(青島理工大學(xué) 機(jī)械工程學(xué)院，青島 266033)
摘 要: 為彌補(bǔ)現(xiàn)有航空鈦合金切削加工本構(gòu)模型研究的不足，提出基于正交切削理論的材料本構(gòu)模型構(gòu)建方法。根據(jù)正交切削理論建立剪切區(qū)內(nèi)應(yīng)力、應(yīng)變、應(yīng)變率、溫度以及二維切削力的數(shù)學(xué)模型，開(kāi)發(fā)以剪切區(qū)長(zhǎng)度和厚度比值為迭代變量的建模技術(shù)，結(jié)合動(dòng)態(tài)壓縮力學(xué)性能實(shí)驗(yàn)(SHPB實(shí)驗(yàn))和直角銑削實(shí)驗(yàn)，通過(guò)對(duì)各變形參數(shù)的數(shù)學(xué)求解，建立航空鈦合金切削加工本構(gòu)模型。在此基礎(chǔ)上，進(jìn)行材料本構(gòu)模型的分析和實(shí)驗(yàn)驗(yàn)證。結(jié)果表明：航空鈦合金材料在切削加工中具有明顯的應(yīng)變硬化特性、溫度敏感特性和應(yīng)變率敏感特性；鈦合金隨著應(yīng)變率的增大，流動(dòng)應(yīng)力的增量逐漸減小，材料的應(yīng)變率敏感性降低。
關(guān)鍵字: 鈦合金；切削加工；正交切削理論；本構(gòu)模型
（School of Mechanical Engineering, Qingdao Technological University, Qingdao 266033, China）
Abstract:To make up the shortcoming of the current researches in material constitutive model during cutting process, a construction method of material constitutive model based on orthogonal cutting theory was presented. According to the orthonal cutting theory, the mathematic model of stress, strain, strain rate and temperature in shear zone, as well as the two-dimensional cutting force, was established. The constrution technology of material constitutive model by taking the ratio of length to depth in shear zone as an iterative variable was developed. With the split Hopkinson pressure bar (SHPB) compression experiment and orthogonal cutting experiment, the material deformation physical quantities were solved and the material constitutive model was established. The prediction values of material constitutive model were compared with the cutting experiment ones, and they are found to be in good agreement. The results show that titanium alloy material has obvious strain hardening characteristic, temperature sensitivity characteristic and strain rate sensitivity characteristic during cutting process. And with the increase of strain rate, the flow stress increment decreases, and the strain rate sensitivity characteristic decreases.
Key words: titanium alloy; cutting process; orthogonal cutting theory; constitutive model
