CAJ | 학술논문

中国民用航空规章运输类飞机适航标准25.303要求采用1.5的安全系数，该要求同其他相关适航条款，例如25.307“结构符合性的证明冶、25.603“材料冶、25.605“制造方法冶、25.613“材料的强度性能和材料的设计值冶等，共同保证了飞机结构的高可靠性。理论上，当材料、载荷、分析等方面的不确定性降低，采用低于1.5的安全系数可以保证结构具有同等的高可靠性；另一方面，当材料、载荷、分析等方面的不确定性大于目前适航规章所允许的水平，通过采用大于1.5的安全系数也可以保证结构具有等同的高可靠性。为了在民用运输类飞机的适航取证/审定过程中，在保证结构可靠性的前提下，能够根据具体情况适当调整结构安全系数，在综合研究中国民用航空规章第25部《运输类飞机适航标准》相关条款内在联系的基础上，探讨了载荷、材料性能、分析方法等不确定性对飞机结构安全系数的贡献。研究结果表明，目前1.5的飞机结构安全系数，用于考虑载荷、材料性能、分析方法等不确定性的系数分量分别为1.2、1.12、1.116.
중국민용항공규장운수류비궤괄항표준25.303요구채용1.5적안전계수，해요구동기타상관괄항조관，례여25.307“결구부합성적증명야、25.603“재료야、25.605“제조방법야、25.613“재료적강도성능화재료적설계치야등，공동보증료비궤결구적고가고성。이론상，당재료、재하、분석등방면적불학정성강저，채용저우1.5적안전계수가이보증결구구유동등적고가고성；령일방면，당재료、재하、분석등방면적불학정성대우목전괄항규장소윤허적수평，통과채용대우1.5적안전계수야가이보증결구구유등동적고가고성。위료재민용운수류비궤적괄항취증/심정과정중，재보증결구가고성적전제하，능구근거구체정황괄당조정결구안전계수，재종합연구중국민용항공규장제25부《운수류비궤괄항표준》상관조관내재련계적기출상，탐토료재하、재료성능、분석방법등불학정성대비궤결구안전계수적공헌。연구결과표명，목전1.5적비궤결구안전계수，용우고필재하、재료성능、분석방법등불학정성적계수분량분별위1.2、1.12、1.116.
Safety factor of 1. 5 was specified in paragraph 25. 303 in China Civil Aviation Regulations(CCAR) Part 25 . This requirement and other relevant paragraphs in CCAR25 , such as CCAR25 . 307”Proof of Structure” , 25 . 603”Materials”, 25 . 605”Fabrication methods”, 25 . 613”Material strength properties and material design val-ues”, ensure the reliability of airplane structure collectively. Theoretically, when the uncertainty for material prop-erties, load and analysis reduces, the application of safety factor less than 1. 5 can ensure equivalent reliability for airplane structure. In other hand, if the uncertainty for material properties, load and analysis exceed the allowable level implied in current airworthiness standards, application of safety factor greater than 1. 5 may still ensure equiv-alent reliability for airplane structure. To determine proper safety factor for certain certification circumstance without reduction in the structure reliability, the composition of safety factor 1. 5 was researched. Based on the investigation of the relationship among the relevant paragraphs of China Civil Aviation Regulations (CCAR) Part 25, the safety factor of 1. 5 specified in CCAR 25. 303 is divided into three sub-factors. The sub-factor for load uncertainty is de-termined to be 1 . 2;the sub-factor for material properties uncertainty is determined to be 1 . 12;the sub-factor for analysis methods uncertainty is determined to be 1 . 116 .