost of the design process of the electronic equipment being evaluated, and facilitating the improvement and maintenance of functional electronic equipment.

[0042] Beneficial effects:

[0043] 1. The present invention discloses a method for evaluating the impact functional failure of electronic equipment based on pseudo-velocity spectrum, and establishes a nonlinear structural impact dynamics model with viscous damping according to the geometric and functional equipment characteristics. The functional failure criterion is set, the dominant frequency of the equipment is determined by numerical methods, the equipment is equivalent to a single-degree-of-freedom structure, the equal failure reference parameters are calculated with the critical static load, and the functional failure reference boundary is drawn. The impact waveform parameters are selected according to the actual impact environment, and the critical impact load of the equipment impact functional failure under different impact waveforms and different signal frequencies is calculated. The pseudo-velocity spectrum characteristics of all critical impact loads are analyzed, the equal failure reference parameters are corrected, and the equipment impact functional failure boundary containing upper and lower limits is established. According to the impact functional failure boundary of the electronic equipment, the impact functional failure evaluation of the electronic equipment can be realized. The present invention has the advantages of low cost, high precision, and high speed.

[0044] 2. The present invention discloses a method for assessing the impact functional failure of electronic equipment based on a pseudo-velocity spectrum. The impact functional failure boundary of the electronic equipment is composed of two upper and lower broken lines. Each broken line is composed of two to three line segments. The mechanical parameters corresponding to the line segments are corrected by the equal failure acceleration reference, the equal failure pseudo-velocity reference, and the equal failure displacement reference. The impact functional failure boundary of the electronic equipment indicates that when the peak value of the pseudo-velocity spectrum of a given impact waveform is lower than the given lower limit of the impact functional failure boundary, the impact load will not cause the electronic equipment to fail. When the peak value of the pseudo-velocity spectrum of a given impact waveform is higher than the given upper limit of the impact functional failure boundary, the impact load will definitely cause the electronic equipment to fail.

[0045] 3. The present invention discloses a method for evaluating the impact functional failure of electronic equipment based on pseudo-velocity spectrum. After the electronic equipment is approximated as a single-degree-of-freedom structure, its functional boundary mainly depends on the waveform characteristics of the applied impact load. The equal failure reference parameters of the equipment can be determined by the critical acceleration static load. The waveform coefficient is adjusted according to the actual impact environment, and the impact signal frequency under each impact waveform is transformed to obtain all critical impact loads. The four-coordinate pseudo-velocity spectrum characteristics of all critical impact loads are analyzed to obtain the upper and lower limits of the functional failure boundary of the electronic equipment, which can quickly improve the efficiency of evaluating electronic equipment under impact environment.

[0046] 4. The present invention discloses a method for evaluating the impact functional failure of electronic equipment based on pseudo-velocity spectrum, which can be applied to many impact engineering fields. Electronic equipment such as relays, circuit breakers, solenoid valves, starters, etc. are widely used in engineering fields such as aerospace, satellites, ships, missiles, and transportation. Most of these electronic equipment can be equivalent to a single-degree-of-freedom system with its dominant frequency as the natural frequency. Therefore, the present invention can directly evaluate the functional failure behavior of electronic equipment in a given impact environment based on the pseudo-velocity spectrum of the impact environment and the impact functional failure boundary of the electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0048] Figure 1 Flowchart for calculating critical impact load for functional failure;

[0049] Figure 2 Draw a flow chart for the failure boundary of electronic equipment shock function;

[0050] Figure 3 This is a schematic diagram of a double reed relay;

[0051] Figure 4 Schematic diagram of the finite difference method;

[0052] Figure 5 This is the frequency domain diagram of the free vibration response at the contacts of the double reed relay;

[0053] Figure 6 Schematic diagram of the failure boundary of the impact function of the double reed relay. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings and specific embodiments of the present invention. The specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0055] like Figure 1 and Figure 2 As shown, the electronic device impact failure assessment method based on pseudo velocity spectrum disclosed in this embodiment is for Figure 3The impact failure assessment of an aerospace electromagnetic relay consisting of a set of dynamic and static reeds is shown in the figure. This system is a dual-reed electromagnetic relay with one end fixed. U represents the dynamic reed, and V represents the static reed. The mechanical parameters of the dynamic and static reeds and contacts are shown in Table 1. The system dimensions are as follows: the dynamic reed has a length of L1 = 5 mm, a width of B1 = 1 mm, and a height of H1 = 0.1 mm; the static reed has a length of L2 = 4 mm, a width of B2 = 1 mm, and a height of H2 = 0.2 mm. The contact dimensions are R1 = 0.36 mm, R2 = 0.4 mm, and h2 = 0.16 mm. The contact is located d = 3.5 mm from the fixed end of the reed. The dynamic and static reed contacts can be viewed as contact between a sphere and a plane. Initially, the dynamic and static reeds are preloaded, achieved through positional constraints. The static preload force F0 is applied to the dynamic and static reeds.

[0056] Table 1 Mechanical parameters of relay model

[0057]

[0058] like Figure 1 As shown, the present embodiment discloses a method for evaluating the impact failure of an electronic device based on a pseudo velocity spectrum, which performs an impact failure evaluation on the functional contact structure. The specific implementation steps are as follows:

[0059] Step 1: Establish an impact dynamics model of the double reed relay system and use explicit calculation methods to calculate the dynamic response of the equipment.

[0060] The device parameter model is established based on the geometric characteristics of the double reed relay. When the double reed relay foundation is subjected to vertical load, the device may fail due to impact. The dynamic and static reeds can be equivalent to two Euler–Bernoulli beams, and the contacts on the reeds are equivalent to the concentrated mass m. The contact relationship between the dynamic and static reed contacts is analyzed using Hertz contact theory with nonlinear springs to obtain a simplified model as follows: Figure 3 shown.

[0061] When the contact system is equivalent, the moving spring contact in the system is a spherical surface, and the static spring contact is a plane. For two non-coordinated continuous curved surfaces, the contact area is much smaller than the outline size. Through the small strain assumption and the ideal surface contact and frictionless assumption, it can be equivalent to the Hertz contact of the spherical contact type. It is regarded as an initially compressed nonlinear spring, and its force-displacement relationship is shown in Equation (7):

[0062]

[0063] Where E1, E2, v1, v2 are the Young's modulus and Poisson's ratio of the sphere and plane materials respectively, and R0 is the radius of the sphere. From this, we can get the spring compression δ0=1.37*10 -5mm, and the contact pressure F0 = 0.11 N. At this point, the modeling of the double reed relay system is completed.

[0064] The finite difference method (FDM) is used to solve the dynamic response of the double reed system. The boundary conditions, material properties, and the interaction force between contacts can be directly reflected in the control equations. The beam is divided into uniformly distributed nodes along the length direction. When analyzing the force of the microelement, the influence of the inertial force corresponding to the vibration of the concentrated mass m and the interaction force F between contacts must be considered. Then, based on the force and torque balance and the material mechanics relationship, the dynamic differential equation of the static and dynamic reed containing the contact mass m and the contact force F between contacts is obtained as shown in Equation (8):

[0065]

[0066] Finite difference principle such as Figure 4 As shown, the time discretization and space discretization of the beam dynamics differential equation are as follows:

[0067]

[0068] Where i is the spatial sequence, j is the time sequence, Δx is the spatial step, Δt is the time step, z i,j is the base excitation applied by the outside world at node i at time j, K is the nonlinear stiffness coefficient in Hertzian contact, c is the structural damping coefficient, which is generally taken as 0.05 in engineering, ρ is the cantilever beam material density, A is the cantilever beam cross-sectional area, E and I are the elastic modulus and section inertia moment of the cantilever beam, respectively, and δ is the Dirac function.

[0069] By discretizing the time variable t and the space variable x in the above manner, the impact dynamics model (10) of the form (1) is obtained:

[0070]

[0071] Among them, M D is the quality coefficient matrix, C D is the viscous damping coefficient matrix, K D is the stiffness coefficient matrix, and F(t) is the time-varying impact load vector to be input.

[0072] The response is calculated using explicit dynamics, and the numerical solution of the displacement response variable y(x,t) at any discrete node is obtained by solving a set of linear equations and performing cyclic iterations.

[0073] Step 2: Determine the critical failure area of the double reed relay, examine the relationship between the response of the critical failure area and the relay failure, and establish the failure criterion P of the double reed relay.

[0074] For this double reed relay, the critical failure area is at the contacts of the two reeds. The failure criterion is the difference in relative displacement between the two reed contacts, that is, whether the two reed contacts are separated:

[0075] P:max(D U -D V )≥R critic =α·D max =δ0 (11)

[0076] Among them D U and D V are the displacement responses of the key areas of failure of the dynamic and static reeds, D max is the maximum displacement in this area.

[0077] Step 3: Apply a constant acceleration load to the double reed relay and calculate the dynamic response of the device according to the method in step 1. Use the functional failure criterion P in step 2 to determine whether the device function fails under the constant acceleration load. Adjust the impact load amplitude until the relay fails to function and obtain the critical failure static load. Static load amplitude A D .

[0078] Apply a constant vertical acceleration load to the double reed relay, calculate the response using the model obtained in step 1, adjust the impact signal amplitude A, and examine the response of the key area of functional failure using the functional failure criterion P obtained in step 2 to find the critical failure static load of the equipment. Static load amplitude A D =3057G.

[0079] Step 4: Extract critical failure static load The displacement response y(d,t) at the contact point after release is converted into a frequency domain signal Y(f) through Fourier transform, and plotted as follows: Figure 5 As shown in the frequency domain diagram, by analyzing the frequency domain signal Y(f), the dominant frequency f0 = 4650 Hz of the device can be obtained; the device is equivalent to a single degree of freedom structure with a natural frequency of f0 = 4650 Hz.

[0080] Step 5: For the equivalent single-degree-of-freedom structure in step 4, according to the functional failure behavior characteristics of the single-degree-of-freedom system in the impact environment, the critical failure static load amplitude A obtained in step 3 is obtained. D The equal failure reference parameter of the single degree of freedom structure is obtained by converting Equation (4a, 4b), which is the equal failure displacement reference D c , equal failure acceleration benchmark A c and equal failure pseudo speed reference V c .

[0081] Three equal failure benchmark parameters (D c、A c 、V c ):

[0082] A c =3057G (12a)

[0083] V c =1.026m / s (12b)

[0084] D c =3.513×10 -5 m (12c)

[0085] Step 6: Determine the impact function failure reference boundary of the double reed relay based on the three equal failure reference parameters obtained in step 5. The result is as follows: Figure 6 Indicated by the green line segment.

[0086] Step 7: According to the actual working conditions of the double-reed electromagnetic relay, take the impulse waveform coefficient range as χ i ∈[0,3].

[0087] Step 8: For any shock waveform coefficient χ in step 7 i , set the impulse signal frequency range f j ∈[100,50000], for any frequency f j The corresponding impulse signal a ij (t), repeat the operation of calculating the critical load in step 3 to obtain the corresponding critical impact load Adjust the impact load frequency and impact waveform coefficient, repeat the critical impact load calculation operation, and obtain all critical impact loads Draw the impact response spectra of all critical impact loads on the functional failure reference boundary diagram in step six, analyze the characteristics of the impact response spectrum, obtain the correction coefficient η, select the failure boundary control parameter, and correct the functional failure reference boundary by the correction coefficient η to obtain the upper and lower limits of the functional failure boundary of the equipment.

[0088] Adjust the waveform factor χ i and the corresponding frequency f j Repeat the operation in step 3 to obtain the critical impact load All critical shock loads Draw it on the functional failure reference boundary diagram in step 6, analyze the impact response spectrum characteristics, and select the failure boundary control parameter A L 、V L 、A U 、D U , we can get the scaling factor η L =0.981, η U =9.814. After correction, the control parameters for the upper and lower limits of the impact function failure boundary are:

[0089] A L =3000G,V L =1.007m / s (13a)

[0090] A U =30000G,D U =3.45×10 -4 m (13b)

[0091] The upper and lower limits of the failure boundary are plotted on the same four-axis pseudo-velocity spectrum, such as Figure 6 Indicated by the red line segment.

[0092] To verify the correctness of the shock function failure boundary of the double reed relay obtained by the above process, first take any two shock signals a1(t) and a2(t) and plot them on the same four-coordinate drawing. The peak values of the pseudo-velocity spectra of the two signals are A1 and A2 respectively, so that A1 is above the upper limit of the failure boundary and A2 is below the lower limit of the failure boundary. The dynamic response of the device under the two signals is calculated. It can be seen that the acceleration signal a1(t) causes the double reed relay to fail, and the acceleration signal a2(t) does not cause the relay contact function to fail. By analyzing the response results, it can be obtained that for shock signals of arbitrary waveforms and arbitrary shock frequencies, as long as their four-coordinate pseudo-velocity shock spectrum is below the lower limit of the shock failure boundary, the relay will not fail; if their four-coordinate pseudo-velocity shock spectrum is above the upper limit of the shock failure boundary, the relay will definitely fail.

[0093] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for evaluating electronic device impact failure based on pseudo-velocity spectrum, characterized by: The following steps are included: Step 1: Establish a system impact dynamics model with viscous damping and construct a numerical method to solve the dynamic response of the equipment; Step 2: Calibrate the critical area of electronic equipment failure based on the maximum relative displacement D of the critical area of functional failure max , maximum pseudo speed V max Or maximum acceleration response A max Relationship with equipment function failure, establish equipment function failure criterion P; Step 3: Apply a constant acceleration load to the device and calculate the device dynamic response using the numerical method in step 1. Use the functional failure criterion P in step 2 to determine whether the device function fails under the constant acceleration load. If not, adjust the constant acceleration load amplitude and repeat the load failure determination operation. If failure occurs, the constant acceleration load at this time is the critical failure static load The static load amplitude is A D ; Step 4: Extract critical failure static load a D (t) The response signal x(t) of the critical area of functional failure after release is converted into a frequency domain signal X(f) through Fourier transform. The dominant frequency f0 of the device can be obtained by analyzing the frequency domain signal X(f), and the device is equivalent to a single degree of freedom structure with a natural frequency of f0; Step 5: For the equivalent single-degree-of-freedom structure in step 4, according to the functional failure behavior characteristics of the single-degree-of-freedom system in the impact environment, the critical failure static load amplitude A obtained in step 3 is obtained. D The equal failure reference parameter of the single degree of freedom structure is obtained by converting Equation (4a, 4b), which is the equal failure displacement reference D c , equal failure acceleration benchmark A c and equal failure pseudo speed reference V c ; Step 6: Determine the impact function failure reference boundary of the electronic device based on the three equal failure reference parameters in step 5; Step 7: Decompose the real shock environment into a finite number of arbitrary shock waveforms as shown in formula (5). According to the actual working conditions of the electronic equipment, select the shock waveform coefficient range χ i ∈[χ min ,χ max ]; Step 8: For any shock waveform coefficient χ in step 7 i , set the impulse signal frequency range f j ∈[f min ,f max ], for any frequency f j The corresponding impulse signal a ij (t), repeat the operation of calculating the critical load in step 3 to obtain the corresponding critical impact load Adjust the impact load frequency and impact waveform coefficient, repeat the critical impact load calculation operation, and obtain all critical impact loads In step six, the impact response spectra of all critical impact loads are plotted on the functional failure reference boundary diagram, and the characteristics of the impact response spectrum are analyzed to obtain the correction coefficient η. The failure boundary control parameter is selected, and the functional failure reference boundary is corrected by the correction coefficient η to obtain the upper and lower limits of the functional failure boundary of the equipment. That is, the impact functional failure assessment of the electronic equipment is realized based on the pseudo-velocity spectrum.

2. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 1, wherein: According to steps one to eight, the impact functional failure evaluation of the electronic equipment is implemented. Combined with the upper and lower limits of the impact functional failure boundary of the electronic equipment output in step eight, the impact functional failure mechanism of the evaluated electronic equipment is analyzed, and the functional failure behavior of the electronic equipment under any impact environment is evaluated quickly and efficiently, thereby reducing the trial and error cost of the design process of the evaluated electronic equipment, and facilitating the improvement and maintenance of functional electronic equipment.

3. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 2, wherein: The implementation method of step one is: A parametric model is established based on the geometric and functional characteristics of the electronic device. Through impact load path analysis, the parametric model is simplified into a mechanically equivalent combination of beams, plates, and shell structures that can characterize the impact characteristics of the device, resulting in a simplified model. The corresponding material constitutive, boundary conditions, and interaction relationships are applied to the simplified model to establish an impact dynamics model: Where M is the mass coefficient matrix, C is the viscous damping coefficient matrix, K is the stiffness coefficient matrix, and F(t) is the time-varying impact load vector to be input; The impact dynamics model shown in equation (1) is solved using explicit numerical calculation methods to obtain the dynamic response x of the equipment.

4. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 3, wherein: The implementation method of step 2 is: Analyze the geometric weaknesses and functionally sensitive areas of the equipment to identify the critical areas most prone to functional failure under impact conditions. These areas typically include connection points, sensitive components, and supporting structures. Determine the relationship between response and functional failure based on the dynamic response characteristics of the key area of functional failure; Based on the maximum relative displacement of the critical area of functional failure (D max ), maximum pseudo speed (V nax ) or maximum acceleration response (A max ), establish the functional failure criterion P of the equipment: Among them, R i is the dynamic response parameter of the key area, R critic is the critical threshold; select a single parameter criterion or a multi-parameter joint criterion based on the functional characteristics of the device: R critic =α·D max +β·V max +γ·A max (3) Among them, α, β, and γ are all proportional coefficients greater than zero.

5. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 4, characterized in that: The implementation method of step three is: For a device under a given shock load, when the frequency of the low-frequency shock is low enough, the absolute acceleration response at any position is equal to the acceleration corresponding to the shock load applied to the device; Apply a constant acceleration load to the device and calculate the dynamic response of the device according to the method in step 1. Determine the failure of the device under the constant acceleration load according to the functional failure criterion P in step 2. By adjusting the amplitude of the constant acceleration load, the critical failure static load is obtained. The static load amplitude is A D .

6. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 5, wherein: The implementation method of step five is: After the electronic device is equivalent to a single-degree-of-freedom structure with a known natural frequency, the three equal-failure reference parameters are converted using equations (4a, 4b) while considering damping: A c =A D (4a) 7. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 6, wherein: The implementation method of step six is: The three equal failure benchmark parameters (D c 、A c 、V c ) is drawn on the same four-axis pseudo velocity spectrum, and three line segments are obtained, which intersect at one point. The vertical coordinate of the intersection point corresponds to the equal failure pseudo velocity reference V c The horizontal axis corresponds to the natural frequency f0 of the single-degree-of-freedom structure, and the combination of the three line segments is the impact function failure reference boundary of the electronic equipment.

8. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 7, wherein: The implementation method of step seven is: The true shock waveform is characterized by the following formula: Where A0 is the amplitude, t is the time variable, θ is the phase (taken as zero), ξ P is the exponential damping ratio, ω p =2πf p is the angular frequency, f p is the shock frequency, χ is the shock waveform coefficient, and the waveform coefficient range is selected according to the actual shock environment of the equipment. i ∈[χ min ,χ max ].

9. The method for evaluating electronic device impact failure based on pseudo-velocity spectrum according to claim 8, characterized in that: The implementation method of step eight is: For any shock waveform coefficient χ i ∈[χ min ,χ max ] at any frequency f j ∈[f min ,f max ], there is a corresponding impact signal a ij (t), the critical impact load can be obtained by repeating the operation in step 3 By adjusting the shock wave coefficient and impulse signal frequency, all critical shock loads can be obtained. Plot all critical impact loads on a four-axis pseudo-velocity spectrum Analyze the boundary characteristics of the impact functional failure spectrum to obtain the correction coefficient η, select the failure boundary control parameter, and correct the functional failure reference boundary in step 6 according to formula (6); Among them, A c ,V c ,D C are equal failure benchmark parameters, representing equal failure displacement benchmark, equal failure acceleration benchmark and equal failure pseudo velocity benchmark, η L is the lower limit correction coefficient (0<η L ≤1), used to determine the lower limit of the equal failure boundary, η U is the upper limit correction coefficient (η U >1), used to determine the upper limit of the equal failure boundary, A L ,V L ,D L For the L The revised lower limit control parameter of failure boundary, A U ,V U ,D U For the U Modified upper limit control parameter of failure boundary; The functional failure boundary of the equipment is constructed in the four-coordinate pseudo-velocity spectrum by formula (6). The boundary consists of two upper and lower broken lines. Each broken line consists of two to three line segments. The lower broken line segment is the lower limit of the functional failure boundary of the equipment, corresponding to the selected lower limit control parameter of the failure boundary (A L ,V L ,D L ); the upper broken line segment is the upper limit of the equipment function failure boundary, corresponding to the selected failure boundary upper limit control parameter (A U ,V U ,D U ); When the peak value of the pseudo-velocity spectrum of a given shock waveform is higher than the given upper limit of the shock functional failure boundary, the shock load will cause the electronic equipment to fail; when the peak value of the pseudo-velocity spectrum of a given shock waveform is lower than the given lower limit of the shock functional failure boundary, the shock load will not cause the electronic equipment to fail.

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