100 results about "Intensity factor" patented technology

The present invention is directed to a substantially unrecrystallized rolled aluminum alloy product, obtained from a plate with a thickness of at least 30 mm, comprising 2.2 to 3.9 wt. % Cu, 0.7 to 2.1 wt. % Li, 0.2 to 0.8 wt. % Mg, 0.2 to 0.5 wt. % Mn, 0.04 to 0.18 wt. % Zr, less than 0.05 wt. % Zn, and optionally 0.1 to 0.5 wt. % Ag, remainder aluminum and unavoidable impurities having a low propensity to crack branching during L-S a fatigue test. A product of the invention has a crack deviation angle Θ of at least 20° under a maximum equivalent stress intensity factor Keff max of 10 MPa √m for a S-L cracked test sample under a mixed mode I and mode II loading wherein the angle Ψ between a plane perpendicular to the initial crack direction and the load direction is 75°

The invention discloses an optimization method of the shortest emergency logistics path based on the fish swarm ant colony algorithm. The congestion factor is introduced into the basic ant colony algorithm to solve the optimization problem of the shortest emergency logistics path and enhance the search for emergency logistics. The ability to optimize the best solution for the path reduces the possibility of the basic ant colony algorithm falling into a local optimum. (1) Input the number of ants, the maximum number of iterations and the maximum load capacity of the vehicle, select the emergency situation, and input the importance of residual pheromone, the importance of heuristic pheromone, evaporation coefficient and intensity coefficient; (2) Find the shortest emergency logistics route : (1) Establish the model of the shortest emergency logistics route optimization problem; (2) The solution process of the model; (3) Display the distribution route results and the performance comparison results of the algorithm in solving the shortest emergency logistics route optimization problem. The optimization scheme for finding emergency logistics routes in the present invention is more efficient.

The invention relates to a method for estimating the remaining fatigue life of a main metal structure of a crane. The method is applied to the compiling of actually measured load spectrums, the measurement of material fatigue crack propagation curves, the nondestructive detection of hazardous locations and the estimation of the remaining fatigue life of the main metal structures of the large cranes at relatively higher working levels in shipyards, ports and the like, and is also applied to the estimation of the remaining fatigue life of the cranes of other types. The method comprises the following steps of: (1) acquisition of the load spectrum; (2) measurement of material performance; (3) detection of an initial crack location and an initial crack size; (4) acquisition of a crack stress intensity factor; and (5) estimation of the remaining fatigue life. In the method, factors such as the existence of a crack in the structure, the detection of the location and size of the actually crack, and the like are taken into account, and the nondestructive detection is performed on the hazardous location; therefore, the remaining fatigue life of the metal structure of the crane can be accurately estimated.

The invention provides a decoding method based on edge intensity factors for conducting the de-blocking filter in the video compression processing, wherein, the acquisition of edge intensity factors is finished before the acquisition of the predication macro-block data and the residual block data. The method has the advantages that the current macro-block information can be released from a memory area in advance, and the needed information for the reference to macro blocks share the information existed in other storage area, so that the on-chip memory space in the decoding device is not exclusively occupied, and the memory space is in no need of being externally connected. Therefore, the demand on the memory device is reduced, the problems, such as the delay caused by the repeated memory, and the like are reduced, and the system efficiency is improved.

The invention relates to a photovoltaic model establishment method applicable to the dynamic overall-process simulation of a power system. A photovoltaic generation module is modeled, a temperature factor and an illumination intensity factor in the medium and long-term process have the characteristics of fluctuation and indeterminacy, and an implementation method of a photovoltaic maximum power tracing model for the dynamic overall-process simulation of the power system is provided in consideration of the influence on photovoltaic generation caused by the change of the two factors. The photovoltaic maximum power tracing model adjusts the working voltage of a photovoltaic cell panel according to the volt-ampere characteristics of a photovoltaic power supply by using a maximum power point tracing control method, so that the photovoltaic cell panel can work in a maximum power output state, solar energy is utilized to the greatest extent, and the efficiency and performance of the photovoltaic generation are effectively improved. An inverter effectively controls the injection current of axes d and q by virtue of an inner ring current control loop and an outer ring current control loop, so that active power and reactive power can be controlled. The whole model meets requirements for electromechanical transient overall-process simulation and medium and long-term dynamic overall-process simulation of the power system.

The invention discloses a fatigue life prediction method for a friction stir welded component based on small crack propagation, and belongs to the technical field of fatigue diagnosis and analysis ofmechanical structures. The method comprises the steps that a bone-shaped flat plate sample is prepared, fatigue small crack propagation replica tests under different stress loads and different stressratios are conducted on different areas of a joint, and a secant method is adopted for calculating the propagation rate of small cracks; a New-Raju model is adopted for calculating the stress intensity factor range of the small cracks of the joint; c values in the depth direction and a / 2 values in the vertical direction of semi-arc shapes of fatigue crack propagation zones in fracture shapes of different areas of the joint, and the depth-to-length ratio 2c / a of the cracks is calculated; a curve of the propagation rate of the cracks along with the change of the stress intensity factor range isdrawn; an effective stress intensity factor is calculated; a formula of the propagation rate of the small cracks is determined; an initial crack size a0 and a critical crack size ac are determined; the formula of the propagation rate of the small cracks is integrated to obtain the fatigue life of the welded component. By means of the scheme, the fatigue life of the friction stir welded component can be more easily and accurately predicted.

The embodiment of the invention discloses a method for automatically controlling the terminal vibration intensity and a terminal adopting the method. The terminal comprises a detection device, a control device and a vibration device; the detection device is used for detecting the terminal vibration intensity and outputting the information indicating the terminal vibration intensity; the control device is used for processing the information indicating the terminal vibration intensity and acquiring the vibration intensity factors for adjusting the vibration intensity, and controlling the vibration intensity of the vibration device according to the vibration intensity factors; and the vibration device is used for executing the vibration of the corresponding vibration intensity. The method and the terminal of the embodiment of the invention can automatically adjust the vibration intensity according to the difference of the external environments, thereby fitting the different application environments.

The invention provides a method for testing the fracture toughness of rattan canes based on a three-point bending mode. The method comprises the following steps: preparing a sample, and regulating a water content rate so as to obtain a sample of which the water content rate is 10-12%; recording a load-crack opening displacement (PV) curve, measuring actual crack depths, and calculating critical loads PQ and critical stress intensity factors KQ. According to the method provided by the invention, the crack opening displacement is measured by a C.O.D Gauge, and the test precision is improved. Aiming at the characteristics of the rattan materials, the sampling method for testing the fracture toughness of rattan canes is ensured, and the measured results having high accuracy and good reproducibility are obtained. The calculation method for testing the fracture toughness of rattan cane, provided by the invention, provides qualitative and quantitative bases for the utilization of the rattan canes.

The invention, a testing method for mode I crack dynamic fracture overall process parameters under blast loading, discloses the testing method for the dynamic crack initiation toughness, dynamic expansion toughness and dynamic crack arrest toughness of mode I crack under blast loading, and belongs to the technical field of geotechnical engineering. The configuration of an internal single crack disc specimen with a large size is an autonomous design; testing results cannot be influenced by reflected extension waves and transmission waves; and the method is suitable for researching the crack growth rate and growth behavior of the whole process. Blast loading adopts an 8# detonator; numeral calculation adopts a finite element difference software AUTODYN; and a result basically accords with atest. A load stress time history curve can be input into a finite element program ABAQUS; the time history curve of a dynamic stress intensity factor can be obtained; and the dynamic fracture toughness of a material can be determined through the fracture time of a crack. The specimen is simple in configuration and easy in processing; the test is concise and clear in process and convenient in operation; and researches on crack dynamic growth behavior and tests on the dynamic fracture toughness can be realized.

The invention discloses a temperature adjusting method which comprises the following steps that: current temperature value is measured and deviation e is obtained according to the current temperature value; when the absolute value of e is more than a second deviation threshold and is less than or equal to a first deviation threshold, P, I and D is adjusted and the proportional action and integral action in control is increased while derivative action is weakened; when the absolute value e is more than or equal to zero and is less than or equal to the second deviation threshold, P, I and D is adjusted and the proportional action, integral action and derivative action in control is weakened; according to a third deviation threshold A and the deviation e, integral action intensity factor is adjusted; according to the adjusted P, I, D and integral action intensity factor, the increment of control quantity is obtained; moreover, temperature is adjusted according to the increment of control quantity. The invention also discloses a temperature adjusting device. In addition, the invention can effectively reduce the overshoot and oscillation phenomena during temperature control.

The invention provides an evaluation method and device for the full gear contact fatigue life based on crack producing and expanding. The method comprises that a maximal contact stress in a gear contact surface is calculated according to a maximal contact stress model; 2D static, 3D static, 2D dynamic and 3D dynamic models are constructed on the basis of a numerical calculation theory and an equivalent boundary condition, and maximal contact stress of corresponding gear contact surfaces are obtained on the basis of the models; the maximal contact stresses obtained on the basis of the four models are compared with the maximal contact stress obtained via the maximal contact stress model, and an optimal numerical calculation model is determined; a gear contact fatigue producing life evaluation model is constructed; the range of effective stress intensity factor values is determined; a gear contact fatigue expanding life evaluation model is constructed; and the full gear contact fatigue life is evaluated according to the gear contact fatigue producing life evaluation model and the gear contact fatigue expanding life evaluation model.

Axial tension is applied to an optical fiber that had been scored at the intended cleave location, wherein the axial tension is applied in a time-varying manner to maintain the stress intensity factor for crack on the fiber within an acceptable level to produce a stable crack growth at a reasonable rate to cleave the fiber without requiring polishing of the end surface. Careful control of the applied tension force with time acts to control the velocity of the propagating crack by maintaining substantially constant stress intensity factor. The applied axial tension force is reduced with time and / or crack growth (as crack propagates). As a result, the strain energy in the fiber material is released by formation of a single plane with an optical quality surface without requiring polishing. A substantially flat optical surface of enhanced optical quality is formed at the cleaved end of the optical fiber.

The invention discloses a method for estimating the stress intensity factors of surface cracks on the typical welding structure of a ship body. The method comprises the following steps: determining the surface maximum opening displacement of crakes according to a certain measuring method; estimating stress intensity factor values in the depth directions of cracks on a plate-plate welding member and a pipe joint structure. By adopting the method for calculating the stress intensity factor of a welding member provided by the invention, the defect that the tip stress intensity factors of cracks cannot be grasped at any time is overcome, a novel thought is provided for the measurement of stress intensity factor values, a stress intensity factor measuring method at a laboratory stage is closer to practical engineering, and a foundation is laid for the grasp of the tip stress intensity factors of cracks containing crake damage practical engineering structures.

Using information about the position, orientation, and shape of a crack appeared in a judged material and information about the structure of the judged material as parameters, the stress intensity factor KI of the crack is found. Based on the stress intensity factor KI, hydrogen embrittlement cracking of the judged material is judged. The crack growth rate and possibility of brittle fracture can be judged by comparing the stress intensity factor KI with the critical stress intensity factor KIH for crack initiation or the critical stress intensity factor KIC-H for brittle fracture about the temper embrittled steel which absorbs approximately 2.0 ppm hydrogen.

A deblocking apparatus is provided. The deblocking apparatus includes a filter, a blocking detection module and a blending unit. The filter receives a target pixel of a pixel matrix to generate a filtered target pixel. The blocking detection module generates a deblocking intensity factor according to the pixel matrix. The blending unit receives the target pixel and the filtered target pixel, and dynamically blends the target pixel and the filtered target pixel to output an output pixel according to the deblocking intensity factor.

A method is described for determining when a ceramic component on a platform should be replaced. The method includes determining the parameters vo, Kc, n, and ψr for the component, where vo and n are empirically determined parameters, Kc is a critical stress intensity factor, ψr is a geometry factor for the material in the form of the component, determining a relationship of between platform operational parameters to the generation of stress at the surface of interest of the component, determining an initial crack size of a crack within the component at installation, tracking operational parameters of the platform throughout a course of usage of the component, calculating the corresponding stress at the crack location due to the tracked operational parameters, and calculating a numerical solution that illustrates a crack growth rate velocity and tracks a size of the crack over time.

The invention provides a weld joint fatigue life prediction method, which comprises the following steps of obtaining node force and moment of a weld joint unit node through analysis by finite element software; then, according to the identical power application principle, obtaining the corresponding linear force and moment through the calculation by the node force and the moment of the weld joint unit node; obtaining the normal structure stress and the shearing structure stress in the thickness direction of the weld joint through conversion calculation; performing correction according to the actual expansion angle of cracks in the thickness direction; obtaining a corresponding equivalent stress intensity factor through the calculation on the corrected normal structure stress and shearing structure stress, and thus obtaining an average equivalent stress intensity factor on the practical crack expansion path; and using the average equivalent stress intensity factor as an evaluation parameter of the weld joint fatigue service. The weld joint fatigue life prediction method has the beneficial effects that the solution of a large-scale matrix equation is not needed, so that the calculation efficiency is greatly improved; and the method has the advantages of high calculation efficiency and high prediction precision.

The invention discloses a method for predicting upper and lower bounds of bounded uncertain plane crack stress intensity factors based on a fractal theory. According to a geometric model including a crack structure, the geometric model is divided into a conventional region and a fractal region of crack tips by using an artificial boundary to establish a bounded uncertain structural static force response solution model in the conventional region; a William's general solution is used as an interpolation function to establish a bounded uncertain structural static force response solution model in the fractal region; then, assembly is performed to obtain a whole bounded uncertain structural static force response solution model including a crack structure, the upper and lower bounds of bounded uncertain generalized coordinates are calculated by adopting a first-order Taylor expansion based interval analysis method, and further the upper and lower bounds of the bounded uncertain plane crack stress intensity factors are calculated. The upper and lower bounds of the bounded uncertain plane crack stress intensity factors are calculated are accurately and efficiently obtained by adopting the method, and objective and effective data is provided for reliability evaluation and design of structures.

A method for determining when a ceramic component on a platform should be replaced. The method includes determining parameters for the ceramic component, the parameters include empirically determined a critical stress intensity factor, and a geometry factor for the ceramic component. The method also includes determining a relationship between platform operational parameters to the generation of stress at the surface of interest of the ceramic component, determining an initial crack size of a crack within the ceramic component at installation, tracking operational parameters of the platform throughout a course of usage of the ceramic component, calculating the corresponding stress at the crack location due to the tracked operational parameters, and calculating a numerical solution that illustrates a crack growth rate velocity and tracks a size of the crack over time. The ceramic component is replaced based on the crack growth rate velocity and the size of the crack.

The invention discloses a testing method for dynamic crack arrest toughness of an I-type crack under a middle-low speed impact load, and belongs to the technical field of rock and concrete engineering. A test piece is a V-shaped side open single crack half-bordered test piece designed by an inventor. The test piece has a V-shaped bottom boundary, and generates an oblique-upward compression wave under an impact load, and the horizontal component of the compression wave has a compression effect on an expansion crack, thereby further preventing cracking of the expansion crack. The testing methodadopts a middle-low speed drop hammer impact test device, finite element difference software AUTODYN is used for simulation calculation, and results are basically consistent with test results. An obtained load stress time history curve is inputted into finite element program ABAQUS, and a time-history curve of a dynamic stress intensity factor of the I-type crack is obtained. Finally, the dynamiccrack arrest toughness of a material is determined by the crack arrest time of the crack. The testing method for the dynamic crack arrest toughness of the pure I-type crack under the middle-low speedimpact load has the advantages of simple test piece configuration, easy processing, simple and clear test procedure and convenient operation, and is suitable for the research of crack dynamic expansion behaviors and dynamic fracture toughness tests.

The invention discloses a wave type dynamic data reconstruction method based on a singular boundary method. A wave equation time elementary solution is directly used as a kernel function, a source point intensity factor is used for replacing a source point singular item, no numerical value integrals, no singular integrals and no mesh generation are related, the wave equation time elementary solution is directly used as the kernel function, no complex mathematical manipulation exists, and the simple and efficient characters meet the feature requirements of wave type dynamic data reconstruction for quickness, stability and precision of the data reconstruction technology. Experiment comparisons show that when the technology is used for processing the wave type dynamic data reconstruction problem, under the condition of obtaining the similar precision, generally, only about 10% of time taken by a traditional linear boundary element algorithm is consumed, and the method has the advantages that the precision is high, calculation is quick, mathematics is simple, and the procedure is simple and convenient to conduct and can be applied to the engineering technical fields such as sound wave noise reduction, sea wave energy dissipation, earthquake prediction and other wave type data reconstruction and image processing.

The invention discloses a stress corrosion test method and a stress corrosion test device for a metal sheet pre-cracked sample. The method comprises the following steps of: fixing one end of the sample on a bearing wall, clamping the other end of the sample by using an upper clamping plate and a lower clamping plate and fixing; clamping a test section of the sample by using a corrosion environment test box; pre-estimating the initially applied stress field intensity factor according to the threshold stress field intensity factor of crack propagation of similar metal materials, wherein the pre-estimated value is greater than the threshold stress field intensity factor of the crack propagation of the metal materials; loading stress to the metal sheet sample, measuring the crack length of the sheet sample to obtain a crack stress field intensity factor, and stopping loading the stress when the crack stress field intensity factor is equal to the pre-estimated value; filling a corrosion medium in the corrosion environment test box; measuring the length of a crack at the tip of the pre-cracked sample at intervals of certain time; and measuring the crack length and the loaded stress after the crack stress field intensity factor is stabilized to obtain the threshold stress field intensity factor of stress corrosion crack propagation. The method is convenient to operate and high in measuring accuracy.

The invention discloses an analytic method of irregular building seismic response considering an SSI (soil-structure interaction) general plane, comprising the operating steps of: firstly, representing mass eccentricity of each layer of a structure by using a polar coordinate and constructing a mass eccentricity structure dynamic equation under a bi-directional seismic action; secondly, representing SSI with five-DOF (degree of freedom) impedance function; thirdly, selecting a structural model, determining model parameters of soil and structure and constructing a general dynamic equation considering SSI general mass eccentricity structure; and fourthly, performing translation-torsion coupling response analysis to the general mass eccentricity structure in a frequency domain based on unitization of an intensity factor of an earthquake spectra. According to the method, influences of coaxial mass eccentricity and non-coaxial mass eccentricity to translation-torsion response of the structure in the case of general mass eccentricity are respectively analyzed, and an arithmetic mean square root of plane central displacement and acceleration of each layer of the structure is calculated and obtained. The method is characterized in that the polar coordinate is employed to represent the non-coaxial eccentricity of the structure. The method has the advantages that the eccentric position of the structure can be flexibly set; and the influence of the non-coaxial eccentricity to the seismic response of the structure is given.

The invention discloses an information hiding method based on the combination of image normalization and principal component analysis (PCA). The information hiding method belongs to the technical area of a computer image processing and information security. Based on the theory of image normalization and invariant centroid, the information hiding method has a good resistance to the geometric attack. Before implanting the hidden information, the chaotic technology is utilized to carry out the encryption processing on the hidden images so that the confidentiality and security of the hidden information are effectively improved. According to the features of the visual system---illuminance masking and texture masking, a perceptual masking template is designed to determine the intensity factor embedded by each sub-block hidden information and then the hidden information is embedded into multiple subspaces of the images so that the information embedding capacity of the cover images can be effectively improved.

The invention belongs to a deep sea engineering technology and particularly relates to a spherical shell surface three-dimensional crack propagation fatigue life calculation method. The method comprises the following steps of establishing a complete spherical pressure-resistant shell initial geometric model; endowing the spherical shell model with material parameters and section attributes, dividing grids, and setting boundary and load conditions; establishing an initial crack model; endowing material parameters to the crack model, defining section attributes, dividing grids and determining the positions of the grids; importing the two models to generate a complete spherical shell finite element numerical model locally containing surface crack defects; solving an initial crack leading edgestress intensity factor value by adopting an M integral method; reading and running a fatigue life calculation model program; setting automatic crack propagation parameters; and obtaining a sphericalshell surface three-dimensional crack propagation fatigue life numerical value based on a self-defined propagation program. According to the method, finite element analysis software and fracture mechanics analysis software are combined to calculate the three-dimensional crack propagation fatigue life of the surface of the spherical shell, and applicability of the method is verified through numerical simulation.

In a method of determining a fatigue crack lifetime of a low-alloy steel material coming in contact with high-pressure hydrogen in a high-pressure hydrogen environment, estimate a fatigue crack acceleration starting point KmaxT of the low-alloy steel material using a crack-growth threshold stress intensity factor KIH-R obtained through a rising load test on the low-alloy steel material in a high-pressure hydrogen environment. The high-pressure hydrogen environment of the rising load test is a high-pressure hydrogen environment which has the same pressure and atmosphere as in the high-pressure hydrogen environment in which KmaxT is estimated and in which the test temperature tolerance between both environments is ±5° C.

The invention discloses a model for simulating overload hysteresis effect in fatigue crack propagation. The model is executed in the following steps of: judging a crack propagation state through the position of a crack tip, and deducing an expression of a hysteresis-free stress intensity factor by adoption of a piecewise function form according to a hysteresis state judgement condition; considering an overload cutoff ratio of a material as a function of a fatigue load stress ratio; and when a weakening function, for hysteresis effect generated by tensile overload, of compressive load is considered, importing a weakening factor to correct a residual stress intensity factor in an overload influence area. Experiments verify that the relative differences between a life value calculated by a model and experiment values are within + / -5%.

The invention discloses an explosion loading electric measurement-dynamic photoelasticity hybrid experiment system and method. The system comprises a laser light source (1), a beam expanding mirror (2), a convex lens A (3), a polaroid A (4), a quarter-wave plate A (5), a quarter-wave plate B (6), a polaroid B (7), a convex lens B (8), a high-speed camera (9), a computer (10), an experiment loadingplatform(11), a delay and controller (12), a multi-channel pulse igniter (13), a super-dynamic strain gauge (14), a data acquisition instrument (15), a test piece (33), explosive cartridges(34), a bridge box, a signal line, a shield line and a strain gauge. The system combines the advantages of two experiment methods, can measure various mechanical parameters, such as moving crack spreading speed, crack tip region strain, dynamic stress intensity factor and dynamic fracture toughness, and can also obtain information of test piece total stress field dynamic photoelastic fringes and focal speckle series images and the like; and by comprehensively comparing and analyzing the data obtained by the two methods simultaneously, a propagation mechanism of explosion-induced moving cracks and interaction of the moving cracks during the propagation process can be studied more accurately, scientifically and quantitatively.