IMPACT RESPONSE OF ALUMINIUM ALLOY FOAMS UNDER COMPLEX STRESS STATES

Authors

  • ZHIWEI ZHOU
  • BUYUN SU
  • ZHIHUA WANG
  • XUEFENG SHU
  • LONGMAO ZHAO

Keywords:

FOAMS, DYNAMIC BIAXIAL LOADING, FAILURE MODE, DYNAMIC FAILURE SURFACE

Abstract

A SERIES OF DYNAMIC BIAXIAL TESTS WERE CONDUCTED ON A CLOSED-CELL ALUMINUM ALLOY FOAMS IN ORDER TO DETERMINE THE EXPERIMENTAL FAILURE SURFACE UNDER IMPACT LOADING CONDITIONS. QUASI-STATIC BIAIXAL TESTS HAVE ALSO BEEN PERFORMED TO INVESTIGATE FAILURE MECHANISM UNDER DIFFERENT STRESS PATHS. THREE TYPICAL TYPES OF DEFORMATION MODES CAN BE OBSERVED, WHICH CORRESPONDS TO THE DIFFERENT FAILURE MECHANISM. THE FAILURE LOCI OF THE FOAM FROM QUASI-STATIC TO DYNAMIC LOADING CONDITIONS ARE DETERMINATED EXPERIMENTALLY IN PRINCIPAL STRESS PLANE. A SIGNIϬCANT DYNAMIC STRENGTH ENHANCEMENT IS IDENTIFIED. THE EXPANSION OF THE FAILURE LOCUS FROM THE QUASI-STATIC TO THE DYNAMIC TEST IS ALMOST ISOTROPIC. A MODIFIED FAILURE CRITERION FOR THE METALLIC FOAMS IS PROPOSED TO PREDICT FAILURE LOCUS AS A FUNCTION OF STRAIN RATE. THIS RATE-DEPENDENCE FAILURE CRITERION IS CAPABLE OF GIVING A GOOD DESCRIPTION OF THE BIAXIAL FAILURE STRESSES OVER A WIDE RANGE OF THE STRAIN RATES.

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Published

2016-01-05

Issue

Section

Articles