Self-Healing Composite Structures Using Multiple Through-thickness Microvascular Channels

: Self-healing composites using microvascular channel networks have been intensively studied.Microvascular networks in composite in-plane directions are normallyutilized to deliver healing agentstodamagedareas.However,thischannelconfigurationisnotoptimaltoformrobust networks and to infuse large damaged areas. This study proposes a self-healing system using multiple short microvascular channels in the through-thickness direction. First, the impregnation advantageofusing thischannelconfiguration isconfirmed through delamination infiltration tests. Next,thefeasibilityofthischannelconfigurationisevaluatedbytensiletestsandfour-pointbending tests.Doublecantileverbeamtestswerethenconductedtoconfirmitshealing function.Finally,this system is applied to composite stiffened panels and the healing performance is evaluated using compression testing following panel indentation. The healing system almost fully recovered the originalstrength,confirming itshigh potentialunderpracticalconditions.Additionally,theweight reduction potential of the self-healing system was discussed through a strength comparison of specimens with different thicknesses.