Modal power flow analysis of a damaged composite plate

Abstract

Variation of the modal reactive power distribution of a damaged composite plate is mode led and analyzed both analytically and numerically. Large variation of local reactive power flow in or around the damage region of a plate under resonant vibration is related to the change of strain and kinetic energies in the damage region. Feasibility of damage identification based on the detection of this local variation of modal reactive power flow in a structure is studied. Compared with the damage identification techniques based on the determination of the active power flow in a damaged plate, the proposed method only requires data of a vibration mode shape of the structure and it is easier to apply in practice. Modal power flow of an orthotropic plate with a region of reduced stiffness in the plate is analyzed. Numerical tests show that the proposed method is effective for detection of the damage and the modal power flow is more sensitive 10 the change of plate stiffness than the strain mode shape in the test case.