航天半硬壳结构模型简化方法研究  

Study on the Model Simplification Methods of Aerospace Semirigid Shell Structures

作　　者：赵阳[1] 许博谦[1] 李玉韦 ZHAO Yang;XU Boqian;LI Yuwei(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033;Department of Engineering Mechanics,Dalian University of Technology,Dalian 116024)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]大连理工大学工程力学系,大连116024

出　　处：《长春理工大学学报（自然科学版）》2019年第3期1-6,共6页Journal of Changchun University of Science and Technology(Natural Science Edition)

基　　金：国家重点研发计划项目(2016YFE0205000)

摘　　要：蒙皮桁条结构和网格加筋结构因具有较高的比强度和比刚度而广泛应用于火箭结构当中,其详尽的有限元模型自由度规模大,静力分析计算效率低。为了提高计算效率,研究提出了面向蒙皮桁条结构的优化定解法和面向网格加筋结构的等效性能法。在大直径蒙皮桁条结构按照横截面积相等简化为梁-壳模型后,可以保证轴向拉压刚度和弯曲刚度不变,但会出现扭转刚度不匹配的情况。采用尺寸优化的方法,通过调整蒙皮厚度来修正模型刚度,进一步利用局部单胞的弯曲刚度相同,便可确定简化模型的最终尺寸。对于周期性的网格加筋结构,采用改进的渐近均匀化方法,获取结构单胞的刚度信息,进而可建立与精细模型性能一致的光筒模型。算例表明,采用本文提出的两种模型简化方法得到的简化模型与精细模型之间的刚度误差可保证在5%以内,验证了简化方法的有效性。Skin-stringer structures and grid stiffened structures have been widely used in launch vehicles for their high specific strength and specific rigidity,its detailed finite element model usually has a large degree of freedom,resulting in low computational efficiency of the static analysis. In order to improve the computational efficiency,with regard to skin-stringer structures and grid stiffened structures,an optimization method based on equivalent stiffness and a property equivalent method based on asymptotic homogenization theory are proposed respectively. When large diameter skin-stringer structures are simplified to beam-shell mixed structures,although the axial tensile stiffness and bending stiffness can be guaranteed,the torsional stiffness error will occur. Adopting size optimization method,not only can the torsional stiffness be amended by adjusting the thickness of the skin;but also the final size of the simplified model will be settled by using the local unit cell’s bending stiffness. As for periodic grid stiffened structures,the stiffness matrixes of unit cells can be obtained by using improved asymptotic homogenization method(NIAH) so that a simplified model which has the same mechanical properties as the original model’s will be got. Results of the illustrative example indicate that the stiffness error is within five percent between the simplified models got by using these two methods and the original models. In the meanwhile,the results demonstrate the effectiveness of these simplification methods.

关 键 词：运载火箭 蒙皮桁条结构 网格加筋结构 刚度等效 模型简化 

分 类 号：V475.1[航空宇航科学与技术—飞行器设计] O343.2[理学—固体力学]