Design of extended & coped beam shear plate connections and welding of heavy plates and shapes

拟议的研究旨在改善加拿大对结构钢剪切片连接和利用厚板和厚轧件的焊接组件的知识、设计和详细规定。ADF Group Inc.和他们在DPhV的工程师在应用现有设计程序方面遇到了困难，并发现这些连接和焊接组件存在潜在的性能问题。法兰厚度超过50 mm的大型轧制型材(通常称为“巨型型材”)和组合的大型型材将是本研究项目的第一个组成部分。ADF Group Inc.最近制造的厚钢板组合箱柱使用了75 mm厚的钢板和带有双层钢板的厚轧截面，导致大量开裂的构件不得不报废和重新铺设。断裂是在完全没有使用载荷的情况下发生的，而是由收缩应力或热切割表面的残余应力引起的。据报道，该行业的总亏损接近200万美元。对于不同等级的钢材，需要研究如何焊接这些厚型钢的详细建议，因为由于加拿大的抗震和抗爆设计，它们的使用量正在上升。拟议研究的第二部分涉及剪切片连接的性能和设计。目前由加拿大钢结构学会推荐的设计程序仅限于相对较小的配置单柱螺栓。对于梁-梁连接节点，在使用扩展剪力翼片或连接的梁-剪力翼片连接时，缺乏设计指南。轴向荷载对组合剪力连接的影响是特别重要的。将对具有代表性的剪切片连接进行测试，并对厚板和型材进行材料测试。此外，还将对剪切片连接进行有限元建模，以评估较大范围的加载方案和较大截面的焊接程序。总体目标是推荐设计和焊接程序。

The proposed research directed towards improving the state of knowledge, design and detailing provisions in Canada of structural steel shear tab connections and of welded assemblies that utilize thick plates and heavy rolled sections. ADF Group Inc. and their engineers at DPHV have experienced difficulties in applying existing design procedures and have found potential performance issues with these connections and welded assemblies. Heavy rolled shapes, typically called "jumbo sections", with flange thicknesses exceeding 50 mm and built-up heavy shapes will be the subject of the first component of this research project. The recent fabrication by ADF Group Inc. of heavy steel plate built-up box columns that utilized 75mm thick steel plates and heavy rolled sections with doubler plates resulted in a significant number of cracked members that had to be scrapped and refabricated. The fractures occurred in the complete absence of service load, and were instead caused by either shrinkage stresses or by residual stresses on the thermally cut surface. The total industry loss was reported to approach $2M. Research to develop detailed recommendations on how to weld these heavy shapes is needed for different steel grades since their use is on the rise due to seismic and blast-resistant design in Canada. The second component of the proposed research addresses the behaviour and design of shear tab connections. The current design procedure recommended by the Canadian Institute of Steel Construction is limited to relatively small configurations with a single column of bolts. A lack of design guidance exists for beam-to-girder connections where either an extended shear tab or a coped beam-to-shear tab connection is used. The influence of axial load in the connection combined with shear is of particular interest. Testing of representative shear tab connections as well as material tests of the heavy plates and shapes will be carried out. This will be supplemented with finite element modeling of the shear tab connections to evaluate a wider range of loading scenarios and of welding procedures for the heavy sections. The general objective is to recommend design and welding procedures.