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

在第一个供资期间，开发了方法基础，以现实地模拟由小型砖制成的砌体的承载行为（在静态单向或循环平面内剪切-压缩-加载下，其作用在墙的中平面或偏心），并以数字准确地表示它。可以证明，TUM的创新单元格测试装置（墙壁的周期性重复元素：砖，轴承，纵向和对接接头）在项目中得到了进一步发展，也可以有效地使用其紧凑的测试样本来系统地分析实心砖的小型砌体的复杂损伤行为。在第一个供资阶段无法完全完成与大型剪力墙试验的验证和比较，仅限于偏心荷载应用（偏心板支撑）。因此，在第二个供资阶段，将进行补充的偏心单胞和剪力墙试验。此外，除了迄今为止考虑的实心多孔砖之外，还将包括小型多孔砖（中心/偏心）;由于正交各向异性特性，与实心砖砌体相比，预计荷载传递和破坏机制将发生显着变化。此外，不同的壁厚和砖的安排是要考虑，以便能够评估这些参数的影响，在单位电池测试更精确的第一次。最后，将尝试现实地代表承载性能的加固墙与小规模的测试装置。数值模型将进一步开发的基础上获得的新的实验结果的基础上解决和验证的其他问题。计划增加的光纤传感器（例如在迫击炮接缝中）将提供关于复杂的承重机制的宝贵的额外信息，并丰富和进一步改进模拟模型。在项目成功完成后，将提供一种经过科学验证的方法和一个模拟模型，该模型以单元法为基础，可以对现有建筑物中各种小型砌体的承载和损坏行为进行现实的预测（由实心砖或多孔砖制成，各种类型的砖排列）承受单调/循环、中心或偏心剪压荷载。因此，与大规模测试（楼层高的剪力墙）相比，可以使用更灵活、更强大的工具来实际评估现有建筑物在各种荷载情况下的行为。此外，迄今尚未处理的配置可以相对容易地添加到整个方法中。

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.