https://mecha101.blogspot.com/2020/05/impact-test.html In impact testing a sudden load is being applied to the material being tested to estimate the amount of energy that would be needed to fracture a notch (crack propagation) or we can say that it is the strength/capacity of a material to withstand sudden load. Shafts, bolts, anvils and dies are most common examples of items being subjected to impact testing.

2. https://mecha101.blogspot.com/2020/05/impact-test.html
Impact Test

3.  In impact testing a sudden load is being applied to
the material being tested to estimate the amount of
energy that would be needed to fracture a notch
(crack propagation) or we can say that it is the
strength/capacity of a material to withstand sudden
load. Shafts, bolts, anvils and dies are most common
examples of items being subjected to impact testing.
 Toughness can be defined as strength of a material
that it withstands fracture (crack Initiation) when it is
subjected to impact (sudden) load.

4. Two basic types of impact testing are
1) Charpy impact test
The material is placed /used as a simple beam with
the load applied at the center.
The position of hammer is set to 140°
The material is supported horizontally from two sides
2) Izod test
The material is placed /used as a cantilever beam.
The position of hammer is set to 90°

7. How to measure absorbed energy
 First the hammer is being raised to a specific height
(suppose H) with a specific amount of load that would be
released from that height H to strike the material
 The hammer with a knife edge hits the material and
fractures it at the notch
 The hammer then swing to a lower height than that
of H lets say the lower height is h
 The impact energy is being calculated from the difference
of the two heights i.e. H and h

8. Procedure
 First select the type of test required/ needed to be
performed i.e. either Charpy or Izod
 After that select the type of hammer both tests uses
different types of hammer and then tighten the wedge
and strikes screws
 Fix the hammer at specific position i.e. at required
angle
 Position the material to be tested on a support of the
block

9.  Bring the hammer close to material to make sure that
it would make a contact with the material after being
released
 Pointer should give a reading of 170 J for Izod test
and 300 J for charpy test
 Remove the material and test hammer for any
frictional losses which should be less than 0.8 for
Izod test and 1.5 for charpy test
 Now you can perform the test