STIFFNESS IDENTIFICATION OF LAMINATED COMPOSITE SHAFTS

Distributions of bending stiffness along the spans of laminated compos ite shafts are determined via a non-destructive evaluation approach. T he finite element method formulated on the assumption of uniform bendi ng stiffness within each element is used in the deflection analysis of the shafts. Differences between measured and theoretically predicted deflections at any two points on a shaft are used to construct an erro r function for deflection. The identification of bending stiffness is formulated as a minimization problem in which the elemental bending st iffnesses are determined to make the error function a global minimum. A global minimization technique and a bounding method for establishing side constraints are presented to solve the above minimization proble m. Experiments are performed to study the feasibility and applications of the proposed method. (C) 1998 Elsevier Science Ltd. All rights res erved.