Kim Jin Young, Liu Zezhou, Weon Byung Mook, Cohen Tal, Hui Chung-Yuen, Dufresne Eric R, Style Robert W
School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, South Korea.
Department of Mechanical and Aerospace Engineering, Field of Theoretical and Applied Mechanics, Cornell University, Ithaca, NY 14853, USA.
Sci Adv. 2020 Mar 27;6(13):eaaz0418. doi: 10.1126/sciadv.aaz0418. eCollection 2020 Mar.
Cavitation is a common damage mechanism in soft solids. Here, we study this using a phase separation technique in stretched, elastic solids to controllably nucleate and grow small cavities by several orders of magnitude. The ability to make stable cavities of different sizes, as well as the huge range of accessible strains, allows us to systematically study the early stages of cavity expansion. Cavities grow in a scale-free manner, accompanied by irreversible bond breakage that is distributed around the growing cavity rather than being localized to a crack tip. Furthermore, cavities appear to grow at constant driving pressure. This has strong analogies with the plasticity that occurs surrounding a growing void in ductile metals. In particular, we find that, although elastomers are normally considered as brittle materials, small-scale cavity expansion is more like a ductile process. Our results have broad implications for understanding and controlling failure in soft solids.
空化是软固体中一种常见的损伤机制。在此，我们利用拉伸弹性固体中的相分离技术来研究这一现象，通过该技术可控地使小空洞成核并生长几个数量级。制造不同尺寸稳定空洞的能力以及可达到的巨大应变范围，使我们能够系统地研究空洞扩展的早期阶段。空洞以无标度方式生长，伴随着不可逆的键断裂，这种键断裂分布在生长中的空洞周围，而不是局限于裂纹尖端。此外，空洞似乎在恒定驱动压力下生长。这与韧性金属中生长空洞周围发生的塑性有很强的相似性。特别是，我们发现，尽管弹性体通常被视为脆性材料，但小尺度空洞扩展更像是一个韧性过程。我们的结果对于理解和控制软固体中的失效具有广泛的意义。
