文档介绍：南京航空航天大学
硕士学位论文
薄壁金属结构耐撞性优化研究
姓名:何成
申请学位级别:硕士
专业:工程力学
指导教师:陈
2010-12
南京航空航天大学硕士学位论文
摘要
金属薄壁管因其具有稳定且可观的吸能特性被广泛应用于提高结构的耐撞性能,已达到保
护乘员与贵重物品的目的。随着计算机仿真技术的迅速发展,工程界逐步将非线性有限元分析
作为耐撞性研究的常用分析手段。但是多年以来一直没有对分析对象的网格疏密程度这个影响
分析精度的前提问题提出合适的标准,另外现阶段的耐撞性优化工作较多的集中理论研究,或
构造响应面对单个薄壁管试件进行优化,将优化试件应用于工程实际结构中极为罕见。因此,
本文以实际工程研究为背景,以瞬态非线性有限元分析技术为手段,研究了薄壁管耐撞性优化
的若干关键问题,具体内容如下:
研究了多种全局近似函数的构造方法,利用数值算例对不同方法构造的近似函数精度进行
了比较;研究了低速冲击情况下,网格密度分别对铝合金薄壁圆柱管和普通碳素钢薄壁圆柱管
的失效模式、接触力以及能量吸收的影响。提出了针对不同研究对象的网格划分依据;采用全
局近似函数方法对薄壁金属管进行了耐撞性多目标优化,并对使用不同构造方法构造的近似函
数精度进行了比较,给出了通用性最好的构造方法;最后将优化后的薄壁管成功运用于实际航
空结构中,实现了提高机身耐撞性能的目的。

关键词:薄壁金属管,全局近似函数,网格密度,耐撞性优化,机身
I
薄壁金属结构耐撞性优化设计
ABSTRACT
With a stable and remarkable energy absorption capacity, metal thin-walled tube is widely used
to improve crashworthiness of the structure and protect the safety of occupant. With the rapid
development puter simulation technology, the nonlinear finite element analysis monly
used as crashworthiness analysis methods. But the question of grid density effect on the calculation
results and the appropriate standard of grid density is still no answer for many years, in addition, on
the present stage the study of crashworthiness optimization mostly focused on the theory, and
constructed response surface to optimize metal thin-walled which used in engineering practice is
extremely rare. Therefore, this paper studied several key issues of crashworthiness optimization of
thin-walled tube by the transient nonlinear finite element analysis technology in engineering
background, The content is as follow.
Methods based on experiment design for constructing the global approximate function is
investigated pared. The effect of thin-walled cylindrical tube with different materials and grid
density on failure modes, contact forces and energy absorption has been studied in the low velocity
impact cases. giving the proposal of grid density for different subjects. The multi-objective
optimi