73 results about "Limit load" patented technology

The invention discloses a shield segment heterogeneous modeling crack and limit simulation method. The method comprises the following steps: constructing an aggregate three-dimensional model database; generating a heterogeneous aggregate accumulation model; establishing a concrete shield segment three-dimensional model; defining a model material constitutive relation and a damage criterion; setting an equivalent field staged loading working condition and a boundary condition; grid division and nonlinear static simulation solution are carried out; and constructing a crack response monitoring and output module, and executing judgment of a structure limit state. High-precision construction and multi-stage loading simulation of a shield segment model are realized by reconstructing a concrete microstructure and steel bar arrangement information and combining a field loading force value and a boundary condition; and a nonlinear material constitutive and damage evolution criterion is introduced, the whole-process response of the crack is captured, a limit state criterion is set, and automatic identification and damage form judgment of the bending resistance limit load are completed. According to the method, a technical path capable of being popularized is provided for shield segment structure performance evaluation, ultimate bearing prediction and a crack control strategy.

The invention relates to the field of steel member engineering, in particular to a prestressed concrete combined double-chamber box-section bent steel member and a manufacturing method thereof, and the manufacturing method comprises the following steps: S1, welding an inner box chamber and forming an assembly hole; s2, first bolts and second bolts are inserted into the assembly holes; s3, first bolts and second bolts are initially screwed to apply inward prestress to the two webs and the two flange plates, and the side wall of the inner box chamber is made to generate inward concave elastic pre-deformation; s4, welding the outer box chamber and the reinforcing plate; s5, an expansion material is injected into a cavity of the inner box chamber; s6, the expansion material expands to enable deformation of a web plate and a flange plate of the inner box chamber to be reset to the design form; and S7, finally screwing the bolt and stabilizing the pressure. The circumferential confining pressure state of the expansion material is achieved through the prestress bolt system, the compressive strength of the expansion material is multiplied, and therefore the axial compression buckling ultimate load, the compressive bearing capacity and the stability of the bending component are greatly improved.

The invention discloses a method for dynamically evaluating the ultimate bearing capacity of a layered damage composite material cylindrical pressure-resistant shell in the field of deep sea equipment structure health monitoring, which comprises the following steps of: establishing a nonlinear relationship between a critical buckling load of an unlayered composite material cylindrical shell and a critical buckling load of a layered composite material cylindrical shell, and calculating an attenuation coefficient of each group of samples; measuring inner and outer layer strain values of the to-be-evaluated composite cylindrical shell, detecting extreme value statistics and cumulative sum based on change points of the inner and outer strain values, judging that the position of the point is layered, constructing a layering point set, calculating five layering characteristic parameters of the to-be-evaluated composite cylindrical shell based on the layering point set, and substituting the five layering characteristic parameters into an attenuation coefficient formula, obtaining a critical load of the to-be-evaluated composite cylindrical shell; according to the method, through combination of dual-surface strain cooperative monitoring and a regression model, prediction of critical buckling loads in a service state is realized, environments such as shell thickness fluctuation, salt spray corrosion, interface fracture parameter measurement errors and impact loads are compatible, strain gauge monitoring and limit load online evaluation are fused, and a dual evaluation system is formed.

The invention relates to the field of steel member engineering, in particular to a high-strength steel combined multi-chamber box-section bent steel member and a manufacturing method thereof, and the manufacturing method comprises the following specific steps: S1, obtaining the design form of the steel member; s2, preparing an outer side chamber of the steel member; s3, prestress is applied to the outer side chamber in the axial direction of the outer side chamber so that the outer side chamber can be bent to a first form, a first eccentric value of the first form is obtained, and the first eccentric value is larger than the designed eccentric value; s4, top pressure towards the inner side of the bend is applied to the first form to a second form, the second form is in a pre-tightening state, a second eccentric value of the second form is obtained, and the second eccentric value is smaller than the designed eccentric value; s5, the outer side chamber is kept in the second form, and the matched inner side chamber is welded to obtain the steel member; and S6, after the force is unloaded, the inner side chamber is subjected to pre-tensile stress, the outer side chamber is subjected to pre-compressive stress, and the steel member is obtained. Pre-tensile stress is applied to the inner side of the steel member, pre-compressive stress is applied to the outer side of the steel member, and therefore the axial compression buckling ultimate load of the bent steel member is increased.

The invention provides a tower bottom limit load reduction method based on blade pre-variable pitch automatic optimization. The method comprises the steps that an initial variable pitch power interval and an initial pre-variable pitch angle are set; calculating a plurality of tower bottom combined bending moment loads under different wind speeds under the working condition of DLC1.3, and respectively drawing a power-load scatter diagram and a power-load envelope curve diagram according to the maximum load value of the tower bottom combined bending moment and the power of the wind turbine generator when the load value appears; after the pre-variable pitch angle is adjusted, the multiple tower bottom combined bending moment loads under the DLC1.3 working condition and different wind speeds are calculated again, and the maximum value in the multiple tower bottom combined bending moment loads is taken as the maximum tower bottom combined bending moment load value; the maximum load value of the tower bottom combined bending moment is compared with the target load of the tower bottom combined bending moment, and if the maximum load value is smaller than the target load value, calculation of tower bottom limit load reduction is completed. The blade pitch angle can be controlled to change along with the change of power, so that the aerodynamic force borne by the wind wheel is reduced, the tower bottom load is reduced, and the purpose of reducing the tower bottom limit load is achieved.

The invention discloses a deep foundation bearing capacity characteristic value calculation method and system based on data fusion. The method comprises the steps that data collection is completed through a deep load test, and a load settlement curve and a settlement time logarithmic curve are formed; generating a smooth curve; identifying a slope mutation point of the curve by adopting a first-order derivative mutation method, wherein a load corresponding to the mutation point is a proportional limit load; if the slope abrupt change point is not recognized, the curve is set as a slowly changing curve; extracting the slope and the slope change rate of the curve under each level of load, and completing the judgment and correction of the limit load by fusing the multi-dimensional data of the two curves and combining preset thresholds including the settlement amount and the settlement stabilization time; and further calculating the bearing capacity characteristic value of the deep foundation by combining the numerical relationship between the ultimate load and the proportional limit load.

To enable a more accurate assessment of delayed fracture characteristics in a sheared end surface. A method for assessing delayed fracture characteristics for assessing the delayed fracture characteristics of a sheared end surface of a metal sheet included: a test including a step of restraining a metal sheet in a state where a predetermined load stress is loaded to a sheared surface of the metal sheet and a step of placing the metal sheet for a predetermined time in a predetermined hydrogen entry environment in the restrained state; and a step of determining a limit load stress being a load stress at the limit where a delayed fracture in the sheared surface of the metal sheet does not occur based on the results of the test and setting a stress margin to the occurrence of the delayed fracture in the sheared end surface of the metal sheet based on the determined limit load stress, in which the determined stress margin is set as an index of the assessment of the delayed fracture characteristics of the sheared end surface of the metal sheet.

The invention discloses a shield butt joint section curtain grouting additional load determination method, and relates to the technical field of geotechnical engineering grouting, and the method comprises the steps: carrying out the preprocessing of obtained grouting measurement data, obtaining an envelope point set, and carrying out the fitting optimization based on an envelope line function model, and obtaining an optimized envelope line function; calculating an ultimate load, attenuating the ultimate load to a preset engineering allowable threshold value to obtain an ultimate load acting distance, and determining boundary conditions through an envelope line intercept analysis method; and correcting the limit load according to a preset grouting load safety coefficient to obtain a corrected limit load, and performing inversion correction in combination with the grouting measurement data to obtain a final limit load and a final boundary condition. According to the method, the significant action range and the most unfavorable load condition of the grouting load are determined by capturing the spatial distribution and evolution law of the additional soil pressure field caused by grouting, and accurate load boundary conditions are provided for model analysis or finite element calculation.

The invention provides a method, a system and equipment for evaluating fatigue performance of an inner ring rib steel pipe concrete joint. The method comprises the following steps: calculating structural geometric parameters of the jacket foundation according to an ultimate load condition; obtaining a fatigue load time history curve through load simulation based on the parameters; a node hot spot stress cycle amplitude is obtained through finite element analysis; and finally, calculating fatigue accumulated damage through an S-N curve specially fitted for the inner ring rib steel pipe concrete node, and performing evaluation. The method can solve the technical problems that an existing fatigue evaluation method does not consider the specific structure, material and process characteristics of the inner ring rib steel pipe concrete joint, so that the evaluation result discreteness is large, the accuracy is insufficient, and the requirement for accurate evaluation of the fatigue life of the complex space joint of the offshore wind turbine generator is difficult to meet.

The invention relates to the technical field of windlass load detection, and discloses a windlass load test device for windlass production, which comprises a base plate I, a base plate II, a test pit, an elevated seat, a test slope and a horizontal test channel, and is characterized in that the front end of the base plate I is fixedly connected with the base plate II; a rectangular test pit is formed in the position, close to the middle end, of the first base plate, a pit bottom protection base is connected to the bottom of the test pit in a pouring mode, the periphery of the inner wall of the pit bottom protection base is filled with multi-stage buffer pits, and a first supporting frame is arranged at the position, close to the left side, of the top of the pit bottom protection base and connected through rivets. The test device can provide three test effects of vertical lifting and horizontal and inclined load dragging, fully solves the problem of single function of the current test device, carries out limit load test through variable load weight in the loading process, and has a limit test protection function while carrying out complete limit test by deploying a plurality of protection components.

The invention relates to the technical field of wind generating sets, and discloses a transmission system design parameter optimization method and device based on fan complete machine dynamics simulation, and the method comprises the steps: constructing a complete machine dynamics model and a rigid body transmission system dynamics model; assembling the complete machine dynamic model and the rigid body transmission system dynamic model to obtain a rigid-flexible coupling complete machine refined dynamic model; operating parameters of the rigid-flexible coupling complete machine refined dynamic model during simulation are collected, and simulation operating parameters are obtained; and performing optimization processing on the design parameters of the rigid-flexible coupling complete machine refined dynamic model by adopting the simulation operation parameters to obtain optimized design parameters. The method is used for predicting resonance risk points and resonance excitation sources through analysis and modal shape analysis; the method can be used for analyzing the influence of a main bearing, a box body, a planet carrier, a gear load transmission path, a shaft system deformation condition, an emergency shutdown condition, a paddle clamping power-down condition, a short-circuit condition and other working conditions on key stressed parts of a transmission system under the limit load.

The invention relates to the technical field of metal structure stability finite element analysis, in particular to a stability limit load calculation method based on a dichotomy and a computer program product, and the method comprises the steps: carrying out the structural modeling of a target structural part, completing the finite element pretreatment, applying an initial load to a modeled structure, obtaining an initial maximum Mises stress value of the structure, and calculating the stability limit load of the target structural part. According to the elastic field linear superposition principle and the stability upper limit principle, the initial load range [Flower, Fupper] of the stability limit load is calculated, then the load range is iteratively updated by adopting a dichotomy method until the convergence condition is met, the final stability limit load is obtained, the total calculation frequency is reduced by 40%-60%, and the final stability limit load is obtained. Meanwhile, full-process automation from load setting to result judgment is achieved, and the requirement for manual intervention is remarkably reduced.

The application discloses a kind of based on digital-analog collaborative driving's dynamic stress field identification method of steel-concrete transition zone of mixed tower wind turbine unit, comprising: creating macroscopic wind turbine cabin mixed tower foundation coupling dynamics numerical analysis model, the calculated displacement of steel-concrete transition zone of mixed tower wind turbine unit multibody dynamics analysis model under the action load of shutdown operating condition is obtained;In the steel-concrete connection transition section of mixed tower wind turbine tower drum, the complementary layout of displacement sensor and accelerometer of LVDT electromagnetic induction principle is designed, and the predicted displacement is obtained;The contact stiffness and interface friction coefficient of the contact element of steel-concrete transition zone microscopic slip and debonding behavior of wind turbine multibody dynamics analysis model are inverted, and the dynamic stress field of steel-concrete transition zone under the action of tower top limit load is calculated.The application realizes the cross-scale perception of steel-concrete interface complex stress field and the real-time early warning of hidden damage by heterogeneous sensor network, nonlinear multibody dynamics modeling and data model two-way coupling mechanism.

The present application relates to the field of nondestructive testing, and provides a composite laminated sheet interlaminar damage identification and failure determination method, comprising: collecting acoustic emission signals of a composite laminated sheet in a short beam shear test, and extracting amplitude intensity and peak frequency; classifying and identifying damage categories in an interlaminar shear failure process; calculating a relative cumulative count of acoustic emission signals of each damage, and synchronously calculating a load change increment, and constructing a relationship curve of both and time; determining a damage starting time according to an initial change feature point of the relationship curve relative to the cumulative count curve, and cooperatively determining an interlaminar shear failure point in combination with a mutation feature of the load increment curve, and outputting a failure point load value as a limit load of interlaminar shear strength. The present application also provides a device, equipment and medium applying the method. The present application effectively identifies damage modes and determines an interlaminar shear failure starting point, and accurately determines a shear strength of a laminated sheet.

The invention belongs to the technical field of aircraft structural strength analysis, and particularly relates to a metal material stress plasticity correction method. The method comprises the steps that firstly, material parameters of the aircraft metal material structure are obtained; step 2, adopting a linear finite element static strength analysis method to obtain stress distribution of the aircraft metal material structure under the action of a limit load, and if the stress meets a preset condition, entering step 3; 3, according to the material parameters, the Ramberg-Osgood nonlinear hardening index during tensile failure is corrected, and the corrected nonlinear hardening index is obtained; and 4, constructing a stress equation, and substituting the nonlinear hardening index into the stress equation to obtain the real stress of the aircraft metal material structure after plastic correction. According to the method, the metal material stress of the aircraft metal material structure can be conveniently and quickly subjected to plastic correction.

The application discloses a kind of local reinforcement selected area laser melting deposition high-strength titanium alloy preparation method and system, belong to additive manufacturing technical field.The local reinforcement selected area laser melting deposition high-strength titanium alloy preparation method provided by the application, by establishing target titanium alloy structure three-dimensional model and carrying out finite element limit load simulation analysis, stress distribution and potential dangerous area are identified;Based on the analysis result, the performance requirement is divided, the material enhanced local area is determined, and the laser scanning path and powder feeder movement trajectory are planned;Path file is imported into composite equipment to set process parameters;Titanium-based composite material powder is selectively laid in the enhanced area, and a locally reinforced structure is obtained by selective laser melting.The scheme realizes the spatial selective distribution of powder composition, forms a uniform distribution of high-stress areas, significantly improves the local strength and maintains the overall strength and plasticity matching, effectively solves the problem of insufficient performance matching of titanium alloy components under complex load.

The invention discloses an aerospace equipment structure limit load inversion method based on historical maintenance data, and belongs to the related technical field of digital twinning. The method comprises the following steps: firstly, counting historical maintenance data of aerospace equipment, extracting and fitting the number of cycles of a target structure from service to damage, and determining the statistical life of the target structure; secondly, establishing a finite element model according to the actual loading condition of the target structure, and applying a load to obtain a stress field and a strain field of the target structure; thirdly, a fatigue prediction life calculation model based on the stress field and the strain field is established, and the fatigue prediction life is obtained. And finally, carrying out parameter optimization by taking the load as an optimization variable and taking an absolute value of a difference value between the minimum fatigue prediction life and the statistical life as an optimization target to obtain a limit load inversion result. According to the method, the most matched limit load amplitude is iteratively optimized by fully utilizing historical maintenance data and utilizing an optimization method, and powerful support can be provided for further operation maintenance, optimization design and the like of the structure.

The invention discloses a mechanical measuring instrument overrun protection mechanism with a self-recovery function and a debugging method thereof, and relates to the technical field of mechanical measuring instruments. The over-limit protection mechanism comprises a fixed connecting part, a floating part, an elastic deformation part and an overload limiting part; the fixed connecting part and the floating part are connected with the elastic deformation part to form a quadrilateral structure, the floating part always moves parallel to the fixed connecting part when bearing a tested load force, and a gap is reserved between the overload limiting part and the floating part and is used for limiting overload displacement of the floating part; when the floating part is stressed and deformed to a limit position, the floating part is in contact with the overload limiting part to limit further displacement of the floating part, so that the force transmitted to the measuring instrument is not increased any more; and after the over-limit load is unloaded, the elastic deformation part automatically resets, so that the clearance between the floating part and the overload limiting part is recovered. According to the over-limit protection mechanism, elastic deformation without frictional resistance can be achieved on the premise that parallel deformation guiding is achieved, over-limit protection is achieved in cooperation with a fixed limiting mechanism, and normal work can be automatically recovered after over-limit force is unloaded.

The present invention belongs to the field of anchor cable detection, and specifically relates to a detection method and device for an anchor head assembly in a safety pressure dispersion anchor cable. The method detects data such as deformation load and its variation range, limit load, deformation amount, and forms no less than three curve correspondences through time, load and deformation amount: a p-s curve, a p-t curve and an s-t curve, etc.; the performance of the assembly is comprehensively evaluated through no less than three curves and measured parameters, and used as a basis for determining the performance of the assembly; compared with the prior art, the present invention can be used as an important basis for evaluating the quality of the assembly product of the anchor cable, and based on these data, the allowable deformation between the sliding P anchor and the fixed P anchor can be reasonably planned, which makes an important contribution to the theoretical design of the assembly product of the anchor cable in different application scenarios, and the measurement method of the present invention is simple and easy to implement.

The present invention discloses a method for calculating the ultimate load of the failure of the side columns of double-span and multi-span floor slabs under fire, which includes the following steps: S1, dividing the plate into arc-shaped micro-elements, and assuming the force of three adjacent beams of the failed side columns; S2, determining the distribution of the force on the beam based on conservative estimation; S3, calculating the deflection curve equation of the beam at normal temperature according to the deflection definition of the beam; S4, determining the deflection curve equation caused by the thermal gradient, substituting the deflection curve equation at normal temperature into the deflection curve equation to calculate the deflection curve equation caused by the thermal gradient at the top and bottom of the beam; S5, calculating the change of unit bearing capacity of fan-shaped areas of different radii caused by the stretching membrane effect based on the plate balance method and the principle of additional moment caused by the plastic hinge line; finally, based on the principle of the force of the double-span floor slab, further obtaining the calculation method of the floor slab bearing capacity of the failure of the side columns of the multi-span floor slab. The present invention proposes a new bearing capacity calculation method, which is faster and more convenient than the existing method.

The invention relates to an analysis and calculation method for a blade root connection structure of a wind driven generator, and the method comprises the steps: constructing a finite element model for coupling a blade shell unit and a blade root entity unit, and defining the material attributes of all parts; and a coupling connection relation between the blade shell unit and the blade root entity unit is set to simulate a real force transmission path. Then, target pre-tightening force is applied to the connecting bolts and locked, and distributed working loads are applied to the blade shell units at different angles in the pre-tightening state, so that the bending moment of the end of the blade root is larger than the limit load at the angle. And solving and calculating the loaded model, extracting stress data for connecting the bolt and the bolt sleeve, and performing strength and fatigue analysis on the bolt and the bolt sleeve based on the data. According to the method, the accuracy of stress calculation of the blade root connecting structure and the model precision are remarkably improved by introducing the geometric characteristics, the rigidity characteristics and the distributed load transmission path of the real blade, so that more reliable guidance is provided for design of the wind power blade root and the connecting structure.

The invention provides a method and device for determining a jacking of a full framing, a storage medium, computer equipment and a program product. The method comprises the steps that the rotational rigidity of a top node in the full framing and the actual jacking load of the full framing are obtained; initial structure parameters of the candidate jacking are determined; circularly executing the following steps to adjust the structural parameters of the candidate jacking until the candidate jacking meets the design requirements: acquiring the bending line rigidity of the candidate jacking; on the basis of a preset mathematical model, the length coefficient of the candidate jacking is calculated according to the rotational rigidity and the bending line rigidity, and the preset mathematical model is obtained through analysis on the basis of an energy method under the condition that the semi-rigidity of the top node is considered; determining the stability limit load of the candidate jacking according to the length coefficient and the bending line rigidity; according to the stable limit load and the actual jacking load, whether the candidate jacking meets the design requirement or not is determined; and if not, modifying the structural parameters of the candidate jacking, and returning to the step of acquiring the bending line rigidity of the candidate jacking.

The application belongs to the field of fatigue life calculation, and particularly relates to a wheel disc crack propagation life calculation method based on a stress intensity factor critical value. The method comprises the following steps: obtaining stress or strain distribution of the wheel disc under a limit load working condition; pre-preparing an initial crack at a feature part of the wheel disc, and calculating a stress intensity factor distribution curve of a crack front under the limit load working condition; according to a first crack propagation plan, terminating the propagation when the stress intensity factor of the crack front reaches a material fracture toughness Kc, and obtaining a crack propagation morphology and a stress intensity factor distribution curve; obtaining stress or strain distribution of the wheel disc under a type I cyclic peak load working condition; calculating a maximum stress intensity factor K C ′ corresponding to the crack propagation morphology under the type I cyclic peak load working condition; and taking the maximum stress intensity factor K C ′ as a crack termination propagation condition, and calculating a crack propagation life. The crack propagation life is more conservative and has higher safety.

The present application belongs to the field of fatigue life calculation, and particularly relates to a method for calculating the crack propagation life of a wheel considering a restricted load condition. The method comprises: obtaining the stress or strain distribution of the wheel under the action of a Class I cyclic peak load condition; prefabricating an initial crack at a characteristic portion of the wheel to obtain a stress intensity factor distribution curve of the initial crack front; performing crack propagation under the action of the Class I cyclic peak load condition according to the first crack propagation plan to obtain crack propagation morphologies of different crack propagation sizes; obtaining the stress or strain distribution of the wheel under the restricted load condition; calculating the maximum stress intensity factor of the crack front corresponding to each of the crack propagation morphologies; fitting the relationship curve between the crack propagation size and the maximum stress intensity factor to predict the critical crack size; and calculating the crack propagation life. The crack propagation life given in the present application is more conservative and safer.

Method for damping loads acting on a loading unit (100) for transporting transport elements (103) in an overload case to protect against damage, wherein measured values ​​(62) about the current state of the loading unit (100) are recorded by a sensor device (61) and wherein at least one damping device (2) is controlled by the measured values ​​(62), characterized by that a shearing device (42) is provided on the loading unit (100) which shears off when the load acting on the loading unit (100) exceeds a predetermined level (66), and that a control device (48) detects an overload case (63) from the recorded measured values ​​(62) when a shear sensor (67) detects shearing of the shear device (42), and that the damping of the damping device (2) is set to a predetermined high value at least immediately after the detection of the overload case (63), and the damping set to a high value is maintained for a predetermined time period (67) after the detection of an overload case (63), and the damping is reduced to a lower damping (71) after the predetermined time period (67) in order to initially increase the load on transport elements (103) transported on the loading unit (100) up to a predetermined limit load (64) and then reduce it after the predetermined time period (67).

The invention provides a suspension type microgravity simulation system parameter calculation method and device and electronic equipment, the suspension type microgravity simulation system comprises a support and a plurality of suspension pieces connected to the support, and each suspension piece comprises an extension spring. The calculation method comprises the following steps: calculating the weight borne by a single suspension piece according to the number of the suspension pieces and the weight of an accessory to be tested, calculating the maximum tension borne by the single suspension piece according to the weight borne by the single suspension piece, and calculating the limit load of the single suspension piece according to the maximum tension borne by the single suspension piece, and the diameter, the spring pitch diameter and the single-circle rigidity of the single extension spring are determined according to the limit load of the single suspension piece. The suspension type microgravity simulation system keeps the low-frequency characteristic, can meet the microgravity simulation requirements of different numbers of gravity unloading points and different vertical suspension lengths, can also adapt to flexible to-be-tested accessories with different loads and different sizes, and is good in adaptability.

The invention discloses a blade shimmy bending moment limit load reduction method based on an impeller azimuth angle, which comprises the following steps: S1.1, acquiring the azimuth angle of a blade on an impeller rotating plane; s1.2, judging whether the fan is in a converter load shedding working condition or not; s1.3, judging whether the azimuth angle of a blade in advance of nine o'clock from the clockwise direction is smaller than a set azimuth angle or not at the load shedding moment, if so, performing synchronous control on the three blades by taking the maximum blade angle as a reference, and if not, entering the next step; s1.4, paddle opening or paddle closing control is conducted on the blades, and paddle opening is stopped after the paddle opening amplitude of the blades reaches a set threshold value; s1.5, after the blades reach nine o'clock, the blades are collected at a third set speed; and S1.6, judging whether the three blades respectively finish one paddle opening action or not, if so, performing synchronous control on the three blades of the fan by taking the maximum paddle angle as a reference, and if not, returning to the step S1.4. On the premise that the operation power of the wind driven generator does not need to be reduced, the shimmy bending moment limit load of each section of the blade can be effectively reduced.

The invention provides an additive manufacturing material fatigue strength prediction method based on a microscopic image, and the method comprises the steps: obtaining the basic parameters of a material sample, and enabling the material sample to be obtained through the additive manufacturing technology; a microscopic image of the surface of the material sample is obtained, and microscopic information of the material sample is further determined; a material constitutive model based on a dislocation mechanism is adopted, a crystal plasticity finite element model is constructed based on the microscopic information of the material sample, and material constitutive parameters in the constructed model are calibrated based on the basic parameters of the material sample; and carrying out multi-scale stability analysis on the crystal plasticity finite element model, judging whether the model is in a stable state or not by extracting accumulated plastic strain based on a direct periodic method during analysis, carrying out iteration based on a dichotomy to obtain a stability limit load of the model in the stable state, and taking the stability limit load as the fatigue strength of the material sample. By adopting the scheme, the fatigue strength of the additive manufacturing material can be accurately predicted.

The invention discloses a method and system for evaluating the failure state of a hydrogen conveying pipeline. The method comprises the steps that the hydrogen enrichment concentration of the hydrogen conveying pipeline to be evaluated is determined; the limit load of the current pipeline under the hydrogen-containing condition is calculated according to parameters such as the hydrogen enrichment concentration, the pipeline structure size, the pipe mechanical property and the crack shape size; according to the limit load, constructing a failure evaluation curve of the current hydrogen pipeline containing the cracks, and calculating to obtain a dimensionless load factor and a dimensionless stress intensity factor required by current evaluation; and according to the dimensionless load factor and the dimensionless stress intensity factor, determining the safety state of the current hydrogen conveying pipeline by using the failure evaluation curve.

The invention relates to the technical field of hot isostatic pressing equipment design and manufacturing, and discloses a buckling failure judgment method of a prestressed steel wire winding core cylinder for hot isostatic pressing equipment, which comprises the following steps: acquiring basic information of a target core cylinder; determining an inner cylinder radius deformation value caused by winding operation of the target core cylinder under the pre-tightening working condition; equivalent external pressure borne by the outer wall of the outer cylinder under the winding effect is obtained; determining a plurality of comprehensive influence coefficients for correcting the buckling limit based on physical and geometric characteristics between the inner cylinder and the outer cylinder; the structure parameters, the material parameters and the multiple comprehensive influence coefficients are combined, a limit state equation of the core cylinder is established, and the buckling limit load of the target core cylinder without instability under the action of prestressed steel wire winding is calculated; and calculating the ratio of the buckling limit load to the equivalent external pressure, comparing the ratio with a preset safety coefficient, and judging whether the target core cylinder is subjected to buckling failure or not. According to the method, accurate evaluation of the buckling failure of the double-layer cylinder wall core cylinder structure for the hot isostatic pressing equipment is realized.