(1. 中南大學(xué) 機(jī)電工程學(xué)院，長(zhǎng)沙 410083；
2. 深海礦產(chǎn)資源開發(fā)利用技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410012)
摘 要: 深海礦物分布在幾百米到幾千米深的高靜水壓力環(huán)境中，礦物周圍的高靜水壓力可能會(huì)顯著影響其切割特性。為了研究高靜水壓下海底多金屬硫化物(SMS)的破碎特性及其力學(xué)性能對(duì)破碎過程的影響，建立了高圍壓條件下截齒切割SMS的模型。采用了一種力鏈圍壓模擬靜水圍壓的作用，圍壓能適應(yīng)試樣切削過程中的不規(guī)則邊界并在切割過程中進(jìn)行更新。在此基礎(chǔ)上，分析了試樣切削過程中裂紋演化過程、應(yīng)力分布特征和載荷變化規(guī)律。結(jié)果表明：圍壓對(duì)切削過程有顯著影響，隨著圍壓的增加，刀具載荷線性增加，載荷波動(dòng)減小，裂紋擴(kuò)展受到抑制。同時(shí)，在高圍壓條件下，刀具的前刀面上產(chǎn)生條狀切屑，表明其破壞模式由脆性模式向延性模式轉(zhuǎn)變。
關(guān)鍵字: 圍壓；切削機(jī)理；離散元；多金屬硫化物；力鏈
（1.School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Deep Sea Mineral Resources Development and Utilization Technology, Changsha 410012, China）
Abstract:Deep-sea minerals are distributed in a high hydrostatic pressure environment with hundreds to thousands of meters deep, and the high hydrostatic pressure around minerals may significantly influence their cutting characteristics. In order to study the fragmentation characteristics of cutting seafloor massive sulfides (SMS) under high hydrostatic pressure and how its mechanical properties influence the fragmentation process, a model for cutting SMS with a pick under high confining pressure was established. In this paper, a force chain method was used to simulate confining pressure, which could adapt to the irregular boundary of the sample and update in the cutting process. On this basis, the crack evolution process, stress distribution characteristics and load variation law were analyzed. The results show that the confining pressure significantly affects the cutting process. With the increase of confining pressure, the tool load increases linearly, the load fluctuation decreases, and the crack propagation is restrained. Meanwhile, under high confining pressure, the strip chips are generated on the rake face, which indicates that the failure mode of seafloor massive sulfide transfers from brittle mode to ductile mode.
Key words: confining pressure; cutting mechanism; discrete element method; SMS; force chain
