Many researchers have carried out a lot of studies on these factors affecting the safety of scaffold structures. The scaffold collapses are caused by overload, geometric imperfections, joint connections, and foundation failures. It attracts more and more attention of researchers to the stability and safety issues of cuplock scaffolds. Some serious collapse accidents happened in China during the last several years. Cuplock scaffold structure is only used as a temporary facility in construction, so the safety issues are overlooked sometimes. In China, cuplock scaffolds are promoted promptly in recent years due to their low cost to manufacture, simplicity to assemble and disassemble, and high load capacity. Cuplock scaffolds are often used in the US and Asia. Cuplock scaffold is one of the scaffold structures which are made from prefabricated components. There are two major types of scaffold structures: one is made from prefabricated components and the other is made from steel tubes or bamboo.
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Scaffolds are widely used in the construction of permanent works such as buildings and bridges. The experimental results show that looseness index increases as the connection gets loose. Besides, a sensor looseness index matrix (SLIM) is derived to indicate the looseness of the cuplock connection. Experimental results show that shear PZT has better performance than stress PZT to be used as actuator and sensor for the wavelet packet analysis based structural health monitoring. Wavelet packet analysis is applied to analyze the transmitted signal energy between two PZTs through cuplok connection.
![scaffold meaning in chinese scaffold meaning in chinese](https://cdn.goodao.net/ebilgroup/H714d64d0fdae43e8974b51be83f361f9aHigh-Space-Utilization-Radio-Shuttle-Cart-Pallet.jpg)
In order to detect the looseness of cuplock connection, three stress PZTs and three shear PZTs used as transducers are mounted onto vertical bar and cross bars of cuplok scaffold. Contemporary structural health monitoring method is reviewed in this paper at first, and then we proposed wavelet packet analysis based method. The looseness of cuplock scaffold connection plays a significant role in the stability of the structure. The cuplock scaffolds are widely used as a temporary facility in the bridge and other constructions.