Conducting experiments using scaled models is a highly efficient and cost-effective approach to predicting structural dynamic responses to blast loads. However, accurate representation of the prototype in a scaled model is hindered by the strain rate effect of the materials, thus limiting the application of scaled model tests. To address this issue, this paper proposes a theoretical correction method for scaling the dynamic response of steel beams subjected to blast loads. This method allows for direct and quantitative evaluation of the error caused by the strain rate effect on the similarity of the maximum mid-span displacement of the beam without the need to modify the charge mass or stand-off distance. In addition, the proposed method eliminates the need for extensive model tests. The accuracy of the proposed method is verified through numerical simulations. The results demonstrate that the strain rate effect scarcely influences the geometric similarity of the maximum mid-span displacement of the beam in the elastic response stage. However, in the plastic response stage, the maximum mid-span displacement of the beam does not conform to geometric similarity. Accordingly, the similarity of the maximum mid-span displacement of the beam can be expressed as the product of the geometric scale factor and calculated strain rate correction coefficient. These theoretical innovations can significantly enhance the reliability of scaled-model tests, help extrapolate scaled-model test results back to the prototype, and reduce the difficulty and consumption of field blast tests.

中文翻译：

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缩放爆炸荷载下钢梁动态响应的理论方法

使用比例模型进行实验是预测结构对爆炸载荷的动态响应的一种高效且经济高效的方法。然而，材料的应变率效应阻碍了缩比模型中原型的准确表示，从而限制了缩比模型测试的应用。为了解决这个问题，本文提出了一种缩放钢梁在爆炸荷载作用下的动态响应的理论校正方法。该方法可以直接定量评估应变率对梁最大跨中位移相似性影响所引起的误差，而无需修改装药质量或间隔距离。此外，所提出的方法消除了广泛的模型测试的需要。通过数值模拟验证了该方法的准确性。结果表明，应变率效应对弹性响应阶段梁最大跨中位移的几何相似性影响不大。然而，在塑性响应阶段，梁的最大跨中位移不符合几何相似性。据此，梁最大跨中位移的相似度可表示为几何比例因子与计算应变率修正系数的乘积。这些理论创新可以显着提高缩比模型试验的可靠性，有助于将缩比模型试验结果反推至原型，降低现场爆破试验的难度和消耗。