OTM/HOTM极限力学仿真在小行星防御中的应用

OTM/HOTM Extreme Thermomechanical Simulations in Asteroid Defense

小行星撞击地球是人类生存面临的重大威胁之一,减缓或避免小行星撞击是学术界和国际社会关注的热点问题。动能撞击、侵彻爆炸或激光烧蚀是当前小行星防御的几个主要手段,其涉及超高速撞击、极限条件下的热-力-化学强耦合等现象。高效高精度预测行星材料在极限热力学条件下的动态响应机制是开展计算仿真的难点,其对计算方法、材料模型与高性能计算都提出了极大的挑战。本文介绍了描述极限条件下材料超大变形、熔化气化、流固与热流固耦合、自由表面、多体接触、碎裂、层裂与碎片云等复杂物理现象的多物理场、多尺度强耦合的OTM/HOTM最优运输无网格系列方法,并初步探讨了基于此方法发展的ESCAAS极限力学仿真平台在小行星防御中的应用,为动能撞击等小行星防御手段提供相关理论与技术支撑。

Asteroid impact on Earth is one of the major threats to human being.Asteroid defense is a hot issue in the academic sector and the international community.Kinetic impact deflecting asteroid orbits or destroying asteroids is one of the main means of asteroid defense.However, these measures involve strong thermal-mechanical-chemical interactive phenomena under extreme conditions such as hypervelocity impact, penetrating explosion and laser ablation.High-efficiency and high-precision prediction of the dynamic response mechanism of materials under extreme thermodynamic conditions is a difficult issue in computational simulation, which poses great challenges to computational methods, material models, and high-performance computing.This paper introduces a series of OTM/HOTM methods for describing complex physical phenomena such as ultra-large deformation, melting, gasification, fluid-structure interaction, thermal-fluid-structure interaction, free surface, multi-body contact, fragmentation, spallation and debris cloud of materials under extreme conditions.Finally, the application of ESCAAS, an extreme mechanics simulation platform developed based on OTM/HOTM method, in asteroid defense measures is preliminarily discussed, which provides relevant theoretical and technical support for asteroid defense methods such as kinetic impact.