Conventional fiber reinforced composite materials exhibit higher specific stiffness and strength than ones exhibited by traditional metal materials. Applications of composite materials lead to weight reduction and energy savings. The matrix system usually a polymeric, ceramic, or a metallic material. The properties are tailorable in plane; however, further enhancement is possible by creating a sandwich material system like fiber metal laminates, honeycomb and foam core, and even by reinforcing the matrix material using nano-materials (e.g., nanotubes, nano-fibers, silica particles, etc.,) and chopped fibers. Engineers also may use 3-dimensional stitched, braided or fabric materials. Performing durability and damage tolerance analysis on structural components made of such advanced composites material systems is a difficult task as range of stiffness, Poisson’s ratio and strength properties are desired for such analysis. The challenge comes from difficulty in performing reliable mechanical tests on nano-materials in a less expensive way.
It is highly desirable to be able to simulate structural components made of these advanced materials subjected to static, fatigue or impact loading conditions. It is also desirable that the simulation be done without any extensive finite element modeling or several expensive coupons level test data. Recall that usual finite element approach requires extensive modeling efforts whereby the engineer models all the constituents without knowledge of complete set of mechanical material properties, or homogenized model ignoring any possible fiber matrix level root cause issues.
Since in advance complex material systems the root cause for damage initiation is the constituents, it is vital that constituent level damage evolution be accounted accurately during the load increment without extensive modeling efforts. We recommend the following approach for simulating such problems:
Material characterization is done using the following tools:
Joint Publications with key Aerospace Industry and University Partners: