Development and Application-oriented Validation of a Reliable Smoothed Particle Hydrodynamics Discretization for Solids to describe Friction Stir Welding

用于描述搅拌摩擦焊接的可靠固体平滑粒子流体动力学离散化的开发和面向应用的验证

• 批准号: 388107621
• 负责人: Professor Dr.-Ing. Peter Eberhard
• 金额: --
• 依托单位: Institut für Technische und Numerische Mechanik (ITM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/388107621?language=en
• 关键词: Development; Application; oriented; Validation; Reliable

This research is a second phase of the project, devoted to the accurate simulation of the friction stir welding (FSW) process by means of the Smoothed Particle Hydrodynamics (SPH) method. FSW is a solid state welding process, which is described by multiple interdependent physical phenomena, including plasticity with high strains and strain rates, inelastic heat generation, friction, and solid state bonding. The SPH discretization method, with its meshless nature, provides a framework, which is capable of dealing with large deformations and various physical effects.In the first phase of the project, a novel physically based material model was developed and implemented in order to provide an improved material behavior description specific for FSW. The issue of the particle orientation was also investigated, resolved and tested, followed by the documentation in form of a publication. As a part of the second package, a research on discretization-error based adaptivity in SPH was conducted, providing an original strategy dealing with particle refinement and coarsening.The overall objective of the second phase of the project developed from the first phase. To achieve a major improvement of the SPH formulation for solids, and by these means not only to provide a precise simulation of FSW, but also to develop a reliable, innovative simulation technique, which is able to deal with the simulation of a wide range of industrial applications. Due to the fact that FSW combines variable characteristics, which are also common for many other industrial processes, it offers a sufficient background for a later transfer of he research results.As the time frame of the preceding project was shortened and did not allow to deal with all the aspects in full, they are translated into this project. Some final improvements of the material model by including precipitation hardening and validation of adaption of the discretization are to be accomplished, as well as the development of a material bonding criterion are to be performed in full. Additionally, during the first part of the project, further areas of research were determined. These include an improved SPH stabilization formulation, extension of the friction model based on material behavior, and enhancement and validation of the thermal behavior model. As a final step, the improved SPH solid formulation will be applied to the FSW process in order to predict the final joined geometry, quality of the weld, and microstructural behavior. The precision of the prediction will be examined through comparison with experiments conducted by the IMWF.

这项研究是该项目的第二阶段，用于通过平滑的粒子流体动力学（SPH）方法来精确模拟摩擦搅拌焊接（FSW）过程。 FSW是一个固态焊接过程，由多种相互依存的物理现象描述，包括具有高应变和应变速率的可塑性，无弹性热，摩擦和固态粘结。 SPH离散化方法具有其无网状性质，提供了一个框架，该框架能够处理大变形和各种物理效果。在项目的第一阶段，开发和实施了一种新型的基于物理的材料模型，以提供针对FSW的改进的材料行为描述。还研究了，解决和测试粒子方向问题，然后以出版物形式进行文档。作为第二条软件包的一部分，对SPH进行了基于离散化的适应性的研究，提供了一种原始的策略，该策略涉及粒子的细化和变形。从第一阶段开发的项目第二阶段的总体目标。为了实现SPH配方的重大改进，通过这些方法不仅提供了FSW的精确模拟，而且还可以开发可靠的创新模拟技术，该技术能够处理广泛的工业应用模拟。由于FSW结合了可变特征，这对于许多其他工业流程也很常见，因此它为以后的HE研究结果提供了足够的背景。由于缩短了前一个项目的时间范围，并且不允许完整处理所有方面，因此它们被转化为该项目。将要全面执行材料模型的最终改进，包括降水量硬化和离散化适应性的验证以及材料键合标准的开发。此外，在项目的第一部分中，确定了进一步的研究领域。这些包括改进的SPH稳定配方，基于材料行为的摩擦模型扩展以及增强和验证热行为模型。最后一步，改进的SPH固体配方将应用于FSW工艺，以预测最终连接的几何形状，焊缝的质量和微结构行为。预测的精度将通过与IMWF进行的实验进行比较来检查。