Accession Number:

ADA370207

Title:

Optimization of Textile Composite Toughness

Descriptive Note:

Final Technical rept. 10 Jul 95-30 Jun 99

Corporate Author:

ROCKWELL INTERNATIONAL CORP THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s):

Report Date:

1999-07-07

Pagination or Media Count:

249.0

Abstract:

We have designed, made, and tested novel composites, including composites of chains, braided composites, and knitted composites, which show exceptionally high energy absorption under tensile loading. Values per unit volume range up to 60 MJcu m and per unit mass up to 25 Jg. Analytical micromechanical models have led to design rules, which indicate that energy absorption per unit volume of up to 250-300 MJcu m is attainable with chain composites and energy absorption per unit mass of 50-100 Jg with knitted or braided composites. The delocalisation mechanisms that underlie high energy absorption have been demonstrated by ballistic impact tests to continue at strain rates up to 104. In fact, the energy absorption increases at high strain rate, which is attributed to hardening of the polymeric matrix material. A computational model of failure and damage distribution in textile composites called the Binary Model has also been developed. The entire failure sequence, involving multiple, random local failure events, nonlinear load transfer mechanisms, plasticity, multiple matrix cracking, and pullout phenomena has been simulated successfully.

Subject Categories:

  • Laminates and Composite Materials
  • Textiles

Distribution Statement:

APPROVED FOR PUBLIC RELEASE