12 results about "Stress ratio" patented technology

This invention discloses a concrete mix design and manufacturing method for underground engineering concrete in a coupled environment of underground environment and load, relating to the field of underground engineering concrete technology. It aims to address the problem that traditional concrete mix design does not fully consider the coupling effect of underground environment and load. The underground environment includes groundwater erosion, wet-dry cycle, and temperature fluctuation; the load includes stress ratio. α s Dynamic load frequency and dynamic load amplitude α d This leads to technical problems such as insufficient erosion resistance, crack resistance, and mechanical stability of concrete, resulting in a short service life. This mix design is based on quantitative analysis of coupled environmental parameters. With cement, composite admixtures, recycled aggregates, modifiers, water, and additives as core components, the basic mix proportion is determined through a mapping model between "environment-load" coupled parameters and component content. The target mix proportion is then obtained through orthogonal experimental optimization. The manufacturing method includes four core steps: raw material pretreatment, graded mixing, gradient curing, and coupled environmental simulation curing.

The application discloses a steel structure installation measurement method, which comprises the following steps: establishing and maintaining a hierarchical dynamic measurement reference system, wherein the system comprises at least one fixed first-level absolute reference and one second-level partition dynamic reference arranged on a body of an installed steel structure; arranging strain sensors at key positions of the steel structure to monitor stress changes of the components in the installation process in real time; taking the second-level partition dynamic reference as a reference, measuring the geometric pose of a component to be installed; meanwhile, comparing real-time stress data obtained in the second step with theoretical expected values; and coupling analysis is performed based on the geometric measurement result and the stress comparison result in the third step, including generating adjustment suggestions for the geometric pose of the component when the stress deviation exceeds an allowable threshold, so that the installation tends to be in a low-stress natural state; and the target pose of the component installation is a predicted installation shape obtained based on simulation analysis and calculation of a construction process, and the shape is an intermediate state of the structure after bearing subsequent loads and deforming to tend to a design shape.

The application provides an aero-engine part creep-fatigue life design method. A part finite element model is established, mission profile stress analysis is carried out to obtain the principal stress cycle peak stress σ max and the principal stress cycle stress ratio R of the dangerous position of the part; a creep-fatigue interaction judgment criterion is established by using the relationship between (1-R)*σ max and twice the material proportional limit 2σ s ; a creep-fatigue damage interaction envelope line of the part is established; the creep-fatigue life of the dangerous position of the part is calculated based on the relationship between (1-R)*σ max and 2σ s . The relationship between (1-R)*σ max and 2σ s is used as the judgment criterion, the constraint relationship of temperature and load on the creep-fatigue interaction effect is comprehensively considered; the creep-fatigue interaction damage limit with reliability indexes is determined through the interaction damage envelope line with specific confidence and survival rate requirements; the creep-fatigue life calculation method considers the influence of stress relaxation on creep damage and fatigue damage in the cycle process, and the applicability of the analysis method under different stress states is ensured.

The application discloses a kind of baffle type stability discrimination method of one-word steel plate concrete composite wall component. The stability parameters of the component in plane and out of plane are obtained by calculating and processing the wall component, and the initial stability stress ratio of each is obtained by initializing calculation. The final stability stress ratio is obtained by iterative cycle processing according to the current stability stress ratio. The stability discrimination result of the wall component is obtained by judging and processing the final stability stress ratio obtained by the iteration of in-plane and out-of-plane. The stress ratio initial value formula considering the stability coefficient is introduced by the strength formula stress ratio analytical solution, which greatly improves the iteration efficiency, and the numerical differential form is used to gradually approach the stability stress ratio, which has faster convergence speed.

The application discloses a kind of high-throughput test methods for fatigue resistance of additive remanufacturing axle, comprising: establishing the finite element model of full-size axle-wheel assembly, taking the characteristic stress value of the target additive remanufacturing area on the surface of additive remanufacturing axle under the load condition required by full-size axle performance test specification;Establish the finite element model of test sample and prepare the test sample;The upper surface and the lower surface of the test sample are respectively symmetrically provided with two test sections, and unloading grooves are respectively formed on the two sides of each test section;Loading simulation is carried out on the test sample model, and the displacement value of the test sample model is determined when the determined characteristic stress value is reached;The determined displacement value is used as the core displacement control parameter, the actuator of the fatigue testing machine is used to apply alternating load with a stress ratio of-1 to the test sample to simulate the rotary bending stress state of the axle, and the test of the test sample is carried out.

This invention discloses a physical-data fusion-based method for rapid stress spectrum modeling and fatigue life prediction of bridge cranes, belonging to the field of crane structure safety assessment technology. Addressing the problems of low efficiency in traditional finite element stress calculation, the lack of consideration for the influence of variable stress ratios in conventional crack propagation models, and unreasonable handling of multiple alternating loads in a single working cycle, this invention establishes a stress sample library by building a finite element model of the crane's main beam and uses a gradient boosting decision tree model to achieve rapid stress prediction at critical points. Based on measured load spectra, the maximum and minimum stress values ​​of a single cycle are extracted to generate a stress spectrum. The Walker formula is used to correct the crack propagation rate, and the life prediction is completed by combining a periodic sample cycle method. This invention improves the efficiency of stress spectrum acquisition, ensuring that the stress spectrum compilation closely reflects actual service conditions, while correcting the life prediction deviation caused by variable stress ratios. It can be used for fatigue safety assessment and life prediction of in-service bridge crane metal structures, demonstrating high engineering practicality.

The application provides a kind of angle steel time-varying corrosion bearing capacity evaluation method and system for realizing smart grid, and relates to the technical field of digital operation and maintenance of transmission line.The method obtains the basic parameters and internal force of the tower angle steel component;According to the angle steel corrosion damage criterion, combined with the initial size, atmospheric pollution grade and corrosion life, the damaged section thickness and cross-sectional area of the angle steel component at this time are calculated;Based on the damaged cross-sectional area and the eccentric corrosion influence coefficient when connected with single limb, the axial force bearing capacity of the angle steel component under the time-varying corrosion damage state is calculated and obtained;Finally, the stress ratio is determined according to the internal force and bearing capacity, and the corrosion damage state of the tower is visually evaluated according to the stress ratio.The application breaks through the limitation of traditional static damage iterative calculation, establishes the time-varying corrosion damage relationship between time and angle steel section, thereby realizing efficient and accurate evaluation of bearing capacity, and significantly improving the safety factor and reliability of power grid operation.

The application provides a large deformation grading method combining with drilling parameters and drilling tests, and belongs to the field of tunnel engineering construction. Specifically, the method comprises the following steps: obtaining engineering rock mass quality indexes; obtaining soft rock mass strength through drilling; obtaining strain data by driving a stress-strain measuring rod into the drilling; calculating soft rock ground stress according to the material parameters of the stress-strain measuring rod and the measured strain data, and obtaining a soft rock strength stress ratio in front of a working face; obtaining the surrounding rock deformation amount through vertical deformation calculation of the stress-strain measuring rod, and solving a tunnel longitudinal deformation curve through a formula, so as to calculate the final deformation amount of the surrounding rock; continuously monitoring for a period of time, and calculating the deformation rate of the working face end of the stress-strain measuring rod; and comprehensively obtaining the soft rock tunnel large deformation grading result according to the calculated strength stress ratio, deformation rate and final deformation amount of the surrounding rock. The method can conveniently and quickly grade the large deformation of the soft rock tunnel, the process is simple, the result is accurate and has timeliness, and the method can be widely used in engineering.

The application discloses a kind of plane out-of-plane stability discrimination methods of baffle type special-shaped steel plate concrete composite wall component. For the baffle type special-shaped steel plate concrete composite wall component that has been designed, the out-of-plane stability parameters of the component are calculated and processed, the initial out-of-plane stability stress ratio is obtained by initial calculation, the final out-of-plane stability stress ratio is obtained by iterative cycle processing, and finally the out-of-plane stability result of the baffle type special-shaped steel plate concrete composite wall component is obtained by judgment processing. The application introduces the stress ratio analytical solution of the strength formula and considers the stress ratio initial value processing of the stability coefficient, greatly speeds up the iteration efficiency, and uses the form of numerical differentiation, gradually approaches the stability stress ratio, second-order convergence, and the convergence speed is faster.

The present application relates to the technical field of data processing, in particular to a sand liquefaction influence range evaluation method, device, equipment and medium. According to the soil physical parameters obtained at multiple drilling positions in the target area, the actual cyclic stress ratio and the critical cyclic stress ratio of each drilling position are calculated; the base safety factor is calculated according to the ratio of the critical cyclic stress ratio to the actual cyclic stress ratio; the base safety factor is corrected according to the coarse sand mass proportion of each drilling position to obtain the corrected safety factor; the liquefaction index of each drilling position is obtained according to the corrected safety factor range of the corrected safety factor of each drilling position and the liquefaction index corresponding to the corrected safety factor range; the liquefaction index spatial distribution map of the target area is obtained according to the liquefaction index of all drilling positions and the preset geological complexity index. The present application provides a clear spatial range basis for the targeted arrangement of anti-liquefaction measures, and reduces the judgment ambiguity in engineering decision-making.

The application relates to a saturated sand dynamic constitutive model construction method considering pore pressure fluctuation growth, which comprises the following steps: determining total pore water pressure, which comprises a residual pore pressure component and a transient pore pressure component, and constructing a normalized stress ratio skeleton curve independent of the pore pressure state; correcting the total pore water pressure to obtain a corrected pore water pressure, and updating the average effective stress at the current time by using the corrected pore water pressure; coupling the normalized stress ratio skeleton curve and the updated average effective stress to obtain a maximum shear stress value; taking the maximum shear stress value as a target state point to construct a dynamic virtual hysteresis curve, which describes the stress-strain behavior of saturated sand, can effectively consider the cumulative damage and alternating shear shrinkage-dilation effect of the soil in the cyclic loading process, and can capture the pore pressure development curve and the cyclic shear stress-strain response which are more in line with the test law, thereby providing a valuable tool for evaluating the response and liquefaction strength of saturated sand under undrained cyclic loading conditions.