CN-122021029-A - Structural strength analysis method for small three-degree-of-freedom pasture harvesting header in hilly area

CN122021029ACN 122021029 ACN122021029 ACN 122021029ACN-122021029-A

Abstract

S01, establishing a road surface model and a geometric model of the whole machine of the small-sized forage grass harvesting header in three-dimensional modeling software. S02, importing the pavement model and the header model into multi-body dynamics analysis software, constructing a dynamics simulation model of the movement of the header on the undulating pavement, simulating three-dimensional dynamic adjustment working conditions of the model and obtaining dynamic load data of key connection parts through simulation solution. S03, extracting a load value for hydrostatic strength analysis. S04, taking the extracted load value as a boundary condition, importing the boundary condition into finite element analysis software to analyze and check the static strength of the target key component of the header, returning to the step S01 to modify the header model parameters if the component does not meet the requirements, and repeating the steps S02 to S04. The invention remarkably improves the accuracy and the reliability of the structural design of the small header in hilly areas, and belongs to the field of agricultural machinery computer aided engineering.

Inventors

ZHAO ZUOXI
ZOU WENQI
XU YUANJUN
Shi Shenye
Hou Yingju
ZHANG HAOJIA
ZHANG KANGRUI

Assignees

华南农业大学

Dates

Publication Date: 20260512
Application Date: 20260202

Claims (9)

1. The structural strength analysis method for the small three-degree-of-freedom pasture harvesting header in the hilly area is characterized by comprising the following steps of: S01, establishing a road surface model comprising a simulated rolling characteristic of a hilly area and a geometric model of a whole machine of a small-sized grass harvesting header in three-dimensional modeling software, wherein the header model comprises a three-degree-of-freedom mechanism for realizing pitching, inclination and lifting adjustment; S02, introducing a pavement model and a header model into multi-body dynamics analysis software, adding a constraint, driving and inter-mechanism acting force model, constructing a dynamics simulation model of the motion of the header on the undulating pavement, simulating three-dimensional dynamic adjustment working conditions of the model and obtaining dynamic load data of key connection parts by simulation solution; s03, extracting a load value for static strength analysis from dynamic load data; S04, taking the extracted load value as a boundary condition, importing the boundary condition into finite element analysis software to analyze and check the static strength of the target key component of the header, and returning to the step S01 to modify the header model parameters if the component does not meet the requirements after checking until the design requirements are met, and repeating the steps S02 to S04.
2. The method for analyzing the structural strength of the small three-degree-of-freedom pasture harvesting header for the hilly area according to claim 1, wherein the three-dimensional modeling software is SolidWorks, the multi-body dynamics analysis software is ADAMS, and the finite element analysis software is ANSYS.
3. The method for analyzing the structural strength of the small three-degree-of-freedom pasture harvesting header for the hilly area according to claim 1, wherein the pavement model is constructed according to the relief topography characteristics of the hilly area and is used for simulating real-time contact and impact of the header profile wheels and the ground.
4. The method for analyzing the structural strength of the small three-degree-of-freedom pasture harvesting header in the hilly area according to claim 1, wherein in the step S02, the simulated three-dimensional dynamic adjusting working condition comprises at least one of pitching and lifting adjusting operation of the header on the road surface with wavy fluctuation and inclination adjusting operation on a left transverse slope and a right transverse slope.
5. The method for analyzing the structural strength of the small three-degree-of-freedom pasture harvesting header for the hilly area according to claim 1 is characterized in that in the step S03, the method for extracting the load value is that the dynamic load of the key hinge points and the structural joints obtained after the header is subjected to simulation solution in the preset simulation time length and the integral step length in the multi-body dynamics analysis software is extracted and derived.
6. A method of analysing the structural strength of a small three degree of freedom forage grass harvesting header for hilly areas according to claim 1, wherein in step S04, the load values are applied in the form of moments or forces in the finite element analysis software to the hinge points connecting the or each key component with the pitch, tilt and lift cylinders.
7. The method for analyzing the structural strength of a small three-degree-of-freedom pasture harvesting header for hilly areas according to claim 1, wherein in the step S04, the target key components include a pitching gantry, a tilting support frame and a lifting and adjusting movable frame.
8. A method of analysing the structural strength of a small three degree of freedom forage grass harvesting header for hilly areas according to claim 1, wherein in step S04, the component unsatisfied with requirements means that the component stress or deformation is not satisfied.
9. A method of structural strength analysis for small three degree of freedom pasture harvesting header in hilly areas according to claim 2, wherein dynamic load data is transferred between ADAMS and ANSYS via Excel file.

Description

Structural strength analysis method for small three-degree-of-freedom pasture harvesting header in hilly area Technical Field The invention relates to the field of agricultural machinery computer aided engineering, in particular to a method for accurately analyzing the structural strength of key parts of a small three-degree-of-freedom pasture harvesting header in a south hilly area by combining multi-body dynamics with finite element analysis. Background The small pasture harvesting header suitable for the area needs to have the adjustment capability of three degrees of freedom of pitching, inclination and lifting so as to cope with complex terrains such as transverse slopes, longitudinal slopes and uneven fluctuation and ensure that the stubble height is uniform. The header has compact structure, but key components bear complex alternating load under the combined action of dynamic adjustment and ground impact, and the strength directly determines the reliability and service life of the whole machine under severe working conditions. At present, the strength analysis of the small header parts is mostly carried out by adopting a traditional method (1) an empirical static analysis method, and checking is carried out in ANSYS and other software based on a simplified static assumption. The method seriously ignores continuous impact caused by real fluctuation of a hilly road surface and dynamic coupling load generated in the three-degree-of-freedom linkage adjustment process, so that the analysis result has large deviation from the actual working condition, and the light-weight and high-reliability structural design cannot be effectively guided. (2) The single software analysis method is difficult to efficiently and accurately complete system-level dynamics simulation and component-level detail stress analysis of the pavement in the same platform. Therefore, the prior art lacks a special analysis method which can accurately simulate the dynamic process of the operation of the small three-degree-of-freedom pasture harvesting header on the complex terrain with multiple working conditions and acquire the load to carry out high-precision static strength check, so that blindness exists in mechanical development and the structural safety allowance is difficult to accurately control. Disclosure of Invention Aiming at the technical problems in the prior art, the invention aims to provide the structural strength analysis method for the small three-degree-of-freedom pasture harvesting header in hilly areas, which can integrate a multi-degree-of-freedom road surface model, accurately simulate the three-degree-of-freedom adjustment dynamics process, and use extracted dynamic load for high-precision strength analysis of key components so as to realize more scientific and reliable header structural design. In order to achieve the above purpose, the invention adopts the following technical scheme: a structural strength analysis method for a small three-degree-of-freedom pasture harvesting header in hilly areas comprises the following steps: S01, in three-dimensional modeling software, a road surface model simulating rolling characteristics of a hilly area and a geometric model of a whole machine of the small-sized forage grass harvesting header are built, and the header model comprises a three-degree-of-freedom mechanism for realizing pitching, inclination and lifting adjustment. S02, introducing the pavement model and the header model into multi-body dynamics analysis software, adding constraint, driving and inter-mechanism acting force models, constructing a dynamics simulation model of the movement of the header on the undulating pavement, simulating three-dimensional dynamic adjustment working conditions of the model and obtaining dynamic load data of key connecting parts by simulation solution. S03, extracting a load value for static strength analysis from dynamic load data. S04, taking the extracted load value as a boundary condition, importing the boundary condition into finite element analysis software to analyze and check the static strength of the target key component of the header, and returning to the step S01 to modify the header model parameters if the component does not meet the requirements after checking until the design requirements are met, and repeating the steps S02 to S04. After the method is adopted, the multi-working-condition road surface three-dimensional model is combined with the three-degree-of-freedom header model in dynamic simulation, so that full-element digitization from a geometric model to a load environment is realized, the dynamic simulation environment is more close to a physical real condition, and the accuracy of the extracted load is ensured. Meanwhile, the method becomes an efficient digital design iteration tool, and can rapidly verify the strength performance of different structural schemes and guide the optimal design. The "key connection part" mentioned in step S02 refers to two p