RESIDUAL STRENGTH OF IMPACTED COMPOSITES - ANALYSIS AND TESTS

The influence of impact damage on the structural performance of compos ite laminates was investigated by a joint effort including nondestruct ive evaluation (NDE), mechanical testing, and analysis. The impacted N ASA-Industry Standard Compression After Impact test specimen was chose n. Damage characterization was based on ultrasonic methods. Computeriz ed ultrasonic inspection from both sides of the test panels provided a ccurate information on the damage area. From the NDE data a simplified damage model was constructed and analyzed for strength and stability. Failure loads and modes were predicted. Compression after impact test s were performed for various materials and applied impact energies. Al l test results were in very good agreement with the analytical predict ions.