164 results about "Vibration fatigue" patented technology

The present invention relates to the technical field of mechanical property testing and characterization. Disclosed are a method and apparatus for calculating a crack propagation life of an engine structure in vibration fatigue, which method and apparatus aim to obtain reliable fracture mechanics parameters and a crack propagation rate curve and provide an accurately quantified crack propagation life, so as to provide methodological guidance for the life assessment of reusable engines. The calculation method comprises: acquiring a time-domain random stress spectrum of stress responses in an assessment section in a finite element model of an engine structure; on the basis of the time-domain random stress spectrum, performing finite element analysis processing on a crack model of the engine structure, so as to determine fracture mechanics parameters of a cracked structure; performing a vibration fatigue performance test on a crack propagation rate model, which is set up according to a preset crack propagation mode, and determining, by using parameter identification, a target parameter value corresponding to the crack propagation rate model; and in combination with the parameter value corresponding to the crack propagation rate model and a preset critical crack length value, performing crack propagation life calculation, so as to obtain a target crack propagation life.

The invention provides a crane with vibration fatigue damage deduction and control functions, which comprises a first sample generation module used for generating a first sample data set taking a generated lifting point and load combination as input and taking the fatigue life cycle index as output; the second sample generation module is used for generating a second sample data set taking the control parameter as input and the lifting dynamic load coefficient as output; and the optimization module is used for carrying out load combination according to an output result of the second prediction model and then inputting the load combination result into the first prediction model, carrying out fatigue residual life deduction of the crane, optimizing control parameters and realizing control on fatigue damage of the crane. According to the method, the influence degree of the dynamic load effect on the fatigue life can be deduced, a fatigue damage control strategy is given, the control parameters matched with the deduction result are fed back to the physical entity, regulation, control, improvement and upgrading of the physical entity are guided, fatigue damage delay and control of the crane are achieved, and the method has important engineering value.

The invention discloses a frequency converter maintenance test system with a protection function, which belongs to the technical field of frequency converter testing and comprises a detection seat, a simulation unit for simulating actual working conditions of a frequency conversion control panel is arranged on the detection seat, and a detection mechanism for detecting a diode in the frequency conversion control panel is further arranged on the detection seat. Through dynamic cooperation of the polarization assembly and the rotary simulation disc, the vibration direction of the vibration source can be flexibly adjusted, so that a multi-dimensional vibration scene possibly encountered in actual work of the frequency conversion control panel is covered, and the problem that vibration source simulation is lacked in a traditional frequency converter testing process is solved; an elastic supporting environment of actual installation is simulated through the air bag spring suspension, vibration energy emission distortion caused by rigid fixation is avoided, the accuracy of a large-capacitance vibration fatigue test is improved, automatic step-by-step wiring operation of detection is achieved through cooperation of the detection driving assembly and the universal test meter, and the overall detection wiring efficiency is improved.

The invention discloses an electromagnetic valve vibration fatigue test device and a failure judgment method, and relates to the technical field of electromagnetic valve tests.The electromagnetic valve vibration fatigue test device comprises a test box, a conveying mechanism, a balance weight mechanism, a vibration table, an opening and closing detection mechanism and a clamping detection mechanism; the front end and the rear end of the top in the test box are fixedly connected with counterweight mechanisms, the bottom in the test box is fixedly connected with a vibration table, the right end in the test box is fixedly connected with an opening and closing detection mechanism, and the top of the vibration table is fixedly connected with a clamping detection mechanism and a conveying mechanism; the inlet and outlet pressure of the detected electromagnetic valve is detected through a sensor, failure judgment of the electromagnetic valve is achieved, then the pressure is adjusted through the combination mode of low-speed precise conveying of a piston cylinder and high-speed large-flow conveying of an external fluid conveying box, periodic fluid pressure fluctuation is applied while vibration is conducted, and the real load of the electromagnetic valve is simulated. And the superimposed effect of mechanical vibration and fluid impact is synchronously tested.

The invention provides a method for calculating the vibration fatigue life of a variable frequency air conditioner pipeline system, and relates to the technical field of air conditioners, and the method comprises the steps: building a mathematical model of the maximum stress value and the vibration fatigue life through obtaining the maximum stress value of the pipeline system of a variable frequency air conditioner under various set working conditions and the working frequency corresponding to the maximum stress value; calculating the vibration fatigue life under the set working mode and the environment temperature, calculating the vibration damage of each working condition according to the vibration fatigue life, taking starting and stopping as working conditions, calculating the starting damage and stopping damage, calculating the sum of the vibration damage, the starting damage and the stopping damage of each working condition, and obtaining accumulated damage; the problem that the vibration fatigue life of an existing variable frequency air conditioner pipeline system is not accurate is solved, and the method is suitable for vibration fatigue life calculation of the variable frequency air conditioner pipeline system.

The invention provides a method for monitoring cracks in a high-pressure vibration state of a wind tunnel in real time, and belongs to the technical field of wind tunnels. A piezoelectric ceramic sensor array is arranged on the wall surface of the wind tunnel, a vibration fatigue matrix and a structure resonance matrix are established, and a self-adaptive filtering algorithm is adopted to preprocess sensor signals; establishing a vibration coupling equation set to extract crack characteristic parameters, constructing a dynamic threshold discrimination matrix and a risk assessment matrix, utilizing a multi-sensor data fusion algorithm to accurately position crack positions and sizes, calculating risk levels according to a crack risk assessment index equation, and performing three-level safety discrimination. A complete crack real-time monitoring and risk assessment system in the high-pressure vibration environment is formed, and the technical problems that in the prior art, crack monitoring precision is low in the high-pressure vibration environment, and real-time risk assessment cannot be achieved are solved.

The invention discloses a method for constructing an accelerated life test load spectrum of an integral dropper, which comprises the following steps of: respectively constructing a vibration fatigue load spectrum and a pulse alternating current load spectrum according to simulated fatigue load and current data of the integral dropper, and constructing an accelerated life test load spectrum of the integral dropper after the vibration fatigue load spectrum and the pulse alternating current load spectrum are completed. Performing superposition loading by combining the two, deducing a test loading spectrum of the integral dropper according to a Miner damage principle and an electroplastic effect mechanism, and constructing a fatigue-alternating current impact superposition test loading spectrum; according to the construction method, the action mechanisms of current and mechanical stress are effectively combined on the basis of real working conditions, the working state of the dropper can be reflected more accurately, the actual failure mode of the dropper is better met, the constructed fatigue-alternating current impact superimposed loading spectrum can reflect the stress superimposed effect of the dropper in a complex environment, and the application range of the dropper is widened. By more comprehensively simulating the multi-working-condition environment of the dropper, the reliability of the test result is further improved.

The invention relates to a turbine blade vibration fatigue monitoring method and system based on data fusion, and the method comprises the steps: collecting the vibration data, temperature data and strain data of a turbine blade, and obtaining an original multi-source data set; preprocessing the original multi-source data set to obtain a first data set; extracting features according to the first data set to obtain a feature vector set; dimensionality reduction is carried out on the feature vector set, a feature vector machine after dimensionality reduction is obtained and input into an LSTM model, a vibration fatigue state monitoring result is output, the LSTM model is obtained through training and optimization of a training set, and the training set comprises a historical multi-source data set and a corresponding fatigue life value and fatigue damage degree. According to the method, multi-source data are fused, and a deep learning method is combined, so that the accuracy and the real-time performance of turbine blade vibration fatigue life prediction are improved.

The invention discloses a vibration fatigue life prediction method and system based on a working condition adaptive spectrum. According to the method, load information of a target structure under various service conditions is obtained, and frequency domain load descriptions corresponding to different working conditions are subjected to weighted fusion according to working condition weights, so that a working condition adaptive load spectrum capable of reflecting real service characteristics is constructed; on the basis, frequency domain stress response of the structure under the random vibration condition is obtained in combination with a structural dynamics analysis model, equivalent stress description of dominant fatigue damage is further determined through a multi-axis equivalent criterion, and fatigue damage distribution is calculated through a frequency domain fatigue analysis method; and finally, predicting the vibration fatigue life of the structure in combination with a material fatigue performance curve and an environment-related performance correction relation. Compared with the prior art, the method has the advantages that the multi-working-condition load superposition effect and the service environment influence can be effectively considered, and the accuracy and engineering applicability of vibration fatigue life prediction are improved.

The invention provides a stay wire tower stay cable vortex-induced vibration fatigue life prediction method and system, and relates to the technical field of power transmission line towers, and the method comprises the steps: obtaining sensing detection parameters corresponding to a to-be-detected stay wire tower; the sensing detection parameters comprise sag, sag maximum position stress, specific load, span, altitude difference angle, temperature expansion coefficient, elastic modulus and meteorological parameters; fusing tension data obtained through sensing detection parameters with tension data estimated through a structural mechanical model by adopting a Kalman filtering algorithm, and determining a tension time history of the stay wire structure within a preset time range, determining natural vibration frequencies of the stay wire structure at different moments within the preset time range by combining the wire length and the quality of the stay wire structure; and determining a target oscillation-starting wind speed range by using a first mapping relation between the natural vibration frequency and the oscillation-starting wind speed of the stay wire structure, and determining a life prediction result of the stay wire structure in combination with wind speed distribution and the number of fatigue cycles in the preset time range.

The invention relates to the technical field of weld joint vibration fatigue life evaluation, in particular to a weld joint vibration fatigue life evaluation method based on a simplified modal structure stress method. The method specifically comprises the following steps: establishing a simplified finite element model of a welding structure without welding seam details, and calculating a structural mode of the simplified finite element model; a modal coordinate time history is obtained according to the structural modal, and the modal structural stress at the weld toe is calculated through a linear difference value; superposing the modal coordinate time history and the weld toe modal structure stress to obtain a weld toe structure stress time history; obtaining the change range and cycle index of the structural stress according to the rain flow counting statistics of the structural stress time history at the weld toe; equivalent structure stress is calculated; and calculating by adopting a main S-N curve method to obtain a damage and fatigue evaluation result of the welding seam. The modal structure stress at the weld toe is calculated through the linear difference, weld joint details do not need to be established, the workload of finite element model establishment can be greatly simplified, the modeling complexity is reduced, and the modeling efficiency is improved.

The invention discloses a bogie component vibration fatigue life prediction method considering load periodic evolution, and aims to solve the technical problems that an existing model is coupled in function and low in prediction precision, and a prediction result is a single determined value and cannot meet risk assessment requirements. Comprising the following steps: a) acquiring a historical power spectral density sequence; b) inputting the historical power spectral density sequence into a hybrid degradation prediction model, and predicting axle box vibration power spectral density under any running mileage in the future; c) inputting the axle box vibration power spectral density predicted in the step b) into a nonlinear transfer function model based on artificial intelligence, and calculating the stress power spectral density of the key position of the bogie; d) dynamically determining an optimal calculation mileage step length by the decision-making type artificial intelligence model, and then calculating future prediction fatigue damage; and e) calculating generated actual fatigue damage according to historical monitoring data, and outputting probability distribution of the residual fatigue life of the bogie by integrating future predicted fatigue damage.

The invention relates to a blade Goodman curve correction method, device, equipment and medium considering crystal orientation and a multi-axis stress state, and relates to the technical field of mechanical engineering.The method comprises the steps that a blade Goodman curve is determined based on a correction coefficient obtained through a blade vibration fatigue test and a blade material Goodman curve; static stress and modal stress of the blade under different rotating speeds and maximum displacement and vibration frequency of a blade body under different modals are obtained; calculating allowable vibration stress according to the blade Goldman curve and the static stress, and determining the allowable vibration stress of each point on the blade at different rotating speeds; determining a dynamic stress reserve coefficient corresponding to each point on the blade; according to the circumferential displacement of a sensor preset on the blade at the corresponding position on the blade, the minimum value of the dynamic stress reserve coefficient, the maximum displacement of the blade body and the vibration frequency, limit value calculation is conducted, and the blade amplitude limit value corresponding to the blade is determined. The accuracy of the blade amplitude limit value in the blade stress state monitoring process can be improved.

The invention provides a clamping mechanism for a vibration fatigue test, and belongs to the technical field of vibration fatigue tests.The clamping mechanism comprises a base, the top wall of the base is slidably connected with symmetrically-distributed anti-deviation sliding blocks, the top walls of the anti-deviation sliding blocks are fixedly connected with reinforcing fixing columns, and the top walls of the reinforcing fixing columns are fixedly connected with clamping shells; an adjusting assembly is arranged on the outer wall of the reinforcing fixing column. According to the clamping device, through the arranged pressure detection assembly and the contact state of a conductive ball and a metal ring, real-time monitoring of the clamping force is achieved, once it is detected that clamping is not stable, namely the conductive ring is powered on, the system can make a response rapidly, the adjusting assembly is automatically triggered to compensate the clamping force, and therefore the clamping force is accurately adjusted. According to the dynamic pressure feedback and intelligent adjustment mechanism, the risks of test errors, even object falling and the like caused by object shaking in a vibration test are effectively avoided, and a powerful guarantee is provided for the accuracy and reliability of a test result.

The utility model relates to the technical field of engine turbine bladed disc testing, in particular to a high-pressure turbine bladed disc vibration testing tool which comprises a vibration table, a protection box, a box door, a sealing gasket, a supporting frame, a rotating piece, a nozzle and a transmission piece. A box door is movably arranged in the open groove, the sealing gasket is arranged outside the box door and located between the open groove and the box door, the supporting frame is arranged in the protection box, the rotating piece is used for rotating the nozzle, the nozzle is located above the vibration table, and the conveying piece is used for conveying cold air or hot air into the nozzle and finally spraying the cold air or the hot air out of the nozzle. According to the blade vibration fatigue test device, cold air or hot air in the nozzle can be sprayed to different positions of the turbine blade disc, so that temperature rise or temperature reduction treatment of different positions of the turbine blade disc is realized, the influence of a temperature environment on the vibration fatigue limit of blades of the turbine blade disc is avoided, and the test accuracy of the blade vibration fatigue test is ensured.

The invention discloses a life prediction method suitable for a high-temperature multi-axis random vibration load, relates to data acquisition, processing and life calculation of a random vibration test, and belongs to the field of fatigue performance of a material under the random vibration load. According to the method, a time domain method and a frequency domain method are combined, and an interaction factor is introduced to correct a von Mises equivalent formula, so that the corrected life prediction model is more accurate in life prediction under a multi-axis working condition; and meanwhile, the normal-temperature S-N curve is corrected, so that the corrected life prediction model is more accurate in life prediction under the high-temperature working condition. And mathematical expressions of the parameters are obtained through a multi-axis random vibration fatigue test. The method provided by the invention has clear physical significance and can be used for predicting the fatigue life of the high-temperature multi-axis random vibration.

The invention relates to the technical field of automobile wire harnesses, and particularly discloses an automobile wire harness vibration detection device and method.The automobile wire harness vibration detection device comprises a vibration table, two universal supporting pieces which are symmetrically arranged and have an adjustable interval are installed on the vibration table, two wire harness inserting mechanisms are installed on the two universal supporting pieces, and a first linear motor is fixedly installed above the vibration table; a wire harness fatigue mechanism is installed at the bottom of the transmission end of the first linear motor. The two wire harness plugging mechanisms are jointly connected with a resistance sensor module through flat cables, and the problem that traditional single vibration detection or single fatigue detection cannot cover the vibration-fatigue coupling working condition is solved.

The invention discloses an ultrafast laser strengthening method for improving the vibration fatigue life of titanium alloy, and belongs to the technical field of metal material surface strengthening. The method comprises the following steps: S1, carrying out surface cleaning treatment on a titanium alloy material; s2, carrying out laser strengthening treatment on the surface of the metal material by using ultrafast laser; s3, ABAQUS software is adopted to simulate stress and displacement of the titanium alloy simulation part under the first-order vibration frequency; s4, carrying out a vibration fatigue test, and comparing the vibration fatigue life of the titanium alloy simulation part before and after reinforcement; according to the ultrafast laser strengthening method, ultrahigh-pressure shock wave pressure is generated on the surface of the metal material through induction of ultrafast laser, then a gradient residual compressive stress layer, finer crystal grains and higher dislocation density are formed on the near surface of the metal material, and the vibration fatigue life is prolonged by inhibiting crack initiation; the ultrafast laser strengthening method is high in feasibility and good in strengthening effect and has high application and popularization value.

The invention relates to the technical field of vehicle assembly vibration fatigue tests, in particular to a road load spectrum-based accelerated random vibration spectrum determination method, which comprises the following steps of: selecting i-circle data of each characteristic road surface under full-load, half-load and no-load working conditions as original data of accelerated random vibration spectrum calculation; calculating an impact response spectrum and a fatigue damage spectrum of the i-circle data of each characteristic pavement; respectively accumulating the fatigue damage spectrum statistical values of the three working conditions; packaging the maximum values of the impact response spectrums under the three working conditions; according to a fatigue damage accumulation theory, calculating a fatigue damage spectrum of the total target mileage according to the number of cycles of three working conditions; packaging the maximum value of the impact response spectrum of the whole circle of characteristic pavement under the three working conditions to obtain the maximum value of the overall target mileage impact response spectrum; synthesizing an accelerated random vibration spectrum by using the fatigue damage spectrum of the total target mileage according to a damage equivalence principle; and finally, carrying out ERS calculation on the generated accelerated random vibration spectrum, and checking the correctness and rationality of the accelerated random vibration spectrum.

The invention discloses a vibration fatigue risk assessment method and device for an axial flow blade, a medium and equipment, and relates to the technical field of axial flow compressors, and the method comprises the steps: creating a blade finite element model of a target axial flow blade, and respectively applying a rotating speed and a steady-state aerodynamic load corresponding to each interference working condition point on the target axial flow blade to the blade finite element model, pre-stress modal analysis is carried out, and a finite element modal analysis result corresponding to each interference working condition point is obtained; calculating an allowable modal force of the target axial flow blade under each interference working condition point based on a finite element modal analysis result; calculating a sorting factor of each interference working condition point according to the allowable modal force; and carrying out danger degree sorting on the plurality of interference working condition points on the target axial flow blade based on the sorting factor, and sequentially carrying out vibration fatigue risk assessment on the plurality of interference working condition points according to a descending order of the danger degrees. The vibration fatigue safety analysis period can be shortened, and the analysis efficiency can be improved.

The present invention discloses a test system for inverter maintenance with a protective function, belonging to the field of inverter testing technology. The system includes a detection base, a simulation unit for simulating the actual working conditions of a frequency conversion control board, and a detection mechanism for detecting the internal diode of the frequency conversion control board. The present invention can flexibly adjust the vibration direction of the vibration source through the dynamic coordination of a polarization component and a rotating simulation disk, thereby covering the multi-dimensional vibration scenarios that may be encountered in the actual operation of the frequency conversion control board, solving the problem of lack of vibration source simulation in the traditional frequency conversion test process, and simulating the elastic support environment of the actual installation through an airbag spring suspension, avoiding the distortion of vibration energy emission caused by rigid fixation, thereby improving the accuracy of large-capacitor vibration fatigue testing, and realizing automatic step-by-step wiring operation of the detection by cooperating with a multimeter through the detection drive component, thereby improving the overall detection wiring efficiency.

This utility model discloses a forced vibration fatigue testing device for thin metal sheets, belonging to the field of fatigue life testing technology for thin metal sheet materials. It addresses the problems of low vibration frequency, poor adaptability, and bulky structure in traditional testing devices. The device includes a trapezoidal impact platform base, a housing, a modular support frame, and a drive and detection mechanism. The support frame consists of an experimental support, a test piece platform, and limiting blocks, achieving rapid positioning and height adjustment of the test piece via bolts. The drive and detection mechanism includes symmetrically distributed motor and encoder assemblies. The motor drives the roller shaft via a coupling, causing the rollers to rotate at high frequency. The encoder records data in real time and provides feedback via a touchscreen. The trapezoidal base incorporates a shock-absorbing layer to improve stability, the modular structure reduces structural weight, it is adaptable to thin metal sheets of varying thicknesses, and the integrated touchscreen interface provides convenient operation. This device is suitable for high-precision fatigue life testing of ultra-thin materials such as aerospace flexible components.

This invention provides a novel vibration fatigue testing method for gas turbine blades. Addressing the problems of large specimen wear, long testing time, and limited results associated with traditional step-and-step stress loading methods for obtaining blade fatigue limits, this invention excites blade resonance on an electromagnetic vibration table using novel step-and-step stress loading techniques on identical blade specimens. While retaining the step-and-step matching standard, when limited test data cannot meet the matching requirements, a stress "concession" method is rationally applied based on the turbine blade structure and fatigue strength level to eliminate test data with significant stress deviations, thereby obtaining the median fatigue strength of blades from the same batch. This invention makes stress matching faster and more flexible, requiring only 2-3 stress levels to achieve a test fitting result with a confidence level of over 95%, demonstrating high accuracy. This method is applicable to fatigue limit tests of all gas turbine blades.

The invention discloses an overhead line system electric connecting line vibration fatigue test device, which relates to the technical field of railway overhead line systems, and comprises a high-speed railway overhead line system simulation support and a reciprocating lifting mechanism, and an electric connecting line is connected between a carrier cable and a contact line on the high-speed railway overhead line system simulation support. A reciprocating lifting mechanism is arranged below the connecting position of the electric connecting wire and the contact wire, a bearing block is arranged at the top of the reciprocating lifting mechanism, and the bearing block can make contact with or be away from the connecting position under the action of the reciprocating lifting mechanism. The high-speed railway overhead line system simulation support is used for simulating the real working condition of the electric connecting line, the reciprocating lifting mechanism is used for simulating the working condition of the locomotive pantograph running on the line, the corresponding fatigue life test can be carried out on the service state of the electric connecting line closer to the actual working condition, more accurate experimental data can be obtained, and the test efficiency is improved. And the service life of the electric connecting wire in the corresponding service environment can be accurately predicted.

The invention provides an underwater vehicle equipment support random vibration fatigue simulation prediction method and system. The method comprises the steps that a finite element model is constructed based on the actual installation postures of a halogen lamp support and a halogen lamp in the transportation process; analyzing the modal distribution of the halogen lamp bracket in the installation state, identifying the weak link of the key modal, and analyzing the coupling condition of the modal frequency and the PSD excitation frequency; carrying out random vibration analysis, and determining a stress frequency response function and a stress root mean square RMS stress of the key position; and based on a random vibration analysis result, predicting the fatigue life of the halogen lamp bracket and reproducing a fracture phenomenon. And optimizing the support structure through a strategy of combining free shape optimization and multi-model optimization. According to the method, the service life of the halogen lamp bracket is predicted more accurately, the halogen lamp bracket is optimized, the modal frequency of the bracket is improved, the stress amplitude is reduced, and the fatigue life is prolonged.

The invention discloses a vibration fatigue life prediction method and system of a generator end cover, electronic equipment and a storage medium. The vibration fatigue life prediction method of the generator end cover comprises the following steps: acquiring each order of dominant frequency of the generator end cover; the failure cycle index of the generator end cover is obtained through a test, the preset multiple of the main frequency of any order of the generator end cover serves as the center frequency, acceleration excitation of different magnitudes is applied to the generator end cover, and the equivalent stress of the generator end cover is obtained; performing curve fitting on the failure cycle index and the equivalent stress, and determining a stress-life curve of the generator end cover; and determining the random vibration fatigue damage amount of the generator end cover according to the stress-life curve, and predicting the random vibration fatigue life of the generator end cover according to the random vibration fatigue damage amount of the generator end cover. According to the method, the stress-life curve of the generator end cover is not influenced by the change of the damping-damping ratio, and the efficiency of predicting the vibration fatigue life of the generator end cover can be improved.

The present invention relates to the technical field of rail vehicles, and provides a method and device for compiling a vibration fatigue load spectrum. The method includes: obtaining a vibration acceleration time-domain load obtained based on a line test; determining the effective value distribution of the vibration acceleration load in the vibration acceleration time-domain load according to a preset sample duration; compiling an effective value frequency spectrum of the vibration acceleration load according to the effective value distribution; compiling a multi-level acceleration functional load spectrum according to the effective value frequency spectrum and the sample duration; inputting the multi-level acceleration functional load spectrum into a bench test to obtain fatigue damage corresponding to the multi-level acceleration functional load spectrum over the entire design life mileage; calculating a vibration acceleration coefficient according to the fatigue damage; and compiling an acceleration long-life load spectrum according to the acceleration functional load spectrum and the vibration acceleration coefficient. The fatigue damage of the hanging structure calculated by using the acceleration long-life load spectrum compiled by the present invention is basically consistent with the actual damage of the structure.

The invention discloses a cable bridge vibration fatigue testing device and method, and relates to the technical field of testing devices.The cable bridge vibration fatigue testing device comprises a supporting frame and a placing assembly; a mounting hole is formed in the lower side of the supporting frame, and an impact assembly is mounted on the right side of the supporting frame; the placing assembly comprises a placing frame, a first spring, a second spring and a vibration motor; the cable bridge vibration fatigue test method comprises the following steps: S1, fixing and initializing a sample: horizontally placing the cable bridge sample in a placing frame, starting a first motor of a clamping assembly to drive a bidirectional screw rod to rotate, and driving clamping plates on two sides to synchronously and oppositely move until a rubber plate is tightly attached to the side surface of the sample to complete transverse clamping, the multi-axis composite vibration in an actual scene can be reproduced, the vibration intensity can be rapidly adjusted, and the cable bridge can be prevented from slipping during testing.

The present invention belongs to the field of fatigue testing of plate test pieces, and particularly relates to a lateral vibration and axial superposition fatigue test device. The superposition fatigue test device includes: an upper clamping assembly, a lower clamping assembly, and an excitation assembly. The upper clamping assembly and the lower clamping assembly are used to clamp the test piece and are connected to the fatigue testing machine through a pin shaft. The fatigue testing machine provides an axial actuation mode to the test piece. The excitation assembly includes an excitation rod and an exciter. An installation hole is provided on the working section of the test piece. The first end of the excitation rod passes through the installation hole of the test piece and is fixed by a bolt. The excitation rod is perpendicular to the test piece. The exciter provides a lateral actuation mode of a set mode to the test piece through the excitation rod. In the present invention, the axial stress is concentrated on the working section of the test piece. The working section simultaneously bears the superposition of the axial conventional fatigue load and the lateral vibration fatigue load, realizing the multi-axis life estimation under non-proportional loading.

The invention discloses a vibration fatigue finite element analysis method for a vertical low-temperature heat-insulation gas cylinder system. The method comprises the following steps: constructing a three-dimensional model of the vertical low-temperature heat-insulation gas cylinder system by utilizing modeling software; respectively importing the three-dimensional models of the vertical low-temperature heat-insulation gas cylinder system into ANSYS finite element analysis software, setting material attributes according to reality, and performing contact and grid division; setting load and constraint according to the actual vibration test working condition, and calculating the inherent frequency of the vertical low-temperature heat-insulation gas cylinder system in the ANSYS modal analysis module; converting the actually measured pavement unevenness power spectral density or the national standard pavement unevenness power spectral density into a random vibration load, and calculating a random vibration dynamic response by combining the inherent frequency obtained by modal analysis; the random vibration fatigue life of the low-temperature heat-insulation gas cylinder system is determined by combining an S-N curve of a material and a fatigue failure criterion, and theoretical guidance is provided for vibration characteristic research and safety application of the vertical low-temperature heat-insulation gas cylinder system.