Abstract Micro pile hole is a kind of bored with diameter 100~400mm, which has been widely used in the field transmission line engineering recent years, and its formation usually uses DTH (Down-the-Hole) drilling rig. When rigs operate, slag discharge method to use compressed air provided by compressor blow muck directly from bottom ground. However, during process, it difficult out due large cr...

the most promising method for micro scale energy scavenging is via vibration energy harvesting which converts mechanical energy to electrical energy by the effect of coupling between electric fields and mechanical variables. using piezoelectric cantilevers is the most common method for vibration energy harvesting. changing the shape of the cantilevers can lead to changing the generated output v...

Periodic piezoelectric beams have been used for broadband vibration energy harvesting in recent years. In this paper, a periodic folded piezoelectric beam (PFPB) is introduced. The PFPB has special features that distinguish it from other periodic piezoelectric beams. The Adomian decomposition method (ADM) is used to calculate the first two band gaps andtwelve natural frequencies of the PF...