A method for efficient numerical simulation of masonry under centric/eccentric and/or cyclic biaxial loading derived from near-realistic small-scale experimental tests – Extension, enhancement and validation of the unit-cell-methodology for plain and stre

在第一个资助期，制定了方法学基础，以真实地描述小规格砖砌块的承重性能(在静态-单向或循环面内剪切-压缩-荷载作用下，作用于墙的中面或偏心)，并用数字准确地表示。结果表明，本项目进一步发展的TUM创新单元试验装置(墙体的周期性重复单元：砖、承重、纵向和对接节点)也可以有效地利用其紧凑的试验试件来系统地分析实心砖小砌块砌体的复杂破坏行为。仅对于偏心荷载应用(偏心板支撑)，不能在第一供资阶段完全完成与大型剪力墙试验的验证和比较。因此，在第二个筹资阶段，将进行补充偏心单元室和剪力墙试验。此外，除了目前考虑的实心多孔砖外，还将包括小尺寸多孔砖(中心/偏心)；由于正交各向异性的性质，与实心砖砌体相比，荷载传递和破坏机制预计将发生重大变化。此外，还应考虑不同的壁厚和砖布置，以便能够在单元单元试验中第一次更准确地评估这些参数的影响。最后，尝试用小型试验装置真实地反映加固墙体的承载性能。在新的实验结果的基础上，将进一步开发用于解决和验证其他问题的数值模型。计划增加的光纤传感器(例如在砂浆缝中)将提供关于复杂承载机制的宝贵补充信息，并丰富和进一步改进模拟模型。项目成功完成后，将有一个经过科学验证的方法和一个模拟模型，它可以在单调/循环、中心或偏心剪切压缩荷载作用下，对现有建筑物中各种小砌块砖(由实心或多孔砖组成、各种类型的砖排列)的承载和破坏行为做出现实的预测。因此，与大规模测试(楼层高的剪力墙)相比，可以使用一种更灵活、更强大的工具来真实地评估现有建筑在各种加载情况下的行为。此外，到目前为止还没有处理的配置可以相对容易地添加到总体方法中。

In the first funding period, the methodological basis was developed to realistically characterise the load-bearing behaviour (under static-monodirectional or cyclic in-plane shear-compression-loading, which acts either in the mid-plane of the wall or eccentrically) of masonry made of small-format bricks and to represent it numerically accurately. It could be shown that the innovative unit-cell test setup (periodically recurring elements of a wall: bricks, bearing, longitudinal and butt joints) of TUM, which was further developed in the project, can also be used effectively with its compact test specimens to systematically analyse the complex damage behaviour of a small-format masonry with solid bricks. The validation and comparison with large-scale shear wall tests could not be fully completed in the first funding phase only for the eccentric load application (off-centre slab support). In the second funding phase, therefore, supplementary eccentric unit-cell and shear wall tests are to be carried out. In addition, small-format perforated bricks (centric/eccentric) will be included in addition to the solid ones considered so far; due to the orthotropic properties, significant changes in load transfer and damage mechanisms are expected compared to solid brick masonry. In addition, different wall thicknesses and brick arrangements are to be considered in order to be able to evaluate influences from theses parameters in the unit-cell tests more precisely for the first time. Finally, an attempt will be made to realistically represent the load-bearing behaviour of strengthened walls with the small-scale test setup. The numerical model will be further developed for the additional questions addressed and validated on the basis of the new experimental findings obtained. The planned additional fibre-optic sensors (e.g. in the mortar joints) will provide valuable additional information on the complex load-bearing mechanisms and enrich and further improve the simulation model. After successful completion of the project, a scientifically validated methodology and a simulation model will be available which, on the basis of the unit-cell approach, allow realistic predictions to be made of the load-bearing and damage behaviour of a wide variety of small-format masonry in existing buildings (made of solid or perforated bricks, various types of brick arrangement) under monotonic/cyclical, centric or eccentric shear-compression loading. Hereby, a much more flexible and powerful tool is available compared to large-scale tests (storey-high shear walls) to realistically assess existing buildings in terms of their behaviour under a wide range of loading scenarios. In addition, configurations that have not been dealt with so far can be added to the overall methodology comparatively easily.