带自引力的粘结颗粒离散元模型用于碎石堆小行星的碰撞与再累积：公式与数值方案

中文摘要 AI 辅助

本文提出了一种离散元方法，用于研究小型自引力颗粒聚合体的碰撞与引力演化。每个天体被表示为由内聚粘结的球形颗粒组成的复合体，因此碎裂和再累积源于微观层面上短程耗散接触力、不可逆的键断裂准则以及成对牛顿自引力（对所有颗粒对求和，包括单个天体内部的颗粒对）之间的竞争。文中描述了一个数值实验：一种随机顺序堆积程序生成两个粘结的球形聚合体，一次受控的两体相遇（具有可调的接近速度和碰撞参数），以及一次系统的参数扫描，旨在绘制两个天体仅在其相互引力作用下从静止释放后，要么合并成一个单一残余体，要么在低速相遇后无法沉降的条件。在125次模拟碰撞中，56.8%的结果是形成单一残余体。内聚网络在Π_σ≲0.036时保持完整，在接触阻尼比决定的弥散下部分受损，并在Π_σ≈3.59时完全破坏。

英文摘要

I present a discrete-element approach developed to study the collisional and gravitational evolution of small self-gravitating granular aggregates. Each body is represented as a composite of cohesively bonded spherical grains, so that fragmentation and reaccumulation emerge from the microscopic competition between short-range dissipative contact forces, an irreversible bond-breaking criterion, and pairwise Newtonian self-gravity summed over every particle pair, including those internal to a single body. A numerical experiment is described: a random-sequential packing procedure that generates two bonded spherical aggregates, a controlled two-body encounter with tunable approach speed and impact parameter, and a systematic parameter sweep designed to map the conditions under which two bodies launched from rest under their mutual gravity alone either merge into a single remnant or fail to settle after a low-speed encounter. Of the 125 simulated collisions, 56.8\% result in the formation of a single residue. The cohesive network remains intact for $Π_σ\lesssim0.036$, is partially damaged with dispersion determined by the contact damping ratio, and breaks completely for $Π_σ\approx3.59$

发表机构

• Independent research

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