Study on Fracture Toughness of Layered Structure for Fail Safe Design

Abstract

The aim of the current work is to test the development of a failsafe design. The design
consisted of dual layer structuredround bar fabricated by press fitting. Mode II fracture toughness
was measured with circumferential notch test pieces subjected to shear force. Two sets of test pieces
were prepared. The first set was made up of dual layered Al6061T6 alloy. The second set was made
with Al6061 T6 alloy as outer layer and inner layer was made with AISI1045 steel. A rod of
Al6061T6 alloy is also subjected to shear to determine fracture toughness. Fracture toughness values
are calculated using modified Kienzler and Herrmann’sequation. The measuredfracture toughness
values indicated an improvement of 18% in the case of Al6061T6 alloy dual layered structure and
33.33% in the case of AISI1045 steel inner layer and Al6061T6 alloyouter layer structure.