Study on propagation life interval of aluminum alloy skin with multiple cracks based on improved interval method
Multi-site damage of aircraft fuselage skin has always been one of the key issues to be considered in aircraft damage tolerance design and the later stage of aircraft maintenance analysis.To study the life interval of multi-site damage crack,by combining interval theory and interval operation formula,universal grey number theory and universal grey number operation formula,and the relationship between the two operations,a new conversion model between interval number and universal grey number is obtained in this paper to eliminate the problem of interval operation extension and the operation error of universal grey number.By integrating the new conversion model,Paris formula,material properties,material size,load properties,and other influencing factors,the multi-site damage crack propagation life interval of the 2024-T3 aluminum alloy plates is obtained:the multi-site damage crack propagation life interval of 2024-T3 aluminum alloy plate with a thickness of 1.6 mm,unlimited length and width are obtained as[90 531,143 689],and the multi-site damage crack propagation life interval of 2024-T3 aluminum alloy plate with a thickness of 1.6 mm,effective length of 240 mm,and width of 60 mm is obtained as[11 427,114 071].In this paper,it is proved that the model can eliminate the problem of operation extension and operation error by checking the classical mathematical calculation,and the result of the operation can be more accurate by using the model.This paper conducts multi-site damage crack propagation life tests under three different crack angles,and the test results of three tests are consistent with the theoretically predicted multi-site damage crack propagation life interval values,which proves the correctness and effectiveness of the research model in this paper.The two validations prove the generality of the improved conversion formula from different angles and specialties.The research model in this paper provides necessary guidance for the prediction and analysis of multi-site damage crack propagation life.
safety engineeringMulti-Site Damage(MSD)interval operationuniversal grey number operationlife interval2024-T3 aluminum alloy
万方数据
维普
