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Thermo-hyrgo-mechanical processes for the densification and forming of wood: Continuum-mechanical material formulation and structural simulations

用于木材致密化和成型的热湿机械工艺：连续机械材料配方和结构模拟

基本信息

批准号：
233962626
负责人：
Professor Dr.-Ing. Michael Kaliske
金额：
--
依托单位：
Institut für Statik und Dynamik der Tragwerke
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/233962626?language=en
关键词：
Thermo hyrgo mechanical processes densification

项目摘要

Wood has been used as solid wood for the construction of building structures since centuries. Recently, increased ecological as well as technical requirements lead to a demand for improved properties of building materials. The Institut of Steel and Timber Construction of TU Dresden (ISH) develops the technology of wood forming based on the thermo-hygro-mechanical properties of the raw material wood.The numerical simulation of the wood forming process and the behavior of structural components made from formed wood using the finite element method require a realistic constitutive model in order to describe the thermo-hygro-mechanical material behavior of wood at finite deformations.Main aim of the renewal proposal at hand is the preparation of numerical tools and methods for the simulation and design of optimal industrial products made from formed wood. The numerical simulation provides the means to achieve a deep insight into the multi-physical effects and phenomena within the structures during application of the forming technology.The basis for modelling wood densification as well as wood forming is achieved during the first funding period. In order to further develop and to validate the thermo-hygroscopic anisotropic material modelling of wood at large deformations, a comparison of simulation results with experimental data provided by ISH is carried out.Further developments are made by modelling the current density of wood under consideration of its raw material and its bound water. To this purpose, a modification of the mass balance mass of moisture and of displacement dependent continuum mechanical processes are carried out with respect to the simulation of the manufacturing of formed wood.Furthermore, a thermo-hygroscopic finite surface element is formulated as well as related constitutive laws, in order to model the moisture in- and out flow and thermal convective phenomena.Additionally, parameter studies are carried out with respect to the identification of significantly influencing values, since only few qualitative and empirical preliminary work regarding this technology is existing.Finally, realistic and industry-related numerical simulations of structural components made from formed wood are carried out and analyzed, in order to demonstrate the practical applicability of the forming technology and its numerical modelling.

几个世纪以来，木材一直被用作建筑结构的实木。近来，增加的生态以及技术要求导致对建筑材料的改进性能的需求。德累斯顿工业大学钢木结构研究所（ISH）根据原材料木材的热、湿、力学性能开发了木材成形技术，利用有限元法对木材成形过程和成形材构件的性能进行数值模拟，需要一个真实的本构模型来描述木材的热、湿、力学性能，并对木材的热、湿、力学性能进行分析。木材在有限变形下的力学材料行为。目前更新提案的主要目的是为模拟和设计由成形木材制成的最佳工业产品准备数字工具和方法。数值模拟为深入了解成形技术应用过程中结构内的多物理效应和现象提供了手段。在第一个资助期内，为模拟木材致密化和木材成形奠定了基础。为了进一步发展和验证木材在大变形下的热-湿各向异性材料模型，将模拟结果与ISH提供的实验数据进行了比较，并通过考虑木材原材料和结合水的木材电流密度模型进行了进一步的发展。为此，本文针对成形木材制造过程的模拟，对水分的质量平衡质量和位移相关连续力学过程进行了修正。此外，为了模拟水分的进出流动和热对流现象，本文还建立了一个热-湿吸收有限表面单元以及相关的本构关系。参数的研究进行了识别方面的显着影响值，因为只有少数定性和经验的初步工作，关于这一技术是现有的。最后，现实和工业相关的数值模拟的结构部件制成的成型木材进行和分析，以证明成形技术及其数值模拟的实用性。