Accession Number : ADA524282


Title :   A Design Tool for Robust Composite Structures


Descriptive Note : Final rept.


Corporate Author : CALIFORNIA UNIV SANTA BARBARA DEPT OF MATERIALS


Personal Author(s) : Zok, Frank ; Fleck, Norman ; Deshpande, Vikram


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA524282


Report Date : JUN 2010


Pagination or Media Count : 24


Abstract : New opportunities exist for enhancing the impact resistance of organic matrix composites while simultaneously imparting multifunctionality. They draw upon the existence of organic fibers, especially Dyneema. The principal objectives of the present study were to ascertain the fundamental mechanical properties of Dyneema fibers and assess strategies for integrating these fibers into load-bearing structures. The results reveal that the tensile strength of Dyneema composites increases by a factor of 2 and the ductility by almost a factor of 3 over the strain rate range 10-3 s-1 to 104 s- 1. One consequence is that the Dyneema composites outperform by a wide margin (factor of 4) the ballistic resistance of CFRP composites at the same areal density. Moreover, it has been demonstrated that Dyneema composites can be integrated into metallic sandwich panels with either metallic prismatic cores or polymer foam cores using mechanical attachment schemes. When integrated into such structures, the full impact resistance of the composites is realized only when the backside is unconstrained at the impact site and is thus free to deform. Dyneema fibers can also be incorporated into hybrid carbon fiber composites as through-thickness reinforcements, with benefits in impact resistance and retained compressive strength.


Descriptors :   *COMPOSITE STRUCTURES , MECHANICAL PROPERTIES , TENSILE STRENGTH , COMPOSITE MATERIALS , RESISTANCE , SANDWICH PANELS , ORGANIC MATERIALS , DUCTILITY , FOREIGN OBJECT DAMAGE , FIBERS , FIBER REINFORCED COMPOSITES


Subject Categories : LAMINATES AND COMPOSITE MATERIALS


Distribution Statement : APPROVED FOR PUBLIC RELEASE