Design Requirements for Shear Connectors in Encased Steel (SRC) and Concrete Filled Tube (CFT) Construction

9520233 Roeder钢和混凝土复合基础设施和建筑物是抗震设计所需的，因为它们经济地提供了在不利的负载条件下确保良好性能所需的强度和刚度。 然而，复合作用需要钢和混凝土之间的剪切传递。 根据构件在结构中的位置，传递要求是高度可变的。 这种通过滑移传递的损失可能导致强度和刚度的急剧损失，而能量耗散非常小。 剪力连接件可用于在元件之间传递剪力，但它们成本高，工程师有动机尽量减少使用它们。 目前，没有任何指南或规范规定，以帮助他们确定最佳的剪切连接器的位置在美国的做法。 这项研究将提供设计指南，以建立最经济的剪力连接件的要求，在外包钢（SRC）和混凝土填充管（CFT）的建设，同时确保良好的抗震性能。 该项目将包括对现有试验数据的全面审查，以确定可以通过各种CFT和SRC应用开发的抗剪承载力。 将进行一系列实验，以填补现有知识和数据的空白。 蠕变，收缩和泊松效应的研究代表了潜在的问题，在使用债券或粘附的剪切传递机制，并将进行实验。 实验将建立一个更完整的图片粘结应力和剪切传递能力的钢管混凝土和型钢混凝土的应用。 将分析一系列基于本研究项目主题结构的SRC和CFT原型结构，以确定确保满意抗震性能所需的剪力传递需求。 剪切传递能力将与设计指南和建议的需求相关联。 这是一个在民用基础设施系统（CIS）的第一年计划下支持的项目，招标NSF 94-154。 ***

9520233 Roeder Composite steel and concrete infrastructures and buildings are desirable for seismic design, because they economically provide both the strength and stiffness needed to assure good performance under adverse loading conditions. However, composite action requires a shear transfer between the steel and the concrete. The transfer requirements are highly variable depending upon the location of the component in the structure. Los of this transfer through slip may result in a dramatic loss of strength and stiffness with very little energy dissipation. Shear connectors may be used to transfer shear force between elements but they are costly, and engineers are motivated to minimize their use. At present, there are no guidelines or specification provisions to help them determine the best shear connector placement in US practice. This research will provide design guidelines for establishing the most economical shear connector requirements in both encased steel (SRC) and concrete filled tube (CFT) construction, while assuring good seismic performance. This project will consist of a thorough review of existing test data to determine the shear capacity that can be developed with various CFT and SRC applications. A series of experiments will be performed to fill gaps in existing knowledge and data. Studies on creep, shrinkage and the Poisson effect represent potential problems in using bond or adhesion for the shear transfer mechanism, and experiments will be performed. The experiments will establish a more complete picture of bond stress and shear transfer capacity for both CFT and SRC applications. A range of SRC and CFT prototype structures based on the Theme Structures established for this research project will be analyzed to determine the shear transfer demand necessary to assure satisfactory seismic performance. The shear transfer capabilities will be correlated to the demand to develop design guidelines and recommendati ons. This is a project supported under the year 1 program of the Civil Infrastructure Systems (CIS), solicitation NSF 94-154. ***