A Simplified Elastic Stiffness Estimation of Unidirectional Carbon-Fiber-Reinforced Coupon Using the In-Plane Velocity Anisotropy of Lamb Waves

We propose a simplified method for estimating the five elastic stiffnesses of a unidirectional carbon-fiber-reinforced plastic (UD-CFRP) coupon from the velocity anisotropy of laser-excited Lamb waves. This method utilizes the in-plane orientation dependence of the Rayleigh wave velocities which are estimated from the velocity dispersions of the zero-th-order antisymmetric Lamb (A 0 -Lamb) wave. We estimated the five elastic stiffnesses of UD-CFRP coupons by utilizing the simplex-assisted inverse scheme, and compared the obtained values with those determined by the strain gauge method. The proposed method was found to be effective for estimating the stiffnesses of anisotropic materials. However, the inverse scheme must be modified to improve the accuracy of measurement of some stiffnesses.