Question

In a machining operation the chip thickness ratio is $0.3$ and the back rake angle of the tool is ${10}^o$. What is the value of the shear strain?

• A. $0.31$
• B. $0.13$
• C. $3.00$
• D. $3.34$

Answer 1

The correct option is D $3.34$

$r=0.3,\alpha ={10}^o$
$\varphi =ta{n}^{-1}\left(\frac{rcos\alpha }{1-rsin\alpha }\right)$
$\varphi =ta{n}^{-1}\left(\frac{0.3cos{10}^o}{1-0.3sin{10}^o}\right)$
$={17.3}^o$
$\text{Shear strain}=cot\varphi +tan(\varphi -\alpha )$
$=cot17.3+tan\left(7.3\right)={3.34}^o$