使用超高速碰撞数值仿真技术,结合自主开发的碎片识别统计方法,以Iridium33与Cosmos2251卫星在轨撞击解体事件为例,进行了在轨卫星碰撞解体碎片分析。通过有限元方法(FEM)与光滑粒子流体动力学(SPH)的复合算法,从图形角度识别出碎片云中的大碎片,然后利用二值图转换与二值图连通域的快速统计,提取出了碎片数目、尺寸、位置、速度和质量等信息。碎片识别结果表明大部分大碎片由Cosmos2251产生,大碎片统计结果与空间监测网(SSN)观测值相符,表明了该方法的有效性。研究结果同时表明正撞击区内的材料大部分转化为了小碎片,大碎片则由远离正撞击区的材料产生。为了度量撞击破碎程度,定义了等效正撞击质量的特征量,通过分析发现大碎片的总质量只与等效正撞击质量相关,与撞击点无关,对于小碎片总质量也有相同的结论。
Debris analysis method of on-orbit satellite collision is presented in this paper. Hypervelocity impact simulation technique and self-developed fragment identification and statistics method are applied to analyzing fragmentation process of Iridium33 and Cosmos2251 collision as an instance. Using a combined method of finite element method (FEM) and smoothed particle hydrodynamics (SPH), large fragments are identified from the debris cloud. Then with binary image conversion and statistics of connectedness regions on the image, the amount, size, position, velocity and mass of each fragment are determined. Simulation results show that most large fragments are generated from Cosmos2251 and the quantity of fragments is in agreement with space surveillance network (SSN) observation data, which shows the effectiveness of the proposed method. Most materials in the normal impact region are converted into small fragments after the impact while the large fragments are from materials far from the normal impact region. To measure the degree of spall, equivalent normal impact mass is defined. The computation results show that the total mass of either large or small fragments is only determined by equivalent normal impact mass despite various impact locations.
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