张拉膜结构模型全过程试验研究

Study on full process experiment of full scale tensioned membrane structure

本文对一较大的足尺张拉膜结构模型进行了张拉成型和荷载试验,并进行了模型的自振频率测量试验。通过对该模型张拉成型阶段索、膜内应力值的测量表明,张拉膜结构在预应力阶段基本符合等应力假设,但在拉索附近由于边缘效应,膜内应力并不均匀。模型的荷载试验表明,在正常使用荷载作用下结构基本处于弹性工作状态。模型的自振频率测量试验证明,张拉膜结构振动存在与空气耦合引起的附加质量影响,其阻尼比值及变化规律与一般刚性结构存在明显差异。

The shape forming processing and loading experiment of a full scale tensioned membrane structure model was carried out with the model frequency measured. Through the data of stresses measured on cables and membrane during shape forming process, it was shown that tensioned membrane basically following the equal stress hypothesis in pretensioning stage. But in the areas near cables, the membrane stress was not uniformly distributed due to the edge effect. Loading experiment proved that under normal load effect the structure was basically in plastic working state. Through model vibration measure experiment, it was shown that additional mass led by coupling of membrane and air existed when the model vibrates. The amount and varying regularity of damping ratio are far different from the traditional rigid frame structure.