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1.The tesile test (cont’ d) Because of necking, the capacity of the ma-terial for plastic deformation in tension, i. e.the ductility, is not truly indicated by thestrain to fracture measured along the gaugelength. A longer gauge length would give asmaller value. A better measure of ductility isthe reduction of area at the narrowest part of theneck. This can be expressed as a logarithmicstrain in the form ln (A_0/A_1) where A_0 andA_1 are the initial and final areas. In an ideallyductile material a total reduction of area occurs,
1.The tesile test (cont ’d) Because of necking, the capacity of the ma-terial for plastic deformation in tension, iethe ductility, is not truly indicated by therain to fracture measured along the gaugelength. A longer gauge length would give Asmaller value. A better measure of ductility is the reduction of area at the narrowest part of the neck. This can be expressed as a logarithmic strain in the form ln (A_0 / A_1) where A_0 and A_1 are the initial and final areas. In an ideally conductive material a total reduction of area occurs,