Ultra‐high performance concrete‐normal strength concrete (UHPC‐NC) composite beam is a brand‐new composite structure. UHPC‐NC composite beam not only has the interfacial problem of the two materials, but its shear resistance should be investigated, which directly determines the mechanical performance and engineering value. In this article, the finite element analysis (FEA) method combined with the UHPC‐NC composite beam shear experiment are used to analyze the shear resistance of the composite beam and the influence of the interfacial zone on the shear behavior. The shear span‐to‐depth ratio, UHPC layer, and longitudinal reinforcement of specimens are designed to study the shear mechanism. Then the FEA model is used to simulate the cooperative working properties of the concrete beam and the UHPC layer, which includes two conditions—slip and no‐slip. The shear resistance, load‐span deflection curve and the strain of longitudinal reinforcement of the UHPC‐NC composite beams are analyzed and studied in combination with the results of shear experiment. The results show that the UHPC‐NC composite beam can effectively improve the ultimate shear resistance and ductility of the beam. At the same time, the interfacial zone of UHPC‐NC composite beam at the ultimate stage is a weak area, the cracking of that will has adverse effects on the mechanical properties of the composite beam, which needs to be paid attention to in the structural design.

中文翻译：

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超高性能混凝土—正常强度混凝土组合梁抗剪强度的数值分析

超高性能混凝土-标准强度混凝土（UHPC-NC）复合梁是一种全新的复合结构。UHPC-NC复合梁不仅存在两种材料的界面问题，还应研究其抗剪强度，这直接决定了机械性能和工程价值。本文将有限元分析（FEA）方法与UHPC-NC复合梁剪切试验相结合，用于分析复合梁的抗剪强度以及界面区域对剪切性能的影响。设计了剪切跨度比，UHPC层和标本的纵向钢筋，以研究剪切机理。然后使用FEA模型来模拟混凝土梁和UHPC层的协同工作特性，其中包括两个条件：滑移和不滑移。结合剪切试验结果，对UHPC-NC复合梁的抗剪承载力，挠度曲线和纵向钢筋应变进行了分析研究。结果表明，UHPC-NC复合梁可以有效提高梁的极限抗剪强度和延性。同时，UHPC-NC组合梁在最终阶段的界面区域为薄弱区域，其开裂会对组合梁的力学性能产生不利影响，在结构上应引起重视。设计。结果表明，UHPC-NC复合梁可以有效提高梁的极限抗剪强度和延性。同时，UHPC-NC组合梁在最终阶段的界面区域为薄弱区域，其开裂会对组合梁的力学性能产生不利影响，在结构上应引起重视。设计。结果表明，UHPC-NC复合梁可以有效提高梁的极限抗剪强度和延性。同时，UHPC-NC组合梁在最终阶段的界面区域为薄弱区域，其开裂会对组合梁的力学性能产生不利影响，在结构上应引起重视。设计。