The load-carrying capacities and failure patterns of reinforced concrete components can be significantly changed by membrane effects. However, limited work has been carried out to investigate the blast resistance of Hybrid Fiber Reinforced Lightweight Aggregate Concrete (HFR-LWC) members accompanying membrane action. This paper presents a theoretical approach to quantitatively depicting the membrane behavior and its contribution on the behavior of HFR-LWC beams under close-range blast loadings, and the suitability of the proposed model is validated by a series of field tests. An improved Single-Degree-of-Freedom (SDOF) model was employed to describe the dynamic responses of beam-like members under blast loadings accompanying membrane action, where the mass-load coefficient is determined according to the nonuniformly distributed load induced by close-range explosion, and the membrane action is characterized by an in-plane (longitudinal) force and a resisting moment. The elasto-plastic and recovery responses of HFR-LWC beams under the combined action of blast load and membrane force were analyzed by the promoted model. A specially built end-constrain clamp was developed to provide membrane action for the beam member when they are subjected to blast load simultaneously. It is demonstrated that the analytical displacement-time histories are in good agreement with experimental results before peak deflections and that the improved SDOF model is an acceptable tool for predicting the behavior of HFR-LWC beams under blast loadings accompanying membrane action.

膜效应可以显着改变钢筋混凝土构件的承载能力和破坏方式。但是，为研究伴随膜作用的混合纤维增强轻质骨料混凝土（HFR-LWC）构件的抗爆炸性，已经开展了有限的工作。本文提出了一种定量描述近距离爆炸载荷下膜行为及其对HFR-LWC梁行为的贡献的理论方法，并通过一系列现场试验验证了该模型的适用性。改进的单度自由度（SDOF）模型用于描述爆炸作用下伴随膜作用的梁状构件的动力响应，其中，质量载荷系数是根据近距离爆炸引起的不均匀分布载荷确定的，而膜作用的特征在于面内（纵向）力和阻力。利用改进模型分析了爆炸荷载和膜力共同作用下的HFR-LWC梁的弹塑性和恢复响应。开发了一种特殊构造的末端约束夹具，以便在梁构件同时承受爆炸载荷时为梁构件提供膜作用。结果表明，分析的位移时间历史与峰值偏转之前的实验结果非常吻合，改进的SDOF模型是预测HFR-LWC梁在爆炸作用下伴随膜作用的行为的可接受工具。膜的作用以面内（纵向）力和阻力为特征。利用改进模型分析了爆炸荷载和膜力共同作用下的HFR-LWC梁的弹塑性和恢复响应。开发了一种特殊构造的末端约束夹具，以便在梁构件同时承受爆炸载荷时为梁构件提供膜作用。结果表明，分析的位移时间历史与峰值偏转之前的实验结果非常吻合，改进的SDOF模型是预测HFR-LWC梁在爆炸作用下伴随膜作用的行为的可接受工具。膜的作用以面内（纵向）力和阻力为特征。利用改进模型分析了爆炸荷载和膜力共同作用下的HFR-LWC梁的弹塑性和恢复响应。开发了一种特殊构造的末端约束夹具，以便在梁构件同时承受爆炸载荷时为梁构件提供膜作用。结果表明，分析的位移时间历史与峰值偏转之前的实验结果非常吻合，改进的SDOF模型是预测HFR-LWC梁在爆炸作用下伴随膜作用的行为的可接受工具。利用改进模型分析了爆炸荷载和膜力共同作用下的HFR-LWC梁的弹塑性和恢复响应。开发了一种特殊构造的末端约束夹具，以便在梁构件同时承受爆炸载荷时为梁构件提供膜作用。结果表明，分析的位移时间历史与峰值偏转之前的实验结果非常吻合，改进的SDOF模型是预测HFR-LWC梁在爆炸作用下伴随膜作用的行为的可接受工具。利用改进模型分析了爆炸荷载和膜力共同作用下的HFR-LWC梁的弹塑性和恢复响应。开发了一种特殊构造的末端约束夹具，以便在梁构件同时承受爆炸载荷时为梁构件提供膜作用。结果表明，分析的位移时间历史与峰值偏转之前的实验结果非常吻合，改进的SDOF模型是预测HFR-LWC梁在爆炸作用下伴随膜作用的行为的可接受工具。