地外天体采样器冲击机构应力波传递特性研究

Research on the Stress Wave Characteristics of Outer Planet Sampler Impact Mechanism

利用有限元数值计算方法仿真并分析了地外天体采样器冲击机构在冲击钻进过程中应力波的产生、传递及其钻进碎岩效果。采用一种新的有限元前处理方法建立冲击系统激振块、钻杆和钻头的三维模型和岩石材料模型。模拟分析了采样器在冲击钻进时应力波在钻杆中的传播过程及钻具对底部岩石材料的破碎效果。仿真结果表明,在冲击碰撞发生时,冲击能量以应力波的形式产生,沿着钻杆向底部传播并不断衰减,当其传递到最底端时发生反射。应力波的形貌、能量随时间的变化情况和钻具对岩石材料的破碎侵入情况均与实际情况和理论分析一致,验证了理论分析的正确性和这种建模仿真方法的有效性,为航天采样器冲击机构的设计和优化提供了一定的依据。

Stress wave generation,transferring and drilling effects during drilling rock of the impact mechanical system of outer planet sampler were simulated and analyzed by using finite element method.The three-dimensional model of the impact hummer,the drilling rod,the drilling bit and the finite element model for rock were established by using a new type of FEA preprocess method.The propagation process of stress wave in drilling rod and the breaking effects of rock at bottom were simulated and analyzed.The stimulation results showed that when impact collision happened,the impact energy was generated in the form of stress wave,propagated along the drill rod to the bottom and attenuated constantly,and the reflection occurred when it was transmitted to the bottom end.The changes of stress wave morphology,energy over time and the fracture and invasion of rock materials by drilling tools were consistent with the actual situation and theoretical conclusions.The correctness of theoretical analysis and the validity of this simulation method were verified,which provided certain gist for design and optimization of spaceflight sampler impact mechanism.