【作者】 李超；

【导师】 李洪双；

【作者基本信息】 南京航空航天大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 复合材料多钉连接是航空航天结构中一种常用的连接形式,连接结构强度直接影响飞行器的安全和寿命。在结构设计的初始阶段有限元法和实验法效率较低,而解析法可以简单高效的预测钉载分配情况。复合材料多钉连接结构的强度通过有限元方法可进行准确分析。因此研究复合材料多钉连接结构钉载分配和强度的影响因素至关重要。在传统的弹簧质量模型钉载计算方法的基础上,应用一种三线段解析法研究复合材料多钉连接结构的钉载分配。在MATLAB环境中实现该算法并编制计算程序。该算法能够准确高效地预测复合材料多钉连接结构的钉载分配,计算结果与实验法相比,预测误差较小。因此,在复合材料连接结构初始设计阶段三线段解析法求解钉载有着较高的参考价值。基于三线段解析法和空间分割方法,本文对复合材料多钉连接的钉载分配和连接结构位移进行全局灵敏度分析,研究了输入变量随机性对复合材料多钉连接结构输出响应的影响。基于空间分割求解Sobol指标,通过比较指标值大小对不确定性输入变量进行重要性排序。本文基于ABAQUS软件的二次开发和Python语言编程实现预测复合材料多钉连接结构的强度,进一步运用基于空间分割计算Sobol指标表征输入变量对连接结构强度随机性的影响。更多还原

【Abstract】 Multi-bolt composite joints are a common connection form in aerospace structure.The strength of the multi-bolt composite joints directly affect the safety and life of the aircraft.In the preliminary phase of structural design,neither finite element method(FEM)nor experimental method is efficient,but the analytical method can predict the load distributions in the multi-bolt composite joints simply and efficiently.The strength of the multi-bolt composite joints can be accurately analyzed by the finite element method.Therefore It is essential to study the load distributions and strength of multi-bolt composite joints.Based on the traditional method for calculating the bolt load of a spring mass model,applying an analytical trilinear method predicts the load distributions in multi-bolt composite joints.The algorithm is implemented in MATLAB environment and the calculation program is compiled.The algorithm accurately and efficiently predicts the load distributions in the multi-bolt composite joints.Compared with the experimental method,the calculation results has less error.Therefore,the calculation results of the analytical trilinear method have high reference value in the initial design stage of the multi-bolt composite joints.Based on analytical trilinear method and the analytical trilinear method,the global sensitivity analysis of the load distributions and the displacement of the multi-bolt composite joints is carried out.The influence of randomness of input variables on the output response of multi-bolt composite joints is studied The Sobol index is solved based on the sample space partition.The importance of the uncertain input variables can be ranked by the index values.Based on the secondary development of ABAQUS software and Python programming to predict the strength of the multi-bolt composite joints,the sample space partition is further used to calculate the Sobol index to characterize random influence of the input variable connection form strength.更多还原