The shape and dimensions of reinforced-concrete beams with half-joint or ‘dapped’ ends often represent a problem in structural design. If suitable geometry is not provided properly to the re-entrant corner, a diagonal tension crack may grow rapidly and failure will occur with little or no warning. In the study reported in this paper, two-dimensional finite-element analysis was adopted to investigate the effects of variation of some main parameters such as shear-span-to-depth ratio, the length ratio and the depth ratio. The analysis covered 29 specimens with half-joint ends, which had conventionally detailed reinforcement with an adequate development length of the longitudinal tension reinforcement beyond the re-entrant section. The structural behaviour of the specimens was compared and validated with previous experimental results from the literature. In addition, failure loads were compared with calculated values predicted by common codes and various equations. The results showed that shear capacity increases by reducing the nominal shear-span-to-depth ratio, reducing the length ratio or increasing the depth ratio. Moreover, the finite-element model was generally found to be in good agreement with previous test data.

中文翻译：

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半节点钢筋混凝土梁的数值研究

具有半接缝或“搭接”端部的钢筋混凝土梁的形状和尺寸通常代表结构设计中的问题。如果未正确地为凹角提供合适的几何形状，则对角线张力裂纹可能会迅速增长，并且会在很少或没有警告的情况下发生故障。在本文报道的研究中，采用二维有限元分析来研究一些主要参数（如剪切跨度与深度之比，长度比和深度比）变化的影响。分析覆盖了29个具有半接头端部的标本，这些标本具有常规的详细钢筋，并具有超过凹入部分的足够长度的纵向拉伸钢筋。比较了样品的结构行为，并与文献先前的实验结果进行了验证。另外，将失效载荷与通用代码和各种方程式预测的计算值进行了比较。结果表明，通过减小标称剪切跨度与深度之比，减小长度之比或增加深度之比，可以提高剪切能力。此外，通常发现有限元模型与先前的测试数据非常吻合。