Advanced Materials Research Vol. 1081

Abstract: Based on structure and composition characteristics of engine oil, the new algorithm for its Infrared Spectrum (IR) Identification has been put forward. The Hit Quality Index and Related Hit Quality Index are widely used in Infrared Spectrum Identification recently. The two methods don’t take the importance of the variables into consideration and cannot distinguish the unobvious variation in IR spectra. Therefore the diversity weight factor was introduced into the new algorithm to promote its selectivity. The experimental results had shown that the new spectrum similarity evaluation index could distinguish the unobvious spectrum variations and to improve the infrared spectrum identification capability of engine oils.

Abstract: A damage identification method is proposed to identify the damage style and the damage parameters. By driving a pair of PZT patches out phase and in phase, the electric admittance of the PZT is obtained. The damage parameters are then identified from the changes of the admittance spectra caused by the appearance of damage. By comparing the identification result, the damage style can be determined and the damage parameters can be obtained. The middle basic particle swarm optimization algorithm is employed as a global search technique to back-calculate the damage. Experiments are carried out on beams. The results demonstrate that the proposed method is able to identify the damage style, and can effectively and reliably locate and quantify the damage in the beam.