Vibration transmission and energy flow analysis of L-shaped laminated composite structure based on a substructure method

This study investigates the vibration power flow characteristics of a harmonically excited L-shaped laminated composite structure with flat sub-plates connected at a right angle. A substructure-based power flow analysis (SPFA) method is developed based on analytical, numerical, and hybrid approaches of determining the receptance functions of sub-plates and by using the force balance and geometrical compatibility conditions at the coupling edge. The SPFA methods are then used to evaluate the vibration energy input into the structure and energy transmission through the coupling edge. The power flow density vector is defined, and its time-averaged value is used to clearly illustrate the energy sources and sinks as well as the energy transmission paths within the sub-plates. The influence of different combinations of fibre orientations for the sub-plates and the excited dominant global modes of the joined structure on the major vibration energy transfer paths are investigated. It is found that the fibre orientation can have significant effects on transmission paths and potential positions of sinks. From the vibration energy flow perspective, the fibre angles of the integrated laminated composite structure can be tailored for desirable energy transmission paths.