371 results about "Bending stiffness" patented technology

The present invention relates to an umbilical cable bending stiffness testing device and method. The device comprises a workbench; a measuring groove is formed in the top of the workbench; a fixing assembly is arranged in the measuring groove, and the fixing assembly is used for fixing two ends of an umbilical cable; a mounting plate is fixedly connected to the bottom of the workbench; a mounting frame is fixedly connected to the upper surface of the mounting plate; a threaded rod is rotatably connected between the lower surface of the mounting frame and the upper surface of the mounting plate; obtained data is transmitted to a dynamic data acquisition system by means of a displacement monitor body; the dynamic data acquisition system calculates obtained parameters to obtain bending stiffness curves of the umbilical cable under different curvatures. Moreover, because the device is in rigid connection with the umbilical cable by means of two sets of hoops, the problem of stress concentration caused by flexible connection of a steel strand rope is avoided, and the rigid connection ensures that tensile loads can be applied to two points of the umbilical cable in a balanced manner during an experiment, thereby improving the accuracy of bending stiffness testing results.

The invention provides a shield tunnel construction period segment longitudinal dynamic floating prediction method, and relates to the field of shield tunnel segment floating prediction.The method comprises the steps that the static upward floating force and the dynamic upward floating force of a shield tunnel are calculated by considering the timeliness of slurry, and the characteristic of nonlinear change of the rigidity of a circular seam connector is considered; the method comprises the following steps: dividing bending-resistant and shearing-resistant deformation modes of a circular seam joint, further deducing bending rigidity and shearing rigidity of a tenon-type joint in each deformation stage, deducing a shield tail segment longitudinal floating prediction model of the circular seam joint in the shield tunnel construction period, and constructing a nonlinear iterative algorithm of shield tunnel longitudinal deformation according to the theories; and acquiring parameter data of actual engineering, and inputting the parameter data into the duct piece floating prediction model to obtain a duct piece floating value. By means of the method, accurate prediction of floating deformation of the shield tail segment in large shield tunneling can be achieved, an effective scientific basis is provided for large-diameter shield tunneling construction, the problems that parameter decision of shield tunneling machine operators is difficult, and the segment floating control effect is poor are solved, and structural diseases caused by too large floating of the shield tail segment are eliminated.

The invention discloses a rigid rod frequency ratio method axial force identification method. The method comprises the following steps: (1) according to engineering data, obtaining whether a rigid rod is a pressure rod or a pull rod, and obtaining related parameters of the rigid rod: the linear density m of the rigid rod, the length L of the rigid rod and the flexural rigidity EI of the rigid rod; (2) vibration signals of the rigid rod are collected on site through a vibration sensor, and multi-order frequency of the rigid rod is obtained through analysis; (3) selecting a corresponding method to calculate the frequency ratio of the rigid rod according to whether the rigid rod is a compression rod or a pull rod and boundary conditions, and calculating the axial force of the rigid rod through a frequency ratio method; and (4) checking the relative flexural rigidity xi of the rigid rod, and evaluating the axial force identification precision of the rigid rod. According to the method, a unified calculation method for identifying the axial force of the rigid pull rod and the pressing rod is established through a frequency ratio method, the method is easy to use and has good precision, and a practical new method is provided for identifying the axial force of the rigid rod.

The invention belongs to the technical field of workpiece precision control, and discloses a precision control system and method for a large-curvature and shallow-drawing formed part, and the method comprises the steps: obtaining initial geometric parameters and material mechanical property parameters of the formed part; establishing a finite element analysis model of the formed part; discretizing the finite element analysis model of the formed part into n nodes, and calculating stress distribution at the n nodes of the formed part in the unloading process, strain energy generated by rebound and rebound bending moment formed by the strain energy; based on the stress characteristics of the n nodes, carrying out characteristic clustering on the n nodes to obtain m node areas; solving the overall rebound deformation and rebound strain energy of the m node areas by using an eagle-eye algorithm; the tolerance range is preset, the rebound bending rigidity of the corresponding area of the node area with the rebound deformation exceeding the tolerance range is increased on the basis of the characteristic geometrical shape design, the deformation generated by rebound bending moment is offset, and the size precision and shape quality of the large-curvature and shallow-drawing forming part are effectively improved.

The invention provides a reinforcing beam reinforced by adopting an out-of-service wind power blade and a method for determining the bending rigidity. According to the reinforcing beam, a plurality of grooves are formed in at least one surface of a reinforced concrete beam; the reinforcing layer comprises reinforcing ribs and a cement-based composite matrix, a plurality of protrusions are arranged on the surface of the cement-based composite matrix, the protrusions are arranged at intervals in the length direction of the cement-based composite matrix, and the protrusions are correspondingly embedded into the grooves, so that the reinforcing layer is connected with the reinforced concrete beam to obtain a reinforced concrete reinforced beam; wherein the reinforcing ribs are obtained by disassembling and cutting a main beam of the retired wind power blade. According to the reinforcing beam, the combining capacity of the reinforced concrete beam and the reinforcing layer is high, mutual slippage is avoided, the retired wind power blade composite material resources are utilized, the environment is protected, and the cost is saved while high-performance reinforcing treatment can be conducted on the damaged reinforced concrete beam structure or the reinforced concrete beam structure with insufficient bearing capacity.

The invention provides a gear crack rigidity calculation and system vibration coupling solution method considering slice coupling, which comprises the following steps of: calculating bending rigidity, shearing rigidity and axial compression rigidity of slice gear teeth by adopting a slicing method based on gear tooth number, modulus and gear pair dynamic meshing force to obtain gear tooth rigidity of the slice gear teeth; according to whether the gear has cracks or not, slice coupling rigidities in the healthy state and the crack state of the gear are calculated in combination with the gear tooth rigidities of slice gear teeth; calculating the crack-containing gear time-varying meshing stiffness of a single gear pair by combining the contact stiffness and the matrix stiffness of the gear; based on the outer diameter, the inner diameter and the number of rolling bodies of the ball bearing, the bearing supporting force is calculated by combining the dynamic load borne by the bearing; and according to the time-varying meshing stiffness of the crack-containing gear of the single gear pair and the bearing supporting force, a gear-bearing-coupling system kinetic equation is constructed, and the vibration response of the gear-bearing-coupling system is solved. The method can provide reference for early fault diagnosis of the wind turbine generator gearbox.

A shaft for a golf club includes a tip end configured to couple to a golf club head; a butt end opposite to the tip end; and a butt end portion that extends in a butt-to-tip direction from the butt end by at least 50 mm and has an average rate of change of bending stiffness in a tip-to-butt direction, wherein a greatest rate of change of bending stiffness of the shaft in the tip-to-butt direction is at least 2.7 times the average rate of change of bending stiffness of the butt end portion.

The invention discloses a wind turbine blade trailing edge beam and core material lap joint sandwich initial failure position prediction method, and relates to the technical field of wind turbine blade structure damage failure prediction methods. Damage of a sandwich structure panel and a core material in a shear failure mode is characterized as a lap joint sandwich structure formed by combining a laminated plate area, a conventional sandwich area and an inclined plane lap joint sandwich structure area; respectively calculating the cross section bending rigidity of the conventional sandwich structure, the neutral layer position of the inclined plane lap joint sandwich structure and the cross section bending rigidity distribution of the inclined plane lap joint sandwich structure, and calculating the cross section bending rigidity distribution of the inclined plane lap joint sandwich structure on the basis of the neutral layer distribution function inflection point in the length direction of the inclined plane lap joint sandwich structure and the descending slope of the cross section bending rigidity distribution function; the initial failure position of the lap joint sandwich structure of the blade trailing edge beam and the trailing edge core material is predicted. The method provides an important theoretical basis for in-service wind power blade design, health prediction and repair decision making, and has great method innovation and engineering application values.

The invention discloses a silicon carbide wafer detection device and method.According to the silicon carbide wafer detection device, a detection table is detachably and fixedly connected with a silicon carbide wafer, and the detection table is provided with a hollow part for containing the silicon carbide wafer; the silicon carbide wafer can have a space for generating elastic deformation along the axial direction of the silicon carbide wafer under the condition of being fixed; load is provided for the silicon carbide wafer through the pneumatic part of the detection unit, so that the silicon carbide wafer deforms in the axial direction of the silicon carbide wafer, the deformation quantity generated by the silicon carbide wafer in the axial direction of the silicon carbide wafer is detected through the detection part, and therefore the bending rigidity of the silicon carbide wafer can be calculated, and quantification of the rigidity of the silicon carbide wafer is achieved. And a reference basis is provided for the quality of the silicon carbide wafer.

The present disclosure provides a machine learning-based method for measuring bending stiffness of a fabric, comprising: obtaining an image of a fabric to be tested placed on a three-dimensional geometric object; and determining the bending stiffness of the fabric to be tested by inputting the image of the fabric to be tested into a trained deep neural network.

The invention discloses an acoustic black hole structure and a vibration damping device.The acoustic black hole structure comprises an acoustic black hole body and a damping layer, the acoustic black hole body is provided with a uniform thickness area and an acoustic black hole area, the acoustic black hole area is provided with a plurality of grooves, the grooves are distributed from the first end to the second end of the acoustic black hole area, and the damping layer is arranged between the first end and the second end of the acoustic black hole area. The depths of the grooves are gradually increased in the direction from the first end to the second end, and the damping layer is arranged in the acoustic black hole area. By machining the groove in the acoustic black hole area, the local bending rigidity of the acoustic black hole body is changed, the bending wave speed of the acoustic black hole body is reduced, the acoustic black hole effect is achieved, due to the arrangement of the groove, the local resonance effect can be utilized, and then structural vibration suppression in the low-frequency range is achieved; the problem that a traditional acoustic black hole structure is poor in low-frequency-band vibration reduction effect is solved, in addition, thickness cutting of an acoustic black hole area of an original structure is avoided, and the manufacturing difficulty and the requirement for the precision of machining equipment are lowered.

The invention provides a parameter determination method and device for an elastic flywheel, a storage medium and electronic equipment, and the method comprises the steps: constructing an optimization model, and carrying out the solving calculation of the optimization model according to an optimization variable, a constraint condition and an optimization target, and obtaining a calculation result; wherein the optimization variables are the number of the middle diaphragms, the thickness of a single middle diaphragm and the position relation between any two middle diaphragms, the constraint conditions are the total thickness of the diaphragms and the minimum strength range of the diaphragms, and the optimization target is to minimize the bending rigidity of the middle diaphragms; the target solution of the calculation result comprises the target diaphragm number of the middle diaphragms, the target thickness of each middle diaphragm and the target position relation between any two middle diaphragms. According to the method, under the condition that the torsional rigidity is not changed, the bending rigidity and strength are flexibly controlled by flexibly combining the number of diaphragms, the thickness of the diaphragms, the arrangement sequence of the diaphragms and the like, so that the effects of high reliability and shafting centering compensation capability are considered.

The invention discloses an aircraft panel impact test boundary stiffness equivalent simulation method and device, and belongs to the technical field of aircraft ground tests. According to the equivalent simulation device, a local wall plate test piece is adopted to replace an overall fuselage frame to carry out an impact test, a supporting rack is arranged on a base, and a vertical rigidity simulation spring assembly and a bending rigidity simulation device are borne on the basis of the supporting rack; a torsional rigidity simulation spring assembly and a longitudinal rigidity simulation spring assembly are arranged on the bending rigidity simulation device, and a local wallboard test piece is installed on the bending rigidity simulation device. According to the simulation device, the boundary rigidity of the aircraft panel when the aircraft panel is impacted is decomposed into torsional rigidity, vertical rigidity and longitudinal rigidity, so that the boundary rigidity is converted into three groups of linear springs in different directions for rigidity simulation, accurate simulation of the boundary rigidity is ensured, decoupling of boundary rigidity simulation is also realized, and the simulation accuracy is improved. And the design difficulty of the test device is reduced.

The embodiment of the invention discloses a method for determining the dynamic response characteristics of power equipment in a damaged state, and the method comprises the steps: obtaining the structural damping ratio and the jth flexural rigidity ratio of the power equipment, and the ground motion acceleration at the jth moment and the ground motion acceleration at the (j + 1) th moment, which are inputted from the outside, and then determining the natural vibration frequency according to the jth flexural rigidity ratio, determining an acceleration increment, a speed increment and a displacement increment according to the natural vibration frequency, the structural damping ratio, the seismic acceleration at the jth moment and the seismic acceleration at the (j + 1) th moment, and finally determining an acceleration response at the (j + 1) th moment, a speed response at the (j + 1) th moment and a displacement response at the (j + 1) th moment according to the acceleration increment, the speed increment and the displacement increment; and different devices can be finely reinforced, so that the structural layout and the material selection are optimized, the anti-seismic performance of the devices is improved, and the vibration amplitude and the damage degree of the devices in an earthquake are reduced.

The invention discloses a frame structure design method based on rigidity reduction. The method comprises the following steps that 1, rod end bending moments Mb and Mc and axial force Nc of frame beams and columns are obtained through calculation; step 2, obtaining actual reinforcement areas Asb0 and Asc0, section sizes and concrete strength of frame beams and columns; 3, the equivalent stiffness Kb1 of the frame beam is obtained through calculation according to the formula Kb1 = Mb0.75y / phi b0.75y; 4, the equivalent stiffness Kc1 of the frame column is obtained through calculation according to the formula Kc1 = Mc0.75y / phi c0.75y; 5, comparing the equivalent stiffness of the frame beam and the frame column with the initial flexural stiffness, and ending after the deviation is less than or equal to 15%; 6, calculating a shear force design value of the frame beam, calculating stirrups needing to be configured for the frame beam, and rechecking a shear-resistant section; and 7, calculating a shear force design value of the frame column, calculating stirrups needing to be configured for the frame column, and rechecking a shear-resistant section. Compared with the prior art, an overall calculation model of the frame structure is established, the real rigidity of a structural member is obtained through multiple iterations, section reinforcement is optimized, and the reinforcement amount is reduced; and the overall anti-seismic performance is improved.

The invention provides a method and a system for analyzing influence of local loading and unloading on deformation of an existing shield tunnel, and relates to the field of influence of foundation pit construction on the existing tunnel. The method comprises the steps that shield tunnel vertical additional stress caused by foundation pit excavation is calculated through a Mindlin stress solution; analyzing the influence of the longitudinal axial force on the flexural rigidity and shear rigidity of the circular seam joint, and dividing a joint deformation mode into three stages according to the relative magnitude of the axial force and the bending moment and the vertical displacement between rings; a tunnel displacement control equation is established based on a Winkler foundation model, loop iteration is conducted through a state space method, and the rigidity of a circular seam joint is dynamically adjusted to be matched with the final deformation mode of the circular seam joint; and finally, constructing a prediction system, and outputting a deformation value of the shield tunnel by inputting the number of iterations and parameters of a foundation pit, bolts, concrete and segments. By means of the method, deformation prediction of the existing shield tunnel can be achieved for foundation pit construction, an effective scientific basis is provided for foundation pit engineering construction, the problem that parameter decision of operators on a construction site is difficult is solved, and foundation pit engineering site construction is truly guided.

The invention relates to a method for evaluating a steel structure splicing node, which comprises the following steps of: (a) after the steel structure splicing node is disassembled, acquiring defect information of the steel structure splicing node; (b) obtaining a correction factor of the rotational rigidity of the steel structure splicing node according to the defect information; (c) obtaining the theoretical shear stiffness and the theoretical bending stiffness of the steel structure splicing joint; (d) according to the correction factor, the theoretical shear stiffness and the theoretical bending stiffness, the actual rotational stiffness of the steel structure splicing joint is obtained; (e) after all the steel structure splicing joints are installed, the actual geometric morphology of the steel structure splicing joints is obtained; (f) the actual bearing capacity of the steel structure splicing joint is obtained according to the actual geometrical morphology and the actual rotational rigidity; (g) obtaining the design bearing capacity of the steel structure splicing joint; and (h) evaluating the reusability of the steel structure splicing joint according to the actual bearing capacity and the designed bearing capacity of the steel structure splicing joint.

The invention discloses a damage quantitative evaluation method based on an intelligent agent model and knocking scanning, and aims to realize accurate recognition and quantitative evaluation of beam structure damage through the agent model. The evaluation method comprises the following steps: firstly, according to a theoretical relational expression of a beam structure, selecting a cross-sectional inertia moment, a structure length, a damage position and a detection vehicle equivalent acceleration as input random variables, and taking a bending stiffness ratio of a damage position as a damage quantitative index, constructing and optimizing an agent model; establishing a nonlinear mapping relation between input and output; secondly, applying excitation by utilizing an intelligent knocking scanning detection vehicle, acquiring an acceleration signal, processing the signal by adopting a time-frequency analysis technology, and extracting feature information related to structural damage; and finally, predicting a damage quantitative index according to the agent model in combination with the identified damage position and feature data, and verifying and outputting a result.

The present application provides a pre-stressed anti-vibration hammer and a pre-stress determination method and system, the pre-stressed anti-vibration hammer comprising a gapped steel strand, an assembly integrated hammer head and an anchoring clamp, wherein the gapped steel strand comprises a central layer round wire, a middle layer molded wire and an outer layer round wire from inside to outside; a gap is provided between the central layer round wire and the middle layer molded wire, and the gap is filled with a lubricating grease, such that the friction resistance between the central layer round wire and the middle layer molded wire is reduced, and pre-applying a stress to the central layer round wire is facilitated; the middle layer molded wire is of an arch structure, and the arch body structure increases the moment of inertia for a circle center, such that the bending rigidity of the steel strand is enhanced; and two ends of the central layer round wire are connected with the assembly integrated hammer head, the anchoring clamp is assembled in a hollow portion of one end of the assembly integrated hammer head away from the central layer round wire, and is configured to clamp the central layer round wire to which a target stress is pre-applied, a tensile stress generated by an impact load firstly counteracts the tensile stress generated between the outer layer round wire and a middle layer strand after the stress is pre-applied, and the bending rigidity of the steel strand can be increased.

The invention provides a calculation method and system for a herringbone micro anti-slide pile structure, the herringbone micro anti-slide pile structure is dispersed, and the interaction between a micro pile and a stratum is simplified into transverse and axial non-linear springs acting on nodes; determining nonlinear spring parameters; calculating the soil displacement and direction of each micro pile structure according to the landslide mass motion characteristics; establishing a structural overall stiffness matrix; establishing an overall increment balance equation set including the spring stiffness; the landslide mass displacement is divided into a plurality of displacement increments to be solved respectively, the spring stiffness and the pile bending stiffness are updated after each increment step, and the internal force and deformation of the herringbone micro pile structure under the corresponding landslide mass displacement effect are obtained through accumulation. According to the calculation method and system for the herringbone miniature anti-slide pile structure, material and geometric nonlinearity of the pile and interaction nonlinearity of the pile and the stratum can be considered at the same time, and calculation precision and efficiency are high.

The invention belongs to the related technical field of health detection, and discloses a structural system identification method and equipment during pouring construction of an arch bridge cantilever, and the method comprises the following steps: dividing the construction process of the arch bridge cantilever into a plurality of construction stages, and designing a measuring point position based on an observability state equation of the corresponding construction stage, and performing structural system identification on each construction stage by utilizing an observability technology one by one to obtain the bending rigidity and the axial rigidity of all arch rib beam units in the corresponding construction stage. According to the method, in each construction stage of arch bridge cantilever casting, the equivalent stiffness matrix equation is converted into the observable state equation, the observable state equation is solved through the null-space method, analytical solutions of the axial stiffness and the bending stiffness of arch rib beam section units in each construction stage are obtained, and the recognition precision is improved.

The invention discloses an intelligent beam flexural rigidity monitoring method based on a bending wave transfer function, which comprises the following steps: connecting a piezoelectric sensor with a high-frequency signal acquisition instrument to acquire an elastic wave signal in a beam, and deriving two kinds of bending waves in the beam based on the bending wave transfer function, namely the transfer characteristics of a propagation wave and a near-field wave; according to the present invention, the wave velocities and the attenuation characteristics of the two bending waves are different, the wave velocity of the propagation wave is increased along with the increase of the section stiffness, the propagation characteristic is strong, and the wave velocity change rule of the near-field wave is complex and is easily attenuated, such that the vibration excitation device is arranged at the reasonable position, and the vibration excitation device is adopted to transversely impact the beam body and excite the bending waves so as to achieve the bending wave vibration excitation. The near-field wave interference is filtered by using the attenuation characteristic of the near-field wave, the wave velocity of the bending propagation wave is accurately identified by combining wavelet transform, the relational expression of the wave velocity and the section stiffness is deduced by using the bending wave transfer function, the real-time change of the section stiffness of the beam is obtained by inversion, and the evolutionary process of the bending stiffness of the beam is monitored in a lossless and real-time manner.

The invention discloses an isogeometry-based composite material thin shell dynamics prediction method, and belongs to the field of composite material thin shell dynamics behavior prediction. The implementation method comprises the steps that geometric modeling is conducted on the composite thin shell based on an isogeometric analysis method, unification of geometric modeling and numerical analysis is achieved through a non-uniform B spline (NURBS), and a composite thin shell geometric model is obtained; calculating a tensile stiffness matrix, a tensile-bending coupling stiffness matrix and a bending stiffness matrix of the composite material thin shell through the composite material parameters; establishing a kinetic model of the composite material thin shell unit through continuous medium mechanics, assembling the kinetic model to obtain an overall kinetic model of the composite material thin shell, and establishing a kinetic equation of the composite material thin shell based on the overall kinetic model of the composite material thin shell and the stiffness matrix; a kinetic equation is solved based on a generalized alpha implicit time integration algorithm, the kinetic behavior of the composite thin shell under the action of an external force F is predicted, and the stability and precision of thin shell kinetic behavior prediction are improved.

The invention belongs to the field of helicopter structure fatigue design, and relates to a large-size composite material blade transition section fatigue test method. The method comprises the following steps: defining a blade load and a coordinate system; determining test loads of an examination area and an examination section of the blade transition section, wherein the test loads comprise centrifugal force, flapping bending moment and shimmy bending moment; the length of the test piece is determined, and two test loading points are arranged on the two sides of the transition section; transforming the test piece to obtain a paddle transformation piece; the paddle transformation piece comprises a paddle root section, a transition section and a partial airfoil section; according to the structural size of a blade root hole, a blade extension piece connected with the root is designed and manufactured, one end of the extension piece is connected with a blade root section connecting hole through a bolt, and the other end of the extension piece is provided with a connecting joint used for being connected with a test bed constraint mechanism; the section size of the metal extension piece enables the bending rigidity EI of the metal extension piece to be close to the bending rigidity of the paddle; and pasting a strain gauge on the examination profile, and calibrating.

The rear floor structure comprises a longitudinal beam section, a cross beam section and a plurality of reinforcing ribs, the longitudinal beam section, the cross beam section and the reinforcing ribs are integrally formed, and the longitudinal beam section comprises a first longitudinal beam and a second longitudinal beam which extend in the length direction of the vehicle and are distributed in the width direction of the vehicle at intervals; the cross beam section comprises a first cross beam and a second cross beam which are distributed between the first longitudinal beam and the second longitudinal beam at intervals, and the first longitudinal beam, the first cross beam, the second longitudinal beam and the second cross beam are sequentially connected end to end to form a hollow annular structure; the reinforcing ribs extend in the length direction of the longitudinal beam section and the transverse beam section and are longitudinally and transversely connected in the connecting area of the longitudinal beam section and the transverse beam section to form a first closed-loop structure and a second closed-loop structure, and the first closed-loop structure and the second closed-loop structure are distributed in an annular array mode relative to the hollow area of the annular structure. And the first closed-loop structures are distributed on the inner side of the second closed-loop structure at intervals. The torsion and bending rigidity of the rear structure of the vehicle can be effectively improved, and the requirement for light weight of the vehicle is met.

The invention relates to a construction method for reinforcing a landslide through prefabricated high-bending-resistance anti-slide piles, and belongs to the technical field of slope reinforcing engineering. In order to solve the problems that a traditional anti-slide pile is insufficient in flexural rigidity and difficult to reinforce after construction, the I-shaped anti-slide pile structure is adopted and is formed by connecting an upper wing plate pile, a lower wing plate pile and a web pile through a mortise and tenon joint structure, and the flexural rigidity is 3.69 times and 4.15 times that of a square pile and a round pile respectively. During construction, the upper wing plate piles are firstly driven to penetrate through the sliding surface, then the unit piles are formed through mortise and tenon connection of the web piles and the lower wing plate piles, and the continuous underground diaphragm wall is formed by repeatedly driving and utilizing the side mortise and tenon structures of the adjacent pile bodies. Water-absorbent resin (the water absorption rate is larger than or equal to 80 g / g) is smeared at the mortise and tenon joint, the functions of sealing and reducing the pore water pressure are achieved, and the slope stability is improved. The anti-slide pile is suitable for landslide reinforcement of soft soil and complex stratums, modular expansion construction can be achieved, adaptability is high, and the mechanical property and engineering applicability of the anti-slide pile are effectively improved.

The utility model belongs to the technical field of steel structures, and particularly relates to I-shaped steel for a bridge, which comprises an I-shaped steel body, a plurality of holes are uniformly distributed on a web of the I-shaped steel body, and foamed aluminum is filled in each hole. A plurality of reinforcing ribs are further arranged on a web of the I-shaped steel body, the reinforcing ribs and the holes are distributed in a staggered mode, every two adjacent I-shaped steel bodies are connected through a connecting mechanism, the holes are of a hexagonal structure and evenly divided into a plurality of groups, and the multiple groups of holes are evenly distributed in the length direction of the I-shaped steel body. The plurality of groups of holes and the plurality of reinforcing ribs are alternately distributed; according to the utility model, the plurality of holes are formed in the I-shaped steel body, and the foamed aluminum is filled in each hole to form a'metal framework + core material 'composite structure, so that compared with a solid web, the weight is reduced by 25%-30%, and the flexural rigidity is improved at the same time; the adjacent I-shaped steel is connected through the connecting mechanism, and detachable connection is achieved.

The present invention relates to an evaluation method for steel structure splicing nodes, comprising the following steps: (a) obtaining defect information of the steel structure splicing nodes after the steel structure splicing nodes are disassembled; (b) obtaining a correction factor of the rotational stiffness of the steel structure splicing nodes based on the defect information; (c) obtaining the theoretical shear stiffness and theoretical bending stiffness of the steel structure splicing nodes; (d) obtaining the actual rotational stiffness of the steel structure splicing nodes based on the correction factor, the theoretical shear stiffness and the theoretical bending stiffness; (e) obtaining the actual geometric shape of the steel structure splicing nodes after all steel structure splicing nodes are installed; (f) obtaining the actual bearing capacity of the steel structure splicing nodes based on the actual geometric shape and the actual rotational stiffness; (g) obtaining the design bearing capacity of the steel structure splicing nodes; and (h) evaluating the reusability of the steel structure splicing nodes based on the actual bearing capacity and the design bearing capacity of the steel structure splicing nodes.

The utility model provides a kind of electronic thoracoscope with universal bending insertion part, including operating part and insertion part extending along length direction, the insertion part includes front end portion, active bending section, passive bending section and rigid pipe section from distal end to proximal end in order, the front end portion is equipped with optical imaging module and illumination light source;Active bending section is set in the proximal end of the front end portion, by multiple jointed snake bone unit, actively bends in response to operating part control;Passive bending section is connected to the proximal end of active bending section, the passive bending section has universal bending characteristic and the bending stiffness of the passive bending section is less than active bending section;Rigid pipe section is connected to the proximal end of passive bending section.The utility model expands the observation range of thoracoscope by passive bending section, reduces observation blind area, avoids the direct confrontation of active bending section and the rigid structure of guide sleeve inlet, prolongs the service life of equipment, reduces the loss risk of equipment.

The present application relates to a kind of pre-tensioned steel wire rope lateral impact response calculation method considering geometric and friction nonlinear coupling.First, the linear tensile constitutive model of pre-tensioned steel wire rope is constructed, Von Kármán large deflection theory is introduced, and the geometric hardening relationship of the nonlinear growth of axial tension with lateral deflection is established;Subsequently, a bilinear bending stiffness model is constructed to calculate the critical anti-sliding torque that evolves dynamically with tension;Based on the principle of energy conservation and Rayleigh-Ritz method, the system total potential energy functional of axial tensile potential energy and nonlinear bending potential energy is constructed, and the maximum impact deflection and tension response of the steel wire rope are obtained by solving the energy residual equation, the maximum response is substituted back into the constitutive equation, and the maximum nominal stress of the midspan cross section, the maximum axial tension and the extension length of the internal slip zone are calculated.The present application has very high calculation efficiency compared with full-size finite element simulation, and is suitable for the rapid design and safety evaluation of steel wire rope protection system.