Development of an Embedded Crack Method for the Shear Behavior of Reinforced Concrete Structures

研究的重点是发展一种用于评估混凝土和砌体结构使用性能和安全性的嵌入式裂缝分析方法。 钢筋混凝土/砌体结构由于延性材料和脆性材料的共同作用，其受力性能十分复杂。 随着钢筋的增加，不同的极限状态和破坏模式，从韧性到脆性，可以在混凝土/砌体结构中发展，这取决于加载条件以及钢筋的数量。 捕捉这些机制的能力对于现有民用基础设施系统的评估以及新结构的设计至关重要。 现有的分析方法，使用离散或涂抹裂纹建模方法遭受的一些缺点。 弥散裂纹法不能反映钢筋混凝土深梁和剪力墙的脆性剪切行为，而离散裂纹法不适合模拟弥散裂纹。 因此，第三种方法的基础上，有效的，因为它不需要重新划分网格，这是经常需要在离散裂纹分析，它是能够根除的主要缺陷的涂抹裂纹的方法，通过引入一个位移不连续的单元域。 这是一个新的概念，并有一个良好的理论基础上的变分原理。

The focus of the research is to develop an embedded crack analytical method for assessing the serviceability and safety of concrete and masonry structures. The behavior of reinforced concrete/masonry structures is complicated due to the interaction of ductile and brittle materials. With the addition of steel reinforcement, different limit states and failure modes, ranging from ductile to brittle, can evolve in concrete/masonry structures, depending on the loading conditions as well as the quantity of reinforcement. The ability to capture these mechanisms is of primary importance for the evaluation of existing civil infrastructure systems as well as for the design of new structures. Existing analytical methods using the discrete or smeared crack modeling approach suffer from a number of shortcomings. The smeared crack approach cannot capture the brittle shear behavior of reinforced concrete deep beams and shear walls, while the discrete crack approach is not suitable for modeling diffuse cracks. Hence, a third approach based on an efficient in that it does not require remeshing, which is often needed in the discrete crack analysis, and it is able to eradicate the major deficiencies of the smeared crack approach by introducing a displacement discontinuity within the element domain. The concept is new and has a sound theoretical basis founded on variational principles.