Any known methods for testing impact properties of thin composites?

When the materials are adequately thin, it becomes important to understand the effect of the shape of the impactor.

For example, a knife point or icepick point will penetrate the thin stock but a golf ball or marble or hailstone will do local damage before penetration.

Of course, the same considerations apply to thin metal stock versus standard charpy bars as well.

You might want to think through what you want to learn from the impact test in terms of what material response or component strctural response is important to you.

At one time, people were arguing that for composite panels there is no universally meaningful "Impact Test".

That position seems very likely to be correct from my experience.

Jim