Characterization and modelling of the nonlinear material behaviour of coated fabrics for architectural membrane structures II

建筑膜结构涂层织物非线性材料行为的表征和建模 II

• 批准号: 278626677
• 负责人: Professor Dr.-Ing. Daniel Balzani
• 金额: --
• 依托单位: Institut für Metall- und Leichtbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/278626677?language=en
• 关键词: Characterization; modelling; nonlinear; material; behaviour

Textile membrane structures made of coated fabrics are nowadays a firmly established constructive form in civil engineering, in particular for the unsupported roofing of large areas. The adequate incorporation of material stiffness forms the basis for a predictive modeling of the membrane in Finite Element models and thus for the calculation of mechanical load and displacement in the membrane and in the substructure, ensuring damage-free constructions, safety and profitability. Coated fabric membranes show an anisotropic and highly nonlinear stress-strain-behaviour in biaxial tension tests. As a result of external loading, softening of the material is observed leading to permanent strains which increase with cyclic loading and which show a saturating behaviour under fixed maximum load. The additional strains resulting from this preconditioning are essential to be considered when dimensioning a membrane structure, which, however, is not the case in nowadays practice due to a lack of suitable models. Moreover, the nonlinear stress-strain-behaviour is currently approximated by linear elastic formulations which yield an insufficient accuracy in the prediction of stresses and displacements. This shows that there is a fundamental knowledge gap with respect to the characterization and modeling of the nonlinear material response, which is planned to be closed in this research project. Central goal of this project is to develop concepts for the incorporation of load- and structure-dependent nonlinear material properties of textile membranes for the structural computation of membrane constructions. The main innovations and thus research goals are as follows: 1. Development of a procedure for biaxial tension tests to identify structure- and load-dependent material behaviour of textile membranes, which is adapted to the real load situation and which account for the prestress and preconditioning process under external loading. 2. Development of two methods for finite element calculations for the consideration of the nonlinear material properties of textile membranes base on: a. Load- and structure-dependent fictitious elastic constants and b. Continuum-mechanical material model for the description of the nonlinear inelastic material properties. 3. Validation of the methods developed in 2. based on experimental large-construction experiments mainly focusing on two structure types (plane and saddle-shaped form) for the assessment of displacements and stresses in real membrane structures. 4. Extension of the method using fictitious elastic constants to further structural shapes (e.g. high point membrane and 4-point sail) by comparative analysis with the nonlinear model.

如今，由涂层织物制成的纺织膜结构是土木工程中牢固建立的建设性形式，尤其是大面积的不受支持的屋顶。材料刚度的足够掺入构成了在有限元模型中膜进行预测建模的基础，从而计算膜和子结构中的机械负载和位移，从而确保无损害的结构，安全性和利润率。涂层织物膜在双轴张力测试中显示出各向异性和高度非线性应力 - 弯曲。由于外部加载，观察到材料的软化导致永久性菌株随环状载荷而增加，并且在固定最大负载下显示出饱和行为。当膜结构尺寸尺寸时，必须考虑这种预处理产生的其他菌株，但是，由于缺乏合适的模型，在当今的实践中并非如此。此外，目前，非线性应力应变 - 行为是由线性弹性制剂近似的，这些弹性制剂在预测应力和位移时产生了不足的精度。这表明，关于非线性材料响应的表征和建模存在基本知识差距，该研究计划在该研究项目中封闭。该项目的核心目标是开发概念，以结合纺织膜的载荷和结构依赖性非线性材料特性，以用于膜结构的结构计算。主要创新和因此研究目标如下：1。开发双轴张力测试的程序，以识别纺织膜的结构和负载依赖性的物质行为，该行为适应了实际负载状况，并说明了Prestress和Prestress and the Prestress和外部加载下的预处理过程。 2。开发两种用于考虑纺织膜非线性材料特性的有限元计算方法基础：负载和结构依赖性虚拟弹性常数和b。连续机械材料模型，用于描述非线性非弹性材料特性。 3。基于实验性大型建筑实验中开发的方法的验证，主要集中于两种结构类型（平面和鞍形形式），以评估实际膜结构中的位移和应力。 4。使用虚拟弹性常数扩展该方法，以通过与非线性模型进行比较分析，以进一步的结构形状（例如高点膜和4点帆）。