Problem $1$ Problem $1$

Since the material is brittle, the effect of stress concentrations near the discontinuities must be

considered.

For the hole:

The maximum stress is ${}_{\text{m}\text{a}\text{x}}=K_t{}_0=2\mathrm{.}7(138\mathrm{.}89)=375$MPa

For the notch

The maximum stress is ${}_{\text{m}\text{a}\text{x}}=K_t{}_0=2\mathrm{.}5(147\mathrm{.}06)=367\mathrm{.}65$MPa

For the fillet

The maximum stress is $326\mathrm{.}39$ MPa

The hole is most dangerous.

The $3-$mm$-$thick brittle bar is loaded axially with a constant force $F$ of $15kN.D=40mm$ and $d=$

$36$ mm $.$ The radius of insert hole, notch and fillet are $2mm,3mm$ and $1$ mm $,$ respectively. Which

section is most dangerous $($the hole, notch or fillet$)?$

For the notch, you can find a graph to determine stress concentration factor in the Appendix table. SECOND IMAGE IS THE ANSWER KEY