29 results about "Force balance equation" patented technology

The invention discloses a dynamic modeling tracking control method for a self-adaptive fiber placement compaction mechanism, and belongs to the technical field of specific model calculation systems, and the method comprises the following steps: S1, building a kinematic model of the self-adaptive fiber placement compaction mechanism; s2, establishing a workpiece surface model, and solving tangent point coordinates and position coordinates of the driving wheel, the driven wheel and the ground; s3, according to the force balance equation and the moment balance equation of each rod, the relation between each bearing reaction and the external force is solved; s4, establishing a dynamic model of the driving device; and S5, error analysis and optimization are carried out, and it is ensured that the main pressure is within the fluctuation range. According to the device, it can be ensured that the rollers output constant compaction force when the abrupt change molded surface structure is laid, and the forming defect caused by uneven compaction force is avoided.

The invention discloses a vehicle three-way cooperative auxiliary control method fusing PINN tire transverse and longitudinal force prediction. Comprising the following steps: constructing a dynamic model of a vehicle based on a force balance equation and a moment balance equation of the vehicle; constructing a physical information neural network model; training the physical information neural network model by taking the dynamic model as a dynamic constraint and taking the minimum physical residual error loss as a target to obtain a physical prediction model; the physical prediction model is fused, a cost function with the longitudinal resultant force, the additional yawing moment, the slippage loss power and the motor loss power of the vehicle under the action of the auxiliary control quantity as factors is constructed, the cost function is solved with the minimum cost function as the target, and the minimum cost function is obtained. The auxiliary control quantity used for conducting three-way cooperative auxiliary control on the vehicle is obtained; and adopting the auxiliary control quantity pair. According to the method, the problems that tire model parameters are difficult to calibrate and the cost is high during vehicle three-way cooperative auxiliary control, and key performance indexes of a cost function in a nonlinear optimization problem have characterization defects are solved.

Disclosed is a roller taper grinding method for a planetary roller screw mechanism. The method includes steps as follows: step 1: determining basic parameters and a bearing capacity of a planetary roller screw mechanism to be machined; step 2: establishing deformation and force balance equations of the planetary roller screw mechanism according to the basic parameters and the bearing capacity of the planetary roller screw mechanism determined in step 1; step 3: iteratively computing an optimal grinding taper angle of roller grinding according to the deformation and force balance equations established in step 2; step 4: determining process parameters of roller grinding; and step 5: grinding a roller taper of the planetary roller screw mechanism by a machine tool according to the process parameters determined in step 4.

The application discloses a method for analyzing bearing capacity of two-span concrete floor slabs under column end constraints, comprising: obtaining position parameters of the concrete floor slabs, calculating displacement coefficients of different beams based on the position parameters; establishing slab plane equations of a yield line load stage based on the displacement coefficients, obtaining slab rotation angles of each slab along x and y coordinate axes based on the slab plane equations; calculating yield line load values according to the virtual work principle based on the slab rotation angles; calculating membrane force parameters based on force balance equations, moment balance equations and elliptical regions of each slab; establishing plane equations of each slab under a limit state, calculating bearing capacity increase coefficients according to the plane equations; obtaining a total increase coefficient based on the force equivalence principle, and obtaining a limit bearing capacity based on the total increase coefficient and the yield line load values. The application can make the bearing capacity of the reinforced concrete floor slabs under column end constraints have a smaller error compared with the actual situation.

The present invention discloses a method for designing high-speed multi-rotor blades. In the method, the approximate range of blade sizes is first limited by known basic data and expected data to obtain the force balance equation of the drone. Then, a sufficient number of specific blade sizes that meet the limited range are given. By comparing expected performance indicators, data is screened from the given blade sizes, adjusted in a random crossover manner, and screened again. This is repeated multiple times until the expected performance indicators can be obtained. If the expected performance indicators cannot be obtained, the initial amount of specific blade size data is increased, the output volume of each screening is reduced, and the screening process is executed again.

The present application relates to the technical field of fluid control valve, specifically to a pilot pressure reducing valve pilot pressure pipe length optimization design method. The present application uses the force balance equation containing time lag to obtain the critical time lag of the system generating periodic oscillation, then establishes the length constraint equation of the pilot pressure pipe through the relationship between the pipe length and the critical time lag, finally uses the iterative method to obtain the maximum allowable length of the pilot pressure pipe, and then outputs the actual length according to the field installation requirement, which can provide adjustment suggestions for different installation conditions and has wide adaptability. At the same time, the reasonable range of the pilot pressure pipe length can be determined at the design stage, the pilot pressure pipe can be avoided to be replaced repeatedly on site, the installation cost is reduced, and the consistency of the valve is improved.

The application relates to a wave compensation system modeling and pose control method based on a Stewart platform, which comprises the following steps: step 1, performing dynamic analysis on a shipborne Stewart platform and obtaining a force balance equation; step 2, calculating the action of a gangway mechanism on the upper platform of the Stewart platform; step 3, expanding the force balance equation based on the action of the gangway mechanism on the upper platform of the Stewart platform, and then establishing a dynamic model of the shipborne Stewart platform considering the gangway; and step 4, designing a Stewart platform pose controller based on a backstepping method to control the pose of the Stewart platform. Compared with the prior art, the application has the advantages of improving the precision of wave compensation and improving the pose control precision.

The present invention relates to a design method for a parallel mechanism with both high normal stiffness and high lateral stiffness, comprising the following steps: S1, determining the motion freedom requirements of the parallel mechanism dynamic platform, establishing the mechanism motion spinor system and constraint spinor system, and establishing the branch constraint spinor system and motion spinor system of the parallel mechanism; S2, establishing a force transmission model of the parallel mechanism, and determining the maximum design criterion for normal stiffness; S3, establishing the force balance equation of the parallel mechanism, introducing an auxiliary configuration to provide an additional force system to adjust the overall stress state of the mechanism, and determining the design criterion for maximizing lateral stiffness; S4, combining the maximum design criterion for normal stiffness and the design criterion for maximizing lateral stiffness with the dynamic and static force model to obtain a parallel mechanism with both high normal stiffness and high lateral stiffness. The present invention establishes a design criterion for maximum normal stiffness of the parallel mechanism to maximize the normal stiffness of the mechanism, and has important application prospects in parallel mechanisms under heavy load conditions.

The invention relates to a method for calculating the flexural capacity of a hogging moment area of a reinforced concrete composite beam based on a UHPC thin layer. The method comprises the steps that a test piece is prepared, measuring points are arranged, a load strain curve and a loading result graph of the test piece are obtained through a pressure loading test, and flexural performance characterization is determined. Determining an associated stress area of the composite beam according to the bending resistance characterization, presetting a first assumption condition, and performing derivation based on a strain expression, an internal force expression and a force balance equation to obtain a calculation expression of a cracking bending moment; presetting a second assumption condition, deducing and determining the position of a plastic neutral shaft, establishing a moment balance equation, and deducing according to the section strain expression, the internal force expression and the moment balance equation to obtain a calculation expression of the flexural capacity of the composite beam.

The application discloses a kind of stirling generator performance prediction method.This method is established by force balance equation and volume equation to the gas distribution piston, power piston, compression cavity and expansion cavity inside stirling generator respectively, combined with ideal gas equation, mass conservation equation and energy conservation equation, constructs the heat-dynamics coupling model of stirling generator including kinetic parameters and thermodynamic parameters;According to the input kinetic parameters, the running frequency, displacement amplitude of gas distribution piston and power piston and the phase difference of two pistons are calculated;Further solve the thermodynamic model, obtain the change of temperature, pressure, mass and mass flow of working medium;Then the results are substituted into motor model, obtain effective voltage, effective current and effective electric power;Through heat-dynamics coupling solution and combined with motor model, the whole process of heat-work-electricity conversion is solved and calculated, so as to realize the heat-dynamics-electricity parameter prediction of stirling generator, provide theoretical guidance for whole machine fault diagnosis and optimization design.

The invention discloses a method for leveling the balance stress of a double-hanging-point independent double-string type suspension fitting string. The method comprises the following steps: S1, creating an independent double-hanging-string type balance stress model; s2, stress parameters are calculated; S3, an independent double-hanging string type balance stress leveling calculation equation is formed; s4, the string type stress values under various working conditions are judged through stress analysis; S5, the leveling value of the difference value delta of the front-side independent string type and the rear-side independent string type is calculated according to different stress conditions; according to the scheme, the stress analysis model can be established according to the situation that the independent double-hanging-point string type in the large-fluctuation mountainous area section cannot achieve stress balance, and detailed numerical values of all parameters needed in the stress balance state are obtained by analyzing the stress balance equation. According to the calculated parameters, stress leveling can be effectively carried out on the whole string type, and the problem that each independent branch string does not reach the planned stress is solved.

The invention discloses a method for analyzing an integral swing structure with asymmetrical rigidity around a strong axis and a weak axis of the structure. The method comprises the following steps: S1, designing an upper structure; s2, calculating the shear force of the base; s3, the shear bearing capacity of the vertical tension-compression energy dissipation limiting support is designed; s4, establishing a mechanical analysis model, and solving a force balance equation; s5, a rigid body displacement proportion u3 / u is preset, and the basic rotation rigidity KSy of the upper structure around the weak axis side is solved; s6, calculating the rigidity of the vertical bearing damping body according to the axial force of the bottom of the upper structure under the action of the gravity load; s7, the basic rotation rigidity Ksx of the upper structure around the strong axis side is calculated; s8, the basic rotation rigidity Ksx of the side, around the strong axis, of the upper structure is substituted into the force balance equation, the lateral stiffness of the side, around the strong axis, of the upper structure is calculated, and the section size of a beam or a column is adjusted; s9, a vertical tension and compression energy consumption limiting support is designed; s10, estimating a damping ratio, and carrying out earthquake time history response analysis; and checking whether a corresponding limit value and a performance target of the specification are met.

The invention relates to the technical field of cushion collar design, and particularly provides a design method of a labyrinth cushion collar, a cushion structure, a hydraulic oil cylinder and a hoist, the design method comprises the following steps: firstly, determining the length, the inner diameter and the outer diameter of the cushion collar according to the size and energy conservation of the hydraulic oil cylinder; secondly, deriving a throttling area curve of the outer surface of the cushion collar according to a force balance equation and a flow equation of a hydraulic oil cylinder piston so as to determine the tapping position of a damping hole in the cushion collar; then the number and the hole diameter of damping holes are determined according to the expected buffer pressure curve and acceleration curve; according to an energy dissipation mechanism and the mathematical model of the cushion collar, the flow resistance series and the flow channel structure of the cushion collar are determined; according to the model, the buffer speed curve and the buffer pressure curve of the buffer sleeve are quickly obtained from the peak pressure and the maximum initial speed, and according to test verification, the method can quickly and accurately design the buffer device meeting the requirement of high-speed heavy-load operation of the quick hydraulic hoist, and the problem that the complex flow channel buffer device is difficult to design and verify is solved.

Provided is a design method for a self-compensation structure of a cam-lobe hydraulic motor plate distribution system, which comprises that follow steps: firstly, establishing a force balance equation, a pressure distribution equation and a flow balance equation for each balance chamber, setting a boundary condition, and setting an expected nominal clearance; selecting a fit clearance for simultaneous solutions, and obtaining a set of solutions of areas; taking a maximum value in this set of solutions as the median, and setting a set of area values in the optimization design; further solving changing curves of the nominal clearance and the total leakage of the distribution system with the rotation angle of the cylinder block, and calculating the average value of various curves after the operation is smooth, and designing the self-compensation structure based on selection of the optimal combination of the fit clearance and area.

The invention discloses a design method and device for reducing the using amount of lower chord steel bars of a laminated slab and a terminal, and the method comprises the steps that a target balance equation is constructed, and the target balance equation is an axial force balance equation of a plane truss prefabricated bottom plate component in the laminated slab in the construction stage; obtaining a target relational expression based on the target balance equation, wherein the target relational expression represents a cross section size relationship between an upper chord steel bar and a lower chord steel bar of the steel bar truss; and designing the lower chord steel bar diameter of the target steel bar truss based on the target relational expression. According to the method, the cross section size relationship between the lower chord steel bars and the upper chord steel bars of the target steel bar truss is inferred reversely by constructing the target balance equation, so that the dosage ratio of the upper chord steel bars and the lower chord steel bars is more reasonable, the design dosage of the lower chord steel bars of the steel bar truss is effectively reduced, and the production cost of the laminated slab is reduced.

The invention relates to the technical field of bridge engineering, in particular to a method and system for determining the bearing capacity of a prefabricated assembled pier under the bending shear-torsion effect, and the method comprises the steps: determining a stress damage model of the prefabricated assembled pier and analyzing assumed conditions, and then building a limit axial force expression and a shear force balance equation; deducing the limit axial force expression, the shearing force balance equation, the bending moment equation and the torque equation to obtain a unified analysis equation of the prefabricated assembled bridge pier; building a joint torsional bearing capacity calculation formula based on the shear bearing capacity data and the joint stress condition; performing peak load calculation and test comparison on different prefabricated assembled piers according to the unified analysis equation of the prefabricated assembled piers and the joint torsional bearing capacity calculation formula. According to the method, the combined action of the pressure, the bending moment, the shearing force and the torque is comprehensively considered, the stress condition of the prefabricated assembled pier can be reflected more accurately, and accurate prediction of the peak bearing capacity and the peak torque of the prefabricated assembled pier under the action of the bending shear-torsion load is achieved.

The present application relates to a kind of shield tunnel steel plate reinforced joint bending carrying capacity calculation method, comprising the following steps: 1) the virtual strain of the inner edge of joint surface is obtained when calculating steel plate reinforcement, and the critical compression zone height of bolt yielding and the critical compression zone height of steel plate yielding when section failure;2) assume that joint surface is in a certain failure state, based on the axial force balance equation under the failure state, corresponding steel plate reinforced joint joint surface compression zone height is obtained by trial;3) whether joint surface compression zone height meets the range requirement of current failure state, if yes, then execute step 4), if not, then replace another failure state, return to step 2);4) the steel plate reinforced joint joint surface compression zone height obtained in step 2) is substituted into the bending moment balance equation under the current failure state, and the limit bending moment is calculated and obtained.Compared with prior art, the present application has the advantages of effectively reducing workload, improving efficiency and the like.

The application discloses a fan-shaped stiffened pipe plate node structure stress analytical calculation method, and relates to the field of stress calculation of a steel structure pipe plate node of a power transmission tower. The method comprises the following steps: firstly, a calculation section is selected, a curved beam calculation model is established, and an internal force equation is established; a displacement response is calculated by using a unit load method; internal force and node stiffness are solved by combining displacement coordination and force balance equations; then, the model is improved into an elastic support curved beam model; flexibility coefficients and displacement free terms are calculated; spring counter forces are solved and are superimposed to correct the internal force; after the rotational spring stiffness is calibrated, the node structure stress is output; the application provides a closed analytical solution of the structure stress, and does not need complex finite element modeling, thereby simplifying the process, reducing the cost, filling the technical gap, providing a basis for fine design of node fatigue resistance, and improving the bearing performance and service safety of the node of the power transmission tower.

The application provides a mechanical property analysis method and system of CFRP grid reinforced concrete, parameters and loading schemes of a stress analysis model of a CFRP grid concrete beam are acquired, a linear softening model is used for a CFRP grid and a concrete interface bonding slip relationship; a known beam with the same height and bearing external bending moment is constructed; in a first stage with a crack bottom width less than a critical crack width, load, crack parameters and stress distribution characteristics in a crack expansion process are calculated according to geometric characteristics, concrete characteristics and CFRP characteristics of the known beam; in a second stage with the crack bottom width greater than or equal to the critical crack width, a force balance equation is described, a relationship between the crack bottom width and the compressive stress of the top of the section is defined, and the load, crack parameters and stress distribution characteristics in the crack expansion process are calculated. The application considers post-cracking tensile stress in the concrete, bonding slip behavior between the CFRP and the concrete, and the result is accurate.

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 shear lag estimation method for a box girder with a reinforcing structure, and comprises the following steps: S10: establishing a structural model for the box girder based on an analogy bar method, distributing the area of the reinforcing structure to simulation bars and simulation plates, and outputting the equivalent area of the simulation bars and the equivalent thickness of the simulation plates; S20: establishing stress balance equations and deformation coordination equations for the simulation bars, and outputting differential equations of shear flow; S30: outputting the shear flow of the simulation bars and the shear flow of the reinforcing structure according to the differential equations of the shear flow; and S40: outputting the stress of the simulation bars. The shear lag estimation method for the box girder with the reinforcing structure has the beneficial effects of wide application range and being capable of being used for guiding engineering design, and solves the defects of the traditional analogy bar method that cannot process the reinforcing structure.

The invention discloses a method for analyzing geometric errors of a linear feeding system under any attitude. The method comprises the following steps of: constructing a representation method of the linear feeding system under any attitude; testing and decomposing guide rail assembly errors, and establishing a stress balance equation of the linear feeding system; the geometric error of the moving part is solved; performing geometric error traceability analysis, and determining main factors influencing the geometric error of the moving part; the method for analyzing the geometric error under any attitude is developed for different linear feeding system configurations, a stress balance equation of the linear feeding system under any attitude is established, the geometric error of a moving part is solved, traceability is achieved by comparing the influence degrees of different factors on the geometric error, and the accuracy of the geometric error analysis is improved. In order to solve the problems of assembly precision verification, structure optimization, active precision design and the like of the linear feeding system, the invention further comprises a system, equipment and a medium for realizing the method.

This invention relates to the field of fluid control valve technology, specifically to a method and system for predicting the dynamic stability of a pilot-operated pressure reducing valve. The invention establishes a force balance equation containing p-Laplace terms and derives the stability criterion S for the pressure reducing valve to determine whether the valve system is stable. This allows for the assessment of whether parameter combinations will lead to oscillations during the design phase, avoiding trial and error and enabling the prediction of the pressure reducing valve's stability. The criterion is simple in form, can be calculated using a calculator or Excel, does not rely on complex simulations, and is highly concise. Furthermore, its p-value is adjustable, making it applicable to different media and operating conditions, thus offering wide applicability. This system can be embedded in an intelligent valve controller to achieve real-time stability warnings.

A platform for testing the excavation resistance of a small-sized backhoe excavator is provided. The testing platform comprises a bucket, a mechanical arm device, a measuring device, a workbench frame, and a control device. The bucket is hinged to the mechanical arm device, which is fixed on the workbench frame; the control device is electrically connected to the measuring device, data acquired by the measuring device is used to construct a force balance equation, and through force analysis, excavation resistance is obtained.

The application discloses a kind of ball screw contact characteristic calculation method and system, input ball screw size parameter and external load, the correlation equation of preliminary establishment ball stress and axial load;Combined with the balance condition of force, the displacement variation of raceway contact point under axial load is solved;Add the rotational speed parameter of ball screw, calculate the position offset of raceway contact point when high speed rotates, and update the contact angle between ball and screw / nut;Through geometric constraint equation and kinematic analysis, the centrifugal force and gyroscopic moment generated by high-speed rotation of ball are quantified;On the basis of original static model, superimpose centrifugal force, gyroscopic effect and friction force of contact surface, and rebuild axial, radial stress balance equation containing dynamic factors;The geometric constraint equation is associated with multidimensional mechanics equation, numerical calculation is carried out using Newton iteration method, and finally the contact characteristics considering uneven load distribution and containing high-speed rotation influence are obtained.

The invention discloses a method for tunnel face load of an aeolian sand stratum tunnel, belongs to the field of tunnel engineering supporting structure design, and solves the problem that a theoretical model of an existing method cannot fully consider mechanical behavior characteristics of special stratums such as aeolian sand and the like, so that the precision of a calculation result is insufficient. The method comprises the steps of establishing a slip mass calculation model considering an included angle between a fracture surface and a horizontal plane based on a Taisha theory, performing calculation to obtain a lateral pressure coefficient, and performing simplification solution on a vertical stress balance equation to obtain a tunnel face load value; according to the tunnel face load calculation method, the tunnel face load calculation method is improved, the calculation formula of the tunnel face load value is obtained by simplifying and solving the vertical stress balance equation, the actual stress state of the aeolian sand stratum can be reflected more accurately, and therefore the precision of the calculation result is improved, and finally more accurate load value can be provided for tunnel supporting structure design; therefore, the safety and stability of the structure are enhanced, and the risk of structure failure caused by inaccurate load calculation is reduced.

This invention discloses an online method for testing the longitudinal force and adhesion coefficient of the wheel / rail of railway vehicles. This method analyzes the forces acting on the wheelset to establish force and moment balance equations. Based on the longitudinal, transverse, and vertical accelerations of the axlebox vibration and the primary longitudinal, transverse, and vertical displacements on both sides of the axle, measured by acceleration sensors mounted on the axles, the wheel / rail vertical force and longitudinal force are calculated, and the adhesion coefficient is calculated. This method addresses issues such as existing testing methods ignoring the adhesion saturation effect, failing to consider the time-varying characteristics of the wheel / rail vertical force, and inadequately measuring the longitudinal force and adhesion coefficient.

The invention provides a self-resetting filler wall frame four-broken-line load-displacement curve prediction model construction method. According to the method, the nonlinear response of the structure is decomposed into four linear stages with obvious physical significance, namely an elastic stage, an elastic-plastic stage, a plastic stage and a recovery stage. The model is based on a mechanical model and a deformation coordination relation of structural key components (prestressed steel bars, energy consumption angle steel and reinforced concrete), and analytical calculation is carried out by establishing a force balance equation of nodes. The provided four-broken-line analytical model can quickly predict the complete nonlinear response of the self-resetting framework without complex iterative calculation or large-scale finite element analysis, the original analysis process of several hours is shortened to the minute level, and the scheme comparison, selection and optimization efficiency in the design stage is greatly improved.

The application provides an aircraft suspension structure load calculation method, and belongs to the technical field of aircraft structure strength calculation. The method comprises the following steps: determining the connection form of the aircraft suspension structure, establishing a simplified mechanical model of the aircraft suspension structure, and determining the load of the front joint, the rear joint, the left pull rod and the right pull rod according to the connection form of the aircraft suspension structure, and determining the position parameters of the front joint, the rear joint, the left pull rod and the right pull rod according to the geometric positions of the components of the aircraft suspension structure. The load balance equation and the distance balance equation of the aircraft suspension structure are established according to the load, the position parameters and the simplified mechanical model of the components. The load of each component in three directions is obtained by solving the load balance equation and the distance balance equation, and then the total load of each component in three directions is calculated, which is the load of the aircraft suspension structure. The load of the aircraft suspension structure can be quickly obtained.