捆绑连接结构局部非线性及对火箭动力学行为的影响分析

As the key force transmission component of core booster and roll boosters of strap on launch vehicle, the mechanical characteristics of strap-on joints directly influences the dynamic behavior of the vehilce, and also influences the launch safety and reliability furtherly. The connatural factors of strap-on joints such as clearance, friction, contact, pre-tightened force will bring obviously nonlinear mechanical characteristics. Along with the devlopment of the new strap-on launch vehicle’s in our country, the study on local nonlinearity of strap-on joints and its influence mechanism on dynamic behavior of launch vehicle is obviously valuable, these problems are systematically studied, which aims at the new strap-on launch vehicle of our country. The main content include: The fine finite element model based on the modified Coulomb friction model and is established and validated by principle experiments. On this basis, the simplified dynamic hypostatic model of the strap-on joints and the responding parameter identification methods are stdudied. The dynamic model of strap-on launch vehicle which considers the nonlinearity of strap-on joints is established. The numerical algorithms about nonlinear dynamic equations of local nonlinear systems are proposed. The dynamic characteristics and dynamical response of launch vehicle are analyzed. The results in this research will be valuable for the structure design and attitude control system design in the new strap on launch vehicles of our country.

捆绑连接结构作为捆绑火箭芯级和助推器之间的关键传力部件，其力学特性直接影响火箭的动力学行为，进而影响火箭发射安全性和可靠性。捆绑连接结构固有的间隙、摩擦、接触、预紧力等因素使其具有明显的局部非线性，随着我国新型捆绑火箭研制的深入，开展捆绑连接结构局部非线性及其对火箭动力学行为的影响分析具有重要意义。本项目以我国某新型捆绑火箭为研究对象，针对该问题进行系统研究。主要内容包括：基于修正Coulomb摩擦模型开展捆绑连接结构精细有限元建模，并开展原理性试验验证；基于数值模拟和试验结果开展连接结构简化动力学机理建模和模型参数辨识；建立考虑捆绑连接结构局部非线性的捆绑火箭动力学模型，提出面向火箭局部非线性动力学方程组的数值求解算法；分析捆绑连接结构局部非线性对火箭动特性和动响应的影响机理。相关研究可为我国新型捆绑火箭结构和姿控系统设计提供参考。

捆绑连接结构作为捆绑火箭芯级和助推器之间的关键传力部件，其力学特性直接影响火箭的动力学行为，进而影响火箭发射安全性和可靠性。捆绑连接结构固有的间隙、摩擦、接触、预紧力等因素使其具有明显的局部非线性，随着我国新型捆绑火箭研制的深入，开展捆绑连接结构局部非线性及其对火箭动力学行为的影响分析具有重要意义。. 本项目以某新型捆绑火箭为研究对象，开展了捆绑连接结构非线性力学特性分析、简化建模与模型参数辨识、考虑捆绑连接结构局部非线性的火箭动力学建模、捆绑连接结构局部非线性对火箭动力学行为的影响分析等工作。项目取得的成果包括：.（1）准确获取了捆绑连接结构的非线性力学特性，为后续准确模拟捆绑连接结构和开展更加精确的火箭结构动力学分析奠定了基础；.（2）给出了一种捆绑连杆简化动力学模型及其模型参数辨识方法，并对辨识误差进行了分析；.（3）建立了考虑捆绑连杆非线性的火箭动力学模型。该模型对助推器个数、发动机个数、贮箱个数均没有限制，具有一定通用性，全面考虑了火箭复杂空间模态、刚-晃-弹耦合特征以及捆绑连杆局部非线性因素；.（4）分析了捆绑连杆局部非线性对火箭动力学特性和动响应的影响，结果发现影响很小，且分析了相关原因。. 本项目紧密结合工程型号进行，所取得的成果已经直接应用于工程实际，为某新型捆绑火箭姿控系统的研制提供了重要技术支撑，产生了良好的应用效果。项目研究成果在国防和国家安全领域具有重要的应用价值。