36 results about "Nonlinear finite element model" patented technology

The invention discloses a method, device, equipment and medium for static aero-elastic correction of wind tunnel test data. The method includes: performing numerical simulation of fluid mechanics based on a three-dimensional structured fluid grid of a wing test model to obtain aerodynamic load data on the surface of the wing test model; Structural finite element numerical analysis, to obtain the difference between the current wing displacement and the previous wing displacement; if the difference between the current wing displacement and the previous wing displacement is less than the preset difference, then based on the obtained The aerodynamic force difference of the wing test model is obtained, and the modified aerodynamic force of the wing test model is obtained. The above method uses the three-dimensional structured fluid grid of the wing test model and the geometric nonlinear finite element model to iteratively solve the aerodynamic difference of the wing test model obtained by multiple iterations, and then obtains the modified aerodynamic force of the wing test model.

The invention relates to a mechanical environment prediction method of lunar probe soft landing impact, and belongs to the technical field of deep space exploration. According to the method, a non-linear finite element model of probe lunar surface soft landing is established, model reduction is conducted on a probe according to the generalized dynamic condensation method, and therefore the purpose of improving the solving efficiency is achieved; then, non-linear finite element solving is conducted on the reduced model to obtain a dynamic response of the structure of the probe; after an acceleration speed response at a concerted position is obtained, the shock spectrum of the acceleration speed response of the structure is calculated according to a recursion digital filtering method, wherein the shock spectrum is used for describing the dynamic environment of probe landing impact; at last, a maximum expected environment is obtained by the adoption of a spectrum enveloping method, wherein the maximum expected environment is used for setting the designing and testing conditions of equipment. By means of the mechanical environment prediction method, the solving efficiency is improved and the product designing period is shortened.

A bridge model updating method, system, storage medium and equipment based on vehicle-bridge coupling force correction belong to the field of engineering technology. The purpose of the present invention is to solve the problem that there is no refined update method for the bridge model at present, resulting in low simulation accuracy. The present invention obtains the bridge structure dynamic response of the bridge structure under the load of heavy-duty vehicles through the sensors arranged on the bridge structure; according to the bridge vertical vibration acceleration a o and vertical deflection y o , and the heavy-duty vehicle speed u 车 , reconstruct the table response of the shaking table, and obtain the interaction force of the vehicle-bridge coupling model; establish a nonlinear finite element model of the bridge structure, take the vehicle-bridge interaction force as the external force, and take the dynamic response of the bridge structure as the structural response. The linear parameter identification method completes the correction of the finite element model of the bridge structure. The present invention is mainly used for updating bridge models.

The embodiment of the invention provides a railway fastener elastic strip breakage splashing risk prediction method and device, and relates to the technical field of traffic safety. The method comprises the following steps: establishing a three-dimensional nonlinear finite element model and setting the three-dimensional nonlinear finite element model in a service state; establishing a coupling space simulation model of the vehicle and the steel rail; according to the coupling space simulation model, dynamic response data between the vehicle and the steel rail under the condition of corrugationof the steel rail are obtained, inputting the dynamic response data as excitation into a three-dimensional nonlinear finite element model; fracture splashing risk data of the elastic strip is obtained. The method has the advantages that the spatter track can be simulated according to the fracture spatter risk data, accordingly, spatter risks of the elastic strips can be predicted according to thefracture spatter risk data of the elastic strips, risk prediction results can be acquired, comprehensive protection measures can be taken for fracture spatter of the elastic strips, and safe runningof trains during running can be guaranteed.

The present invention relates to the technical field of mechanical engineering and mathematics research, in particular to an asymmetric variable acceleration planning method based on the optimal distribution of main frequency energy in the time domain, including nonlinear finite element models containing kinematic freedom and parameterized motion functions as boundary conditions Solve the positioning process; judge whether the amplitude of the execution end after the drive stops meets the positioning accuracy, if not, continue to solve, if it is satisfied, the vibration energy decay time; judge whether the target response time is the minimum value, if it is the minimum value, determine the setting The motion parameter is the optimal parameter, if it is not the minimum value, calculate the motion parameter gradient and step size, and reset the motion parameters to solve. Through the above method, the present invention solves the problem of motion planning of high-speed and high-acceleration mechanisms that have nonlinear effects such as large flexible deformation and precise positioning requirements, and can realize precise positioning and position / force smooth switching under high acceleration conditions, and is also applicable to traditional A solution to the actuator motion planning problem.

The invention provides a method, system and storage medium for predicting the nonlinear wind-induced response of a suspension bridge. Firstly, CFD numerically simulates various aerodynamic time histories of the main beam section under different combinations of reduced wind speeds and amplitudes, and then uses the nonlinear minimum The square fitting method identifies all the aerodynamic parameters in the unified nonlinear unsteady aerodynamic time-domain model, and compares them with the CFD calculation results for verification; then the unified aerodynamic model is compared with the three-dimensional nonlinear finite element model of the bridge The coupled solution predicts the nonlinear wind-induced response of the bridge when the wind speed increases from zero to a preset limit wind speed. The unified aerodynamic time-domain model of the present invention includes mathematical expressions of static wind force, self-excited force, buffeting force, vertical vortex force and torsional vortex force and their corresponding parameters, and realizes bridges in different wind speed ranges. The accurate prediction of nonlinear wind-induced response provides an important reference for the evaluation of the wind resistance performance of suspension bridges during strong / typhoon experiences.

The invention discloses a complex variable differential sensitivity-based nonlinear structure finite element model correction method, which comprises the following steps of firstly, establishing a nonlinear finite element initial analysis model of a structure; secondly, performing complex step perturbation on a to-be-corrected parameter in the structure, and calculating nonlinear dynamic responsesensitivity; thirdly, measuring response data of the structure, and establishing an objective function of nonlinear model correction; and finally, performing least square optimization on the measureddynamic response and the analyzed dynamic response so as to realize nonlinear finite element model correction, so that the structural parameters of the nonlinear finite element analysis model can be corrected, and the calculation precision of the analysis model is improved.