摘要
复合材料壳体裙连接区是固体火箭发动机与弹体之间载荷传递的关键部位,直接影响固体火箭结构的性能和可靠性。基于响应面代理模型建立结构功能函数,采用渐进损伤方法分析结构极限承载力,采用验算点法进行非线性可靠度计算,求解出结构的可靠度-载荷曲线;分析了复合材料、界面强度、缠绕角度和橡胶层厚度等的分散性对结构轴向承载能力的影响,探究了初始分层缺陷对结构可靠度的影响。结果表明:在考虑各类参数的分散性时,裙连接区极限载荷下的可靠度只有50.5%;若要使结构具有99%以上的可靠度,最大载荷应比极限载荷小7.2%;对裙连接区极限承载能力影响最大的参数是复合材料纵向刚度,其次是螺旋缠绕角,其余参数影响较小;小尺寸的分层缺陷对结构承载能力影响不大,但当缺陷尺寸超过一个临界值后,结构承载能力会显著降低。在结构功能函数中引入关于缺陷尺寸的概率分布和强度衰减因子,反映缺陷的影响。考虑分层缺陷随机性的可靠度-载荷曲线出现平台阶段,这对发动机结构可靠度分析至关重要。
The lap structure between skirt and composite case(LBSCC)in a solid rocket motor is a crucial load transfer region between the motor and the missile body,significantly affecting the overall structural performance and reliability.In this study,a structural performance function was established based on a response surface surrogate model,and the ultimate bearing capacity was analyzed using a progressive damage model.Nonlinear reliability assessment was then performed using the design point method to obtain the reliability-load curve.The effects of parameter variability including composite material properties,interface strength,winding angle,and rubber layer thickness on the axial load-bearing capacity were examined,and the influence of initial delamination defects on structural reliability was explored.The results indicate that when parameter dispersion is considered,the reliability at the ultimate load is only 50.5%.To achieve a reliability exceeding 99%,the maximum applied load should be limited to 92.8%of the ultimate load.Among the parameters,the longitudinal stiffness of the composite material has the greatest impact on the ultimate bearing capacity,followed by the winding angle,while other parameters have a relatively minor effect.Although small delamination defects have little influence on the structural performance,defect sizes exceeding a critical threshold lead to a significant reduction in load capacity.By incorporating the probability distribution of defect sizes along with an strength attenuation factor into the structural performance function,the effect of delamination defects is effectively characterized.Notably,the emergence of a plateau in the reliability-load curve due to defect randomness is critical for the reliability analysis of rocket motor structures.
作者
席近远
王晨
高佳乐
文立华
校金友
荣俊杰
XI Jinyuan;WANG Chen;GAO Jiale;WEN Lihua;XIAO Jinyou;RONG Junjie(Northwestern Polytechnical University,Xi'an 710072,China;Xi'an Aerospace Propulsion Test Technology Institute,Xi'an 710100,China)
出处
《固体火箭技术》
北大核心
2025年第6期912-921,共10页
Journal of Solid Rocket Technology
基金
省部级项目。
关键词
固体火箭发动机
复合材料壳体裙连接区
分层缺陷
结构可靠度分析
solid rocket motor
lap structure between skirt and composite case
delamination defects
structural reliability analysis
