Analysis and Design of Pierced Deep Beams and Shear Walls

穿孔深梁和剪力墙在建筑业中应用广泛。为了实用和施工方便，大多数开口都是长方形的。这会导致应力集中，导致裂缝从开口的角落延伸。裂缝的宽度经常超过规范规定的使用极限，在许多情况下，由此产生的开口变形会导致使用问题，从而导致不必要的维护成本。本项目旨在开发穿孔深梁和剪力墙的分析方法和设计规则，允许确定和限制使用开裂和极限强度，从而允许合理设计此类部件。该项目的目标将通过首先开发一种新的数值模型来实现，该模型能够模拟这些部件在各种加载条件下的开孔行为。该数值模型将采用一种令人兴奋的新计算技术--比例边界有限元方法，以便能够有效地模拟开口拐角处的应力集中、裂纹萌生和裂纹扩展。模型将通过足尺深梁试验和缩尺模型剪力墙试验进行验证。这一详细的数值模型将用于评估和改进现有一致的压杆模型，用于穿孔深梁的极限强度设计。同时，将制定预测裂缝宽度的简化方法。对于有穿透力的深梁，将开发满足使用标准的简单设计表。对于剪力墙，将开发和研究两种方法。第一种是基于开口上等效连梁的弯矩和剪力的伪经验关联(基于实际中通常使用的线弹性框架分析)。在第二种方法中，将构造一个适合包含在框架分析程序包中的简化单元。这将允许直接预测裂纹开口，并允许更准确地分析降低刚度对结构响应的整体影响。将对典型配置进行调查，并提出适当的代码规定，以确保满足现有的适用性标准。

Pierced deep beams and shear walls are widely used in the construction industry. For utility and ease of construction, most openings are rectangular in shape. This leads to stress concentrations which cause cracks to extend from the corners of the openings. The width of the cracks often exceeds the serviceability limits indicated by the code, and in many cases the resulting distortion of the opening causes serviceability problems, resulting in unnecessary maintenance costs. This project aims to develop methods of analysis and design rules for pierced deep beams and shear walls which will permit determination and limitation of serviceability cracking together with ultimate strength, allowing rational design of such components. The aims of the project will be accomplished by first developing a novel numerical model capable of simulating the behaviour of openings in these components under a variety of loading conditions. This numerical model will employ an exciting new computational technique, the scaled boundary finite element method, to permit efficient modelling of the stress concentration, crack initiation and crack propagation from the corners of the openings. The model will be verified by application to full-scale deep beam tests and scale model shear wall tests. This detailed numerical model will be used to evaluate and refine existing consistent strut-tie models for ultimate strength design of pierced deep beams. At the same time simplified approaches for the prediction of crack widths will be formulated. For deep beams with penetrations simple design tables for satisfaction of serviceability criteria will be developed. For shear walls, two approaches will be developed and investigated. The first will be based on pseudo-empirical correlation of moment and shear in the equivalent link beams over the opening (based on the linear elastic frame-type analysis typically used in practice). In the second approach a simplified element suitable for inclusion in frame analysis packages will be constructed. This will permit prediction of crack openings directly and allow more accurate analysis of the global effects of reduced stiffness on the structural response. Typical configurations will be investigated and suitable code provisions will be proposed to ensure that existing serviceability criteria are satisfied.