Charpy V-Notch Toughness

E_{Charpy} = m g h_{1} - m g h_{2} (absorbed energy)

CVN energy vs temperature locates the ductile-to-brittle transition. FCC metals (austenitic stainless, Al) stay tough; BCC steels can go brittle in the cold. Civil: fracture-critical steel, bridges in cold regions.

$E$ (J or ft·lb): Absorbed energy
$D B T T$: Ductile–brittle transition temperature

Step-by-step solved example

Pendulum 20 kg, h1=1.2 m, h2=0.4 m. Absorbed energy?

Absorbed energy vs temperature — DBTT on a toughness curve.

1. Δh
1.2−0.4=0.8 m.
2. E
20×9.81×0.8=157 J.

Answer: 157 J

10 practice questions

0/10 correct

1.A higher Charpy energy means

2.DBTT is a concern for

3.Austenitic stainless (FCC) typically shows

4.Notch-sensitive materials have

5.If h2=h1, absorbed energy is

6.ft·lb to J: multiply by

7.Upper-shelf energy is

8.Welding may raise DBTT in the HAZ because

9.Charpy is not a design stress; it is

10.m=10 kg, Δh=0.5 m: E≈