109 results about "Structure Failures" patented technology

A method for predicting a blade structure failure within a coupled blade structure including a plurality of blades supported for rotation on a rotor and a shroud structure coupling the blades. The method includes the steps of determining displacements of a plurality of predetermined circumferential locations on the shroud structure during rotation of the blade row, where the displacements are provided as a function of time relative to the periodic rotation of the shroud structure for time intervals that are integer multiples of rotor rotation. A signal characteristic related to vibrational mode and a nodal diameter of the shroud structure is derived based on the displacements of the circumferential locations on the shroud structure.

The invention discloses an optimization design method of a composite material wing panel. The optimization design method comprises the following steps: (1) carrying out finite element simulation modeling on the main structure of a wing; (2) applying a load and boundary condition to a finite element wing box section model; (3) calculating an integral wing box finite element model, and extracting the internal load of a structure; (4) designing a layup library, and calculating the laminate attributes of all layers in the layup library to obtain a rigidity matrix and an equivalent elastic modulus; (5) aiming at the calculation requirements of different structural unit initial dimensions and different failure modes of a skin stringer to carry out secondary distribution calculation on the load; (6) calculating the design allowable value of each structure failure mode of the panel; (7) calculating the safety margin of each BAY of a panel structure; (8) setting a maximum slope rate of panel layup arrangement and an adjacent area laminate throwing layer, setting the Poisson ratio difference value coefficient and the stiffness ratio of the stringer and the skin, and regulating the layer if a design range is not met; (9) if the design does not meet weight requirements, requiring to circularly carrying out the steps (1) to (8) to regulate the lay and the dimension until structure weight requirements are met. According to the method, the design and optimization working efficiency of the integral panel of the composite material is improved, and research and development cost is saved.

The fixed cutter drill bit disclosed utilizes a unique piloting section and reaming section carefully designed to impart several specific operational advantages. In the piloting section, cutting structures have been arranged so as to create offsetting cutting forces that result in a net zero imbalance during operation. Furthermore, the piloting section utilizes carefully placed shock studs which aid in protecting the primary cutting structure. In addition, the location of the fluid supply nozzles on the body of the reamer section serves to indicate the occurrence of a catastrophic cutting structure failure below the pilot gage.

A system and method for structural health monitoring (SHM) of a physical structure, such as an aircraft component. The system may comprise a central data acquisition module and a plurality of wireless, self-contained sensor wafers bonded to a surface of the physical structure. The central data acquisition module and the sensor wafers may be communicably coupled in a hierarchical order. If any of the sensor wafers detects a structural fault, it may be stored in a memory of the central data acquisition module for retrieval by maintenance personnel. If one or more of the sensor wafers malfunctions, the central data acquisition module may reconfigure the hierarchical order in which the sensor wafers communicate to exclude the malfunctioning sensor wafer or wafers. The sensor wafers may include a sensor, circuitry, a wireless antenna, and a power source.

A detection and alarm system comprises a piezoelectric film sensor and associated circuitry. The sensor detects acoustic emission signals from metallic objects under stress upon which it is affixed. The associated circuitry receives electronic signals from the sensor, creates and evaluates a sensor output value including rate ratio and frequency content of such signals within preset time limits. This data allows the detection of impending failure, an alarm condition, of the metallic object by identifying significant changes in the rate of emission of such sensor signals. An alarm condition may then trigger an alarm signal to warn of such impending failure.

A system for quickly and reliably detecting a failed structure includes a signal source, a cable attached to the structure, an anti-slip cable anchor, a signal detector, and user indicator. When the structure fails, the cable attached to the structure is also broken. The user indicator is operable to display the status of the cable. The cable breaks due to exceeding the elastic modulus of the cable, caused by elongation of the distance between two fixed points caused by the failing structure. Electric power must be provided to each signal source, signal detector and user indicator.

The invention relates to a composite material structure failure analysis method based on mesomechanics degradation model, and three dimensional basic material performances of the composite material are input parameters, and material performances of the composite material after damage are obtained by mesomechanics calculating method, and seven common failure modes are taken into consideration, which comprise: fiber stretch, fiber compression, matrix stretch, matrix compression, fiber-matrix shearing, layered stretch and layered compression, and finally the material degradation mode in composite material progressive damage analysis is obtained for carrying out failure analysis of the composite material structure; the invention not only can accurately predict structure failure, but also can predict failure mode and position of the structure. According to the composite material structure failure analysis method based on mesomechanics degradation model provided by the invention, the material degradation model is obtained by theory analysis, thereby connecting macroscopic failure and microscomic mechanism of composite material, and compared to the present material degradation model based on experience or test, time and test cost are substantially reduced.

The invention discloses a method for predicting the service life of a reinforced concrete bridge under the conditions of seasonal corrosion and fatigue coupling. The method comprises the steps: dividing the service life of the reinforced concrete bridge into three stages: corrosion initiation-pure fatigue crack development stage, a rust pit and fatigue crack competing development stage and a structure failure stage; establishing an initial reinforcing steel bar corrosion model and a rust pit growth model based on the Fick second diffusion law and the consideration of the influence of concreterust expansion cracking damage; testing and simulating a reinforcing steel bar crack propagation rule under the influence of a four-season environment, and determining fatigue crack growth characterization parameters; constructing a stress intensity factor model considering the influence of stress concentration, and proposing a steel bar corrosion fatigue crack growth analysis method correspondingto a four-season environment; enabling the structural failure criterion to be clear, combining with the vehicle load observation information, performing the systematic consideration of the competitive coupling relation between rust pit growth and fatigue crack growth, judging a failure mode in real time, and achieving the prediction of the service life of the bridge. The method is novel and reasonable, and can provide technical support for safety assessment of the concrete bridge.

The invention discloses a whole-course analysis method for the impact damage and the residual intensity of a sutured composite material. The method comprises the following steps that: (1) carrying outtransient stress analysis on the sutured composite material under an impact load; (2) determining the impact damage criterion of the sutured composite material; (3) determining the mechanical property degeneration method of the impact damage of the sutured composite material; (4) carrying out the statics analysis of the sutured composite material; (5) determining the residual intensity damage criterion of the sutured composite material; (6) determining the material performance degeneration method of the sutured composite material; and (7) determining the structure failure criterion of the sutured composite material. The invention provides the whole-course analysis method for the impact damage and the residual intensity of the sutured composite material, practical situations, including thepractical damage type, the damage degree and the like, of the impacted composite material structure are considered, and in addition, accuracy fore predicting the residual intensity can be improved without observing the impact damage. The method disclosed by the invention is high in consistency, good in extensibility, high in prediction accuracy and has a considerable engineering application prospect.

A method of designing a cable dome structure based on a cable dome bearing whole process analysis. The cable dome bearing whole process has three stages comprising a ridge cable relaxation, a ring cable yield and a structure failure.

The invention discloses an aircraft structure checking task planning method based on risk and cost analysis. The checking mode comprises traditional structure non-destructive detection and structure health monitoring. The method comprises the steps that based on the principle of probability damage tolerance analysis, the calculation model of single flight failure probability of an aircraft structure element is established; based on the model, a cumulative risk calculation model of a fleet in a certain period of time is established; in the existing aircraft structure plan maintenance mode, the maintenance cost calculation model of the aircraft structure element in the service life cycle is established, wherein the calculation model comprises structure checking cost, repair cost and false alarm cost; the single flight failure risk and fleet cumulative risk are used as the risk assessment indicators of a structure maintenance policy; under the premise that a safety risk requirement is satisfied, the optimal structure checking policy can be determined according to the analysis of the structure whole service life cycle maintenance cost. The optimal structure checking interval and repair threshold can be determined based on the tradeoff between the structure failure risk and the service life cycle maintenance cost.

A structural health monitoring circuit apparatus and method are based on electrical impedance variations of a piezoelectric patch, which is attached to a structure to be monitored. The circuit compares a known good sweep of frequency-impedance pairs with a contemporaneous sweep to generate an alarm when an error bound is exceeded. The impedance of the piezoelectric patch is determined though adjustment of a variable reactance in a bridge configuration. By suitable design of the bridge elements, the electrical impedance of the piezoelectric patch may be directly measured. A microprocessor controlled version of this device consumes less than 2 W of power, which may be further reduced by further large scale integration or reduction to a state machine on a programmable gate array. Ultimately, this device may give personnel warnings to aircraft, automobiles, bridges, elevated roads, buildings, or home structural failures.

A system for detecting the onset of structural failure in a structural element subject to a mechanical load comprises a metering array, a signal processor, and an output processor. The metering array measures physical quantities associated with the structural element. The signal processor transforms the measured physical quantities into a series of sample mode spectra, and the output processor generates output as a function of the series of sample mode spectra. Methods are also disclosed for detecting the onset of failure in a structural element subject to a mechanical load, for structural testing, and for structural health monitoring.

The invention discloses a reliability robust design method for a multi-failure mode of a superdeep well lifting container. The method includes the following steps of (1) determining structural parameters, material properties and dynamic load randomness of the lifting container, and adopting an experiment design method for figuring out a random response to a structure failure under random parameters; (2) according to a failure criterion of the lifting container, creating a reliability performance function under each failure mode; (3) taking the probability correlation among the failure modes into account, and adopting a copula theory for creating a combined probability model of correlative failures; (4) creating a system reliability model correlative with failures of the lifting container under the combination of the combined probability model; (5) creating a sensitivity model of the system reliability of the lifting container for each random parameter; (6) under the combination of an optimization design model, creating a lifting container reliability robust optimization design model with the combined failure probability and parameter sensitivity as constrains.

The invention relates to a progressive damage model-based full-SiC composite multi-nail connection structure failure analysis method. The method comprises the following steps of: (1) establishing a bilinear constitutive model of materials on the basis of C / SiC composite material mechanical property test; (2) establishing a composite material structure three-dimensional finite element model according to a C / SiC composite material multi-nail connection structure geometric parameter; (3) carrying out stress analysis on the basis of the composite material structure three-dimensional finite elementmodel; (4) predicting failure states of the composite materials by applying a failure criterion suitable for C / SiC composite materials; (5) carrying out material rigidity degeneration on the failurematerials according to a degeneration model; and (6) judging whether damages in the composite materials cause structure damage or not, and if the judging result is negative, continuously carrying outloading until the materials fail. The method is suitable for engineering application, and is capable of effectively analyzing and predicting the failure of C / SiC composite material multi-nail connection structures, remarkably reducing the test cost and providing references for engineering practices.

A building anchor system includes a pair of elongate anchor rods (1,2), an anchor rod coupling joint (3) for joining the anchor rods end-on-end, the anchor rod coupling joint comprising or including a sleeve (4, 5, 6&7) for connection to an end of one of the anchor rods (1) a slideable arm (8) receivable in the sleeve for connection to an end of the other anchor rod (2) a closed slot within the arm or sleeve for slideably receiving the free end of a stop member (13) by which movement of the anchor rods along their major axis is possible to the extent allowed by the length of the slot, and frictional adjustment means (6,7) acting between the arm and the sleeve by which they may be joined and by which the force required to move them with respect to each other can be selectively varied. The invention also extends of a method of preventing or inhibiting catastrophic structural failure of a building by installing one or more anchor systems of the type described.

The invention is a measuring method for media arcing reliability relating to time. The method uses high temperature constant voltage stress to carry on TDDB reliability measurement to integrated circuit grid oxidizing and media layer measuring structure. The measuring method is carried on according to following steps: constructs the measuring system, at first the measuring structures are connected in parallel, then the sample is put into the high temperature box, and connected to external resistance in series, finally, the external resistance is connected to the measuring desk; puts high temperature and constant voltage stress to the measuring structure; measures the voltage on external resistance, judges if there has measuring structure failure; when some measuring structure is failure, the sample is taken out form the high temperature box, and they are placed on the measuring desk to measure each measuring structure failure or not; records the failure time of each sample according to the failure criterion until the experiment is finished.

An intake manifold is provided that comprises a plurality of intake manifold runners 12, and each intake manifold runner comprises at least one elongated rib 15 and at least one elongated blister 14. The elongated rib 15 and the at least one elongated blister 14 operate together to control structural failure of the intake manifold in an impact event. Specifically, the elongated rib acts to receive and concentrate load while the at least one elongated blister provides an area of intentional failure, thus restricting the failure to a focused area on the intake manifold.

The invention relates to a reservoir group outlet structure failure assessment method based on the Bayesian network. The reservoir group outlet structure failure assessment method includes the steps of establishing a Bayesian network topological structure, determining respective probability, calculating spillway system failure probability, and calculating the integral failure probability. The Bayesian network for failure probability determination is combined with a conventional event tree for determining stepped reservoir group spillway facility failure, and calculating the probability of downstream control step failure caused by upstream dam bursting flood is added as needed to form a complete Bayesian spillway facility failure assessment network. A reservoir group outlet structure failure is a complex multivariable system, and the assessment system can be used to analyze common cause failure and conduct backward inference. The assessment system can scientifically determine the value of information and determine whether new information needs to be acquired, so that the outlet structure failure analysis is gradually improved and becomes more scientific.

The invention discloses a simultaneous monitoring method for welded steel truss structure fatigue failure process. The method comprises the following steps: step 1, damageable parts under structural material levels are confirmed through building a finite element model of a welded steel structure and conducting static analysis; step 2, feature response parameters of the damageable parts under each structural material level are confirmed and a corresponding testing scheme is set; step 3, a sensor location project and positions under each structural material level are confirmed, and measures of installing, debugging, noise reduction arrangement and disturbance releasing are finished; and step 4, fatigue loading is exerted to a structure, and welded steel truss materials, components, the failure process under the structural levels, the feature response and the evolution process with a fatigue cycle are monitored simultaneously through a plurality of testing technical means. Compared with a traditional and common structure failure assessment method, the simultaneous monitoring method is capable of reflecting the whole failure process of the structure and the feature response of each level comprehensively, and is beneficial for understanding and researching the failure process and failure mechanism of the structure.

The invention discloses a structural hierarchy type finite element simulation analysis method under complex load conditions; the method comprises the following steps: S1, building a cabin body main structure full-scale finite element model as the first level master model; S2, aiming at a main structure failure mode and carrying out finite element calculation, wherein a calculation method contains structural stability analysis and static force intensity analysis; S3, carrying out danger assessment for a local instability position having a main structure instability load lower than 1.5 times of the designed load, and selecting a refinement analysis area; S4, carrying out danger assessment for a stress danger area having a main structure intensity residue coefficient lower than 1.3, and selecting a refinement analysis area; S5, building a finite element 1st level sub model according to the refinement analysis areas in S3 and S4; S6, building a finite element connecting model between the sub model and the master model; S7, submitting finite element calculation for the sum model having a transition model; S8, repeating S1-S7 until the model is exquisite enough.

The invention discloses a structure failure mode diagnosing method, which comprises the following steps: performing a low-magnitude vibration test and a high-magnitude vibration test on a vibration table for the first time; then performing the low-magnitude vibration test on the vibration table for the second time; respectively comparing sound spectrums of the first time low-magnitude vibration test and the second time low-magnitude vibration test, sound spectrums of the first time low-magnitude vibration test and the high-magnitude vibration, and sound spectrums of the high-magnitude test and the first time low-magnitude vibration test; according to the comparison results, preliminarily judging whether the structure of a spacecraft goes out of order, and further performing the characteristic analysis for the sound spectrum data and comparing with cases in a failure mode database; and finally, diagnosing the failure mode of the spacecraft. The structure failure model diagnosing method disclosed by the invention realizes structure failure mode diagnosis of the spacecraft during the vibration tests, and improves the technology level of the vibration tests.

A dolly is disclosed for a semi-trailer that has a compromised structure due to a load shift or an accident. The semi-trailer dolly can also be used to extricate a semi-trailer stuck under a bridge without damaging the wheels or tires of the semi-trailer. In accordance with an important aspect of the present invention, the dolly is configured to provide transverse support of a semi-trailer in an area between the rear axles of the semi-trailer and the front of the semi-trailer. More particularly, the dolly is configured to provide a uniform transverse lifting force to a semi-trailer in an area between the rear axles of a semi-trailer and the front of a semi-trailer where a structural failure of the semi-trailer is likely to occur. The semi-trailer dolly includes a removable saddle and a wheeled cart that includes lifting mechanisms. The removable saddle can be removed from the wheeled cart and positioned under the trailer. Tow truck boom winches connected to opposite sides of the saddle can then be used to lift the saddle and thus the trailer to enable the wheeled cart to be put in position under the saddle. Once the wheeled cart is positioned under the saddle, adjustable lifting mechanisms on the wheeled cart enable the height of the saddle to be varied. The lifting mechanisms are then used to level the floor of the semi-trailer and provide support for the floor of the semi-trailer 24 so that the breached semi-trailer can be transported by a tractor. The wheeled cart may include self steering wheels which facilitate transport of the breached semi-trailer by a tractor.

The invention provides an intelligent electromechanical impedance sensor used for structure health status monitoring, belonging to the structure health monitoring field, relating to a sensor monitoring a structure health status based on an electromechanical impedance method. The sensor is composed of a power supply management module, a microprocessor module, a wireless communication module, an electromechanical impedance sensing module, a multi-channel change over switch and a piezoelectric patch connection terminal. The sensor can detect mechanical impedance change caused by structure health status change and convert the mechanical impedance change into electrical impedance which is easy to measure. The sensor has the advantages of small volume, wireless communication and convenience of installation on an on-site structure. Through measurement of electromechanical impedance which is coupled of the mechanical impedance and the electrical impedance, necessary information is provided for structure health status monitoring and structure failure prediction based on the electromechanical impedance method.

The embodiment of the invention provides an OLED display panel and a preparation method thereof, a package portion failure determination method, and a display device, and relates to the field of display technology. The problem is solved that occurrence of package structure failure cannot be determined in the manufacturing process of an OLED display in the prior art. The OLED display panel comprises an OLED light-emitting component and a package portion which are located on the first substrate, the OLED light-emitting component is located at a luminous zone of the OLED display panel, and the OLED light-emitting component is coated with the package portion; the OLED display panel further comprises a water vapor detection portion located on the first substrate, the water vapor detection device is arranged between an edge of the luminous zone and an edge of an inner side of the package portion, the water vapor detection portion comprises a hydrophobic film layer and a hydrophilic film layer arranged in a stacking mode, after the hydrophilic film layer absorbs water, and wrinkles are generated at an interface of the hydrophobic film layer and the hydrophilic film layer.