【摘要】 本文用动光弹方法研究了炸药爆炸产生的气体压力对炮孔周围应力场的影响。炸药分别装在两个模型的中心炮孔中。一个模型中为敞露装药,另一个模型将装药容纳在一个特殊的密封装置中。多火花式动态光弹性仪被用来记录膨胀波和剪切波的传播以及裂纹的扩展。文章给出了爆生气体增压作用的一些重要结论:1.密封装药时膨胀波脉冲幅度比敞露装药时的幅度高一倍左右,脉冲宽度也有所增大。2.密封装药时最大径向位移是敞露装药时的2—3.5倍,最大径向和切向应变的绝对值是敞露装药时的2.5倍左右,最大径向和切向应力的绝对值是敞露装药时的2倍左右。3.无论是密封装药或是敞露装药,在入射 P 波的压缩相中,|σ_r|_max对|σ_θ|_max的比值约为3。4.密封装药时炮孔周围的径向裂纹的平均长度为敞露装药时的8/3倍。更多还原

【Abstract】 The effect of gas pressure from explosion on the dynamic stress field formedaround a borehole was investigated with the dynamic photoelastic method.Thecharges were loaded respectively into an centre borehole of two models.In one ofthe models,the charge was put into an open borehole,and in the other model,the charge was put into a sealed container.A multiple-spark dynamic photoelasticapparatus was used to record the propogation of dilatational and shear waves andextension of cracks and fissures.Some important conclusions relevant to theboosting effect of explosion pressure are as follows:1.The amplitude of dilatational wave produced by sealed charge almost doublesthat produced by unsealed charge and the width of the pulse is also increased.2.The maximum radial displacement produced by sealed charge is 2—3.5-foldover the unsealed charge.The absolute values of maximum radial and tangentialstrain of the sealed charge is about 2.5-fold over the unsealed charge.And theabsolute values of maximum radial and tangential stresses are approximately2-fold over that of the unsealed charge.3.The ratio of |σ_r|_max to|σ_θ|_max in the compression phase of incidence P waveis the same,no matter weather the charge is sealed or not.4.The average length of radial cracks and fissures around the borehole withthe sealed charge is about 8/3-fold over that with unsealed charge.更多还原