11 results about "Force balance equation" patented technology

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 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 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 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.

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.

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.

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.