8 results about "Ultimate load" patented technology

The invention discloses a deep foundation bearing capacity characteristic value calculation method and system based on data fusion. The method comprises the steps that data collection is completed through a deep load test, and a load settlement curve and a settlement time logarithmic curve are formed; generating a smooth curve; identifying a slope mutation point of the curve by adopting a first-order derivative mutation method, wherein a load corresponding to the mutation point is a proportional limit load; if the slope abrupt change point is not recognized, the curve is set as a slowly changing curve; extracting the slope and the slope change rate of the curve under each level of load, and completing the judgment and correction of the limit load by fusing the multi-dimensional data of the two curves and combining preset thresholds including the settlement amount and the settlement stabilization time; and further calculating the bearing capacity characteristic value of the deep foundation by combining the numerical relationship between the ultimate load and the proportional limit load.

The invention discloses a shield butt joint section curtain grouting additional load determination method, and relates to the technical field of geotechnical engineering grouting, and the method comprises the steps: carrying out the preprocessing of obtained grouting measurement data, obtaining an envelope point set, and carrying out the fitting optimization based on an envelope line function model, and obtaining an optimized envelope line function; calculating an ultimate load, attenuating the ultimate load to a preset engineering allowable threshold value to obtain an ultimate load acting distance, and determining boundary conditions through an envelope line intercept analysis method; and correcting the limit load according to a preset grouting load safety coefficient to obtain a corrected limit load, and performing inversion correction in combination with the grouting measurement data to obtain a final limit load and a final boundary condition. According to the method, the significant action range and the most unfavorable load condition of the grouting load are determined by capturing the spatial distribution and evolution law of the additional soil pressure field caused by grouting, and accurate load boundary conditions are provided for model analysis or finite element calculation.

The invention belongs to the technical field of aircraft structural strength analysis, and particularly relates to a metal material stress plasticity correction method. The method comprises the steps that firstly, material parameters of the aircraft metal material structure are obtained; step 2, adopting a linear finite element static strength analysis method to obtain stress distribution of the aircraft metal material structure under the action of a limit load, and if the stress meets a preset condition, entering step 3; 3, according to the material parameters, the Ramberg-Osgood nonlinear hardening index during tensile failure is corrected, and the corrected nonlinear hardening index is obtained; and 4, constructing a stress equation, and substituting the nonlinear hardening index into the stress equation to obtain the real stress of the aircraft metal material structure after plastic correction. According to the method, the metal material stress of the aircraft metal material structure can be conveniently and quickly subjected to plastic correction.

This invention proposes a safety assessment method for delaminated composite materials based on the principle of damage non-propagation, belonging to the fields of composite material delaminated damage modeling and composite structure safety assessment. The method includes: constructing ultimate load envelopes that meet the damage non-propagation requirement under different damage sizes; for readily available binary observation data in practical engineering, i.e., whether damage propagates under specific damage sizes and load conditions, connecting discrete observations with a continuous parameter space through a latent variable model; using the Probit link function to map the predicted difference between the load and the ultimate load into a damage propagation probability; and constructing a likelihood model using a Bernoulli likelihood function; and optimizing the ultimate load envelope within a Bayesian framework. This invention can effectively support safety assessment and maintenance decisions for composite material structures in aerospace and other fields.

The invention relates to an analysis and calculation method for a blade root connection structure of a wind driven generator, and the method comprises the steps: constructing a finite element model for coupling a blade shell unit and a blade root entity unit, and defining the material attributes of all parts; and a coupling connection relation between the blade shell unit and the blade root entity unit is set to simulate a real force transmission path. Then, target pre-tightening force is applied to the connecting bolts and locked, and distributed working loads are applied to the blade shell units at different angles in the pre-tightening state, so that the bending moment of the end of the blade root is larger than the limit load at the angle. And solving and calculating the loaded model, extracting stress data for connecting the bolt and the bolt sleeve, and performing strength and fatigue analysis on the bolt and the bolt sleeve based on the data. According to the method, the accuracy of stress calculation of the blade root connecting structure and the model precision are remarkably improved by introducing the geometric characteristics, the rigidity characteristics and the distributed load transmission path of the real blade, so that more reliable guidance is provided for design of the wind power blade root and the connecting structure.

This invention discloses a method for analyzing the ultimate load of arch block instability in an inverted arch stilling basin. Using structural mechanics methods, a mechanical model of arch block instability is established, dividing the instability process into three stages: lifting of the middle arch block, sliding of the two side arch blocks, and warping of the two side arch blocks. Considering engineering safety and reasonable computational complexity, the model is simplified, and a simplified structural mechanics analysis method that facilitates manual calculation is proposed. This method can calculate the ultimate load of arch block instability corresponding to different anchoring forces in an inverted arch stilling basin, providing a reliable theoretical basis for the structural design of inverted arch stilling basins and possessing significant engineering application value.

The application discloses an experimental device for simulating fracture failure of anti-slide piles and a use method thereof, belongs to the technical field of geotechnical engineering reinforcement, adopts modular design, and comprises a pile top module, at least one pile middle module, a pile bottom module and a plurality of variable cross-section ultimate load limiting modules; the pile middle module is an upper and lower plate structure hinged by a flat hinge, the modules are slidably connected through convex and concave guide rails, the ultimate load limiting modules are inserted into aligned wedge-shaped holes, fracture occurs at the middle weak part when the ultimate load is reached, and shear failure and bending failure of the anti-slide pile can be simulated respectively. The fracture load can be accurately controlled by adjusting the thickness of the limiting module, the application has the advantages of simple structure, convenient disassembly and assembly, reusability, high test precision and suitability for research on the fracture failure mechanism of the anti-slide pile under different working conditions.

This disclosure provides a method for controlling a hoisting mechanism used to lift an aircraft in near space, comprising: setting the ultimate load that the aircraft must meet under target operating conditions based on risk factors that may cause abnormalities in the aircraft; establishing a finite element model to characterize the aircraft to be lifted and the hoisting mechanism used to lift the aircraft, and using the ultimate load as the excitation input of the finite element model to calculate the mechanical simulation under the target operating conditions to obtain displacement simulation data of the aircraft under the target operating conditions; manufacturing a solid scale-down model including the aircraft and the hoisting mechanism; adjusting the hoisting rope structure with the structural strength of the solid scale-down model of the aircraft as the limit, so that the solid scale-down model of the aircraft can switch between multiple target operating conditions, and constructing the allowable force envelope of each hoisting rope of the hoisting rope structure; controlling the hoisting mechanism carrying the aircraft based on the allowable force envelope of each hoisting rope, so that the aircraft can switch between multiple target operating conditions, from the lifting stage to the release stage.