气囊着陆缓冲系统冲击动力学模型修正方法

针对气囊着陆缓冲系统的冲击动力学模型修正问题,首先建立了典型气囊着陆缓冲系统的冲击动力学仿真分析模型,考虑到结构动力学模型和气囊模型的相互独立性,提出对回收舱模型和气囊系统模型分别进行修正的分级修正思路;其次定义了关键点处冲击响应,解决了试验数据采样频率和试验触发不一致带来的计算结果与试验结果比较问题;就气囊着陆缓冲系统冲击动力学响应的典型特征,定义冲击响应置信因子评价计算结果与试验结果之间的吻合程度;以关键点冲击响应的试验数据与计算结果之间的误差范数作为修正目标函数,引入增广径向基函数构造修正变量关于修正目标的代理模型,将模型修正问题转换为优化问题进行求解;最后,通过典型气囊着陆缓冲系统冲击动力学试验和计算验证了所提方法的有效性。

Finite Element Model Updating of an Airbag Cushion Landing System

This paper focused on finite element model updating of an airbag cushion landing system. First, Typical finite element model of an airbag cushion landing system was developed. Since Structure model and the airbag model was independent with each other, a systematic model updating strategy was proposed, and precisely for this reason model updating of the recovery module structure and the airbag system were conducted individually. Impact response at key points was introduced here to avoid trouble caused by difference of the sampling frequency and trigger of the test and simulation. Confidence factor ofSthe impact response was defined here to evaluate the matching degree of simulation results and testing results. Error norm of the testing data and simulation results at key points was defined as updating objective, and augmented radial basis functions were introduced to construct agent model of the error norm. Since minimum error norm would lead to ideal model parameters, model updating problem could be transformed into an optimization problem. Impact test of a typical airbag cushion landing system was conducted, and the corresponding simulation was conducted too. Method presented in this paper was demonstrated through comparison of the test results and simulation results.