20 results about "Buckling instability" patented technology

The utility model relates to the technical field of low-cycle fatigue tests, and discloses an anti-buckling tool for a low-cycle fatigue test sheet metal structure, which comprises a fixing assembly and a guide assembly, the fixing assembly comprises an upper fixing piece I, an upper fixing piece II, a lower fixing piece I and a lower fixing piece II, two screws are connected between the first upper fixing piece and the second upper fixing piece, two screws are connected between the first lower fixing piece and the second lower fixing piece, and cushion blocks are arranged on the inner side faces of the first upper fixing piece, the second upper fixing piece, the first lower fixing piece and the second lower fixing piece. Through the fixing assembly, the sample can be conveniently and quickly assembled, the low-cycle fatigue test requirement of the sheet metal structure can be met, and the lateral buckling instability phenomenon between a clamping part of equipment and the buckling-restrained tool can be reduced; through the guide assembly, when the sample bears a tension and compression cyclic load, the lateral buckling instability phenomenon in the thickness direction is prevented, and the stability of the sample is further enhanced.

This application relates to the field of vehicle simulation technology, and particularly to a method and apparatus for simulating the compressive instability of vehicle exterior panels. The method includes: performing finite element modeling of the body-in-white to obtain a body-in-white model; dividing the exterior panel into multiple regions and assigning different thickness attributes to each region to obtain a target body-in-white model; applying constraints to the target body-in-white model to obtain a first target body-in-white model, and setting a pressure head on the exterior panel in the first target body-in-white model; establishing a surface-to-surface contact pair between the pressure head in the first target body-in-white model and the exterior panel to obtain a second target body-in-white model; and controlling the displacement of the pressure head based on the second target body-in-white model to perform compressive instability analysis on the exterior panel to generate compressive instability analysis results. This method can quickly and accurately assess the compressive instability of passenger vehicle exterior panels through preliminary simulation, reducing the risk of compressive instability on the sheet metal surface of passenger vehicle exterior panels.

This invention discloses a method for near-net-shape forming of complex thin-walled irregular-shaped rings based on a dissimilar material cladding, relating to the field of material plastic forming technology. The method includes: determining the required blank material and cross-sectional allowance of the same material for ring rolling forming of the target ring; determining the dissimilar material cladding based on the cross-sectional allowance; the dissimilar material having a higher stiffness than the blank material; fabricating the blank material and the dissimilar material cladding; covering the blank material with the dissimilar material cladding and performing ring rolling to obtain an initial ring; and removing the cladding from the initial ring to obtain the target ring. This invention solves problems such as buckling instability, loss of dimensional accuracy, uneven wall thickness, excessive ellipticity, and large subsequent machining and low material utilization under large allowance design during the rolling process of thin-walled rings. It achieves high-precision near-net-shape forming of large-diameter, thick-walled titanium alloy irregular-shaped rings, improving material utilization and reducing material costs.

A method for calculating the critical value of thermal buckling of a composite metal connection structure includes: obtaining the deformation relationship of the composite metal connection structure based on the stiffness ratio of the connection parts; then correcting the thermal expansion coefficient of the metal in the composite metal connection structure to obtain the corrected thermal expansion coefficient α of the metal in the composite metal connection structure. ′ 2; Based on the critical theory of structural thermal buckling, the modified thermal expansion coefficient α of the metal in the composite metal connection structure is used. ′ 2. The critical temperature difference for buckling instability of the composite metal connection structure was calculated: where ΔT is the critical temperature difference for buckling instability of the composite metal connection structure; μ2 is the Poisson's ratio of the metal material in the composite metal connection structure; m and n are the buckling half-wave numbers of the composite metal connection structure in the length and width directions; and a and b are the length and width of the composite metal connection structure.

The application discloses a kind of super-long pile buckling instability test methods under the action of multiple load combination, comprising: through special data comprehensive computing platform, the multiple load parameters of stratum physical mechanics characteristics, pile structure geometry and axial pressure, lateral thrust and torque are collected, and the interaction relationship of clear parameters is handled by multiple load pile buckling coupling model;Using non-uniform load pile buckling deformation prediction model to deduce the deformation trend of each section of pile body, with the help of super-long pile buckling instability tracing analysis algorithm, locate the key parameters and action interval of instability;Through platform dynamic capture actual deformation and stress distribution data, after comparing and calibrating with deduced result, the critical state parameters of buckling instability and full-range deformation law are optimized and output.The method realizes the accuracy and systematicness of test under multiple load and complex stratum condition, and provides reliable technical support for super-long pile engineering safety design.

This invention discloses a design and manufacturing method for a uniform cross-section explosive load simulator based on gradient elastic metamaterials, relating to the field of impact loading. Addressing the problems of high cost per use and the susceptibility of variable cross-section elastic rods to local buckling instability under high-speed impact leading to waveform distortion in existing simulators, this invention, while maintaining the macroscopic uniform cross-section shape of the simulator, derives the ideal wave impedance gradient required to achieve the target explosive load based on the one-dimensional elastic wave propagation inverse design theory; establishes the mapping relationship between the relative density of a three-period minimal surface (TPMS) metamaterial unit cell and its equivalent mechanical parameters, and inversely solves the spatial relative density distribution function; extracts the waveform through dynamic impact finite element simulation, and introduces an impedance gradient correction factor to perform nonlinear iterative correction of the density function, obtaining a final three-dimensional metamaterial geometric model that accurately matches the waveform, and uses a flexible polymer material for additive manufacturing. This invention achieves the purely elastic, non-destructive, and reusable simulator, perfectly adapting to the stable firing of light gas cannons, and exhibiting excellent anti-instability capability and waveform fidelity under strong dynamic loads.

The invention relates to the technical field of steel structure connecting joints, in particular to a modular steel structure buckling-restrained multi-step energy dissipation beam column joint and a transformer substation, which are suitable for connecting cross beams and stand columns and comprise hinge pieces and energy dissipation assemblies, and first energy dissipation plates comprise the first energy dissipation plate and the second energy dissipation plate; when the swing strength of the cross beam around the axis of the hinge piece relative to the stand column reaches a first threshold value, the first energy consumption plate is bent. When the swing strength of the cross beam around the axis of the hinge piece relative to the stand column reaches a second threshold value, the second energy consumption plate is bent, and the second threshold value is larger than the first threshold value. The method has the beneficial effects that by controlling the local buckling instability behavior of the beam-column joint energy dissipation plate, the bearing capacity is independently regulated and controlled while the initial rigidity of the joint is not changed, and the energy dissipation capacity of the joint is effectively improved; by means of the technical scheme, the problems that plastic hinges at the ends of the beams move outwards and the stand columns and the beams collide and conflict can be solved, and reliability is improved.

The invention discloses a method for simulating the buckling state of a storage tank under the combined action of typhoon and rainfall, and the method comprises the steps: obtaining the wind pressure pulsation and liquid level change characteristics of the typhoon, and generating a non-stationary load sequence; constructing a three-dimensional finite element model of the storage tank, coupling multiple physical fields, and determining initial stress distribution; the overall buckling instability process is simulated, and key node displacement is obtained; judging local stress concentration according to the displacement threshold value to obtain a stress concentration distribution diagram; calculating accumulated damage and resistance deterioration degree under multiple typhoons based on a damage accumulation model; simulating a damage extension track from integral buckling to local damage, analyzing a high-risk area formation mechanism, and predicting a failure mode; and outputting the residual service life index of the storage tank under the composite load in combination with the residual service life evaluation framework. According to the method, accurate pre-judgment and quantitative evaluation of the full-life-cycle failure risk of the storage tank under the typhoon precipitation composite load are realized.

The invention discloses a dynamic pile sinking displacement monitoring system and method based on computer vision. The method comprises the steps of scale mark manufacturing, hardware assembly arrangement, image data collection, pile body displacement analysis, pile body inclination analysis, pile body strain analysis and structural damage early warning. The scale marks are matched with the compensation light source and the high-frame-rate industrial camera, so that the problem that a traditional sensor is easily damaged and interfered in the pile body monitoring process is solved; the strain value of the pile body is obtained through inversion according to the relative distance change of the pile body scale marks at the hammering moment, and real-time, continuous and non-contact monitoring of the strain value of the pile body is achieved; three key parameters of displacement, inclination and dynamic strain are monitored at the same time through the same visual system, the construction problems of pile body inclination overrun, pile body fracture, buckling instability, pile top fragmentation and the like are accurately recognized, early warning is triggered in time, the safety of dynamic pile sinking construction is effectively improved, and the safety risk is reduced.

The invention discloses a boom structure and an aerial work platform, and belongs to the technical field of engineering machinery. The arm support structure comprises a plurality of arm sections which are sequentially arranged in a nested mode, each arm section comprises four side plates, and the long sides of the four side plates are sequentially connected through reinforcing pieces to form a box type structure. The reinforcer is of a cylindrical structure, and the axial direction of the reinforcer is the same as the length direction of the side plate, namely, the side plate is connected to the peripheral wall of the reinforcer. Furthermore, a sliding block is arranged between the four corners of every two adjacent arm sections in a profiling mode. And the two adjacent arm sections realize sliding extension and retraction through the sliding blocks. Compared with a cantilever crane structure in the prior art, the cantilever crane structure has larger rotational inertia, and the reinforcers serve as the corners of the four side plates to occupy part of the section width, so that the buckling instability resistance is enhanced. In addition, the reinforcer can bear the main pressure load of the sliding block, the bending moment received by the welding seam is obviously reduced, and obvious stress concentration of the welding seam near the sliding block is avoided.

The invention belongs to the technical field of composite material structural strength tests, and discloses an edge restraint device and method for a residual strength test of a composite material sheet after impact, and the device comprises a base, a side support, a top plate and a set of edge distributed clamping system. The system is composed of a bottom clamping module, a top clamping module and a plurality of pairs of lateral clamping modules which are arranged side by side and can be independently adjusted, and the bottom edge, the top edge and the two side edges of a test piece can be accurately and adjustably clamped in a distributed mode. Through adjusting mechanisms such as strip-shaped holes, screw holes and puller bolts on each module, optimized attachment with each edge of the test piece and clamping force control can be realized, crushing of the edge of the test piece and premature overall buckling instability in the compression test process are effectively prevented, and the accuracy and reliability of a residual strength test result after impact are ensured. The device is particularly suitable for testing the large-size composite material thin plate.

This invention discloses an electrically controlled switching valve and an air suspension system. The energy-absorbing plate of the electrically controlled switching valve is entirely embedded in an embedded groove. When the moving iron core impacts the energy-absorbing plate, the plate is not subjected to radial shear force. Simultaneously, the arc-shaped boss on the end face can quickly deform to better absorb the instantaneous impact energy upon initial contact, achieving a better energy absorption effect and mitigating the impact force on the main body area of ​​the energy-absorbing plate, thereby reducing the lateral deformation amplitude of the main body area. Furthermore, the arc-shaped boss has gaps between itself and the inner and outer edges of the energy-absorbing plate, providing ample radial expansion space. Combined with the arc-shaped design, buckling instability and localized stress concentration are avoided. Moreover, the movable shaft of the valve core can move relative to the moving iron core. When the valve core contacts the valve seat, the reaction force of the spring can decelerate the moving iron core to a certain extent, reducing the impact force of the moving iron core on the energy-absorbing plate. The combination of these design features effectively improves the service life of the energy-absorbing plate.

The invention discloses an additional type buckling-restrained series mechanism device which comprises a pressed component, a buckling-restrained component and a connecting component. Two rigid sheets are fixedly connected to the pressed component; at least one restraining mechanism is arranged between the two rigid sheets; the restraining mechanism comprises a plurality of rigid blocks which are hinged end to end and connected in series; the rigid blocks at the head and tail ends are respectively hinged with the two rigid sheets; the restraining mechanism and the pressed component are arranged in parallel at an interval, and the restraining mechanism is used for providing lateral restraining when the pressed component is pressed and restraining buckling instability of the pressed component. The rigid blocks and the rigid pieces are connected in series through the micro hinges, through the linkage effect between the series connection mechanisms, overall buckling of the component under the pressure effect can be effectively restrained, effective lateral constraint is provided for the pressed component, and the reliability of the component is improved. And the stress performance of the protected component in the pressed state is improved, meanwhile, the stress performance of the component in the pulled state is not affected, the device has the good buckling prevention capacity, and the ultimate bearing capacity and the energy dissipation capacity of the component are remarkably improved.

The utility model discloses a steel pipe concrete combination column, a latticed column and a reinforcing device. The concrete filled steel tube combination column comprises at least three steel tubes, a first plate, a second plate and a third plate, the at least three steel tubes are arranged in parallel, and the at least three steel tubes are arranged at intervals along an annular track on a plane perpendicular to the axis direction of the steel tubes; a first plate is arranged between every two adjacent steel pipes along the annular track. The multiple second plates are sequentially connected to form an annular pipe column, the annular pipe column and the containing cavity are coaxially arranged, and the annular pipe column is arranged in the containing cavity; one side of each third plate is connected with the second plate, the other side of each third plate is connected with the first plate or the steel pipe, and the multiple third plates are arranged in the second cavity to divide the second cavity into multiple sub-cavities; and a concrete layer is poured in the inner cavity and / or the sub-cavity of the steel pipe. According to the embodiment, the buckling instability resistance and the overall bearing performance can be improved.

The application is a kind of steel cyclic loading test anti-instability device, including instrument upper loading head, first pin bolt, first group of nuts, first threaded clamp, extensometer, first nut, test piece, second nut, second threaded clamp, second group of nuts, second pin bolt, instrument lower loading head and pin bolt hole; the device has lower manufacturing cost, simple installation and smaller size; the pre-tightening force of the threaded bolt is used to complete clamping and limit the translation and rotation of the test sample; through strong constraint of the test piece, the steel compression instability is prevented, so as to realize large strain cyclic loading, and the steel cyclic loading test data can be accurately tested before buckling instability, and the material characteristics reflected by the test are more accurate.

The utility model discloses a steel beam web rectangular orifice reinforcing member in a steel structure building, which comprises a main steel, the right side of the main steel is fixedly connected with a transverse connecting steel, the front side of a transverse connecting steel web is provided with a stiffening rib plate, the top and the bottom of the stiffening rib plate are fixedly connected with a plurality of stiffening plates, and the stiffening plates are fixedly connected with the reinforcing plates. L-shaped plates are fixedly connected to the upper side, the lower side, the left end and the right end of each stiffening rib plate through bolts, the surfaces of the L-shaped plates are fixedly connected with transverse connecting steel through bolts, supporting plates are fixedly connected to the left side and the right side of each stiffening rib plate through bolts, and two opposite inclined supporting plates are fixedly connected to the opposite sides of the top stiffening plates. The main steel and the transverse connecting steel are reinforced during connection through the fixing blocks, deformation of the rectangular opening of the web transverse connecting steel can be limited through the stiffening rib plate, buckling instability under the load effect is prevented, and then the reinforcing plate and the supporting plate reinforce the reinforcing joint at the position, where the rectangular opening is formed, of the transverse connecting steel more stably.

The present application belongs to the technical field of concrete structure stress monitoring, and discloses a steel pipe concrete structure lateral pressure device and a lateral loading instability judgment method. The cloud data control center uses the ICP algorithm to register the real-time point cloud with the pre-stored initial three-dimensional model to realize deformation quantitative analysis and surface defect evaluation, and outputs a strain anomaly index; a real-time demodulation light signal generates a stress distribution matrix, which is uploaded to the cloud data control center, and a difference operation is performed between the stress distribution matrix and a preset reference stress field matrix to generate a stress offset matrix, and an abnormality judgment threshold is dynamically corrected; the strain anomaly index and the stress offset matrix are coupled to construct an abnormality probability model, and the three-dimensional coordinates of the abnormal area are output to complete the abnormal positioning of the local buckling instability of the structure. The present application can effectively prevent the local instability damage of the steel pipe concrete structure.

The invention discloses an oil cylinder fixing structure, a joint size determination method and an aerial work platform, and belongs to the technical field of aerial work engineering machinery and computer aided modeling. The oil cylinder fixing structure comprises an oil cylinder, a check block, a fixing bolt and an arm support connecting plate, a limiting groove is formed in the middle of a mounting connector at the end of the oil cylinder, longitudinal limiting is achieved through matching of a stepped structure and the arm support connecting plate, axial limiting is achieved through the check block inserted into the limiting groove, and the rotating rigidity of the connector is remarkably improved. Meanwhile, according to the method, a finite element model of the oil cylinder connector is established, a linear equivalent algorithm is adopted for rapid iterative design, then a nonlinear equivalent algorithm is adopted for accurate verification, an efficient and reliable design closed loop is formed, and connector size parameters capable of achieving the design load are determined. According to the method, the buckling instability resistance of the oil cylinder is effectively improved, the safety and reliability of the long arm frame of the aerial work platform are guaranteed, and a standardized tool is provided for performance prediction and reliability evaluation.

This invention discloses a method for correcting the buckling critical load of ultra-long piles considering the attenuation of the stiffness of the soil around the pile, relating to the field of pile foundation stability analysis technology in geotechnical engineering. The invention includes the following steps: Step S1, obtaining pile-soil foundation parameters in layers; Step S2, establishing a depth-deformation bivariate model for the stiffness attenuation of the soil around the pile; Step S3, constructing an attenuation-type bivariate foundation buckling control equation; Step S4, dimensionless processing and coupled attenuation iteration-eigenvalue solution; Step S5, calculating the corrected value of the buckling critical load; Step S6, buckling instability discrimination and safety evaluation; Step S7, parameter inversion optimization and establishment of a dedicated database. This invention achieves accurate and efficient calculation of the buckling critical load of ultra-long piles by establishing a depth-deformation bivariate stiffness attenuation model, constructing a buckling control equation with coupled attenuation characteristics, and proposing analytical correction coefficients.

The invention discloses an energy dissipation beam section and an eccentric supporting steel frame, and belongs to the technical field of seismic resistance and shock absorption of structural engineering. Wherein the energy dissipation beam section comprises an energy dissipation main body which is of a hollow box-shaped structure; the end plates are mounted at the two ends of the energy dissipation main body; and the foam concrete is filled in the energy consumption main body. The eccentric supporting steel frame comprises two steel frame columns which are oppositely arranged. One end of the steel frame beam is connected with the upper end of the steel frame column; one end of the inclined support is connected with the steel frame column, and the other end of the inclined support is connected with one end, far away from the steel frame column, of the steel frame beam; the two ends of the energy dissipation beam section are detachably connected with the ends, away from the steel frame columns, of the steel frame beams through the end plates. The problem that an existing energy dissipation beam section needs to adopt a small width-to-thickness ratio and multiple stiffening ribs to give consideration to energy dissipation and buckling instability prevention is solved, the traditional energy dissipation beam section is optimized, the steel consumption is reduced on the premise that the performance is guaranteed, and then the production cost is reduced.