Wave Propagation in an Off-Axis Graphite/Epoxy Composite: Gaussian Two-Cycle Approximation

Problem Statement
At the bottom surface of each figure a two cycle pulse of acoustic energy is launched into a block of unidirectional graphite/epoxy composite whose fibers are oriented at 40 degrees from the bottom surface (off-axis). The purpose of this simulation-visualizaton was to better understand the physical mechanisms: eigenvalue 9wave speeds) and eigenvector (particle displacement vibration directions) solutions for developing a new nondestructive evaluation method (Patent No. 4,499,770).

Visual Insight
From an animated movie of these dat awe were able for the first time to see the physical relationships of bulk waves with Rayleigh surface waves and bulk wave diffractions. We made a new discovery that the slower moving QT-wave must follow the diffraction path of the faster moving QL-wave.