Engineering Commons^™

Analyses Of Quasi-Isotropic Composite Plates Under Quasi-Static Point Loads Simulating Low-Velocity Impact Phenomena, Ajit Dhundiraj Kelkar

Mechanical & Aerospace Engineering Theses & Dissertations

Composite laminates have high strength to density ratios that make them attractive for use in aircraft structures. However, the damage tolerance of these materials is limited because they have very low ultimate strains, no plastic deformation range, and no usable strength in the thickness direction. These limitations are very obvious when laminates are subjected to impact loads. Due to these impact loads, laminates suffer visible and invisible damage. To improve the material performance in impact requires a better understanding of the deformation and damage mechanics under impact type loads.

In thin composite laminates, the first level of visible damage occurs …

Unsteady Transonic Flow Over Slender Bodies, Cevdet Aydun

Mechanical & Aerospace Engineering Theses & Dissertations

The unsteady transonic small disturbance equation for an oscillating slender body is obtained from the full potential equation in cylindrical coordinates by means of a perturbation analysis. The time-dependent body-boundary condition is reduced into a simpler form by matching the outer and inner flows. Also, a time-dependent pressure coefficient over the slender body is derived by means of a matching principle. The simplified form of the body-boundary condition is incorporated into the difference equations at the body axis. This application allows use of the cylindrical coordinate system for the problem. By prescribing several different body-boundary conditions, various modes of body …