Finite Element Analysis of Laser-Induced Damage to Mechanically Loaded Laminated Composites in Helicopters
Abstract
This thesis examines the lethality of laser directed energy weapons in causing structural failure to mechanically loaded laminated composites in helicopters. The analysis is based on a three-dimensional numerical finite element model of a rectangular, incipient, orthotropic compression panel with its edges rotationally restrained. The panel is made of 24 in. x 6 in. graphite/ epoxy laminated composite where the laminate consists of fourteen laminas of different ply orientation angles and two different thicknesses. Data for the degradation of the thermal and mechanical material properties with increasing temperature, as well as temperature dependence thermal response data, were provided. Failure of laminated composites is controversial, even under ambient temperature. However, a successful attempt has been conducted here to predict the mechanical and thermal buckling and post-buckling behavior of the heated panel. This is further complicated by the anisotropic behavior of the composite material and the thermal effect. Even without buckling, the problem is thermally and structurally non-linear. This work can be considered as an above preliminary numerical analysis. It provides insight into using existing codes to obtain approximate solutions good enough for the engineering design, with speed and low cost.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 07, 1991
- Accession Number
- ADB157706
Entities
People
- Mohammed J. Alghatam
Organizations
- United States Army Command and General Staff College