The paper describes the reliability-based optimization of a TT-shaped precast roof girder produced in Austria. An extensive experimental programme was performed using laboratory specimens to gain information on the mechanical fracture parameters of the utilized concrete. Subsequently, destructive shear tests were performed on scaled-down and full-scale girders under laboratory conditions. The experiments helped in the development of an accurate numerical model of the girder. The developed model was consequently used for the advanced stochastic analysis of structural response, followed by reliability-based optimization, which was used to maximize the shear and bending capacities of the girder and minimize production cost under defined reliability constraints. The enormous computational requirements of the double-loop optimization approach were significantly reduced by the utilization of an artificial neural network-based surrogate model instead of the original nonlinear finite element model of the optimized structure.

中文翻译：

---

使用代理模型和双环方法对预应力混凝土屋梁进行基于可靠性的优化

该论文描述了奥地利生产的 TT 形预制屋顶梁的基于可靠性的优化。使用实验室样品进行了广泛的实验程序，以获取有关所用混凝土的机械断裂参数的信息。随后，在实验室条件下对按比例缩小和全尺寸的梁进行破坏性剪切试验。这些实验有助于开发准确的大梁数值模型。因此，开发的模型用于结构响应的高级随机分析，然后是基于可靠性的优化，用于在定义的可靠性约束下最大化梁的剪切和弯曲能力并最小化生产成本。