A technique is proposed to predict crack growth for the estimation of Strain Energy Release Rate (SERR) of Double Cantilever Beam (DCB) bi-metallic specimen, employing ultrasonic Lamb waves. Techniques based on the Time-of-Flight (ToF) of the Turning Lamb Mode (TLM) and Direct Lamb Mode (DLM) explored to determine the crack growth. Sensitivity analysis revealed that the Lamb mode with low velocity is more sensitive to crack growth than that of the high velocity Lamb mode. © (2012) Trans Tech Publications, Switzerland.

Krishnan Balasubramaniam

Department of Mechanical Engineering

CRACK GROWTH PREDICTION

DOUBLE CANTILEVER BEAM

HIGH VELOCITY

LAMB MODES

LOW VELOCITIES

TIME OF FLIGHT

ULTRASONIC LAMB WAVES

Metallic compounds

Strain energy

Ultrasonic testing

Ultrasonic waves

Cracks

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IIT Madras

Advanced Materials Research

Ultrasonic Lamb wave based crack growth prediction for estimation of strain energy release rate

Propagation of the primary anti-symmetric Lamb mode (Ao) in an asymmetrically delaminated cross-ply laminate has been studied through both numerical simulations and experiments employing the air coupled ultrasonic technique. When the Ao mode interacts with the entrance and the exit of an asymmetrically located delamination, in addition to Ao, a mode converted to the primary symmetric Lamb mode (So) also propagates in each of the two sub-laminates as well as the main laminate. These Lamb modes propagate independently in each of the sub-laminates. In addition, turning modes (i.e.the mode propagating in one sub-laminate interacts with delamination edge and starts propagating in the other sub-laminate) and a mode converted turning mode (a new mode is generated during the interaction of turning mode with delamination edge) were also observed in the numerical simulation. The presence of the 'mode converted turning modes' was also validated through the experiments in this study. © 2010 IOP Publishing Ltd.

Smart Materials and Structures

Interaction of guided Lamb waves with an asymmetrically located delamination in a laminated composite plate

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The Journal of Adhesion

Strength of Joints Involving Composites

Journal	Advanced Materials Research
ISSN	10226680
Open Access	No