Simulation of the shrinkage behavior in Fused Deposition Modeling

熔融沉积建模中收缩行为的模拟

• 批准号: 419994631
• 负责人: Professor Dr.-Ing. Elmar Moritzer, since 2/2021
• 金额: --
• 依托单位: Fachgruppe Kunststofftechnologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/419994631?language=en
• 关键词: Simulation; shrinkage; behavior; Fused; Deposition

The aim of the project is to simulate the shrinkage behavior of components manufactured with Fused Deposition Modeling (FDM). By using the shrinkage simulation, the resulting dimensional change of FDM components shall be determined. By means of this dimensional change, optimized shrink factors are derived for the FDM process. These shrink factors are evidently responsible for a high dimensional accuracy. The shrink factor is a scaling along all axes to compensate the process-induced shrinkage of the plastic component. Preliminary investigations have shown that a globally adapted shrink factor (along the spatial directions X, Y and Z) can achieve a significant reduction in the occurring dimensional deviations of test specimens with a constant nominal length. Normally, there are different nominal lengths within a complex part. These nominal lengths can be small dimensions ≤ 10 mm or higher dimensions (≥ 100 mm).Whereas the optimized shrink factor is decisively dependent on the nominal length, a method shall be developed in the second step of the project how to apply locally adapted shrink factors already in the design and construction phase of the component. In order to be able to use the process for the production of individual and small series efficiently and economically, product requirements needs to be fulfilled already with the first component. Therefore, an operating point optimization is not desirable concerning the shrinkage factor, as this would increase the machine time and costs as well. In order to save resources, the shrinkage behavior of FDM parts should be analyzed with simulation technologies. Based on the findings optimum shrinkage factors for higher nominal lengths (up to 400 mm) or new materials, for example, are derived. Therefore, the cooling behavior is examined at a unit cell for determining the shrinkage, which represents the structure of a FDM part. Previously, it is necessary that the processing conditions are determined as well. These have a decisive influence on shrinkage. From the ascertained data of the melting and extrusion analysis, the input variables for the cooling simulation result. The main focus is on temperature and shrinkage simulation, with the aim of determining the resulting dimensional change.Finally, the simulation results are validated and evaluated by means of experimental investigations. The approach of locally applied shrink factors on specific geometries or nominal lengths of a complex demonstrator component has to be examined. Subsequently, the components are measured by means of a coordinate measuring machine and thus are analyzed with regard to the dimensional accuracy.

该项目的目的是模拟熔融沉积成型（FDM）制造的组件的收缩行为。通过使用收缩模拟，应确定FDM组件的最终尺寸变化。通过这种尺寸的变化，最佳的收缩因子，推导出FDM过程。这些收缩系数显然是高尺寸精度的原因。收缩系数是沿着所有轴的缩放比例，以补偿塑料部件的工艺引起的收缩。初步研究表明，全局适应收缩因子（沿着空间方向X、Y和Z）可显著降低标称长度恒定的试样的尺寸偏差。通常，在复杂零件内存在不同的标称长度。这些标称长度可以是≤ 10 mm的小尺寸或更大尺寸（≥ 100 mm）。尽管优化收缩系数决定性地取决于标称长度，但应在项目的第二步中开发一种方法，如何在组件的设计和施工阶段应用局部适应的收缩系数。为了能够有效和经济地使用该工艺生产单个和小批量产品，需要已经用第一个组件满足产品要求。因此，关于收缩系数的操作点优化是不期望的，因为这也会增加机器时间和成本。为了节约资源，需要对FDM制件的收缩行为进行仿真分析。根据这些发现，可以推导出更高标称长度（最大400 mm）或新材料的最佳收缩系数。因此，在单位单元处检查冷却行为以确定代表FDM部件的结构的收缩率。在此之前，还需要确定处理条件。这些对收缩有决定性的影响。根据熔化和挤压分析的确定数据，为冷却模拟结果提供输入变量。重点是温度和收缩模拟，目的是确定由此产生的尺寸变化。最后，通过实验研究对模拟结果进行验证和评估。必须研究在复杂验证机部件的特定几何形状或标称长度上局部应用收缩因子的方法。随后，通过坐标测量机测量部件，从而分析尺寸精度。