355 results about "Structural mechanics" patented technology

The invention provides a finite element analysis method for the temperature action on a prestressed reinforced concrete continuous rigid frame bridge. The finite element analysis method is used for analyzing and calculating the stress and displacement distribution in the construction and finished bridge stage under different temperature gradient models, and provides references for designing and optimizing the prestressed reinforced concrete continuous rigid frame bridge. Through calculational analysis based on finite elements and the structural mechanics, the forward-calculation method is adopted for structural distortion and stress analysis according to the actual construction loading sequence of the bridge structure, so that the complex mechanics problem of box girder temperature self-stress, temperature secondary internal force in a prestressed reinforced concrete statically indeterminate structure and secondary stress of the temperature secondary internal force is solved easily, conveniently and efficiently, and the finite element analysis method has important practical value.

The invention discloses a method for analyzing fluid dynamics and structural mechanics of wind generator blades, which comprises the following steps: combining CFD and CAE methods, determining each parameter of an impeller model by adopting the momentum blade element theory, designing an entity model of the blade, establishing a three-dimensional model of a windmill blade, a hub and a peripheral wind site based on a Gambit software platform, meshing the model by adopting a partial structuring method, setting a proper boundary condition, calculating the performance of a finite element based on a Fluent software platform, extracting the blade torsion and calculating the blade power and the blade efficiency, establishing a blade structural model based on an ansys software platform and meshing the blade structural model, applying load and restraint condition to the blade structural model, analyzing the mode of the blade structure, performing equal torque treatment for pressure distribution acquired by the Fluent software platform, applying pressure surface load to the ansys software platform, calculating the structural mechanics characteristics of the wind generator blades, and extracting blade deformation and stress distribution characteristics.

The invention relates to an aeroelastic stability fluid-structure interaction prediction method of turbo-machine changed interblade phase angles, which predicts the aeroelastic stability of a turbo-machine through the modal pneumatic damping ratio of different interblade phase angles by adopting an energy method. The method adopts the modal analysis containing prestress on established single-sector finite element models, realizes the vibration displacement transfer on the fluid-structure interaction interface through a data transfer method, adopts the dynamic mesh technology for obtaining mesh files taking the interblade phase angles into consideration, is used for unsteady computation fluid mechanic analysis of Junction Box modules in CFX, further obtains the modal pneumatic damping ratio of each interblade phase angle, and is used for predicting the aeroelastic stability. The method based on the fluid-structure interaction fully utilizes the cutting edge technology of the computational structural mechanics and the computation fluid mechanics, ensures the computation precision in each sub system, and improves the computation efficiency through the division of a fixed region and a movable region. The invention has good practical value and wide application prospects in the technical field of turbo-machine simulation.

The present invention relates to a method for measuring steel structure bridge life by utilizing fracture mechanics. It includes an ultrasonic inspection process of steel structure bridge member, and utilizes actually-measured data to correct analog data so as to raise accuracy of structural calculation. Said measurement method includes seven steps: structural mechanics modeling, mechanical model correction, traffic load modeling, traffic load correction, ultrasonic inspection, member fracture mechanics model modeling and bridge structure technical state judgment.

The invention discloses a method for determining the elastic modulus and flexural rigidity of a reinforced concrete beam with a crack, relating to a tension Young's elastic modulus of a reinforced concrete beam with a crack in working, a measuring method of the tension Young's elastic modulus and a determining method of the flexural rigidity. A reinforced concrete beam with a rectangular cross section is manufactured as a test piece to be detected, and the length, width and height of the reinforced concrete beam are shown in the specification; the two ends of the test piece are supported by hinged supports; loads are intensively and symmetrically applied on the positions some distance away from at two points of the supports; the deflection value of the middle part of the test piece span and the strain value of the lowest end of the middle part of the test piece span are detected; a sum computed expression is deduced according to the analytic solution which is given by at theory of different tension-compression modulus under the condition that loading is performed on two points of a simple beam with a rectangular section intensively and symmetrically; and the sum can be accurately calculated by the load value, the defection value and the strain value. The sum determined by the invention contains a crack factor of the reinforced concrete beam within the given load range, and can be used for structural mechanic accurate analysis.

The invention relates to the field of experiment-teaching equipment of 'Structural Mechanics' in colleges and universities; the products of the invention are mainly applied to the experiment teaching of rigid frames, trusses and combined structures in beam structures; the invention is characterized in that: a node plate adopts a split structure, the trusses are arranged between two node plates, a weak connection with a particular shape is arranged on an articulated node plate, and a relatively ideal articulating node can be obtained by utilizing the mechanical property that the weak connection can transmit a relatively large axial force but only can transmit a very small bending moment. By choosing a reasonable connecting way between a rigid node plate and the trusses, the influences on the testing result made by the size effect of the rigid node plate is reduced and a relatively ideal rigid node can be obtained. The node property and the support property can be transferred conveniently. All the tests can realize electrical testing by using the computer data collecting and analyzing. The application of the computer data collecting and analyzing system not only facilitate data collection, but also enriches the experiment-teaching means, which is beneficial for carrying out open experiment-teaching.

The invention relates to load equipment of a tunnel lining structural mechanics property simulation test device. According to the arrangement, a tunnel lining is arranged on a displacement limitation face plate, a load mechanism is radially arranged on the outer surface of the tunnel lining, and the other end of the load mechanism is fixed on an outer retainer plate; the load mechanism is composed of cushion plates, springs and hydraulic jacks, the cushions are arranged along the outer wall of the tunnel lining, the springs are radially arranged on the outer walls of the cushion plates and allow the cushion plates to be connected with the hydraulic jacks, the hydraulic jacks are normally arranged on the outer surface of the tunnel lining, and cylinders of the hydraulic jacks are fixed on the inner wall of the outer retainer plate; under variable work conditions such as different lining types and thickness and different stress conditions, mechanics property simulation is effectively achieved; during the loading, the numerical control hydraulic jacks are adopted to ensure strength and position of stress applied to the lining, bringing convenience to the following data analysis and research, and accordingly the tunnel lining structural mechanics property changes are effectively simulated.

The invention discloses an intelligent bridge monitoring method based on traffic flow control, which is characterized in that: the traffic flow control is introduced into bridge monitoring, a method combining monitoring and forecasting analysis of vehicle load flow, forecasting analysis of bridge structural mechanics response, real-time monitoring of bridge structural safety condition and active control of the traffic flow is adopted, and a reasonable vehicle load model is established through monitoring and forecasting analysis of the vehicle load to be on a bridge so as to perform the forecasting analysis of the bridge structural mechanics response and pre-evaluation of safety condition, and control the traffic flow according to a pre-evaluation result; the bridge safety condition is comprehensively evaluated through bridge theoretical calculation and the analysis of a real-time monitoring result, and the traffic flow is controlled according to an evaluation result; and the active control of the traffic control effectively avoids the damage caused by extra bridge load, prolongs the service life of the bridge, and can reasonably control the traffic flow in an allowed range of ensuring bridge operation safety in special conditions such as strong wind, earthquake and the like.

The invention belongs to the field of railway engineering and provides a high-speed railway plate-type ballastless track structure evaluation method based on CA mortar damage. On the basis of the theories of the comprehensive track structural mechanics, the wheeltrack system dynamics and the finite element, CA mortar damage behavior is simulated accurately through reasonable mechanical simplification by means of large finite element software such as ANSYS and ANSYS/LSDYNA, and different levels of standards of corresponding CA mortar damage maintenance and repair are generated according to the simulation result. With the method, deformation and stress of all components such as a plate-type ballastless track system steel rail, a track plate, a mortar filling layer and the like and parameters such as vibration accelerations of all the components of a vehicle and the track system can be obtained, and thus influences of the CA mortar damage to the stress on the track structure and driving safety and comfort can be effectively evaluated, and the method has important practical significance in maintenance and repair management of plate-type ballastless tracks.

The invention provides a self-starting funneling wind concentration wind power generation system, relates to important comprehensive core technologies such as wind concentration structure, wind tunnel characteristics, fluid transition, the funneling effect, infrastructure material, aerodynamics, structural mechanics, turbine effect, electric energy conversion and belongs to the technical field of funneling wind concentration wind power generation systems. The system consists of a bowler hat type wind concentration device assembly, a strong storm avoidance deflection closing device assembly, a multi-level gradual-expansion air turbine generator device assembly, a funneling type working medium speeder assembly, a reinforced rib anti-seismic component device assembly, an intelligent control man-machine integrated assembly and accessories. The assembled bowler hat type wind concentration device assembly, the strong storm avoidance deflection closing device assembly, the multi-level gradual-expansion air turbine generator device assembly, the funneling type working medium speeder assembly and the reinforced rib anti-seismic component device assembly are sequentially arranged in place, and an intelligent control system and an accessory part are respectively positioned and arranged in place, thereby forming a set of complete self-starting funneling wind concentration wind power generation system.

The invention discloses an experimental device suitable for structural mechanics displacement method teaching presentation and a structural mechanics displacement method presentation method utilizing the device. The device comprises a base 1, a force application valve 2, a rod piece structure 3, a base support 4, an angular point support 5, a directional support 6, a fixed pulley support 7, a dial indicator A10 and a dial indicator B11. The force application valve is mounted on the side face of the base 1, and the rod piece structure 3, the base support 4, the angular point support 5, the directional support 6, the fixed pulley support 7, the dial indicator A10 and the dial indicator B11 are in detachable fit with the base 1 for use. The device is easy to operate, is easily understood in principle, and easy to dismount when the device is combined with a traditional mechanics experimental device.

The invention discloses a track structure mechanical property evaluation method based on vibration noise frequency spectrum feature matching, wherein vibration acceleration and noise radiation, generated when a train passes by, of a track structure in normal and defected states are tested, and consequently a frequency spectrum curve feature database of the acceleration and sound pressure data corresponding to various damage defects is built. The processed to-be-detected track structure vibration and noise test data is compared through the built database, thus, track traffic track structure mechanical state assessment and identification and judging of various damage defects based on vibration noise joint test are realized, the shortcoming of failure in systematic assessment of the track structure mechanical state through single vibration or noise test data in the past is remedied, and safe and steady running of the track traffic is guaranteed.

The invention discloses a modeling method for realizing structural mechanical performance of pipe segment three-dimensional loading. The modeling method mainly includes: analyzing and remodeling geological conditions; making a stratum model; making a contraction rule pipe segment model; designing a pipe segment monitoring system; performing different loading model experiments on pipe segments; collecting and analyzing data. By adopting the method, pipe segment structural mechanical characteristic experiments on working conditions of horizontal and vertical different loading, of pipe segment rings, pipe segment axial geostress difference and pipe segment staggering and eccentric loading in different geological environments can be realized, real simulation of pipe segment loading environment is realized through stratum remodeling, pipe segment structure is processed by utilizing gypsum to realize detailed construction of the pipe segment structure, joint screwed connection is realized, annular and longitudinal strain gauges are distributed for whole-ring pipe segments to realize monitoring of internal force of the pipe segments, and technical support is provided for subsequent shield pipe segment assembling and wall posterior grouting parameter setting.

The invention relates to a joint simulation method for a vehicle-road coupled vibration system. The method comprises the following steps of S1, building a vehicle dynamics model according to a dynamics equation; S2, building a pavement dynamics model according to a structural mechanics finite element equation; and S3, loading the vehicle dynamics model in the pavement dynamics model to generate a tire-pavement contact model, and finishing dynamics analysis of the vehicle-road coupled vibration system. According to the method, joint modeling of the vehicle-road coupled vibration system is realized by adopting efficient engineering software Matlab and Ansys; and by taking Matlab as control software and performing secondary development on Ansys, joint simulation of Matlab and Ansys is realized, and dynamics analysis of the vehicle-road coupled vibration system under complex road and vehicle conditions is finished.

The invention relates to the technical field of tunnel engineering. A method for calculating the surrounding rock pressure of a shallow tunnel comprises the following steps: selecting a convergence deformation monitoring point of the surrounding rock; constructing a structural mechanics model at the monitoring point; deriving a calculation relation between the convergence deformation and the surrounding rock pressure; substituting engineering actual data and convergence monitoring data into the calculation relation to calculate the displacement on the left and right sides of the monitoring point and the convergence deformation of the monitoring points; and calculating the surrounding rock friction angle and the surrounding rock pressure. The method analyzes a relationship between the convergence deformation and the surrounding rock pressure of the sidewall surrounding rock in the construction of a double side wall tunneling method, establishes the structural mechanics model, and obtains the surrounding rock pressure from the field monitoring data by means of back calculation. Compared with a calculation method that depends on empirical parameters, the method of the invnetion is more accurate and more represents the actual surrounding rock pressure of the tunnel, and the convergence deformation data of the tunnel is easier to obtain and the calculation is convenient and accurate.

The invention discloses a calculation method for karst safety thickness of a karst tunnel. The method comprises the steps: A, simplifying the karst tunnel and a dissolved chamber into a structural mechanics model, and respectively calculating maximum shear force and maximum bending moment borne by a complete bed rock and a non-complete bed rock; B, substituting the maximum shear force and the maximum bending moment into a bending strength formula to obtain a safety thickness calculation formula based on the bending strength; C, substituting the maximum shear force and the maximum bending moment into a shear strength formula to obtain a safety thickness calculation formula based on the shear strength; and D, introducing a correction factor n, and correcting the safety thickness calculation formula based on the bending strength and the safety thickness calculation formula based on the shear strength. According to the calculation method for the karst safety thickness of the karst tunnel, a set of relatively complete theoretical calculation method is provided for calculating the safety thickness of the bed rocks of the karst tunnel, so that the safety of the karst tunnel is ensured, and the occurrence of karst geological disasters such as inrush of clay and water and the like can be effectively prevented.

The invention provides a test device and method for simulating ground access type shield tunnel excavation, and the test device comprises a model test groove, a shield segment model, a tunnel excavation device, a transmission system, an adjustable support system, a starting pedestal, a synchronous grouting system, and a monitoring quantity control system. The tunnel excavation device is composed of a steel sleeve with a cutting edge at the front end, a rotary cutting tool and a steel partition plate, and the adjustable support system comprises a counterfort type support, a steel truss base, anL-shaped rotating plate, a rotating shaft and a jack. The ground access type shield tunnel excavation process with a certain slope rate is simulated through the synergistic effect of the adjustable support system and the transmission system in combination with a simple tunnel excavation device for the first time and is closer to engineering practice, test working condition combinations of different excavation slopes and grouting amounts are set, the segment structure mechanical property, the soil body stress release rule and the stratum deformation mechanism of the ground access type shield tunnel are studied, and design and construction guiding can be realized.

The invention provides a structural mechanics experiment platform and belongs to the field of structural mechanics experiment teaching of the major of civil engineering. An upper cross beam, a lower cross beam, upright columns and tie beams form a space reflexive force loading frame through an assembling mode; an H-shaped steel beam in the upper cross beam, the lower cross beam and the web plates of the upright columns are each provided with a linear guide rail; the linear guide rails are provided with sliding dolly platforms, the sliding dolly platforms can be fixed at any positions of the linear guide rails; and an experiment model and a loading device are installed on the sliding dolly platforms. According to the invention, auxiliary devices such as a mobile short upright column, a constraint cross beam, an intermediate cross beam providing a horizontal counterforce and the like are configured, multiple constraints and multi-point multi-directional tensile compression loading on the experiment model are realized, and the quantity, the positions and the directions of constraint points and loading points and the dimensions of the experiment model are not restricted in an effective experiment space. The platform is of a space structure, the experiment space is open, the loading means are abundant, multiple groups of contrast experiments and autonomous design comprehensive experiments are carried out at the same time, and open experiment teaching is facilitated.

The invention provides a multilayer frame teaching experiment model and an experiment method thereof. The multilayer frame teaching experiment model comprises a multilayer frame structure, a static force loading device, a vibration exciter loading device, a vibration table loading device and measurement equipment. A worm gear elevator in the static force loading device realizes loading and unloading of a frame structure through a hand wheel on the worm gear elevator, and furthermore an applied load is displayed on a computer through a force sensor. The multilayer frame teaching experiment model and the experiment method can be used for a displacement method experiment, a double-freedom-system free vibration experiment, a double-freedom-system compulsive vibration experiment and a three-layer rigid frame fundamental frequency experiment according to an approximation method. The multilayer frame teaching experiment model and the experiment method have a beneficial effect of flexible and variable experiment model. A student can independently perform the experiment on the condition of different parameters. A small error between an obtained experiment result and a theoretical value which is calculated according to structural mechanics is realized. The multilayer frame teaching experiment model and the experiment method are suitable for related teaching experiments and further design development in colleges.

The invention discloses a crack damage monitoring and strain field measuring method based on an FBG (Fiber Bragg Grating) sensor array spectrum. The method comprises the following steps: 1, selectinga test specimen to be measured; 2, performing structural mechanics analysis on the test specimen to be measured; 3, sticking a sensor to the test specimen; 4, performing a loading experiment on the test specimen stuck with the FBG sensor to determine an experimental system; 5, performing analysis on a series of obtained spectra to explore the corresponding relation between the characteristic parameters of the spectra and the initial positions of cracks as well as the extension conditions of the cracks; and 6, comparing the stress strain and the distance curve obtained by the FBG sensor with finite element simulation results. By virtue of the steps, crack damage monitoring and crack tip stress field measurement are realized, the corresponding relation between crack damages and spectra is achieved, and the feasibility of the method for measuring the crack tip strain field can be verified through experiments.