摘要
利用缩比模型相似性预报原型结果是研究大型结构冲击响应常用的手段之一。受应变率效应的影响,缩比模型与原型的流动屈服应力相似关系失衡,导致缩比模型试验结果预报原型冲击响应出现偏差。针对这一问题,本文开展缩比模型冲击响应预报结果修正方法研究,提出一种衡量流动屈服应力整体误差的损失函数来量化缩比模型与原型流动屈服应力之间的差异,当损失函数在应变率区间内取最小值时可以得到满足最小整体误差条件的速度相似因子,以此修正缩比模型试验的初始条件和其他物理量的相似因子,达到减小预报误差的效果。为了验证该方法的有效性,开展了数值模拟和冲击试验。结果表明,利用损失函数法可以有效地提高缩比模型的预报精度,能够更准确地预报原型的冲击响应。
Prediction of prototype results by the scaled model is one of the commonly used methods to research the impact response of large structures.Due to the strain rate effect,the similarity relationship between the prototype and the scale model is out of balance,which leads to the deviation of prediction of the prototype impact response by the scaled model test results.For this problem,a modified method for impact response prediction of the scaled model is investigated in this paper.A loss function for measuring the overall error of the flow yield stress is proposed to quantify the deviation between the scaled model and the prototype.When the loss function is minimized in the strain rate range,the velocity scaling factor satisfying the condition of the minimum global error can be obtained,by which the initial condition of the scaled model test and the scaling factors of other relevant quantities can be modified and the prediction error can be reduced finally.To verify the effectiveness of the modified method,numerical simulation and impact tests are carried out.The results show that the loss function method can effectively improve the prediction accuracy of the scaled model,and can predict the impact response of the prototype more accurately.
作者
王悦鑫
何欢
吴添
惠旭龙
WANG Yuexin;HE Huan;WU Tian;XI Xulong(State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Institute of Vibration Engineering Research,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Shanghai Aerospace System Engineering Research Institute,Shanghai 210019,China;Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics,Aircraft Strength Research Institute of China,Xi'an 710065,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第8期463-474,共12页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(12072153)。
关键词
缩比模型
应变率效应
冲击响应
损失函数
相似关系
scaled model
strain rate effect
impact response
loss function
similarity relationship
