Abstract:Shape memory alloys have been widely used in U.S.military aircraft and Airbus/Boeing civil aircraft models,and were first successfully applied in the domestic Yun12F aircraft with airworthiness certification approval.To break through the airworthiness verification technical barriers of imported pipe joints and establish independent airworthiness certification standards,this study conducted systematic tests on domestic shape memory alloy pipe joints for the first time,based on airworthiness verification experience with imported products from the Yun12F.Results demonstrate that domestic joints have reached imported product levels in core performance metrics:flame resistance (5min exposure without failure),burst strength (critical value 35 MPa),pressure stability(21 MPa pressure maintenance qualified),and repeated assembly performance (maintained sealing after 8 disassemblies),all complying with international airworthiness standards.The research identified primary failure modes of domestic memory alloy pipe joints and applicable compliance methods,preliminarily establishing airworthiness verification methodologies.This lays the foundation for developing domestic airworthiness certification methods and standards for shape memory alloy pipe joints.