Cracking mechanisms in ceramic armor – analytical solutions and finite element simulations

The subject of this report is the physics governing ballistic impact on ceramic plates. The report has several goals:

• Develop FFI’s basic knowledge of ballistic impact phenomena.
• Provide a general literature review for anyone interested in learning more about ballistic impact and its relation to contact mechanics.
• Evaluate the usefulness of existing analytical methods that describe the ballistic impact problem. In the long term, the most suitable methods may be used as a first step toward the development of an in-house material model for ceramics.
• Report preliminary ballistic impact simulations in IMPETUS Afea to evaluate its current simulation capabilities.

The first part consists of a detailed literature study of several important cracking mechanisms that may emerge during ballistic loading. In addition, we review analytical models that may form the backbone of a new material model for ceramics subjected to projectile impact. The analytical models capture all of the different crack types observed experimentally.

In the second part, we perform and evaluate concrete ballistic impact simulations in IMPETUS Afea. The simulations are able to capture and describe the specific cracking modes and mechanisms. Yet, in order to calibrate the model, we need to perform several in-house experiments at different scales.

The development of an in-house ceramic material model as well as the calibration of the IMPETUS Afea model seem promising but require more work.