1373 results about "Bending moment" patented technology

The invention discloses a wind turbine generator hoisting construction tower drum operation system and a construction method thereof, and relates to the technical field of intelligent control. The problems that in the prior art, a static tension balance mechanism cannot restrain bending moment abrupt change, steel-concrete interface stress concentration causes microcrack propagation, the wave dynamic load compensation capacity is insufficient, and dynamic rigidity attenuation early warning is lacked are solved. Comprising a dynamic load prediction module, a multi-mode vibration suppression module, an offset compensation module and a digital twinborn decision module, a hoisting load is solved in real time through a multi-physics field coupling model and an improved time sequence deep learning algorithm, and interface crack propagation is suppressed in combination with traveling wave offset control and sweep frequency vibration. An improved Morison equation is adopted to drive a two-stage hydraulic servo to compensate a wave dynamic load, and a digital twin closed-loop correction mechanism is constructed based on a 5G URLLC protocol; the tower drum hoisting precision, the structural safety and the operation reliability under the complex working condition are remarkably improved.

The invention discloses a method for calculating the flexural capacity of a prefabricated segmental girder bridge based on steel shear keys, and belongs to the technical field of fabricated prefabricated segmental girder bridges. According to the method, on the basis of the concrete plasticity theory, a theoretical stress model of bending plastic deformation of the prefabricated segmental girder bridge is constructed, a cracking bending moment calculation formula of the three-section type prefabricated segmental girder bridge is established, and design refinement and design efficiency are improved; based on the fact that the anti-bending bearing capacity of the joint of the segmental beam is mainly determined by deformation of a pressed area of a concrete top plate and limit stress of a steel strand, a calculation formula of the anti-bending bearing capacity of the three-section type prefabricated segmental beam bridge at the joint and the non-joint is provided; according to the method, the plastic deformation of the concrete and the bonding slippage effect of the reinforcing steel bars are considered, the bending bearing capacity of the three-section type prefabricated segmental girder bridge can be accurately calculated, and the calculation method is verified to be safe and reliable through comparison with an experimental value.

The invention discloses a folding wing and rudder design method and an unfolding locking mechanism thereof. The locking mechanism comprises a connecting handle, an elastic torsional spring and a rotating shaft. A locking head and a connector are arranged on the two sides of the bottom of the folding wing or the folding rudder respectively; the design method comprises the steps of obtaining performance parameters, and determining specific indexes such as folding sizes and unfolding time of the folding wing and the rudder. And designing a structural model according to principles of generalization, reliability and the like, and determining geometric parameters of the wing and the rudder. Verifying the strength of parts of the locking mechanism, calculating a plurality of parameters of an elastic torsion spring, and analyzing the unfolding time and synchronism. Finally, consistency checking is conducted based on finite element simulation analysis, torque and bending moment are applied in ABAQUS software according to parameters, the structural strength of the folded rudder is analyzed, and it is ensured that the design meets the requirement. According to the folding wing and rudder design method, through the scientific design process and multi-principle comprehensive application, the high-performance requirement is met, meanwhile, the cost is effectively reduced, the reliability and maintainability of products are improved, and the remarkable beneficial effects are achieved.

The present invention proposes an intermediate diaphragm-free, suspended formwork-free, and negative moment tooth block-free beam bridge, and a design method thereof. The beam bridge includes prefabricated main girders, a wet joint, lower structures, and pier cap transverse beams above the lower structures. The concrete deck slabs of adjacent prefabricated main girders are connected by the wet joint. The design method of the above beam bridge includes the following steps: S1, initial design of the main girders; S2, calculation of the non-uniform deflection of the main girders and the indirect transverse stress of the deck slabs; S3, calculation of the direct transverse stress of the deck slabs; S4, crack resistance verification of the deck slab; S5, optimization of bridge parameters to reduce the stress on the driving surface; S6, completion of the beam bridge design. The beam bridge and its design method effectively solve the problem that the existing intermediate diaphragm-free beam bridge is prone to longitudinal cracking at the joints, and realize the suspension tension without the wet joint suspended formwork of the deck slab and the negative bending moment tendon, and have better mechanical properties and better economic, environmental and social benefits, which can facilitate the promotion and application of such bridges in various types of highways , railways and municipal engineering.

The invention provides a plate anchor ultimate bearing capacity calculation method and device. The method comprises the steps that soil body strain softening, anchor plate geometry and ocean clay initial mechanical parameters are obtained; the method comprises the following steps: constructing a Drucker-Prager elastic-plastic numerical model based on a Cosseerat continuum theory; calculating bearing capacity under different burial depth ratios, inclination angles beta and softening moduli; determining a burial depth ratio demarcation threshold value; constructing a burial depth and dip angle coupled reference bearing capacity formula, which is divided into burial depth ratio lt; 4 and > = 4, respectively using quadratic polynomial and linear regression analysis; constructing a strain softening correction coefficient formula, and fitting in two working conditions; and generating a comprehensive ultimate bearing capacity empirical formula in combination with the reference formula and the correction coefficient formula. According to the method, the rotational degree of freedom and the bending moment balance item are introduced, the grid dependence is reduced in combination with the characteristic length parameter, the comprehensive empirical formula is constructed through large-scale parameterized numerical calculation, and the prediction error is effectively reduced.

The invention discloses an insertion tube and a manufacturing method thereof, an insertion part and an endoscope, and relates to the technical field of medical instruments, the insertion tube comprises an insertion body and an elastic tube, a first reinforcing layer and a second reinforcing layer are arranged in the insertion body, the second reinforcing layer is arranged outside the first reinforcing layer in a surrounding mode, and the first reinforcing layer is provided with a concave part. The first reinforcing layer and the second reinforcing layer can form double limiting and wrapping supporting on the elastic pipe, the concave shape of the concave part of the first reinforcing layer is utilized to be attached to the outer wall outline of the elastic pipe, and the outer side of the second reinforcing layer is matched for enclosing and restraining, so that the installation stability of the elastic pipe in the first channel can be greatly improved; bending moment generated by self-gravity, external force and the like of the elastic tube is effectively counteracted, the elastic tube is prevented from being bent under the action of self-gravity, external force and the like, the whole insertion tube is prevented from deforming along with bending of the elastic tube, and the form stability of the insertion tube in the cavity in the propelling process is guaranteed. And the straightness of a traction rope transmission path and the accurate conduction of a control instruction are ensured.

Disclosed in the present invention are high-rise pile cap equipment under a horizontal load and a centrifuge test method for foundation bearing characteristics thereof. The equipment comprises a model box, a sand layer, a model pile cap, at least eight model piles, a horizontal loading device, at least two laser displacement sensors, an axial force sensor, and a plurality of strain gauges. The method comprises: S1, performing one-way horizontal loading on high-rise pile cap equipment under a horizontal load to obtain an ultimate foundation bearing capacity situation, a model pile body axial force distribution situation, a pile foundation axial force comparison situation, a model pile body bending moment distribution situation, and a model pile body bending moment comparison situation of the equipment; and S2, performing one-way variable amplitude cyclic loading on the high-rise pile cap equipment under the horizontal load to obtain a foundation displacement situation, an effect of the number of cycles on foundation stiffness, an effect of a cyclic load amplitude on the foundation stiffness, and a foundation inclination situation. In this way, the foundation design of the high-rise pile cap can be optimized, and a basis and a reference for evaluating safety of foundation long-term service are provided.

The invention discloses a two-degree-of-freedom clamp capable of adjusting the bending moment and direction of a turbine blade and a test method. The two-degree-of-freedom clamp comprises a blade clamping component, an upper adjustable U-shaped head, a lower adjustable U-shaped head, an upper clamping rod and a lower clamping rod. The blade clamping component is in threaded connection with the upper adjustable U-shaped head and the lower adjustable U-shaped head, the other end of the upper adjustable U-shaped head and the other end of the lower adjustable U-shaped head are connected with the upper clamping rod and the lower clamping rod respectively, and the other end of the upper clamping rod and the other end of the lower clamping rod are connected with an upper clamping head and a lower clamping head of the fatigue testing machine respectively. The upper clamping rod and the upper adjustable U-shaped head are adjustably connected in pairs in the transverse direction intersecting with the vertical axis so as to adjust the eccentricity of the turbine blade load. The eccentric angle of the blade load can be adjusted by adjusting the rotation cycle of the blade clamping component. According to the clamp disclosed by the invention, by adjusting the eccentricity and the eccentricity angle during a turbine blade test, different bending moment directions and relative sizes of different sections during the turbine blade test can be realized, so that the aim of simulating a real load is fulfilled.

The invention discloses a method for calculating stress and deformation of a roller carrier supporting thin-walled cylinder under the action of dead weight, which comprises the following specific steps of: S1, calculating the bending moment and deflection of a cylinder body in the longitudinal direction by adopting an overhanging beam model in the longitudinal direction, and determining the optimal position of the roller carrier in the longitudinal direction according to the maximum bending moment minimization and the maximum deflection minimization of a beam; s2, transversely utilizing symmetry to establish a semicircular curved beam model, and calculating bending moment and displacement in a transverse plane of the cylinder by adopting a Temosinke beam theory; s3, calculating the maximum stress in the cylindrical surface according to the in-surface bending moment, and determining the optimal half wrap angle required by the strength; and S4, calculating the ovality and root-mean-square roundness of the curved beam according to the displacement, and determining the optimal half wrap angle required by deformation. According to the method, the maximum stress and the deformation shape of the thin-walled cylinder are accurately predicted, and the optimal wrap angles of the roller carrier under the strength requirement and the deformation requirement can be determined to be 67.4 degrees and 90 degrees respectively, so that the optimal wrap angle is suggested to be between 67.4 degrees and 90 degrees in engineering.

The invention discloses a double-row anti-slide pile internal force obtaining method and system, and relates to the field of geotechnical engineering.The double-row anti-slide pile internal force obtaining method comprises the steps that indoor experiments are conducted on pile top displacement, pile periphery soil pressure distribution and pile body bending moment and shearing force distribution of a coupling-beam-free double-row anti-slide pile, and the stress characteristics and deformation characteristics of the coupling-beam-free double-row anti-slide pile are obtained; constructing a coupling-beam-free double-row anti-slide pile internal force calculation model; an anti-slide pile is simplified into an elastic foundation beam with a fixed range above a slide surface as a directional support, a pile structure is divided into a load-bearing section and a load-bearing section-built-in section from the directional support, and the internal force of the coupling-beam-free double-row anti-slide pile is determined; the stress and deformation characteristics of the coupling-beam-free double-row anti-slide pile are input into the coupling-beam-free double-row anti-slide pile internal force calculation model, and the internal force of the whole pile body of the coupling-beam-free double-row anti-slide pile is accurately obtained.

The invention relates to the technical field of on-line monitoring, in particular to a wind generating set spindle vibration displacement monitoring method and system, and the method specifically comprises the steps: constructing a gravity bending moment periodic function and a stiffness azimuth modulation strategy, and obtaining spindle endpoint displacement caused by blade gravity; comparing each unit partition on the single blade to obtain a first interference coefficient, and comparing each unit partition with the unit partition of the predicted rotation transfer position to obtain a second interference coefficient; obtaining a third interference coefficient through the gear friction coefficient; establishing a main shaft vibration displacement prediction model, and predicting and outputting a predicted value of the main shaft vibration displacement in the next monitoring time period; and comparing the predicted value of the vibration displacement of the main shaft in the next monitoring time period with the actually measured vibration displacement of the main shaft, and performing abnormal vibration alarm. The problems that in the prior art, under the complex operation condition, the deviation between the predicted value and the measured value of the vibration displacement of the main shaft is too large, and the risk of misinformation or missing report is high are solved.

The invention relates to the technical field of bridge construction, and discloses a guide-beam-free incremental launching construction hoisting balance weight structure for bridge construction, which comprises an incremental launching platform and a gantry crane above the incremental launching platform, the counterweight assembly comprises two slide rails, two wheel carriers, two groups of rollers, a base, a plurality of counterweight blocks, two groups of guide wheels and two pull ropes; and the lubricating assembly is used for lubricating the two groups of rollers. Through the arrangement of the counterweight assembly, the base can move reversely along with the movement of the gantry crane, self-adaptive position adjustment of the multiple counterweight blocks is achieved, the gantry crane and the multiple counterweight blocks are kept in a balanced state on the pushing platform, the bending moment and the shearing force peak value of the pushing platform are reduced, and through the self-adaptive position adjustment, the service life of the pushing platform is prolonged. And the operation of actively adjusting the position of the balancing weight by an operator is reduced, and the operation time is saved.

The invention relates to a bending moment-torque composite loading device for testing the load capacity of a steering engine, and belongs to the technical field of ammunition weapon system testing. In the device, the pressure head, the pressurizing rod and the composite loading slip ring synchronously rotate along with the rotation of the rudder wing, so that the applied pressure can be ensured to be always perpendicular to the rudder surface and is closer to the real wind resistance working condition during flight. The bending moment output device and the torque output device are coupled together through the composite loading slip ring, so that the bending moment and the torque can be loaded at the same time and are closer to the actual flight condition.

The invention discloses a strike-slip fault buried pipeline test loading device capable of considering soil body action, and belongs to the technical field of geotechnical engineering tests. The device comprises a double-shaft loading system, a fixing device, a pipeline system and an axial force and bending moment combined loading system, the device is specifically divided into a three-dimensional adjustable reaction frame, an axial servo actuator, a radial servo actuator, a distribution cross beam with a movable hinged support, a pipe hoop restraint device, a pipeline test piece, an adjustable arc-shaped supporting cushion block, a flange type end plate, a movable hinged support and an adjustable spring set. And meanwhile, a loading curve of the axial force and the bending load of the pipeline under strike-slip fault dislocation is established. And the axial servo actuator and the radial servo actuator carry out four-point bending loading on the pipeline according to the established load applying curve of the axial force and the bending moment. According to the test device and the loading system, the stress state of the oil and gas pipeline under strike-slip fault dislocation can be reproduced, and the failure mode and deformation characteristics of the pipeline without soil constraint under axial force and bending moment loads are disclosed.

The invention provides a counterweight difference adjustment method for hogging moment area jacking of a special-shaped multi-girder steel-concrete composite beam, which comprises the following steps of: establishing a finite element model of the special-shaped multi-girder steel-concrete composite beam, and arranging two ends and the middle part of the special-shaped multi-girder steel-concrete composite beam on a beam column; performing jacking height simulation of different numerical values on the special-shaped multi-girder steel-concrete composite beam at the middle supporting point for many times to obtain a first bridge deck stress result at the middle supporting point; carrying out balance weight difference adjustment finite element simulation on the basis of the first bridge deck stress result, and applying a balance weight along the line type of the main beam to adjust the pre-compressive stress of the bridge deck at the middle fulcrum of the main beam so as to achieve a design target; and the concrete bridge deck is constructed on the basis of counterweight data obtained through counterweight difference adjustment finite element simulation. By establishing a finite element model and carrying out multi-group jacking height simulation and subsequent counterweight difference adjustment simulation, the stress state of the bridge deck at the middle fulcrum of each main beam under different working conditions can be accurately determined. The counter weight is applied on the basis, so that the stress nonuniformity caused by a special-shaped structure and a multi-girder system can be effectively made up, the pre-compressive stress of the bridge deck at the middle supporting point of each girder is more uniform, and the design goal is accurately achieved.

According to the method for designing the reasonable arch axis of the large-span arch bridge based on the hybrid calculation algorithm and the self-adaptive load distribution, an analytic equation method, a curve fitting method and an intelligent optimization algorithm are combined, and by selecting the initial arch axis, introducing a dynamic load distribution model and applying a genetic algorithm and a particle swarm optimization algorithm, the reasonable arch axis of the large-span arch bridge is designed. Global and local optimization is carried out, and the optimal shape and load distribution of the arch axis are ensured. And finally outputting design parameters, such as a control point, a bending moment, thrust and the like. According to the method, the design precision, flexibility and safety can be effectively improved, the material utilization rate is optimized, the cost is reduced, and the method is particularly suitable for design of large-span bridges and has high practical value.

The embodiment of the invention provides a load balancing control method of a variable pitch system, which comprises the following steps of: continuously acquiring blade root bending moment and rotor azimuth angle signals, accurately preprocessing to obtain 1P harmonic information of bending moment in a flapping direction, and updating accumulated wear conditions of each blade under different azimuth angles in real time based on the 1P harmonic information. According to the method, a dynamic abrasion map is established, the active balance variable pitch offset is actively calculated based on the abrasion map, the load is intelligently guided from a heavily-abraded area to a lightly-abraded area, and a refined blade variable pitch angle is finally formed in combination with traditional IPC correction and a collective variable pitch instruction. In this way, key components such as the variable pitch bearing are prevented from bearing overhigh local stress for a long time in a specific azimuth angle, uniform abrasion of rolling bodies or raceways is achieved, and therefore local fatigue damage is remarkably reduced, and the service life of the variable pitch bearing of the wind generating set and the service life of related components are prolonged.

A multi-axial spine testing system includes a physiological motion unit (PMU); a uni-axial test frame having an input; and a fixture configured to be attached to the test frame and facilitates a plurality of primary motions of one or more of the PMU and the fixture. The plurality of primary motions includes a linear motion of the input and a rotational movement of an output. The fixture has an upper assembly directly or indirectly coupled to the input. The upper assembly transfers the linear motion (Tz) of the actuator to the rotational movement (Rx) of the output. The upper assembly and lower assembly apply a bending moment (MX) and an axial compression (Fz) to the PMU. An external transducer collects data related to or generated by at least the plurality of primary motions. The fixture simultaneously provides the bending motion and axial compression to the PMU.

The invention discloses a compression test clamping tool, system and method for a variable-thickness beveled laminated plate composite material, and relates to the technical field of aviation composite material mechanical property testing. The first long chuck and the second long chuck are respectively mounted on a variable-thickness side and an equal-thickness side of the beveled laminated plate sample, and the first long chuck mounted on the variable-thickness side is gradually thickened on a conical beveled layer and a thin section of the beveled laminated plate sample. According to the invention, the additional bending moment caused by eccentricity of a neutral shaft is effectively inhibited through the gradually-changed thickening design of the variable-thickness side long chuck in cooperation with gap control, and active inhibition of buckling instability of a beveling area is realized in combination with rigid fixation and surface roughening treatment of the short chuck; the method has the advantages that buckling instability is restrained, a failure area is accurately positioned, and samples of different configurations are adapted.

The invention discloses a method for estimating the fatigue crack propagation rate of a laminated structure, and belongs to the technical field of laminated structure fatigue crack prediction. The invention aims to solve the problem that the prediction of the existing fatigue crack growth rate cannot be separated from experimental data support. Comprising the following steps: dividing a laminated structure into an upper sub-beam and a lower sub-beam, calculating tangential displacement and normal displacement of a crack interface, and calculating tangential traction force and normal traction force of the layered crack interface by combining the interface fracture toughness of the laminated structure; calculating the total strain energy of the laminated structure by combining the internal stress resultant force, the bending moment and the shear stress resultant force of the upper sub-beam and the lower sub-beam; establishing a laminated structure balance equation and obtaining a control equation set; and solving the control equation set to obtain the theoretically calculated crack length, cycle index, upper sub-beam applied load theoretical value and upper sub-beam displacement theoretical value of the laminated structure under the fatigue load of the laminated structure, calculating to obtain the cycle energy release rate, and further calculating to obtain the crack growth rate. The method is used for estimating the fatigue crack growth rate.

The invention discloses a strength detection tool and method for a composite cabin for an unmanned aerial vehicle. The detection tool comprises a cabin connecting plate, an end fixing device, a force application adjusting device and a deformation measuring structure. The force application adjusting device comprises a one-way stress application structure, a torsional stress application structure and a stress transmission structure. The stress transmission structure is provided with a special-shaped stress plate, a one-way stress transmission piece and a torsional stress transmission assembly. Particularly, a multi-linkage test structure is arranged, and conversion from torsional moment to radial one-way pressure is realized through geometric constraint and contact mechanics principles. According to the detection method, a step-by-step loading and multi-direction detection mode is adopted, initial detection, surface change detection and multi-direction comprehensive detection are achieved, and the preset deformation quantity is rapidly achieved through a displacement control mode by means of the qualified deformation quantity value detected last time. According to the invention, bending moment and torque load detection in four directions of 0 degree, 90 degrees, 180 degrees and 270 degrees can be completed through one-time clamping.

The invention discloses a method for detecting and evaluating anchor bolt cage foundation damage after tower falling of a wind turbine generator, and relates to the technical field of anchor bolt cage damage evaluation.The method comprises the following steps that the position of a tower falling point is determined; dividing tower falling modes according to the distance between the tower falling point and the foundation; performing appearance detection; formulating a field detection scheme based on the determined tower inversion mode; obtaining a load-displacement curve when the anchor bolt is tensioned and unloaded; a tower falling action bending moment calculation method is determined, and tower falling action bending moment is calculated; carrying out checking calculation on the tensile bearing capacity of the anchor bolt and the local pressure bearing capacity of concrete around the lower anchor plate, and determining the damage degree and damage location of a lower anchoring area; and compiling an anchor bolt foundation damage detection report. According to the method, the tower falling mode is divided, a targeted detection scheme is formulated, the plastic damage of the lower anchoring area is analyzed in combination with a pre-tension force removal anchor bolt tension test, meanwhile, the tower falling action bending moment is calculated based on the tower falling mode, bearing capacity checking calculation is carried out, and accurate detection of anchor bolt cage foundation damage and evaluation of residual bearing capacity can be achieved.

A ship rudder blade bending moment simulated loading device and a loading method. The device comprises: a rudder blade (1), a rudderpost (2), a loading mechanism and a control system, wherein the rudder blade (1) is connected to one end of the rudderpost (2), a through radial hole (3) is provided in the center of the rudder blade (1), and the loading mechanism is connected to the rudder blade (1) by means of the radial hole (3). The control system comprises a force sensor (4), an angular displacement sensor (5) and a control box (6), wherein the force sensor (4) is mounted on the loading mechanism, the angular displacement sensor (5) is mounted at the other end of the rudderpost (2), and the control box is connected to the loading mechanism, the force sensor (4) and the angular displacement sensor (5).

The invention relates to a multifunctional test loading device for simulating bending shear torsion performance of a wind power tower, which comprises a counter-force column, a counter-force longitudinal beam, a counter-force cross beam and four actuators, and is characterized in that the counter-force cross beam is fixed at the top of the counter-force longitudinal beam through a bolt and is connected with a first actuator for axially applying pressure; the bottom of the tower drum is connected and fixed through a loading support with a kidney-shaped hole, and the end of the tower drum is connected with a loading beam through a conversion piece and abuts against a first actuator for axial pressure applying and loading. A fourth actuator on one side of the reaction wall is used for applying horizontal shearing force and torque; second and third actuators on the upper and lower sides of the counter-force longitudinal beam are used for applying bending moment; according to the device, loading of multiple load types can be achieved on the tower drum, the complex stress condition possibly borne by the tower drum in the actual use process can be simulated, and loading of any change of a single load of the tower drum can also be simulated; the device is suitable for loading and fixing tower barrels of different types and sizes; and the influence of torsional deformation and horizontal displacement on vertical load loading can be reduced through structural measures.

The invention relates to the technical field of cable-stayed bridge construction, in particular to a cable-stayed bridge cable force determination method based on process control, which comprises a cable-stayed bridge cable tower, a stay cable and a main beam section, a finite element model is established according to the sizes of the cable tower and the main beam section, and after the zero section in the main beam section is simulated and installed, the zero section is determined. Installing first segments on the left side and the right side of the zero segment respectively, tensioning prestressed steel beams in the first segments, operating a finite element model, recording bending moment values of beam ends of the first segments, setting virtual support constraint node vertical and torsional displacement at the beam ends of the first segments, operating a calculation model, and calculating the bending moment values of the first segments; and the vertical counter force and the virtual bending moment value borne by the virtual support are recorded, the virtual support is deleted, a stay cable unit is established between the preset anchor point of the first section and the cable tower anchor point, and different stay cable body internal force is set twice.

The invention discloses an anchor rod frame beam deformation and internal force calculation method based on a transfer matrix method, which comprises the following steps of: establishing a rectangular coordinate system by taking the left end point of a longitudinal beam in any frame beam as an original point, the direction of the longitudinal beam as an x axis and the direction vertical to the mounting plane of the frame beam as a y axis; solving a deflection curve differential equation of the beam based on a Winkler elastic foundation theory to obtain the deflection of the longitudinal beam; superposing the deflection increased due to the action of the anchoring force to obtain a deflection general solution of the i-th section of longitudinal beam under the action of the anchoring force; on the basis of the deflection general solution of the i-th longitudinal beam, according to the differential relationship among the deflection, the corner, the bending moment and the shearing force of any section on the i-th longitudinal beam, obtaining a corner, bending moment and shearing force expression of any section on the i-th longitudinal beam; and the deflection, the corner, the bending moment and the shearing solution of any position of the N sections of beams are calculated through a transfer matrix method. The method can calculate and solve the deformation and internal force of any section of frame beam, improves the accuracy and efficiency, and is more suitable for actual engineering scenes.

A method and apparatus for testing a specimen with pressure, applying a torque using one or more plates coupled to the test specimen, applying a bending moment, and / or applying an axial load, either separately or simultaneously, with or without rotating the specimen, and without the applied forces interfering with each other.

The invention relates to a shear key arrangement device and method for improving the crack resistance of a bridge deck in a hogging moment area of a steel-concrete combined continuous beam bridge, and belongs to the technical field of bridge engineering. Comprising a steel beam, a concrete bridge deck slab and stud shear keys arranged between the steel beam and the concrete bridge deck slab, and the rigidity of the shear keys can be adjusted according to needs so as to improve the stress performance of a concrete slab in a hogging moment area. According to the shear connectivity requirement, the total shear bearing capacity of the studs is calculated, the number of the studs is calculated according to the diameter of the selected stud type, the tensile stress of the concrete in the hogging moment area is calculated and compared with the designed allowable stress, and rigidity adjustment of the shear keys is achieved by changing the diameter and the number of the studs. And meanwhile, the total strength of the stud is kept unchanged. According to the scheme, the stress performance of the concrete slab in the hogging moment area of the steel-concrete combined continuous beam bridge can be effectively improved, meanwhile, the construction process is simplified, the safety is improved, the cost is reduced, the material performance is fully utilized, and the user experience is improved.

The invention discloses a tractor chassis forging and drawing device and relates to the technical field of high-horsepower tractor production, the tractor chassis forging and drawing device comprises a machine base and a supporting assembly, a mold is arranged at one end of the top of the machine base, a chain conveyor is arranged in the machine base, a moving trolley is connected to the top of the machine base, and a clamp is arranged at the top of the moving trolley; the supporting assembly is connected to one side of the moving trolley and comprises a driving plate. Automatic lifting of the supporting mechanism is achieved through magnetic attraction linkage, when the moving trolley is away from the mold, a magnet drives a sliding block to drive a guide base to move, a sliding column ascends to a transverse groove along an inclined groove to be locked, a supporting rod pushes a pulley to make contact with the bottom of a bar to form supporting, and a suspended section between a mold outlet and a clamping point is effectively eliminated through the design; and stress field deviation caused by bending moment generated by the dead weight of the bar is avoided, the pulley structure provides stable bearing and can reduce surface scratches, and the drawing process quality is remarkably improved.

The invention relates to the technical field of rockets, in particular to a supporting device for a rocket and a transferring and erecting integrated launching vehicle. The supporting device comprises an erecting arm body and a plurality of auxiliary supporting mechanisms. The auxiliary supporting mechanism comprises a supporting bracket, a disc spring force limiter and at least two linear guide rails. The pre-pressure of the disc spring force limiter is adjustable, so that the rigidity of the supporting bracket is matched with the rigidity of the rocket body; the linear guide rails are arranged on the two sides of the supporting bracket respectively. According to the supporting device for the rocket and the transferring and erecting integrated launching vehicle, the supporting bracket is kept to be in a balanced state through the linear guide rail, the floating function is achieved, and the clamping stagnation phenomenon is prevented; force limiting supporting is achieved by adjusting the pre-pressure of the disc spring force limiter, the rigidity of the supporting bracket is made to be close to the rigidity of a rocket body, and therefore it is guaranteed that the additional bending moment cross section load generated by the erecting arm to the rocket is within the allowable range.