Elastic Response of Rosette Cylinders under Axisymmetric Loading
Interim rept. Oct 1975-Mar 1976
AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
The problem of the elastic response of a rosette cylinder, i.e., a cylindrical body formed by reinforced composite layers wrapped along spiral trajectories, is formulated and solved through the application of the theory of heterogeneous elasticity. It is shown that 21 elastic coefficients, which in general, are functions of position in the medium, enter the elastic constitutive equations. Certain geometric preliminaries and tensor transformation laws establish the relation between these coefficients and the orthotropic moduli of the basic sheet material. It is also demonstrated that problems involving axisymmetric boundary conditions can be formulated in terms of one space variable, and this class of boundary value problems is solved through a numerical procedure. Included in the response is the influence of environmental dilation, which may be caused by a uniform temperature change andor moisture adsorption. An example problem indicates the potential of rosette construction to drastically reduce stress concentration factors and illustrates significant errors resulting from improper modeling of the material structure.
- Laminates and Composite Materials
- Rocket Engines