The Charpy Test Simulation

This simulation was done more for fun rather than being really useful to some design activity.

Nonetheless it shows how powerful simulations can be. In this case the material properties used to simulate the tensile test shown in a previous news are here implemented into a Charpy Test coupon (U-shape notch) and the simulation is run with two different energies:

1. the one on the left in the videos here below is impacted with 13.7 J (1.393 kg released from a height of 1 m)
2. the one on the right is impacted with 27.3 J (2.786 kg released from a height of 1 m)

In the first case the coupon only partially fails and the hammer bounces back.

In the second case the impact energy is doubled and this is more than enough to let the hammer pass through the coupon.

Some details on the model:

1. the U-shape notch has been chosen to allow a coarser mesh in order to reduce the stable time incremet, thus increasing the solution speed (for details concerning the  Explicit approach see Chapter 14 of the book Computational Structural Engineering); the more classical V-shape notch would have required much smaller elements in the fillet at the bottom of the groove
2. the hammer arm is 1 m long and it is simulated with a rigid element (Kinematic Coupling using the Abaqus nomenclature, RBE2 using the Nastran nomenclature)
3. again to reduce the solution time, the anwil is simulated as a rigid body, whereas the hammer is simulated with solid elements
4. to save simulation time, at the beginning of the analyses the hammer is positioned exactly at the hitting point: an initial velocity corresponding to the kinetic energy (in turn equal to the potential energy of the mass released from a 1 m height) is imposed to the hammer
5. the simulations reported in the animations are run up to 15 ms after the impact