This paper describes a numerical study of the punching shear resistance of unbonded post‐tensioned slabs without shear reinforcement. This research aimed to develop a methodology for modeling unbonded tendons and numerically evaluate the prestressing effects on the punching shear capacity. To validate the modeling approach, a series of well documented experimental tests were simulated using the finite element software DIANA. The nonlinear analyses were performed using three‐dimensional solid elements, incorporating the cracking behavior of concrete by the smeared crack approach. In addition, interface elements were included, providing bond‐slip properties to simulate the friction between tendons and concrete. A good agreement was found between the numerical results and experimental data. Load capacity, cracks patterns, and the prestressing effects were accurately simulated. After the validation, a parametric study was conducted to analyze the influence of distribution, force and profile of prestressing tendons. Finally, the numerical results were compared with current design code provisions and the approach provided by the Critical Shear Crack Theory.

中文翻译：

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无粘结后张混凝土平板冲切承载力的数值研究

本文描述了无粘结后张预应力板的抗冲剪抗力的数值研究。这项研究的目的是开发一种建模无粘结筋的方法，并通过数值方法评估预应力对冲剪能力的影响。为了验证建模方法，使用有限元软件DIANA对一系列有据可查的实验测试进行了仿真。非线性分析是使用三维实体元素进行的，结合了通过涂抹裂纹法进行的混凝土的开裂行为。此外，还包括界面元素，提供了粘滑特性，以模拟筋与混凝土之间的摩擦。在数值结果和实验数据之间找到了很好的一致性。承载能力，裂纹形态，并精确模拟了预应力效果。验证之后，进行了参数研究，以分析预应力筋的分布，力和轮廓的影响。最后，将数值结果与当前的设计规范规定以及临界剪切裂纹理论提供的方法进行了比较。