Interlocking brick assemblies provide a standardized yet challenging testbed for contact-rich and long-horizon robotic manipulation, but existing rigid-body simulators do not faithfully capture snap-fit mechanics. We present BrickSim, the first real-time physics-based simulator for interlocking brick assemblies. BrickSim introduces a compact force-based mechanics model for snap-fit connections and solves the resulting internal force distribution using a structured convex quadratic program. Combined with a hybrid architecture that delegates rigid-body dynamics to the underlying physics engine while handling snap-fit mechanics separately, BrickSim enables real-time, high-fidelity simulation of assembly, disassembly, and structural collapse. On 150 real-world assemblies, BrickSim achieves 100% accuracy in static stability prediction with an average solve time of 5 ms. In dynamic drop tests, it also faithfully reproduces real-world structural collapse, precisely mirroring both the occurrence of breakage and the specific breakage locations. Built on Isaac Sim, BrickSim further supports seamless integration with a wide variety of robots and existing pipelines. We demonstrate robotic construction of brick assemblies using BrickSim, highlighting its potential as a foundation for research in dexterous, long-horizon robotic manipulation. BrickSim is open-source, and the code is available at https://github.com/intelligent-control-lab/BrickSim.

翻译：互锁砖块装配体为接触密集且长时程的机器人操作提供了一个标准化但具有挑战性的测试平台，然而现有的刚体仿真器未能真实地捕捉卡扣配合力学。我们提出了BrickSim，首个用于互锁砖块装配体的实时物理仿真器。BrickSim为卡扣配合连接引入了一种紧凑的基于力学的力学模型，并通过结构化凸二次规划求解由此产生的内力分布。结合一种混合架构——将刚体动力学委托给底层物理引擎，同时单独处理卡扣配合力学——BrickSim能够实现装配、拆卸和结构坍塌的实时高保真仿真。在150个真实世界装配体上，BrickSim在静态稳定性预测中实现了100%的准确率，平均求解时间为5毫秒。在动态跌落测试中，它也能真实地再现现实世界的结构坍塌，精确地反映断裂的发生以及具体的断裂位置。基于Isaac Sim构建的BrickSim进一步支持与多种机器人及现有流程的无缝集成。我们展示了使用BrickSim进行砖块装配体的机器人构建，突显了其作为灵巧、长时程机器人操作研究基础的潜力。BrickSim是开源的，代码可在https://github.com/intelligent-control-lab/BrickSim获取。