International audienceThe friction damper has been widely used to reduce the resonant vibration of blades. The most commonly used methods for studying the dynamic behavior of a blade with a friction damper are direct integration methods. Although the harmonic balance method (HBM) is a well-known method for studying nonlinear vibration problems, generally only a one-term approximation has been proposed to study the nonlinear vibration of a frictionally damped blade. In this work, a HMB procedure with a multiterm approximation is proposed. The results show that the steady-state response and other related behavior of a frictionally damped blade can be predicted accurately and quickly by an HBM with a multiterm approximation

The friction damper has been widely used to reduce the resonant vibration of blades. The most commonly used methods for studying the dynamic behavior of a blade with a friction damper are direct integration methods. Although the harmonic balance method (HBM) is a well known method for studying nonlinear vibration problems, generally only a one–term approximation has been proposed to study the nonlinear vibration of a frictionally damped blade. In this work; a procedure of the HBM with a multi–term approximation is proposed. The results show that the steady state response and other related behavior of a frictionally damped blade can be predicted accurately and quickly by the HBM with a multi–term approximation.

Various methods for the separation and purification of Hb from animal blood have been investigated to establish the optimal and highly reliable purification process. The Hb obtained from various sources, i.e., bovine, pig and human bloods were analyzed and compared using simple and fast analytical methods, including, electrophoresis, isoelectric focusing, and spectroscopy to study the characterization of protein structure. Further investigation along this line will enable us to realize the ultimate objectives of development for artificial RBC substitutes.