一种索穹顶结构初始预应力分布确定的新方法—预载回弹法

A NEW METHOD OF DETERMINING THE INITIAL PRESTRESS DISTRIBUTION OF CABLE DOMES—THE PRELOAD AND REBOUND METHOD

  • 摘要: 对索穹顶结构初始预应力分布的确定进行了研究,提出一种新方法—预载回弹法。该方法首先对索穹顶施加一个预设荷载,提取有利于抵抗预设荷载的内力分布。将该组内力作为预应力施加至结构上,并撤除预载,使结构回弹,通过两阶段变弹性模量迭代计算,收敛后可获得索穹顶结构的整体可行预应力分布。该方法通过施加对称荷载,即可自动实现单元的分组,便于整体可行预应力的判定,并可直接获得多自应力模态结构的优化初始预应力分布。通过算例证明预载回弹法具有很高的精度、较快的收敛速度,求得的整体可行预应力分布直接适用于实际工程应用。

     

    Abstract: The determination of the initial prestress distribution of cable domes is studied and a new method named the Preload and Rebound Method is proposed. A preload is applied to the cable dome first to get the internal force distribution which helps resist the preload. After the preload is removed, the internal force is then applied to the structure as prestress, making the structure rebound. Through the two-stage iterative calculation by using changing elastic modulus, the integrity feasible prestressing distribution of the cable dome is achieved after convergence. By applying a symmetric load, this method automatically groups the members and easily distinguishes the integrity feasible prestressing distribution. The optimized initial prestress distribution of the structure with multi-self-equilibrium stress modes is also directly gained. This method is proved to be accurate and converge fast by several examples. The integrity feasible prestressing distribution obtained through this method can be directly applied to engineering practice.

     

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