Sintering - Modeling of Pressure-, Temperature-, or Time-Dependent Contacts

在大多数现实情况下，当粒子接触时，不能假设接触特性与压力、温度或时间无关。因此，本项目涉及压力、温度和时间相关的接触特性及其对宏观粉末流动行为的影响。选择烧结作为一个可能的例子和起点，所有这些现象都是相关的。这个项目的目的是在粒子失去它们的特性之前，对接触中的粒子进行建模。为此，与温度和压力相关的接触模型必须与T. Staedler， Siegen和M. Kappl， Mainz的接触测量并行开发。然后，许多粒子模拟将适用于所使用的材料，并与马格德堡的J. Tomas一起进行实验验证。在项目的最后阶段，与G. Auernhammer, Mainz， L. Brendel and D. Wolf, Duisburg， A. Kwade, Brunswick， D. Kadau and H. Herrmann， ETH Zurich的项目建立了密切的合作关系。该项目的主要成果将是一个经过验证的数值模型，用于对烧结过程进行定量预测，以及微观宏观方法，这些方法都是嵌入式的，最近已经在开源社区中实现了，例如Yade， lights和MercuryDPM。微观-宏观转变将被用来获得更好的理论本构关系，用于基于接触力学和物理的宏观描述。

In most realistic situations, where particles come in contact, it cannot be assumed that the contact properties are independent of pressure, temperature or time. Therefore, this project involves pressure-, temperature-, and time-dependent contact properties and their influence on the macroscopic powder flow behaviour. Sintering is chosen as one possible example and starting point, where all these phenomena are relevant.The aim of this project is to model the particles in contact, before the particles lose their identity. For this, temperature- and pressure-dependent contact models have to be developed in parallel to the contact-measurements of T. Staedler, Siegen and M. Kappl, Mainz. Many-particle simulations will then be adapted to the materials used and experimentally validated together with J. Tomas, Magdeburg. Close cooperation with the projects of G. Auernhammer, Mainz, L. Brendel and D. Wolf, Duisburg, A. Kwade, Brunswick, and D. Kadau and H. Herrmann, ETH Zurich, has been established in the last project period.The main result of the project will be a validated numerical model for making quantitative predictions about the sintering process, as well as the micro-macro methodology, both embedded and recently implemented in the open-source community, e.g. Yade, LIGGGHTS, and MercuryDPM. The micro-macro transition will then be used to obtain better theoretical constitutive relations for a macroscopic description based on the contact-mechanics and -physics.