Experimental research on damage tolerance and air tightness of typical composite panels

The extensive use of composites in aircraft leads to the problem of damage tolerance after low-speed impact. It is necessary to consider not only the change of mechanical properties but also the change of work properties such as air tightness. In this paper, the damage morphology and air tightness of a typical composite stiffened panel subjected to low-speed impact were experimentally studied. The damage initiation and propagation and the change of air tightness after impact, static compression and compression fatigue were analyzed respectively. It is found from the test that after 120% ultimate load condition and 100,000 times constant amplitude fatigue load condition, the impact damage does not expand, and the air tightness is good and no obvious leakage is observed, indicating that the structural design meets the requirements of damage tolerance and air tightness.