71 results about "Force balance equation" patented technology

The invention discloses a three-dimensional static modeling method of a rope-driven continuous mechanical arm. The method comprises the following steps: (S1) three-dimensional force balance equationsof each equivalent torsion spring are built according to a three-joint false rigid body model to obtain deflection angles of each torsion spring when the rope-driven continuous mechanical arm is suffered from preset rope tension, external force and gravity; (S2) resultant force and resultant torque expressions of the rope tension, external force and gravity to each branch section terminal are built according to the deflection angles of each torsion spring; and (S3) the resultant force and resultant torque expressions of the rope tension, external force and gravity to each branch section terminal are substituted into the three-dimensional force balance equations of each torsion spring to obtain three-dimensional static balance equations of the rope-driven continuous mechanical arm. A two-dimensional plane false rigid body equivalent method is developed into three-dimensional space; and the operation efficiency is greatly improved.

The invention relates to a method for measuring the flexural rigidity of an immersed tube tunnel joint. The method comprises the following steps: 1, applying an axial external water pressure N0 to the immersed tube tunnel joint as an external force applied to a position having a distance of an initial eccentric throw e0 to the neutral axis of the immersed tube tunnel joint; 2, continuously applying prestressed cable pretensions T1 and T2 to the immersed tube tunnel joint; 3, measuring the displacement S0 and the corner theta of a GINA waterstop under the action of N0, T1 and T2; 4, using an immersed tube tunnel joint structure simplification model established by a steel plate and a spring element to calculate the compression amount SF1 and SF2 of the GINA waterstop, the prestressed cable extension amount ST1 and ST2 at a top board and a bottom board, the pressures F1 and F2 of the GINA waterstrop of the top board and the bottom board, and the pulling forces T1 and T2 of the prestressed cables of the bottom plate; and 4, calculating according to a force balancing equation to obtain the flexural rigidity Ktheta of the joint. Compared with the prior art, the method provided by the invention improves the design level and efficiency of the performance of the immersed tube tunnel joint.

The invention provides a calculation method of soil engineering grid tensile force inside multilayer ribbed cushion layer; the method comprises the following steps: firstly judging a pile net composite foundation plane layout parameter, then determining equivalent linear distribution loads at a ribbed cushion layer surface, and the like; determining a cross section parameter of a ribbed cushion layer equivalent composite plate structure; and then based on an elastic grade beam analyzing method, determining a ribbed cushion layer deformation equation and an internal force equation from a deformation coordinate boundary condition; based on the ribbed cushion layer deformation equation and the internal force equation, calculating a soil engineering grid tensile force caused by the deformation when the embankment filled earth subsides; based on an internal force balance equation under an embankment filled earth transverse slide threshold status, calculating the soil engineering grid tensile force caused by the embankment transverse slide; and finally, superposing the soil engineering grid tensile forces caused by the embankment filled earth subside deformation and the transverse slide, thereby obtaining the needed soil engineering grid tensile force parameter. In condition that multiple layers of soil engineering grids are laid on the top cushion layer of the pile net composite foundation piles, the calculation method is able to precisely calculate the tensile force parameter of each layer of soil engineering grid inside the cushion layer.

The invention discloses an evaluation method of shear capacity of aged reinforced concrete beam bridges, which obtains an initial time of corrosion of reinforcing bars in concrete based on a Fick second diffusion law, and obtains an action force of reinforcing bars at a shear inclined crack by considering the reduction of the cross-sectional area of the corroded reinforcing bars and the reductionof the yield strength of the reinforcing bars; the compressive strain at the loading position of the beam top is obtained from the assumption of plane section. According to the stress balance equationof shear-compression section of beam, a formula for calculating the height of compression zone of concrete at the top of critical inclined crack is established. By integrating the height of compression zone, the horizontal force of a non-cracked concrete section is obtained, and the action position thereof is determined by the moment relation. Based on the ultimate shear equilibrium theory, the calculation method of shear bearing capacity of aged reinforced concrete beam bridges is put forward according to the element equilibrium relationship of isolator in shear-compression section of beam.The prediction method of the invention is reasonable and has strong popularization, and can provide technical support for safety evaluation of the service concrete beam bridge.

The invention relates to a trajectory planning method for variable speed drop of composite press. The trajectory planning method comprises: first, the differential command signals are input in a proportional pilot control valve to control the circulation drop of the press and collect signals of the movable beam displacement, return cylinder pressure and instruction; then, the movable beam displacement is treated by differential method to get the falling velocity signal of movable beam and the mathematical model of valve flow is obtained by training the collected parameters by neural network algorithm; then, combining the force balance equation of the return cylinder and the continuity equation of the flow, a comprehensive mathematical model of the falling system is built; finally, with the error integral of the return cylinder pressure as the optimization index, the improved genetic algorithm is used to optimize the cubic wire interpolation trajectory, and the control trajectory of the moving beam falling is obtained. The trajectory planning method for variable speed drop of composite press adopts the movable beam falling instruction path planning method can effectively avoid the impact of rigid and flexible impact system, restrain the system pressure fluctuations and improve the efficiency and accuracy of trajectory planning activities to enhance the transmission beam falling, improving engineering adaptability.

The invention provides a deep foundation pit enclosure wall stress deformation quick calculating method in consideration of wall soil coupling; and the method fully considers a coupling relation of wall soil deformation in the foundation pit excavation unloading process, and has the advantages of high calculating efficiency, more accordance with actual conditions and the like. The method comprisesthe following steps: (1) an elastic foundation beam model is built (an elastic beam is adopted to simulate a ground continuous wall, a spring unit is adopted to simulate a support, a soil spring unitis adopted to simulate in-pit soil, and the soil pressure adopts a non-limit soil pressure model), and related calculating parameters are determined; (2) the after-wall soil pressure distribution iscalculated (the supposed wall deformation is firstly calculated as zero); (3) a stress balance equation of the ground continuous wall is calculated to obtain corresponding wall deformation; (4) wall deformation errors calculated by two times are judged to restrain to a set value; and if requirements are not met, the steps (2) to (4) are repeated until the errors are restrained to the set value toobtain a final wall deformation value; and (5) the wall bending moment and shearing force and the after-wall soil pressure distribution are calculated based on the wall deformation value.

The invention discloses a reverse shape designing method for elastic object manufacturing. The method comprises the following steps that a user assigns a material type, a target shape and a external force set interactively; based on the elastic deformation characteristics of an actual manufactured object, a hyperelastic material model with advanced predictive capacity is used as a representation model of object deformation; based on an asymptotic numerical value method, an advanced non-linear reverse static equilibrium equation is efficiently and precisely resolved, and the obtained shape can be transformed to the target shape designed by the user under a set external force condition; based on expansion of a core algorithm, interactive adjustment of external force, reverse design of multiple object shapes and quick resolving of forward static balance problems are supported; the technology means of quick forming and the like are used for manufacturing actual objects according with the design objects of the user. According to the reverse shape designing method for elastic object manufacturing, shape designing and technology manufacturing are integrated in a seamless mode so that the user can concentrate on designing of the target shape without worrying the influence of elastic deformation on finial product shapes.

The invention discloses a numerical calculation method of internal force of a beam string structure. The method includes establishing a force bearing equilibrium equation set on the basis of the method of static equilibrium and section internal force equilibrium, wherein the force bearing equilibrium equation set is an equation set about the equilibrium relation of a section bending moment Mb of an upper-layered beam, a section shearing force Vb of the upper-layered beam, a section axial force Nb of the upper-layered beam in an optional position with abscissa x of a beam string, a section axial force T of a lower-layered cable, an entire section bending moment Mx of the beam string and an entire section shearing force Vx of the beam string in an optional position with abscissa x of a beam string, among; figuring out an expression about the abscissa x of the beam string from the section bending moment Mb of the upper-layer beam, the section shearing force Vb of the upper-layer beam, the section axial force Nb of the upper-layer beam and the section axial force T of the lower-layer cable, by constructing an equation that external work W is equal to a sum of a bending strain energy Ubn of the upper-layer beam, a compressive strain energy Ubn of the upper-layer beam and a tensile strain energy Ucn of the lower-layer cable, according to the principle of real work. By the aid of the method, the component internal forces of the upper-layer beam and lower-layer cable of the beam string structure can be estimated and calculated rapidly and accurately, and data are supplied for section bearing capacity checking.

The invention provides a gravity balancer which comprises a support, a swing vibrator and an elastic mechanism and is characterized by also comprising a rail, wherein the rail comprises an upper fixed rail and a lower movable rail positioned below; the fixed rail is fixed on the support without moving, and the movable rail is articulated with the support by virtue of a branch hinged shaft; the swing vibrator is in rigid connection with the movable rail, and the elastic mechanism is straddled between the upper fixed rail and the lower movable rail; the upper end and lower end of the elastic mechanism are respectively connected with the fixed rail and the movable rail in a sliding or rolling manner, and the fixed rail is in the shape of a level beeline or a curve; and the floating rail is in the shape of a curve, and the curve shape is obtained by virtue of a force equation or an energy-balance equation or topological optimization. The balancer provided by the invention has the advantages of eliminating the influence of gravitation on a vibrating energy absorbing system and providing a condition for the vibrating energy absorbing system to form a resonance state, thereby providing afoundation for realizing high-efficiency vibrating energy absorbing system.

The invention discloses a method for calculating the fatigue life of a flexible thin-wall bearing in a harmonic reducer. The method comprises the following steps: S1, acquiring structural parameters,materials, attributes and working conditions of the bearing; S2, carrying out stress analysis, and establishing an equivalent external load model; S3, establishing a radial deformation model of the flexible thin-wall bearing, and establishing an elastic compression amount model; S4, establishing a force balance equation and a deformation coordination equation, enabling the deformation coordinationequation of N'contact points at different balls to be simultaneous with the force balance equation, and calculating N 'different contact loads Pi; S5, establishing a rated dynamic load model and an equivalent dynamic load model; and S6, establishing a flexible thin-wall bearing fatigue life model. According to the method, a more practical load distribution model can be established according to the practical deformation of the assembling working condition of the inner ring of the flexible thin-wall bearing, and the fatigue life of the flexible thin-wall bearing can be more accurately calculated.

The invention relates to the field of aircraft landing gear turning load calculation, in particular to a method for calculating turning load of a four-point type aircraft landing gear, and aims to solve the problem that the load of the four-point type aircraft landing gear cannot be precisely calculated by using a conventional aircraft landing gear load calculation method. The method comprises the following steps: establishing a force balance equation of a four-point type aircraft in a turning state in the vertical direction; establishing a pitch moment balance equation of the four-point type aircraft in the turning state; establishing a rolling moment balance equation of the four-point type aircraft in the turning state; and calculating vertical load and lateral load of landing gears. By adopting the method for calculating the turning load of the four-point type aircraft landing gear, as a dynamic balance method is adopted to calculate the load of the four-point type aircraft landing gear, the calculation result is relatively precise, and the portion of vertical load and the lateral load shared by single-side and single landing gears of the aircraft can be relatively really reflected.

The automatic controlled self -destructor of syringe, infusion set and hemostix consists of hydraulic transmission part, spring seat, spring, puncture set and part for setting clinical hydraulic value and constraining force parameter. During the use of the syringe, infusion set and hemostix, the self -destructor has action state depending on the set clinical hydraulic value and the difference between the set clinical hydraulic value and the practical hydraulic value and completes self destruction automatically. In the same time, the self -destructor makes the needle seat of the syringe, the infusion set or the hemostix disintegrated automatically, the needle tip withdrawn automatically and the medium passage cut automatically. Therefore, the syringe, the infusion set and the hemostix with the self- destructor are automatic, reliable, convenient and safe.

The invention discloses a cruise fuel flow calculation method for performance management of a flight management system. The method comprises the following steps of calculating the current gravitational acceleration of an aircraft according to the flight speed, the flight height, the flight position and the flight direction of the aircraft, and then establishing a force balance equation based on a basic pneumatic database; according to the exact weight of the current aircraft, obtaining a pneumatic attack angle in a cruise state through iteration, then calculating the value of the thrust of the aircraft through calculation, and obtaining the fuel flow corresponding to the thrust on the basis of the rotating speed polarity curves given by engines of different models; according to the number of engines of aircrafts of different models, obtaining the real-time fuel oil flow of the aircrafts of the models in the cruising state, and then calculating the related performance of the flight management field, such as flight prediction, fuel oil mileage monitoring, flight cost analysis, etc.

The invention discloses a rated dynamic load determination method for a roller needle bearing mounted on a bolt shaft cantilever. On the basis of the Hertz contact theory, the influence of the flexible deformation of the ferrule and the modification of the roller pin on the load distribution is considered, meanwhile, the influence of the inclination of the roller pin on the load distribution caused by the flexural deformation of the bolt shaft is considered, and a local flexible supporting roller pin bearing mathematical model installed on the cantilever bolt shaft is established. And accurateiterative solution is performed on the force balance equation by adopting a numerical analysis method to obtain load distribution of the roller needle roller bearing under the action of external dynamic load, and further the service life of the bearing is obtained according to a rolling bearing fatigue life calculation theory. And on the basis, a relation curve graph of the fatigue life and the external dynamic load is drawn, and then the rated dynamic load of the roller needle bearing is quickly obtained through the curve graph according to the definition of the rated dynamic load of the rolling bearing.

The invention discloses a measuring device for dynamic braking torque of RV braking system, which comprises a gyroscope, an accelerometer, a strain gauge and a speed encoder. The gyroscope is placed at the position close to the center of mass of the RV to detect the acceleration/deceleration signal of the RV; the accelerometer is installed at the end of the RV to detect the acceleration/deceleration signal of the RV; the strain gauge is arranged at the hook between the tractor and the towed RV, and is used for detecting the tension signal between the tractor and the towed RV; the speed encoderis arranged on the axle of the RV for detecting the angular acceleration signal of the axle of the RV. The strain gauge, gyroscope, speed encoder and accelerometer communication connects acquisitioninstrument; and the acquisition instrument connects to remote computer communication. No brake inspection bench among other equipment is needed for calculating the braking torque . Since detection equipment is already equipped in the original vehicle and no torque sensor is needed, the measurement cost is low. This invention only needs to establish the force balance equation for the RV, to take the moment for the center point of the trailer wheel, and to establish the torque balance equation, so that the braking torque of the vehicle can be obtained in real time, which can provide basic data for further experiments.

The invention discloses a calculation method of grinding force of a spherical base surface of a tapered roller. According to the calculation method, the tapered roller is set to be in rigid contact with two guide wheel discs without sliding at a stable autorotation speed, the rotation speed of an isolating disc is equal to one half of the rotation speed difference between the two guide wheel discs, and the autorotation linear speed of the tapered roller is equal to the difference between the linear speed of the right guide wheel disc and the linear speed of the isolating disc; according to themachining principle of the spherical base surface of the tapered roller, when the spherical base surface of the tapered roller is ground, grinding force is divided into tangential grinding force andnormal grinding force; a force balance equation during grinding of the spherical base surface of the tapered roller is derived; and a grinding contact arc length of the spherical base surface of the tapered roller is calculated, the maximum undeformed cutting thickness is calculated, finally, the grinding force on the spherical base surface of the tapered roller is calculated. The method fully considers the grinding movement track and the forming contact arc length of the tapered roller, is suitable for analyzing the grinding process of the spherical base surface of the tapered roller, promotes the development of a grinding process parameter optimization technology, and improves the grinding machining precision of the tapered roller.

The invention mainly relates to an automobile performance computer-aided primary estimating method, mainly comprising the calculation of automobile control stability and its concrete steps are as follows: firstly establishing a movement model, taking a set of relative reference frame fixed on the automobile, taking the intersection of the center-of-gravity plumb line and side inclined axis of the whole automobile as an origin, using a lengthways horizontal axis of the automobile as an X-axis, using a line vertical to the X-axis and passing through the origin as a Y-axis, and using a plumb axis through the origin as a Z-axis, assuming all the angles on the horizontal plane as well as the corresponding angular speeds and angular accelerations are positive, counter-clockwise; obtaining a Z-axis moment balance equation, a Y-axis force balance equation, a Y-axis moment balance equation, and a main pin-axis moment balance equation. The beneficial effects of the invention comprise effectively forecasting the performance of the automobile products, largely reducing the trial-manufacturing and testing time and expenses and improving the efficiency and quality of automobile design.

The invention provides a servo steel supporting system axial force determining method taking maximum displacement as a control target. The method specifically includes following steps: (1), accordingto actual engineering, building an elastic foundation beam model, and determining related calculation parameters and maximum displacement control requirements; (2), establishing a control balance equation of a servo system elastic foundation beam; (3), determining a regulating support, and correcting a corresponding supporting rigidity matrix; (4), increasing regulating axial force value step by step, and solving a stress balance equation to acquire a corresponding wall displacement value; (5), calculating wall bending moment shear force and each supporting axial force value, and judging whether stress of each component meets a design value or not. On the basis of a servo system control balance equation, each boundary condition under control of axial force is judged through iterative calculation, a servo supporting control axial force determining method is provided, and a theoretical reference can be provided for design construction.

The invention discloses a hobbing process parameter optimization method based on a hobbing cutter spindle vibration response model, which comprises the following steps of: analyzing the stress of a hobbing cutter spindle from the perspective of infinitesimal elements on the basis of the Euler beam theory and the mechanical bending deformation of materials, and establishing a hobbing cutter spindleacting force balance equation and a moment balance equation; obtaining a multivariate mathematical function relational expression of inherent frequency of each order of a hob main shaft and hob mainshaft vibration relative to each machining process parameter through solving, classifying hobbing process parameters, determining gear machining process parameters and hob main shaft process parameters, and finally optimizing the machining process process process parameters. According to the method, a mathematical function relational expression between the vibration quantity of the hob main shaftand each machining process parameter is established based on a vibration mechanism. The influence degree of the machining process parameters on hobbing is analyzed, the optimal machining process parameters are obtained, or the machining process parameter value range meeting the hobbing cutter main shaft precision requirement of the hobbing machine is obtained, and therefore the hobbing vibration amount is reduced, and the machining efficiency is improved.

The invention discloses a method for establishing an unsaturated large-deformation consolidation analysis mathematical model based on a fixed Lagrange coordinate system, which comprises the followingsteps of establishing a mass conservation equation of unsaturated seepage under an Euler coordinate system; under an Euler coordinate system, establishing a force balance equation; mapping the position water head to a fixed Lagrange coordinate system, and establishing a relation equation of an initial void ratio and an instant void ratio of the loose granular material; obtaining an unsaturated seepage mass conservation equation and a force balance equation based on a fixed Lagrange coordinate system; introducing an unsaturated increment constitutive relation; solving the total differential ofthe instant void ratio, the saturation and the mass moisture content of the loose granular material by utilizing a Cramer method, and deriving in a Lagrange coordinate system; sorting to obtain an unsaturated seepage mass conservation equation and a force balance equation which take total stress and suction force as variables under a fixed Lagrange coordinate system; and under a fixed Lagrange coordinate system, obtaining an unsaturated large-deformation consolidation analysis mathematical model.