阅读说明：本技术 一种fdm3d打印机有限元分析及成型精度方法 (Finite element analysis and forming precision method for FDM3D printer ) 是由 吕宁 江波 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种FDM3D打印机有限元分析及成型精度方法,涉及3D打印技术领域；系统分析了熔融沉积成型原理性误差、成型加工误差和后处理误差的主要影响因素；利用ANSYS有限元分析软件,建立熔融沉积成型过程的温度场和应力场分析模型,模拟得到了关键节点温度和应力随时间变化、温度梯度和应力分布规律；利用ANSYS温度场仿真软件对FDM型3D打印机喷头三维模型进行温度场仿真,得出3D打印机喷头的温度场分布；根据温度场仿真结果,为喷头结构进行优化设计,进而提高FDM型3D打印机的打印连续性、效率以及打印工件的表面质量。并对打印参数进行优化设计,以提高成型精度。(The invention discloses a finite element analysis and forming precision method for an FDM3D printer, and relates to the technical field of 3D printing; the system analyzes the main influence factors of the principle error of fused deposition molding, the molding processing error and the post-processing error; establishing a temperature field and stress field analysis model in the fused deposition molding process by using ANSYS finite element analysis software, and simulating to obtain the time variation of the temperature and stress of the key nodes, the temperature gradient and the stress distribution rule; performing temperature field simulation on the three-dimensional model of the FDM type 3D printer nozzle by using ANSYS temperature field simulation software to obtain the temperature field distribution of the 3D printer nozzle; according to the temperature field simulation result, the spray head structure is optimally designed, and therefore the printing continuity and efficiency of the FDM type 3D printer and the surface quality of a printed workpiece are improved. And the printing parameters are optimally designed to improve the forming precision.)

1. A finite element analysis and forming precision method for an FDM3D printer is characterized in that: the method comprises the following steps:

the method comprises the following steps: precision analysis of the FDM type 3D printer:

according to the forming process of the fused deposition forming technology, errors affecting fused deposition forming parts are mainly divided into three types according to the source of the errors: principle error, forming error and post-processing error; from three angles of principle errors, forming machining errors and errors in a post-processing process, factors influencing forming precision in each link in the forming process are carefully analyzed, corresponding solutions are provided, and theoretical guidance is provided for later experiments and researches;

step two: finite element simulation and analysis of the FDM type 3D printer:

inputting and defining model parameter material attributes through ANSYS software, then establishing finite element model mesh division, applying temperature load boundary adjustment after activating a unit, then solving, determining whether the unit is completely activated, if not, entering into activating the unit again, if so, outputting a result, converting the unit type to define the material attributes, then activating the unit again, reading temperature data, loading, then solving, determining whether the unit is completely activated, otherwise, returning to activate the unit, and if so, outputting the result;

step three: the temperature field analysis and the structure optimization of the printing head of the FDM type 3D printer are as follows:

importing model data by using ANSYS software, selecting unit types, defining material attributes, dividing the material attributes, loading, defining boundary conditions, solving and checking results;

step four: optimizing the technological parameters of the FDM type 3D printer:

after the printer is optimized, the printing effect of the 3D printer is tested, the influence rule of the process parameters and the printing quality of a printed piece of the optimized 3D printer is researched on the basis, the influence rule of the process parameters on the printing precision is obtained by designing several groups of different orthogonal experiments and analyzing and demonstrating, and then the reasonable process parameters are determined.

2. The method of claim 1, wherein the method comprises the steps of: and the principle errors in the first step comprise CAD model fitting errors, layered slicing errors and forming machine errors.

3. The method of claim 1, wherein the method comprises the steps of: and forming machining errors in the first step comprise material performance errors and technological parameter errors.

4. The method of claim 1, wherein the method comprises the steps of: the post-processing errors include surface post-processing errors and support removal induced errors.

Technical Field

The invention belongs to the technical field of 3D printing, and particularly relates to a finite element analysis and forming precision method for an FDM3D printer.

Background

The FDM process has the advantages of low forming cost, small equipment volume, simplicity in operation and the like, but also has the problem of low forming precision. The performance of the product often determines the application and popularization degree of the FDM process. How to improve the forming precision of the product becomes a focus of attention of related researchers. The low surface quality of the formed part has severely limited the popularization and application of the fused deposition rapid prototyping technology in the market. Therefore, it is necessary to find out every factor affecting the precision of the formed part from each link of the forming process, and to find out a method for improving the forming precision of the formed part from these factors.

Disclosure of Invention

In order to solve the existing problems; the invention aims to provide a finite element analysis and forming precision method for an FDM3D printer.

The invention discloses a finite element analysis and forming precision method of an FDM3D printer, which comprises the following steps:

the method comprises the following steps: precision analysis of the FDM type 3D printer:

according to the forming process of the fused deposition forming technology, errors affecting fused deposition forming parts are mainly divided into three types according to the source of the errors: principle error, forming error and post-processing error; from three angles of principle errors, forming machining errors and errors in a post-processing process, factors influencing forming precision in each link in the forming process are carefully analyzed, corresponding solutions are provided, and theoretical guidance is provided for later experiments and researches;

step two: finite element simulation and analysis of the FDM type 3D printer:

inputting and defining model parameter material attributes through ANSYS software, establishing finite element model meshing, applying temperature load boundary adjustment after activating a unit, then solving, determining whether the unit is completely activated, if not, entering into activating the unit again, if so, outputting a result, converting the unit type to define the material attributes, then activating the unit again, reading temperature data, loading, then solving, determining whether the unit is completely activated, otherwise, returning to activate the unit, and if so, outputting the result.

Step three: the temperature field analysis and the structure optimization of the printing head of the FDM type 3D printer are as follows:

model data is imported by using ANSYS software, unit types are selected, material attributes are defined, the material attributes are divided, loading is carried out, boundary conditions are defined, then solution is carried out, and results are checked.

Step four: optimizing the technological parameters of the FDM type 3D printer:

after the printer is optimized, the printing effect of the 3D printer is tested, the influence rule of the process parameters and the printing quality of a printed piece of the optimized 3D printer is researched on the basis, the influence rule of the process parameters on the printing precision is obtained by designing several groups of different orthogonal experiments and analyzing and demonstrating, and then the reasonable process parameters are determined.

Preferably, the principle errors in the first step include CAD model fitting errors, slice errors, and molding machine errors.

Preferably, the forming processing error in the first step includes a material performance error and a process parameter error.

Preferably, the post-processing errors include surface post-processing errors and support removal-induced errors.

Compared with the prior art, the invention has the beneficial effects that:

firstly, main influence factors of a principle error, a forming processing error and a post-processing error of fused deposition forming are systematically analyzed; and establishing a temperature field and stress field analysis model in the fused deposition forming process by using ANSYS finite element analysis software, and simulating to obtain the time-dependent change of the temperature and stress of the key nodes, the temperature gradient and the stress distribution rule. And analyzing relevant factors having influences on the temperature field and the stress field. And performing temperature field simulation on the FDM type 3D printer nozzle three-dimensional model by using ANSYS temperature field simulation software to obtain the temperature field distribution of the 3D printer nozzle.

And secondly, carrying out optimization design on the spray head structure according to the simulation result of the temperature field, and further improving the printing continuity and efficiency of the FDM type 3D printer and the surface quality of a printed workpiece. And the printing parameters are optimally designed to improve the forming precision.

Drawings

For ease of illustration, the invention is described in detail by the following detailed description and the accompanying drawings.

FIG. 1 is a flow chart of the precision analysis of an FDM type 3D printer in the invention;

FIG. 2 is a flow chart of finite element simulation and analysis of an FDM type 3D printer in the present invention;

FIG. 3 is a flow chart of temperature field analysis and structure optimization of the printing head of the FDM type 3D printer in the invention.

Detailed Description

In order that the objects, aspects and advantages of the invention will become more apparent, the invention will be described by way of example only, and in connection with the accompanying drawings. It is to be understood that such description is merely illustrative and not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

The specific implementation mode adopts the following technical scheme: the method comprises the following steps:

as shown in fig. 1, step one: precision analysis of the FDM type 3D printer:

according to the forming process of the fused deposition forming technology, errors affecting fused deposition forming parts are mainly divided into three types according to the source of the errors: principle error, forming error and post-processing error; from three angles of principle errors, forming machining errors and errors in a post-processing process, factors influencing forming precision in each link in the forming process are carefully analyzed, corresponding solutions are provided, and theoretical guidance is provided for later experiments and researches;

as shown in fig. 2, step two: finite element simulation and analysis of the FDM type 3D printer:

inputting and defining model parameter material attributes through ANSYS software, establishing finite element model meshing, applying temperature load boundary adjustment after activating a unit, then solving, determining whether the unit is completely activated, if not, entering into activating the unit again, if so, outputting a result, converting the unit type to define the material attributes, then activating the unit again, reading temperature data, loading, then solving, determining whether the unit is completely activated, otherwise, returning to activate the unit, and if so, outputting the result.

ANSYS is large-scale general finite element analysis software, provides support for researching the problem of a dynamically changing field, and is well applied to simulation analysis in various fields of structures, heat, fluid, electromagnetism and the like. The simulation of the dynamic material accumulation process can be realized by applying the cell life and death technology of ANSYS, the change rule of the instantaneous temperature field and stress field in the forming process can be visually seen by the finite element post-processing program, the generation process of the warping deformation of the workpiece can be known, and the influence of each forming process parameter on the temperature field and the stress strain field of the workpiece can be realized. Therefore, finite element analysis is carried out in the forming process, and the method has important significance for reasonably determining process parameters, reducing warping deformation and improving the forming precision of the formed part.

As shown in fig. 3, step three: the temperature field analysis and the structure optimization of the printing head of the FDM type 3D printer are as follows:

model data is imported by using ANSYS software, unit types are selected, material attributes are defined, the material attributes are divided, loading is carried out, boundary conditions are defined, then solution is carried out, and results are checked.

And simulating the temperature field distribution of the spray head, and the temperature field distribution and strain distribution of the printing material by using ANSYS software. According to the data result analysis of the simulated temperature field, the structure of the nozzle of the spray head of the printer, the material and the length of the printing head, the size and the position of the shape with fast heating and the heat dissipation device are optimally designed, so that the optimized spray head structure can effectively improve the problem of material blockage of the spray head and improve the precision of a formed part.

Step four: optimizing the technological parameters of the FDM type 3D printer:

after the printer is optimized, the printing effect of the 3D printer is tested, the influence rule of the process parameters and the printing quality of a printed piece of the optimized 3D printer is researched on the basis, the influence rule of the process parameters on the printing precision is obtained by designing several groups of different orthogonal experiments and analyzing and demonstrating, and then the reasonable process parameters are determined.

Further, the principle errors in the first step include fitting errors of a CAD model, slicing errors of a layering layer and errors of a forming machine.

Further, the forming processing error in the first step includes a material performance error and a process parameter error.

Further, the post-processing errors include surface post-processing errors and support removal induced errors.

The specific implementation mode mainly researches FDM equipment taking PLA as a forming material, and improves the forming precision of a workpiece through numerical simulation and process parameter optimization on the basis of theoretical analysis. The system analyzes the main influence factors of the principle error of fused deposition molding, the molding processing error and the post-processing error; and establishing a temperature field and stress field analysis model in the fused deposition forming process by using ANSYS finite element analysis software, and simulating to obtain the time-dependent change of the temperature and stress of the key nodes, the temperature gradient and the stress distribution rule. And analyzing relevant factors having influences on the temperature field and the stress field. And performing temperature field simulation on the FDM type 3D printer nozzle three-dimensional model by using ANSYS temperature field simulation software to obtain the temperature field distribution of the 3D printer nozzle. According to the temperature field simulation result, the spray head structure is optimally designed, and therefore the printing continuity and efficiency of the FDM type 3D printer and the surface quality of a printed workpiece are improved. And the printing parameters are optimally designed to improve the forming precision.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.