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During a tensile test, a metal has a true strain = 0.08 at a true stress = 37,000 lb/in2. Later, at a true stress = 55,000 lb/in2, true strain = 0.24. Determine the strength coefficient and strain-hardening exponent in the flow curve equation.

User Yuli Hua
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1 Answer

4 votes

Answer:

The strength coefficient and strain-hardening exponent in the flow curve equation are 92038 and 0.3608.

Step-by-step explanation:

Given that,

True stress = 37000

True strain = 0.08

Later,

True stress = 55000

True strain = 0.24

Using formula of true stress


\sigma=K\epsilon^n

We need to make a two equation of true stress

Using formula of true stress


37000=K(0.08)^n....(I)


55000=K(0.24)^n....(I)

Dividing equation (II) and (I)


(55000)/(37000)=((0.24)^n)/((0.08)^n)


1.4865=((0.24)/(0.08))^n


1.4865=3^n

Taking ln in both side


ln(1.4865)=n ln(3)


n=(ln(1.4865))/(ln(3))


n=0.3608

We need to calculate the value of strength coefficient

Put the value of n in equation (I)


37000=K(0.08)^(0.3608)


K=(37000)/(0.08^(0.3608))


K=92038

Hence, The strength coefficient and strain-hardening exponent in the flow curve equation are 92038 and 0.3608.

User Horay
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