18 results about "Statically indeterminate" patented technology

The present invention discloses a method for predicting and modeling the vertical straightness and angular error of a linear axis of a machine tool. First, through probability statistics and the "3σ" product qualification inspection criterion, a sine function with manufacturing error as the amplitude is used to characterize the surface curve of the guide rail during manufacturing. Based on finite element analysis, the pre-tightening force distribution law of the guide rail group bolts under specific assembly processes is revealed, and a deformation model of the guide rail assembly with statically indeterminate analysis is proposed. Finally, considering the superposition effect of manufacturing and assembly, the spatial profile curve equation of the guide rail is established. Furthermore, according to the geometric transformation relationship, the vertical straightness and angular error of the linear axis of the machine tool are calculated. By carrying out uncertainty analysis on the relevant design parameters in the manufacturing and assembly processes of the guide rail, the spatial profile curve of the guide rail obtained by the present invention is more accurate than the regular and periodic sine function assumption in traditional research, which lays a theoretical foundation for the optimization of the original design scheme of the machine tool and the improvement of geometric accuracy.

A method for eliminating redundant force disputes in an over-determined system relates to the field of automatic control technology. It solves the problems of poor control system accuracy, high noise, and low static output caused by redundant force disputes in existing over-determined systems. The method includes: constructing an over-determined system, wherein the over-determined system includes: a conventional rigid body position loop and a redundant force control loop; obtaining a rigid body posture decomposition factor according to the over-determined system; calculating a rigid body posture synthesis factor according to the rigid body posture decomposition factor; calculating a deformation posture decomposition factor according to the rigid body posture synthesis factor; generating a position correction control signal according to the redundant force controller and the deformation posture decomposition factor; generating a position loop control signal according to the posture controller and the rigid body posture decomposition factor; superimposing the position correction control signal and the position loop control signal as the input signal to excite the system, thereby completing the elimination of redundant force disputes. It is applied to the control of over-determined systems in ground test equipment in the fields of transportation, aerospace, civil engineering, etc.

The application discloses a beam structure damage identification method of an exponential optimization modal strain energy method, and steps are as follows: (1) a plurality of mode shape curves before and after beam structure damage are obtained through dynamic testing respectively; (2) the mode shape curvature before and after beam structure damage is calculated by using a central difference method, and then the mode shape curvature curve after damage is adjusted by using an optimal matching method; (3) the mode shape curvature before beam structure damage is subtracted from the adjusted mode shape curvature after damage for a statically determinate structure, and damage positioning is carried out by using mode shape curvature difference curve mutation synthesis for a statically indeterminate structure; (4) the mode shape curvature of a unit is calculated by using the mode shape curvature before beam structure damage and the adjusted mode shape curvature, and damage degree quantification is carried out by using the exponential optimization modal strain energy method. The application can accurately identify the damage position and damage degree of a beam structure, is suitable for different beam structure damage identifications, provides an effective new method for beam structure damage identification, and can be applied to bridge damage evaluation.

This invention discloses an advanced positioning algorithm that, by constructing a statically indeterminate linear equation system, can efficiently integrate data from various stations in a large-scale distributed positioning system and accurately determine the target location in a single calculation. Its innovation lies in utilizing the transformation relationship between polar and rectangular coordinate systems to directly construct a boundary value equation containing mixed variables based on the path difference equation. Through appropriate equation transformation and variable substitution, the algorithm achieves linearization of the boundary value equation, significantly simplifying the calculation process. Furthermore, addressing the decisive influence of the path difference construction method or matrix construction strategy on positioning accuracy, this invention proposes unique path difference construction rules or coefficient matrix construction methods. These rules and methods ensure highly accurate positioning results in practical applications. The new algorithm is not only simple but also significantly improves positioning efficiency, bringing a revolutionary change to large-scale distributed positioning.

The application belongs to the field of bridge health monitoring and rapid detection, and discloses a bridge bending stiffness identification method based on multi-point deflection influence line input, and steps are as follows: firstly, a linear model for solving bending stiffness is established by using measured deflection influence lines at multiple positions of a bridge and linear elasticity theory; then, a redundant dictionary composed of multiple types of global basis functions is used for sparse representation of the bending stiffness distribution curve, and the bending stiffness reconstruction problem is converted into a sparse vector solving problem; finally, a sparse vector solution model with 1-norm regularization constraint is established, and the optimal bending stiffness distribution is obtained by solving the model. l The application can realize continuous bending stiffness curve solving by using multi-point measured deflection influence lines only, is suitable for stiffness evaluation of statically indeterminate in-service bridges such as continuous girder bridges, and has the advantages of strong applicability, high solving efficiency and strong robustness.

The present invention discloses a design optimization method for aircraft tooling lightening holes, belonging to the technical field of aircraft tooling design. The method comprises the following steps: obtaining the load-bearing conditions of each beam on a tooling without lightening holes; simplifying the beams on the tooling into statically indeterminate beams with fixed ends, transforming them into equivalent statically determinate systems when solving the problem, moving the load to the midpoint of the beam according to the force translation theorem, and then calculating the deformation of the beam by superimposing the deformation effects of each section to derive the maximum deformation equation of a cantilever beam with lightening holes when subjected to a concentrated force; determining the stiffness requirements and weight reduction goals of the tooling, and clarifying the limiting conditions of the lightening hole parameters; determining the beam load transfer relationship and determining different optimization strategies based on different load transfer methods; using orthogonal experiments to determine the degree of influence of the lightening hole parameters on the optimization goal, and optimizing the design of the tooling lightening holes based on the test results. The present invention provides new ideas and methods for the design of tooling lightening holes.

The present invention discloses a method for calculating the internal forces of a special segment structure during upward shield construction. The method determines the vertical load and lateral load of the special segment structure; based on the fact that the special segment ring structure is a quadratic indeterminate structure, a displacement coordination equation at the elastic center is established, and the elastic center method is used to analyze the internal forces of the special segment ring; the segments at the openings of the special segment ring structure are approximated as curved thin plates, the stress conditions of the special segment structure are analyzed, and the internal force calculation of the lateral load is corrected; the internal forces of the special segment structure under the action of the vertical load are calculated; and the segment ring internal forces under the action of the lateral load and the vertical load are superimposed to obtain the final internal forces of the special segment. The calculation method proposed by the present invention is simple and has strong applicability, and takes into account the special loads caused by upward shield construction and the influence of the construction opening.

The present invention discloses a method for calculating the load of reinforced earth retaining walls with a simple concept and easy operation. The reinforced earth retaining wall is composed of earth fill, horizontally arranged ties, and grid panel units. The grid panel units include diagonal ties, vertical ties, and horizontal ties. The calculation method includes the following steps: Step 100, numbering the grid panel units from top to bottom and calculating the lateral earth pressure and ties tension acting on any grid panel unit layer based on the static equilibrium condition of the local soil wedge; Step 200, treating the grid panel unit structure as a primary statically indeterminate structure and calculating the axial force and cross-sectional normal stress of the diagonal ties of any grid panel unit layer; Step 300, calculating the axial force, bending moment, shear force, and cross-sectional normal stress of the vertical ties of any grid panel unit layer based on the static equilibrium condition; Step 400, calculating the axial force, bending moment, shear force, and cross-sectional normal stress of the horizontal ties of any grid panel unit layer based on the static equilibrium condition.

The invention discloses an engineering rock mass non-constitutive data driving calculation method. The method comprises the following steps: acquiring geometrical characteristic parameters and spatial distribution rules of structural surfaces in various rock masses based on field geological survey; constructing a discrete fracture network model by adopting a layered and partitioned modeling method; respectively establishing databases of surface fractured rock mass and deep fractured rock mass; constructing a statically indeterminate equation for each data point in the database, and taking a least square method solution as a balance factor matrix; and simulating a stress field, a strain field and a displacement field of the engineering rock mass under the loading and unloading effects based on a non-constitutive data driving calculation method. The method is suitable for simulation analysis of the stress field and the deformation field of the engineering rock mass under external overload and excavation unloading. Aiming at the heterogeneous, discontinuous and anisotropic medium of the engineering rock mass, the method does not need to pre-define the constitutive relationship between the rock and the joint, can more accurately simulate the deformation behavior of the engineering rock mass under the complex geological condition, and provides an efficient and reliable technical means for slope excavation design and stability analysis.

The invention discloses a foundation pit enclosure wall top end displacement calculation method and system based on inclined struts. The method comprises the steps that 1, the foundation pit enclosure wall based on the inclined struts is simplified into a rod piece structure model; 2, the rod piece structure model is of a cubic statically indeterminate structure, redundant constraints of the model are removed, unknown force is used for replacement, and a force normal equation is established; 3, solving unknown force in the force normal equation; and 4, obtaining the displacement of the top end of the enclosure wall by using a virtual force method. According to the calculation method, the displacement of the top end of the enclosure wall based on the inclined strut is simply and quickly calculated, complex parameter calibration or participation of numerous professionals is not needed, and the construction efficiency is greatly improved.

The application discloses a railway passenger car whole vehicle completion method based on an explicit dynamic integral method, and comprises the following steps: obtaining the parameters of materials to be matched with a railway passenger car whole vehicle to be completed; constructing a statically indeterminate balance model of the railway passenger car whole vehicle to be completed, and obtaining the displacement response of the statically indeterminate balance model; calculating first theoretical pad parameters according to the displacement response and the completion requirements of the railway passenger car whole vehicle; inputting the parameters of the materials to be matched into a full connection feedforward neural network, and obtaining second theoretical pad parameters; constructing a linear regression model, combining the first theoretical pad parameters and the second theoretical pad parameters, and outputting the combined parameters as pad parameters to be added; and guiding the railway passenger car whole vehicle to be completed according to the pad parameters to be added. The application can more accurately calculate the required pad parameters, improve the completion precision, reduce repeated operations, and improve the production and maintenance efficiency; through data analysis and machine learning technology, the application can adapt to various physical changes that may occur in the long-term operation of the railway passenger car.

To provide a method for selecting a reinforcing place of an statically indeterminate structure, which enables a column to be reinforced to be properly selected in view of the whole statically indeterminate structure.SOLUTION: This reinforcing place selecting method of the statically indeterminate structure selects a column to be reinforced with the statically indeterminate structure having a plurality of columns and slabs made of reinforced concrete as an object. The method includes a step (S3, S5, S51) of selecting a column that causes a decrease in load of the statically indeterminate structure by using a material damage indicator of concrete of the column calculated by nonlinear finite element analysis using an analysis model of the statically indeterminate structure to be reinforced, and a step (S6, S7) of performing nonlinear finite element analysis again using an analysis model after reinforcement of the selected column and checking a reinforcement effect of the entire statically indeterminate structure based on a result of the nonlinear finite element analysis after reinforcement.SELECTED DRAWING: Figure 1

The invention discloses a reliability analysis method for a bar system structure system without searching a failure mode. The method comprises the following steps: firstly, exporting an elastic stiffness matrix according to a finite element model of a structure, and outputting internal forces of all units; deducting the contribution of the section of a part of rod pieces needing to bear internal force in the structural elastic stiffness matrix, and constructing a virtual stiffness matrix of the rod system structure; eigenvalue decomposition is conducted on the structure virtual stiffness matrix, the minimum eigenvalue of the structure virtual stiffness matrix is output, and the minimum eigenvalue serves as a performance function for judging the failure of the structure system; solving a probability density function of the performance function; and finally, calculating the system reliability and the failure probability of the rod system structure. According to the method, the minimum characteristic value of the virtual stiffness matrix of the structure is used as a performance function for judging the failure of the structure system, the failure mode and correlation analysis of the structure are avoided, a key problem in the reliability calculation of the high-order statically indeterminate rod system structure is solved, and the method is suitable for the reliability analysis of the high-order statically indeterminate rod system structure.

A method for simulating statically indeterminate boundary of static test of a component with connecting joint parts, comprising: performing finite element analysis of actual state of the component; performing finite element analysis of each connecting joint hinge constraint state on the boundary of the component; if the deviation of each connecting joint node force and element strain on the main force transmission path in the actual state of the component and the connecting joint hinge constraint state on the component exceeds the set deviation value, then: on the basis of the connecting joint hinge constraint state on the boundary of the component, releasing displacement constraint of part of the connecting joints in part direction according to relative deformation of each joint in the theoretical state of the component, and applying active load on part of the connecting joints, establishing an updated finite element model according to the new boundary condition, constructing an optimization model to correct the active load, until the deviation of each connecting joint node force and element strain on the main force transmission path is within the set deviation value range in the actual state of the component, and then obtaining the simulation of statically indeterminate boundary of static test of the component.

The present invention discloses a method for determining the bearing capacity of an asymmetric constrained indeterminate reinforced concrete beam. The method comprises the following steps: calculating the bending moment of the fixed section and reducing it, taking the moment at the hinged end support to establish an equilibrium equation; (4) based on the bending moment of the fixed section and the shear force at the fixed end loading point, establishing an internal force equilibrium equation for the fixed end compression rod-tension rod model, and obtaining the relationship between the unilateral concentrated load P borne by the reinforced concrete beam and the load borne by each component; (5) based on the shear force at the hinged end loading point, establishing an internal force equilibrium equation for the hinged end compression rod-tension rod model, and obtaining the relationship between the unilateral concentrated load P borne by the reinforced concrete beam and the load borne by each component; (6) calculating the plastic ultimate bearing capacity of each component and using it as the load borne by each component, calculating multiple P values, and taking the minimum P value as the ultimate bearing capacity of the reinforced concrete beam. The present invention determines the failure mode of the component by determining the location of the damaged component.

The application provides a statically indeterminate multi-point support combined static test system for a multi-hanging missile, which comprises a bearing support module, a tooling module, a static loading module, a test module and a plurality of slider loading tools; the bearing support module comprises a bearing structure and a support structure; the hanging missile comprises a missile body and a plurality of sliders, the plurality of sliders are installed on the missile body and are distributed along the length direction of the missile body; the number of the sliders corresponds to the number of the slider loading tools one by one, and the tooling module is connected with the missile body; the static loading module can provide a force for the missile body through the tooling module; and the test module is used for testing the stress condition of the missile body. The test system scheme of the application is simple and convenient to operate, can safely and reliably perform static test verification on the statically indeterminate multi-point support of the multi-hanging missile, has low test cost, fully meets the requirements of the static test of the multi-hanging missile, and can more truly simulate the real stress state of the missile hanging under the air hanging condition of the missile.

The present invention establishes a method for measuring and verifying the intersection loads of statically indeterminate aircraft engines. First, a strain bridge is designed and installed, and separate load calibration tests are carried out on the engine's inner / outer thrust pins and vertical / horizontal tie rods. The strain-load equations for each intersection load component are established using a stepwise multivariate linear regression method. Then, onboard load calibration tests are carried out on the engine's inner / outer thrust pins and vertical / horizontal tie rods, and the calibration test data are used to establish a method for verifying the rationality and prediction accuracy of the aforementioned strain-load equations. The present invention avoids the problem of multicollinearity in the constructed load equations that affects robustness, improves the equation's prediction accuracy, and provides a technical path for verifying the rationality of constructing strain-load equations for statically indeterminate aircraft engines based on separate load calibration test data, providing reliable support for flight measurements of intersection loads on aircraft engines.

The invention relates to a method for judging the anti-overturning stability of a single-column-pier curve beam bridge, and the method comprises the following steps: S1, calculating the anti-overturning stability effect of a bridge under the dead load action according to the basic principle of structural mechanics on the basis of the mechanical analysis of the displacement of a simply supported statically indeterminate curve beam and the reaction force of a support; s2, on the basis of mechanical analysis of simply supported statically indeterminate curve beam displacement and support reaction force, according to the basic principle of structural mechanics, the overturning instability effect of the bridge under the live load effect is calculated; s3, calculating the anti-overturning stability coefficient of the bridge according to the calculation results of the dead load anti-overturning stability effect and the live load overturning instability effect; and S4, based on the calculation result of the anti-overturning stability coefficient of the single-column-pier curve beam bridge, judging the anti-overturning stability of the bridge according to a standard threshold value. According to the method, the efficiency of calculating and judging the anti-overturning stability of the single-column-pier curve beam bridge can be improved, the popularization of a bridge health monitoring technology is facilitated, and the method has the advantages of simplicity, high efficiency and rapidness.