【摘要】 爆炸荷载由于冲击能量巨大、持续时间极短从而能表现出相当大的破坏作用;同时,由于爆炸冲击波随距离衰减迅速,因而建筑物爆炸破坏的空间特征分布也极其复杂。以钢筋混凝土模型板爆炸试验中采集到的加速度信号为研究对象,利用分形、重标极差理论对RC板中冲击波分形维数D和赫斯特指数H进行计算、分析,结果表明:(1)跨中冲击波分形维数大于支座信号,说明跨中冲击波构成复杂,爆炸反射叠加效应明显;(2)重标极差分析表明,支座及跨中信号的赫斯特指数均大于0.5,说明爆炸冲击作用对板不同部位的作用均有较强的持续性;(3)支座采集点冲击波信号H=0.755、显著大于跨中信号的赫斯特指数(H=0.547),这是由于板端木质夹固吸能作用引起的,这一现象可为分析构件边界约束条件对爆炸效果影响提供启示。更多还原

【Abstract】 The explosion load can cause considerable damage to the building due to its huge impact energy and very short impact time. At the same time, because the explosion shock wave decays rapidly with distance, the characteristics of the buildings destroyed by the explosion are extremely complicated in spatial distribution. A reinforced concrete slab was damaged by shock waves in a explosion test and both of acceleration waves in the middle and end of the plate were collected in this experiment. In further study, we analyzes these signals based on a nonlinear-theory. The results show that:(1) The fractal dimension of signal in the mid-span is larger than that of support, indicating that the composition of the mid-span shock wave is more complex;(2) The Hurst exponents of the blast wave of support and that of the mid-span signal are both greater than 0.5, indicating that the impact of the explosion has a strong continuity on the different parts of the plate;(3) The Hurst exponents of shock wave is 0.755 at the collection point of the support, and it is significantly greater than that of the mid-span signal. This phenomenon can provide enlightenment for analyzing the influence of component boundary constraints on the explosion effect.更多还原