不同耦合介质下脆性材料断裂行为研究

Study on the fracture behavior of brittle materials under different coupled media

为了分析不同耦合介质装药结构下脆性材料的爆破机理问题,通过实验室试验及数值模拟方法对水耦合装药和空气耦合装药爆破效果以及裂纹扩展机理进行研究。在实验中,试件材料采用透明均匀的PMMA(有机玻璃),炸药采用DDNP(二氮烷基苯酚),利用高速摄像机观察压裂和裂纹传播过程,然后从定量和定性两方面对不同耦合介质装药爆破下裂纹传播行为进行分析。观察实验过程以及数值模拟软件LS-DYNA分析结果表明,可以得到空气耦合介质下,试件炮孔周边次生裂纹少,裂纹分叉现象较少,形成规则的贯通裂隙。相比于空气耦合,水耦合介质条件下,炮孔周围形成规则不一的裂纹,破碎区直径增大,横向裂纹增多,对孔壁产生的压力较均匀,破碎效果好。同时在数值模拟分析中得出不同耦合介质装药结构下脆性材料的爆破应力云图和v-m时程曲线图,得出水耦合装药爆破可以获得更高的孔壁初始压力,且对孔壁产生的压力较为均匀,爆破的破碎效果更好。

In order to analyze the blasting mechanism of brittle materials under different coupling medium charge structures,the blasting effects and crack propagation mechanism of water coupling charge and air coupling charge were studied by laboratory tests and numerical simulation methods.In the experiment,transparent and uniform PMMA(organic glass)is used as the material of the test piece,DDNP(diazoalkylphenol)is used as the explosive,and high-speed camera is used to observe the fracturing and crack propagation process.Then,the crack propagation behavior under blasting with different coupling media charges is analyzed from both quantitative and qualitative aspects.The observation of the experimental process and the analysis results of the numerical simulation software LS-DYNA show that under the air coupling medium,there are fewer secondary cracks around the blast hole of the specimen,and there are fewer crack bifurcations,forming regular through cracks.Compared with air coupling,under water coupling medium conditions,regular cracks are formed around the blast hole,the diameter of the crushing zone increases,and the transverse cracks increase.The pressure on the hole wall is uniform,and the crushing effect is good.At the same time,the blasting stress nephogram and v-m time history curve of brittle materials under different coupling medium charge structures are obtained in the numerical simulation analysis,and it is concluded that the water coupling charge blasting can obtain higher initial pressure of the hole wall,and the pressure generated on the hole wall is more uniform,and the blasting fragmentation effect is better.