12 results about "Tangential stiffness" patented technology

The invention discloses a multilevel rock mass mechanical analysis method and system based on near field dynamics, and the method comprises the steps: generating a mica-matrix binary model matched with actual granite based on a K-L random field, mapping the model to a BB-PD model mass point through a DIP method, determining the distribution, the particle size and the content of mica, and determining the particle size of the mica; the mechanical weakening effect is simulated by reducing the normal and tangential stiffness of the mica phase, and the microstructure characterization of the rock is completed. Constructing a structural plane PD numerical model by combining the geometrical characteristics of the structural plane reconnaissance on site and the mechanical parameters of the indoor direct shear test, and analyzing the influence of the geometrical and mechanical characteristics of weak planes such as joints and fractures on the local mechanical properties of the rock mass; the method comprises the following steps of: constructing an engineering scale rock mass numerical model integrated with mechanical properties of a microscopic rock block and a microscopic structural surface by relying on field rock mass discontinuous surface distribution data and indoor test basic mechanical parameters, and finishing analysis on the influence of the overall mechanical properties of the engineering scale rock mass; and the problems of insufficient cross-scale collaboration and the like are solved.

The invention relates to the technical field of simulation calculation, in particular to a simulation calculation method of a U-shaped steel-encased-concrete composite beam, which comprises the following steps: S1, establishing a two-parameter interface equivalent stiffness model of the U-shaped steel-encased-concrete composite beam with a rear anchor bolt; s2, solution and response extraction; s3, calculating a slip residual error and interface energy, and judging whether a target slip feature is met or not according to a double-convergence criterion; if the convergence requirement is not met, adaptively updating the interface parameters and returning to S2 for repeated solution, and if the convergence criterion is met, applying the converged interface rigidity parameters to design feedback of pretightening force selection of the rear anchor bolts and anchor bolt spacing and node construction of the rear anchor bolts. According to the method, the two-parameter interface equivalent stiffness model and the adaptive algorithm based on the slip residual error enable the interface normal stiffness and the interface tangential stiffness to be automatically converged to the target slip characteristic, manual parameter adjustment is avoided, the simulation stability and the calculation precision are improved, and integration of composite beam structure design and simulation analysis is achieved.

This invention discloses a finite element simulation method and system for a suspension bridge tower top saddle. The method includes: collecting multiple types of parameters; iteratively solving for tangential and normal forces based on an initial tangential stiffness matrix; calculating the actual contact friction coefficient based on the coupling relationship between temperature and contact normal pressure; calculating a tangential correction coefficient based on the actual contact friction coefficient, the ratio of tangential to normal forces, and the linkage relationship between the saddle geometric parameters; dynamically adjusting the tangential stiffness matrix based on the correction coefficient, the saddle pre-offset, and the synergistic relationship between cable stress; constructing a finite element model and simulating it; and iteratively optimizing until convergence. The system corresponds to the modules described above. This invention optimizes simulation accuracy through multi-factor coupling and linkage, adapting to complex working conditions and providing reliable support for the design and construction of suspension bridges.

The present invention discloses a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on a chiral torsion design, comprising a base and a chiral torsion buckling unit; the chiral torsion buckling unit comprises a mounting part, a rotating part and a plurality of elastic elements, the rotating part is rotatably connected to the base, the mounting part is coaxially arranged above the rotating part, and the elastic elements are connected between the mounting part and the rotating part at periodic intervals along the circumferential direction; when the chiral torsion buckling unit has no external load, the elastic elements are in an inclined state. The chiral torsion buckling unit will undergo chiral torsion deformation under the action of an external compressive load, generating a buckling platform stress, i.e., a quasi-zero stiffness stage with a dynamic stiffness close to 0. A positive stiffness spring can also be connected in parallel to the chiral torsion buckling to avoid instability caused by torsion and enhance the overall load-bearing capacity. In addition, the vibration isolator has low tangential stiffness, realizes multi-directional low-frequency quasi-zero vibration isolation, and has a compact structure, which effectively solves the problem that the quasi-zero stiffness vibration isolator has low load-bearing capacity and can only act in one direction.

The invention discloses a tunnel rockburst numerical simulation method based on node continuous-discontinuous deformation analysis, and belongs to the field of rockburst numerical simulation. The calculation area is divided into a destructible area and a non-destructible area, adaptive discretization processing is carried out, and joint units are formed; constructing a balance equation in a moment residual form, and performing linearization processing on the balance equation to obtain a displacement increment; adopting a bilinear constitutive model to unify normal and tangential mechanical responses of joint units into a full-quantity linear relation, and defining normal rigidity and tangential rigidity updating principles under different working conditions; constructing a rockburst simulation model based on the updated joint constitutive relationship and contact potential; and driving the rockburst simulation model to operate based on the displacement increment. According to the method, mechanical behavior transformation of rock mass from integrity to damage to block contact is truly reflected, stress waves are effectively absorbed, result distortion caused by boundary reflection waves is avoided, and a reliable stress environment is provided for rockburst simulation in cooperation with scientific initial stress generation.

The present application relates to the technical field of simulation calculation, and particularly relates to a simulation calculation method of a U-shaped outer steel-concrete composite beam, which comprises the following steps: S1: establishing a double-parameter interface equivalent stiffness model of a U-shaped outer steel-concrete composite beam with post-anchoring bolts; S2: solving and response extraction; S3: calculating a slip residual error and interface energy, and judging whether the target slip characteristic is met according to a double-convergence criterion; if the convergence requirement is not met, the interface parameters are updated adaptively and the step S2 is repeated; if the convergence criterion is met, the converged interface stiffness parameters are used for the design feedback of post-anchoring bolt pre-tightening force selection, bolt spacing and joint construction. In the present application, the double-parameter interface equivalent stiffness model and the adaptive algorithm based on the slip residual error make the interface normal stiffness and the interface tangential stiffness automatically converge to the target slip characteristic, avoid manual parameter adjustment, improve the simulation stability and calculation accuracy, and realize the integration of the composite beam construction design and simulation analysis.

The application discloses a fin effect clamp jaw force-deformation theoretical modeling method based on a co-rotation model, decomposes a fin effect clamp jaw structure into a plurality of beam units, decouples local deformation and rigid body motion of each beam unit through co-rotation theoretical modeling, respectively establishes an axial deformation model and a rotational deformation model, and introduces an effective length correction coefficient to consider the influence of physical hinge connection; a tangent stiffness matrix of the beam unit is constructed and assembled into a global tangent stiffness matrix; a Newton-Raphson iteration method is used to realize force balance solving of a load increment step, and a global force-displacement relationship is constructed; and through adjustment of a global node force vector, various planar load scenarios such as single-point, multi-point and distributed load are adapted. The application breaks through the limitation of small deformation assumption, accurately represents large deformation behavior, improves the calculation efficiency by hundreds of times compared with finite elements, controls the average error within 6%, can quantize the influence of structural parameters such as connection type, beam quantity, beam inclination angle and top angle, and provides a theoretical basis for fin effect clamp jaw engineering design.

This invention provides a nonlinear finite element method for determining the critical stability section of an underground cavern. Based on rock mechanics tests in actual engineering, the rock mass strain softening parameters are determined. A secondary development of the rock mass constitutive model is performed based on these parameters. An initial nonlinear finite element model for solving the critical stability section of the underground cavern is constructed based on the secondary developed rock mass constitutive model. The nonlinear finite element model is solved to obtain the overall tangential stiffness of the model at the calculation step. Based on the overall tangential stiffness, the minimum eigenvalue of the overall tangential stiffness matrix is ​​calculated. Based on the minimum eigenvalue, the critical stability section of the underground cavern is determined. This invention directly and quantitatively reflects the essential characteristics of stiffness loss and bearing capacity reduction in the entire cavern structure system after considering complex nonlinear deformation paths, including strain softening, thereby accurately capturing the critical instability moment and potential instability sections.

The present application relates to a method for calculating the internal forces of a shear pin type sliding friction pendulum bearing, comprising: obtaining the external load of the structure, the stiffness matrix and the mass matrix, the shear pin state value and the parameters of the shear pin type sliding friction pendulum bearing; establishing an incremental iterative formula for the structural displacement at time t; determining the calculation formula for the internal forces and tangential stiffness of the shear pin type sliding friction pendulum bearing according to the shear pin state value; substituting the calculation formula for the internal forces and tangential stiffness of the shear pin type sliding friction pendulum bearing into the incremental iterative formula for the structural displacement at time t, and performing iterative calculations until the converged internal forces of the shear pin type sliding friction pendulum bearing are calculated; determining whether to update the shear pin state value, and determining the internal forces of the shear pin sliding friction pendulum bearing at that moment. The present application provides a method and device for calculating the internal forces of a shear pin type sliding friction pendulum bearing, determining the internal forces and tangential stiffness of the bearing according to the shear pin failure state, simulating the limiting effect of the shear pin on the bearing when it is not damaged, and the energy dissipation and shock absorption effect of the sliding friction pendulum after the shear pin is damaged.

The invention discloses a diagnosis method for a post-peak unloading key state point of a thin-wall structure, and particularly relates to the field of thin-wall structure performance analysis. Comprising the following steps: acquiring a displacement sequence, a load sequence, an external work sequence and an elastic strain energy sequence of a composite material with a thin-wall structure in a loading process; according to the difference value of the external work sequence and the elastic strain energy sequence, accumulated dissipated energy of each displacement point is determined; according to the accumulated dissipated energy and the displacement sequence, the dissipated energy change rate of each displacement point is determined; determining a tangent stiffness spectrum of each displacement point according to the load sequence and the displacement sequence to obtain a tangent stiffness spectrum sequence; acquiring a displacement point corresponding to the maximum load as a peak load point; determining a damage starting point in the displacement sequence according to the dissipated energy change rate; and determining an unloading inflection point in the displacement sequence according to the tangent stiffness spectrum sequence. Based on the method, the reliability of the diagnosis conclusion can be improved.

The invention discloses an overall modeling method and system based on a nonlinear elastic potential energy model, and the method comprises the steps: obtaining an equation corresponding to internal elastic potential energy based on a system overall mechanical analysis framework; and obtaining an elastic potential energy equation and a basic stiffness matrix stored by the puncture needle due to deformation. Creating an equation corresponding to the elastic potential energy stored due to the deformation of the biological tissue; creating a corresponding decoupling equation and a tangential stiffness matrix; and in combination with the basic stiffness matrix and the tangential stiffness matrix, creating a total potential energy equation of the coupling system, and in combination with the feeding degree of freedom of the linear electric sliding table, obtaining a final kinematic model of the operable puncture needle system. According to the method, the problem of trajectory prediction of heterogenous tissue puncture is effectively solved, and the interaction modeling precision is remarkably improved.

The invention relates to a chassis system dynamic contact stiffness measurement method, which comprises the following steps of S1, respectively designing a normal stiffness test and a tangential stiffness test according to the Y-direction and Z-direction dynamic characteristics of a brake; s2, the brake is connected with a horizontal layout tool; s3, a plurality of sensors and vibration exciters are installed based on the requirements of the normal rigidity test and the tangential rigidity test; and S4, for testing the brake disc and the friction plate, executing a normal rigidity test of the brake disc and the friction plate system and a tangential rigidity test of the brake disc and the friction plate. Compared with the prior art, the testing device has the advantages of improving the testing precision of the automobile braking system and the like.