爆破工程教学中材料动态力学性能实验及仿真实践

Teaching Experiment and Simulation Practice of Dynamic Mechanical Properties of Materials in Blasting Engineering Course

掌握岩石(体)在爆破动载作用下的动态力学响应是《爆破工程》课程的一项重要教学内容。由于土木或采矿类专业学生缺乏波动力学、岩石动力学等基础理论,采用讲授法讲解岩石动态力学特性的知识点时教学效果较差,影响后续的岩体破碎机理等内容的学习。为此,将岩石类材料的分离式霍普金森压杆实验(Split Hopkinson Pressure Bar,SHPB)应用于《爆破工程》实践教学中,通过测定岩石动态压缩强度,观察试件破坏形态,引导学生理解岩石材料在不同应变率下的动态力学响应。运用有限元软件LS-DYNA对SHPB实验进行数值模拟,再现应力波传播和岩石破坏过程,达到动态冲击的演示功能。实践效果表明:这种教学方式使学生能够直观地感知应力波的传播过程,清晰地了解岩石动态破坏机理,掌握岩石类材料动态力学性能与应变率之间的关系,为进一步学习爆破工程理论奠定基础。

It is an important content in the course of"Blasting Engineering"to master the dynamic mechanical response of rock(body)under the action of blasting dynamic load.Since students majoring in civil or mining engineering lack basic theories such as wave mechanics and rock dynamics,the teaching effect is poor when the knowledge of dynamic mechanical properties of rock is explained in class,which will affect the subsequent learning of rock breakage mechanism.Therefore,the Split Hopkinson Pressure Bar(SHPB)experiment of rock materials is applied to the practical teaching of“Blasting Engineering”.By measuring the dynamic compression strength of rock samples and observing the failure forms of specimens,students are guided to understand the dynamic mechanical response of rock materials under different strain rates.The finite element software LS-DYNA is also used to simulate the SHPB experiment,and the process of stress wave propagation and rock failure is reproduced to achieve the demonstration function of dynamic impact.Practice shows that this teaching method enables students to intuitively perceive the stress wave propagation,clearly understand the dynamic failure mechanism of rock,master the relationship between dynamic mechanical properties of rock materials and strain rate,and lay a foundation for further study of blasting engineering theory.