Spallation and Dynamic Fracture as an Effect of Laser Induced Shock Waves in Carbon Based Composite Materials
Abstract
A high irradiance single beam short pulsed Nd:glass laser was used to generate shock waves in carbon-carbon and carbon epoxy composites. Dynamic brittle fracture at hypervelocity impact conditions was observed as a result of reflected shock waves as tensile waves from the back surface of samples. Successive stages of damage from incipient spallation to complete sample perforation were obtained by increasing gradually the laser energy. The thermo mechanical damage on the front surface as a result of laser interaction with the target material, and the mechanical damage at the back surface as a result of shock wave reflection were characterized by optical and scanning electron microscopy. The failure properties of the carbon composites were related to the processing of densification and graphitization mode. While the failure properties for carbon epoxy composites were related to impact direction versus fiber direction. A comparison was made between spall properties fo carbon epoxy composites with aluminum and iron. A new experimental method was developed to calculate the attenuation of laser generated shock waves. This technique enables also the evaluation of the laser induced spall pressure in different materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1989
- Accession Number
- ADA216540
Entities
People
- I. Gilath
- S. Eliezer
Organizations
- Israel Atomic Energy Commission