AMS 100 01 12 2020 1 AMS coil

AMS 100 01 – 12 - 2020

1 AMS coil - Quench The quench happens in less than 10 seconds As an approximation, I assume the honeycomb, GFRP, outer and inner skins stay at 50 K Ansys is not suitable for time dependent Multiphysics analysis I took the 9 lines in the graph and analyzed the respective time steps The main cause for higher stress will come from the higher current in some turns, not the temperature gradients!

1 AMS coil - Quench Current distribution in the HTS for the same time steps. We can expect the stress to be highest in the last 5 steps of the calculation

1 AMS coil - Quench • The next step is to add the change in current to the model • Left figure show stress during operation • Right figure shows temperature effect during quench • Just the temperature effect helps reduce the azimuthal stress in the coil but increases the stress on the skins. • Worst case for the coil is at the beginning of the quench, for the skins it is at the end when the coil is warm and the skins cold!

1 AMS coil - Quench

1 AMS coil - Quench • The stress in the coil is mostly independent of the position of the quench “wave” • No high stress in the metal components during quench

1 AMS coil - Quench • The maximum and minimum principal stress in the epoxy are ~-30 MPa and – 95 MPa where the maximum shear stress is ~30 MPa • These values are acceptable

1 AMS coil - Quench • Quench at the edge • Quench at 3/4 The current peak is almost the same in all 3 cases and similar to the case shown before. The stress results are very similar to the ones shown before as well • The metal will not yield during quench. • Quench with heaters