爆炸荷载作用下钢筋混凝土构件的缩尺效应

Scaling Effects of Reinforced Concrete Members Under Blast Loads

摘要:

为了研究爆炸荷载作用下钢筋混凝土（RC）构件的缩尺效应，基于现有的不同缩尺系数RC构件的爆炸试验数据，建立数值模型，并重点讨论混凝土材料应变率的缩尺效应，论证采用缩尺有限元模型进行原型结构动力响应预测的可行性。计算结果表明，如果不考虑应变率的缩尺效应，缩尺系数越小，缩尺数值模型的损伤情况和动态响应就越不符合相似率；当缩尺系数为0.1时，比例爆距0.50、0.44 m·kg^-1/3下的RC梁跨中位移误差分别为32.5%、75.1%，比例爆距0.591、0.518 m·kg^-1/3下的RC板跨中位移误差分别为45.08%、46.93%。在对动态增长系数（DIF）曲线进行缩尺后，所得数值模型计算结果更符合相似率，误差在10%之内。最后，提出了采用缩尺试验结果预测原型结构动力响应的流程。

Abstract:

To investigate the scaling effect on reinforced concrete （RC） members under blast loads， numerical models were established based on existing explosion test data from RC members with various scaling factors. The research primarily focused on the scaling effect of the concrete material strain rate and demonstrated the feasibility of using scaled finite element models to predict the dynamic response of prototype structures. The results show that if the scaling effect of strain rate is not considered， the smaller the scaling factor， the less the damage and dynamic response of the scaled numerical model match the similarity criteria. For a scaling factor of 0.1， the mid-span displacement errors of RC beams at scaled blast distances of 0.50 m·kg^-1/3 and 0.44 m·kg^-1/3 are 32.5% and 75.1%， respectively. The mid-span displacement errors of RC slabs at scaled distances of 0.591 m·kg^-1/3 and 0.518 m·kg^-1/3 are 45.08% and 46.93%， respectively. After scaling the dynamic increase factor （DIF） curve， the results of numerical model calculations align more closely with similarity ratios， with errors generally less than 10%. Finally， a process was proposed for predicting the dynamic response of prototype structures using scaled test results.