163 results about "Stressed state" patented technology

The invention relates to a stress analysis method and system based on a small and medium span bridge steel-concrete composite structure, and belongs to the technical field of stress analysis, and the method comprises the following steps: S1, building a finite element parameterized model of a steel-concrete composite bridge; s2, constructing a slippage effect model of a steel-concrete interface based on the constitutive relationship of the steel-concrete composite bridge; s3, applying a moving load working condition, and dividing a load position of the steel-concrete composite bridge through a dynamic grid; s4, solving and correcting the structural stress of the steel-concrete composite bridge; s5, key section stress distribution of the steel-concrete composite bridge is output so as to identify the maximum tension and compression stress area; the method has the beneficial effects that the dynamic change of the load action can be accurately reflected in the model so as to reflect the stress state of the bridge under the actual traffic load; and an accurate structural stress solution is gradually approximated, and a reliable stress analysis result is obtained by comprehensively considering material characteristics, structural geometrical shapes and load distribution factors.

The invention belongs to the technical field of bridge cranes, and provides a bridge crane metal structure fatigue life evaluation method, which comprises the following steps: establishing a bridge crane simulation model through finite element software ANSYS according to a bridge crane structure, and respectively carrying out concentrated analysis on stress under a static working condition and a dynamic working condition to obtain the fatigue life of a bridge crane metal structure. The method comprises the following steps: determining a dangerous stress area, carrying out dominant analysis on stress components of the dangerous stress area under a static condition from a spatial distribution dimension of the stress components, and monitoring a uniaxial stress state of the dangerous stress area under the static condition. Deviation analysis is carried out through the multi-axis stress damage value of the dangerous stress area at the single-multi-axis change time point, the single-axis evaluation error is eliminated through multi-axis stress equivalent correction, and it is ensured that the fatigue life evaluation result is highly consistent with the actual stress damage rule of the structure.

The invention discloses a performance-based fire-resistant design method for a cable system of a large-span suspension bridge. The method comprises the steps of bridge fire-resistant category division, fire intensity division, fire-resistant target determination, adverse fire scene determination, fire response calculation, fire-resistant checking calculation, fire-resistant protection and the like. The bridge fire-resistant category, the fire intensity, the fire-resistant performance and the fire-resistant target are all divided into three levels. The adverse fire scene is determined based on the fire type, fire combustion mode, fire position, wind speed and wind direction influence and combined with the structure stress state; fire response is calculated through thermal-mechanical coupling by adopting a finite element method; the fire-resistant checking calculation can adopt a design method based on overall structure fire-resistant checking calculation or component fire-resistant checking calculation; and when the fire-resistant checking calculation of each component of the cable system does not meet the fire-resistant target, fire-resistant protection design is carried out, and a fire-resistant protection scheme is designed by combining tests and numerical simulation. The fire-resistant design method based on the performance of the suspension bridge cable system is constructed, and reference can be provided for fire-resistant design of the suspension bridge.

The invention discloses a method for predicting high-temperature and complex stress of a ceramic-based composite material based on strain control damage evolution, and belongs to the technical field of stress prediction of ceramic-based composite materials. The method comprises the following steps: determining material high-temperature performance degradation conditions according to temperature; the total strain (mechanical strain and thermal strain) of the material is calculated, and then based on a three-dimensional failure criterion of strain control, six damage initial criterion equations including stretching and compression in the warp direction, the weft direction and the out-of-plane direction are constructed; establishing an evolution model of damage coefficients by introducing a coupling mechanism of damage factors in different directions; combining a multi-linear constitutive relation of the ceramic matrix composite material to construct a rigidity degradation matrix, and realizing rigidity adjustment of the failure unit; and finally deducing a stress-strain relation equation to complete stress prediction of the material under the conditions of high temperature and complex load. The prediction method provided by the invention can accurately predict the complex stress state of the ceramic matrix composite material under the combined action of the high temperature and the mechanical load.

The invention relates to the technical field of electric power engineering structure failure assessment, and discloses a reinforced concrete pole icing failure assessment method, system, device and medium, and the method comprises the steps: collecting the initial data of a pole, and assessing the stress distribution and potential crack position of the pole under a specific load based on the data. According to the stress distribution and the crack position, the expansion condition of the concrete crack is determined, and the stress state of the steel bar is analyzed. And based on the stress state, executing preliminary judgment. And establishing a relation model of the critical fracture value and the critical load of the steel bar in combination with the preliminary judgment result, and calculating the probability of overall failure of the electric pole. By analyzing the stress distribution and potential cracks of the electric pole under different loads, the actual stress state of the electric pole can be accurately predicted. Through fitting the joint distribution of the preset loads, the interaction between the loads is considered, and the evaluation precision is improved. The established relation model provides a basis for electric pole failure probability evaluation based on a preliminary judgment result.

The invention discloses a gradient combination anti-crack diaphragm wall concrete self-constraint stress optimization design method. The method comprises the following steps: firstly, constructing a BIM three-dimensional structure model comprising material performance, temperature gradient and stress state through three-dimensional laser scanning and core sample detection; then, carrying out stress partitioning based on the model, and calculating a self-constraint stress value and a stress transfer attenuation coefficient of each partition; then establishing an expanding agent proportion optimization model, simulating stress redistribution under different doping amount gradients by adopting a finite element algorithm, and screening a minimum effective doping amount meeting a stress homogenization index; and after the anti-cracking effect is verified through dynamic simulation, a final matching scheme is output. According to the method, the BIM technology and the material gradient design are combined, precise control over the concrete self-constraint stress of the underground diaphragm wall and active optimization of the crack resistance are achieved, the technical problem that traditional homogeneous material design is difficult to adapt to complex stress distribution is solved, and the durability and safety of the underground diaphragm wall structure are remarkably improved.

The invention relates to a tunnel single-layer lining embedded grating steel frame structure and a construction method thereof, and belongs to the technical field of highway engineering. The structure is composed of a primary support, a film spraying waterproof layer, a secondary lining and embedded grating steel frames, the embedded grating steel frames are embedded into the primary support and the secondary lining respectively, the effects of transmitting shear stress and coordinating deformation are achieved, the primary support and the secondary lining form a combined beam stress state, and the overall rigidity and bearing capacity of the lining structure are remarkably improved. During construction, the arrangement distance of the grating steel frames is determined through theoretical calculation, and it is ensured that the anti-shearing requirement is met. The method has the advantages of being convenient and fast to construct, high in safety and good in economical efficiency, the lining thickness and the number of reinforcing bars can be effectively reduced, the engineering cost is reduced, meanwhile, the method adapts to tunnel engineering of different surrounding rock grades, the problem that in traditional single-layer lining, shearing force transmission between a primary support and a secondary lining is insufficient is solved, an innovative solution is provided for tunnel lining structure design, and the method is worthy of popularization and application. The method has important engineering application value and popularization prospect.

The invention provides a concrete normal section reinforcement design method and system, electronic equipment and a storage medium. The method comprises the following steps: establishing a section stress model containing multi-layer reinforcement strain distribution based on plane section assumption; the stress state of the whole process of the section from axle center compression to axle center tension is simulated by setting strain proportion parameters of the strain of the outermost reinforcing steel bar on the tension side and the limit pressure strain of the concrete; aiming at a plurality of set strain state control points, calculating stress of each steel bar layer position, contribution of the stress to axial force and bending moment and contribution of the stress to a concrete compression area; and based on the section static balance condition, the optimal reinforcement area meeting the design load requirement is determined through iterative calculation, and the configuration constraint of multiple layers of steel bars is considered in the iterative calculation. The method overcomes the defects that a traditional method overestimates the effect of the pressed steel bars and ignores the strain difference of multiple layers of steel bars, and the accuracy and safety of reinforcement design of high-performance concrete structures such as nuclear islands are remarkably improved.

The invention discloses a method and a device for determining assembly fastening force of a bolt joint part, and relates to the technical field of intelligent manufacturing. The method comprises the steps that three-dimensional point cloud measurement data of a target joint surface are acquired, and the three-dimensional point cloud measurement data comprise geometric distribution error data and / or position error data; generating a target digital twin model according to the target three-dimensional point cloud measurement data; according to the target digital twin model, stress states of a target joint part corresponding to the target joint surface are simulated, and the stress states comprise a static stress state and / or a dynamic stress state; and according to the stress state simulation information, determining a target assembly fastening force of the target joint part. According to the method, the manual dependence degree in the bolt joint part assembling fastening force determination process can be reduced, so that the labor cost in the bolt joint part assembling fastening force determination process is reduced, and the determination precision and the determination efficiency of the bolt joint part assembling fastening force can be improved.

The present application relates to the technical field of structural engineering and discloses a limited-slippage connecting structure and a construction method of the connecting structure. The limited-slippage connecting structure comprises a prefabricated plate, a concrete plate, a welding nail and a flexible sleeve. The concrete plate is arranged on the prefabricated plate, the welding nail is located in the concrete plate, the welding nail comprises a nail column and a nail head arranged at one end of the nail column, the other end of the nail column is connected with the prefabricated plate, and the flexible sleeve is sleeved on the nail column. The limited-slippage connecting structure can provide a proper slippage amount, effectively reduce the tensile stress of the concrete plate, and improve the long-term performance and durability of the concrete plate. At the same time, the limited-slippage connecting structure also has an anti-lifting effect to resist the separation and lifting of the concrete plate, reduce the sudden increase of the partial segment shear force caused by the excessive release of the combined effect, and improve the stress state of the transition section concrete plate.

The utility model relates to the technical field of geotechnical engineering and railway construction, and particularly discloses a vibration reduction and deformation resistance steel sheet pile for deep foundation pit engineering close to an existing railway line, which comprises a steel sheet pile, a vertical load-bearing steel bar, a connecting component, a vibration isolation and reduction interlayer and a protective steel plate. By adopting a composite structure form of steel sheet piles, vibration isolation and reduction interlayers and vertical load-bearing steel bars, the structure reinforcing function and the vibration isolation function are organically combined, and a brand-new supporting structure system is formed; the vertical stressed steel bars are matched with the vibration isolation and reduction interlayer and the damping spring shock absorbers, the vertical stressed steel bars mainly share tensile stress to improve the stress state, the vibration isolation and reduction interlayer mainly absorbs vibration energy to weaken vibration transmission, and the comprehensive performance of the steel sheet pile is remarkably improved through the combined action of the vibration isolation and reduction interlayer and the damping spring shock absorbers; meanwhile, according to the scheme, by optimizing arrangement of the vertical load-bearing steel bars, selection of vibration isolation and reduction materials and arrangement of connecting components, the whole structure has the good reinforcing effect and vibration reduction performance, and construction convenience and economical efficiency are taken into consideration.

The invention relates to the technical field of steel structure engineering construction, in particular to a super-long independent steel column segmented locking type temporary stabilizing device and a construction method thereof, and is suitable for the overall lifting stage of a multi-layer aerial corridor. The device comprises a first locking assembly surrounding a concrete column and providing an X-direction lateral fulcrum; the second locking assembly is fixedly connected to the surface of the steel column to form a force transmission interface; and the connecting conversion assembly connects the steel column and the concrete column into a whole, so that the X-direction load of the steel column is transmitted to the concrete column in sections. The super-long steel columns are temporarily decomposed into short column stress sections with the length not larger than the designed length, and lateral displacement is remarkably restrained. The construction method comprises the steps that the device is installed at the corridor joint, pre-tightening force is synchronously applied, displacement is monitored in real time, overall dismantling is conducted after lifting is completed, and no residue exists after dismantling. The method is not pre-buried and fully recycled, super-long columns are restored to be in a short column stress state, lateral displacement is reduced, steel is saved, the construction period is shortened, green construction and appearance completeness are both considered, and the method is suitable for a large-span corridor overall lifting project.

The invention discloses a rock axial tensile strength and transverse shear strength testing device which comprises a rack, a lower end axial clamp and an upper end axial clamp are arranged in the rack, and a rock sample to be tested is fixed between the lower end axial clamp and the upper end axial clamp; the lower-end axial clamp is fixedly arranged in the rack, and the upper-end axial clamp moves in the rack along the axial direction to apply axial tension to a rock sample to be tested; the rack is internally provided with at least one group of transverse pushing and pressing mechanisms, and the transverse pushing and pressing mechanisms are arranged on the side surface of a to-be-tested rock sample and apply transverse pushing force to the to-be-tested rock sample. According to the invention, the axial tensile strength and the transverse shear strength of the rock sample are tested by axially applying the tensile load and transversely applying the linear pressure load; and a research platform is provided for the mechanical strength change rule of the rock in actual engineering application under different stress state conditions.

The invention provides a method for designing a transverse unbonded prestressed steel bar anchorage device structure of a bridge deck slab, and relates to the technical field of bridge steel bar construction. The design method of the transverse unbonded prestressed steel bar anchorage device structure for the bridge deck slab comprises the following steps that S1, the unbonded prestressed steel bar anchorage device structure suitable for the transverse prestressed steel bar distribution requirement of the bridge deck slab is designed and completed by combining the steel bar distribution space of the bridge deck slab and referring to the size parameters of transverse prestressed flat anchors. According to the method, the occupied space of rib arrangement is small, the requirement for rib arrangement of narrow sections of bridge decks and the like is met, an unbonded structure is adopted, construction is easy, pipeline reservation and later grouting are not needed, the risk that prestressed ribs are corroded and fractured in a high-stress state due to the fact that pipeline grouting is not solid, hole channel slurry leakage or slurry separation is eradicated, and the service life of the prestressed ribs is prolonged. The unbonded prestressed steel bar is anchored in a supporting type threaded mode, the anchoring precision is high, and the tensioning control requirement can be met through one-time precise tensioning.

The invention discloses a combined structure of a height difference concrete beam and a steel pipe concrete column ring beam and a construction method.The combined structure comprises a circular steel pipe concrete column, an integrally-machined ring beam and a variable-height-difference concrete frame beam, the circular steel pipe concrete column comprises a circular steel pipe and self-compacting concrete, and the circular steel pipe is filled with the self-compacting concrete; two reinforcing outer ring plates which are vertically distributed at intervals are fixedly welded to the outer periphery of the circular steel pipe, the ring beam is fixedly connected with the reinforcing outer ring plates, and one end of the concrete frame beam is fixedly connected with the ring beam. According to the combined structure, the height or thickness of the component can be flexibly adjusted according to actual loads and topographic conditions, and the combined structure adapts to various complex working conditions; the stress state of the component can be optimized by changing the height or thickness, and the overall performance of the structure is improved; the component size can be reduced at the part with smaller stress, and the material and the construction cost are saved; complex load distribution and topographic conditions can be effectively adapted, and the bearing capacity and the anti-seismic property of the structure are improved.

The invention discloses a construction method for segmentally cutting and removing arch ribs of a half-through multi-connected arch bridge in a navigable water area, and belongs to the technical field of highway bridges. The method comprises the steps that a zero-stress-state cutting technology system for the H-shaped steel temporary lock catches at the vault is installed, and the H-shaped steel lock catches are used for bearing and gently transferring internal force of the section of the vault in advance before cutting; an arch foot directional collapse auxiliary device is installed, and a guide frame with a guide arc surface is adopted to guide the to-be-dismantled stand column to collapse in the preset direction; an arch foot root vertical back pressure technical system is installed, vertical pressure is applied through a back pressure device, and horizontal thrust of the arch ribs is counteracted in cooperation with the filled profile steel and the pier caps; a temporary opposite-pull device auxiliary dismantling technology system is added to the end of the installed arch rib, and a temporary opposite-pull rod and an anchoring structure for connecting the arch rib and a tie bar are arranged so as to balance structural internal force in the dismantling process. Through the synergistic effect of the four technical systems, safe arch crown cutting, arch springing stability and arch rib force system balance are achieved.

The invention relates to the technical field of engineering support of metal mine high-stress stratums, in particular to a metal mine high-stress stratum ultra-deep vertical shaft oval lining support structure and method.The metal mine high-stress stratum ultra-deep vertical shaft oval lining support structure comprises an oval vertical shaft wall and a composite support system, and the composite support system comprises an initial flexible support, a shaft outer lining and a shaft inner circular lining; the long axis of the oval well wall is arranged in the maximum horizontal principal stress direction of primary rock stress. A traditional round shaft is changed into an oval shaft, the long axis extending direction of the oval shaft is kept consistent with the maximum principal stress direction, the tensile stress area is effectively expanded to the two sides of the long axis, the surrounding rock pressure is effectively released, after optimization, stress distribution is remarkably improved, the maximum principal stress is dominated by pressure stress, and the stress distribution is reduced. Compared with a traditional circular structure, a more reasonable stress state is realized; the minimum principal stress is also greatly reduced after filling, and the overall stress performance is remarkably improved.

The invention relates to a metal plate plastic forming method, in particular to a stamping-bulging composite forming method for an annular corrugated diaphragm of a welded expansion joint. The stress state of the formed diaphragm can be adjusted, the inner side pressure stress of the bent position of the corrugated diaphragm is converted into tensile stress, sufficient plastic deformation occurs in a formed area, and springback is reduced. By adjusting the stamping drawing force and the bulging internal pressure, the equivalent stress distribution of the diaphragm forming area can be more uniform, the stress difference of all the areas is reduced, then the warping of the forming area is reduced after the load is removed, and the forming precision is improved. The large radial stress can be generated in the diaphragm forming area only by applying small pressure to the middle area of the diaphragm blank, the large radial stress is used for adjusting the stress state of the diaphragm forming area, and therefore the high requirement of large bulging pressure on equipment and a die can be avoided.

The invention provides a discrete ballastless track tension-compression fatigue damage rapid calculation method, which comprises the following steps of: uniformly measuring a complex stress state and a simple stress state through a damage energy release rate, and decomposing tension-compression effective stress by utilizing a fourth-order projection tensor, so that the tension-compression effective stress value is equivalent to a uniaxial tension-compression stress value under a uniaxial loading condition; constructing a hyperbolic function with a natural constant as a base and a damage variable as an index on the basis of the damage energy release rate and in combination with three-stage damage characteristics of high-cycle fatigue of the material; carrying out integration on fatigue loading times through tension and compression damage, and deducing to obtain a discrete transcendental differential function of the damage related to the loading times; function variables are defined, an initial value is set, an iteration format is established, the discrete transcendental differential function is solved through a numerical integration method, and a calculation result graph is drawn. The model is simplified, and the calculation efficiency is improved; a high-order tensor stress updating algorithm does not need to be constructed, redundant calculation is reduced, and the data processing efficiency and the calculation speed during parameter analysis are greatly improved.

The invention provides a method, a device, equipment and a medium for evaluating the residual life of a cableway structural component, and the method comprises the steps: carrying out the conformity judgment of a to-be-evaluated component, and determining whether the to-be-evaluated component is a cableway long-acting basic structural component or not; if the to-be-evaluated component is the cableway long-acting basic structure component, multi-stage state judgment with a logic progressive relation is sequentially carried out on the to-be-evaluated component, and the previous-stage judgment is a necessary condition for entering the next-stage judgment; and if the to-be-evaluated part passes the multi-stage state evaluation, evaluating the residual life of the to-be-evaluated part according to the surface state and the stress state of the to-be-evaluated part. By adopting the scheme, the accuracy and the reliability of the residual life estimation result of the cableway structural component are improved.

The utility model relates to the technical field of steel structure bridge joint connection, in particular to a rapid assembly type steel structure bridge joint which comprises a lower stand column, an upper stand column arranged above the lower stand column and a bridge beam perpendicular to the stand columns. The first connecting part is inserted into the second connecting part, one end of the bridge beam is inserted into the second connecting part, the upper stand column and the lower stand column are quickly connected, and a firm connecting structure can be formed by injecting concrete into the square groove. The first connecting part, the second connecting part and the bridge cross beam are tightly connected together, the structural strength of the connecting joint is improved, the durability of the joint is enhanced, the bridge can bear larger loads and more complex stress states, the supporting rod with the adjustable length is arranged on one side of the lower stand column, and the supporting rod is convenient to use. The supporting rods are used for supporting the bridge beam.

The application belongs to the technical field of bridge construction, and is a beam bridge load test method based on time history curve. The method firstly carries out static load test, and then arranges test vehicles at key parts of the test bridge surface by using a step loading mode, and measures deflection points and strain points. Then, the static load test efficiency is calculated through the bridge static load test. According to the step loading mode and the static load test efficiency, a multi-working-condition bridge model is established by using a finite element method to collect time history curves. Finally, dynamic load test is carried out, control sections of each span of the bridge are selected as test sections, and strain fluctuation amplitude, impact coefficient and the like are measured through the dynamic load test. According to the test data, the stress state of the structure under dynamic load is analyzed. The application combines static load test and dynamic load test, can reflect the working performance of the bridge structure under design load, and has high reliability.

This invention discloses a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments, belonging to the field of corrosion and protection technology. The method includes the following steps: establishing a geometric model for simulation and meshing the model; setting material properties, including corrosion kinetic parameters and basic mechanical property parameters; applying boundary conditions to the geometric model to simulate the actual stress state of the high-strength steel plate; formulating a kinetic expression formula for the electrochemical reaction to describe the electrochemical behavior during corrosion; and performing a corrosion kinetic-mechanical coupling analysis to calculate the distribution of corrosion current, corrosion potential, and local corrosion rate. This invention, by constructing a multiphysics model, can accurately extrapolate and predict the dynamic corrosion rate of high-strength steel under different stresses and environmental parameters. It provides crucial theoretical basis and data support for the design, life assessment, and maintenance decisions of marine engineering structures.

The utility model relates to welding piece strength test technical field, concretely is a kind of welding piece strength test device, the fixed subassembly includes four connecting pieces, four the connecting pieces are fixedly connected in the top of fixed frame respectively, the inside of four the connecting pieces is fixedly connected with fixed bottom plate jointly, recess is set up in the inside of fixed bottom plate, four sliding grooves one are set up in the inside of fixed bottom plate. This welding piece strength test device, can guarantee that welding piece is in correct stress state in testing process, avoid the uneven partial stress, sliding or rotation etc. caused by clamping instability, to make the test result real reflection welding piece's strength performance, reduce test error, improve the reliability and repeatability of data, need not frequent adjustment clamp or reinstallation welding piece, can reduce test preparation time and the test interruption frequency caused by clamping problem, make testing process more smooth, to improve overall test efficiency.

The utility model relates to a concrete box girder bridge reinforcing structure for a large longitudinal slope girder bridge, which comprises a box girder main body and flanges, and the flanges are fixedly connected to the left side and the right side of the box girder main body. According to the concrete box girder bridge reinforcing structure for the large longitudinal slope girder bridge, by arranging the reinforcing plates, the upper end and the lower end of the inner wall of the box girder main body have high stability, then by arranging the first notches, the anchoring parts and other parts, high supporting performance can be generated between the two reinforcing plates, and the inner space of the box girder main body can be effectively supported and fixed; by arranging the auxiliary supporting plates, the box girder main body can transmit part of pressure to the reinforced steel plates on the two sides, then the pressure borne by the box girder main body is weakened, the service life of the box girder bridge is prolonged, and finally by arranging second notches, fixing anchor plates and prestressed steel bars, flanges on the two sides can be stably connected with the box girder main body; according to the design, the bearing capacity of the flange can be improved, and the stress state of the flange is improved.

This invention belongs to the field of sheet metal testing technology, and discloses a sheet metal internal angle fatigue testing device and method. The sheet metal internal angle fatigue testing device includes a testing platform, a fixing component, and a pressure applying component. The fixing component includes two blocks and corresponding sliders. The two blocks are adjustablely mounted on the testing platform along a first direction, and the two sliders are slidably mounted on the testing platform along the first direction and located between the two blocks. Both sides of the sheet metal part along the first direction are fixedly connected to the sliders. The pressure applying component is connected to the testing platform and includes a pressure head. The pressure head is used to apply pressure along a second direction to the outer side of the bending angle of the sheet metal part. This accurately simulates the movement characteristics of the sheet metal parts' sides during actual working conditions and the true stress state of the internal angle, ensuring the accuracy of the test results. It is adaptable to the testing needs of different models and specifications of sheet metal parts, and has a wide range of applications and strong versatility.

The application provides a kind of orthotropic steel bridge deck U rib fatigue performance evaluation method and system, related to U rib fatigue performance evaluation technical field, including: constructing U rib model, setting load and environmental parameter working condition combination, simulating residual stress evolution, screening out main control parameter;Residual stress variation coefficient theoretical equation is constructed, and the final formula is obtained after processing;Combination main control parameter, simulate the welding process of no cyclic load, extract the initial value of characteristic parameter;Find the most unfavorable combination, simulate the stress evolution under its action, extract the final value and compare with the initial value to get the change, generate fatigue comprehensive index, compared with the preset threshold to evaluate the fatigue performance of U rib.The application discloses the core mechanism that residual stress, load and environmental factors change the stress state of U rib together, provides a solid theoretical support for U rib fatigue performance evaluation, accurately quantifies the influence of main control parameter on U rib fatigue performance, significantly improves the evaluation result of fatigue performance.

The invention discloses a dynamic simulation method for the ultrasonic welding process of multiple layers of thin plates. According to the method, simulation model combinations of different dimensions are provided, so that the problem of simulation of the mechanical property non-uniformity of the welded joint is effectively solved. The entity unit detailed model can finely present the microstructure characteristics of the welding joint, including the interface reaction area and the welding seam fusion state of each layer of plate, and the shell unit simplified model greatly improves the calculation efficiency on the premise of ensuring the engineering precision; the part impact test simulation model further combines the material failure behavior with the actual working condition. The three models support one another through a unified material failure setting system, the performance difference between a welding seam area and base metal is captured, the dynamic response rule under the impact load is reflected, and the simulation result can truly reproduce the mechanical behavior of a welding joint in the complex stress state.

The invention relates to the technical field of engineering, in particular to a tunnel deformation pressure calculation method and device. Comprising the following steps: S1, acquiring basic parameters of tunnel engineering, including tunnel burial depth, surrounding rock level and tunnel span; s2, according to the construction design, a preliminary bracing scheme of the tunnel is determined, the preliminary bracing scheme comprises sprayed concrete parameters and steel frame parameters, and the flexural rigidity of a preliminary bracing section is calculated; s3, based on the deformation pressure sample data, establishing a relation model between the deformation pressure and the surrounding rock level, the tunnel span and the initial support section flexural rigidity by adopting a multivariate nonlinear regression analysis method; s4, calculating the vertical deformation pressure of the tunnel supporting structure according to the relation model and the basic parameters, and calculating the horizontal deformation pressure; and S5, outputting the vertical deformation pressure and the horizontal deformation pressure. According to the method, the deformation pressure is calculated based on the basic parameters, accurate calculation of the stress state of the tunnel support is achieved according to multi-factor regression analysis and consideration of the support rigidity, and the design is more economical, reasonable, safe and reliable.

The invention provides a super-large-span net rack floor splicing method, and belongs to the technical field of building construction.The method includes the steps that a three-dimensional stress monitoring device is arranged in the net rack splicing process to collect the stress distribution state of gusset plates in real time, and a single-ball-with-single-rod and single-ball-with-double-rod progressive splicing mode is adopted; when the stress concentration coefficient of the gusset plate is close to 75% of a material allowable value, prestress release adjustment is conducted immediately, meanwhile, a plumb bob instrument and a total station are used for continuously measuring the deviation value of the center of sphere position and conducting fine adjustment and resetting, and through a double real-time monitoring feedback mechanism of the stress state and the geometric position, the stress concentration coefficient of the gusset plate is measured; the stress accumulation in the whole splicing process is controlled to be below a safety threshold value, it is ensured that the offset of the axis of the rod piece and the overall deformation of the net rack meet the design requirements, and the technical problem that overall deformation exceeds the limit due to stress accumulation in the super-large-span net rack floor splicing process is solved.