(浙江大學(xué) 流體傳動及控制國家重點實驗室， 杭州 310027)
摘 要: 針對金屬切削加工中材料的高溫度、 高應(yīng)變、 高應(yīng)變率數(shù)據(jù)難以獲取， 無法建立動態(tài)本構(gòu)模型這一技術(shù)難題， 提出基于有限元模擬和“單因素”流動應(yīng)力公式計算的聯(lián)合建模策略。由“單因素”流動應(yīng)力公式反復(fù)計算與模擬應(yīng)變率對應(yīng)的流動應(yīng)力， 基于新的流動應(yīng)力有限元模擬迭代的進行并追求模擬值與實驗結(jié)果的一致， 獲取能反映切削材料力學(xué)性能的“三高”數(shù)據(jù)和流動應(yīng)力數(shù)據(jù)。數(shù)據(jù)分析表明， 應(yīng)變率對流動應(yīng)力具有強化作用， 溫度對流動應(yīng)力具有弱化作用， 穩(wěn)態(tài)變形后， 各應(yīng)力—應(yīng)變曲線都變?yōu)橐粭l趨于與應(yīng)變坐標(biāo)軸平行的直線。 根據(jù)影響規(guī)律選取Zerilli-Armstrong經(jīng)驗?zāi)Ｐ停?采用非線性回歸分析建立起航空鋁合金板材在銑削加工中的動態(tài)本構(gòu)模型。 最后進行實驗驗證，證明了該本構(gòu)模型的正確性。
關(guān)鍵字: 金屬切削加工； 有限元模擬； 回歸分析； 本構(gòu)模型
（ State Key Laboratory of Fluid Power Transmission and Control,
Zhejiang University, Hangzhou 310027, China）
Abstract: High temperature, high strain and high strain-rate of metal material in machining were not easy to get with a general measure method, which made it quite difficult to establish the dynamic constitutive model. To solve this problem, a combined modeling method based on “single factor” flow stress formula calculating and FEM simulation was proposed. The flow stress was repeated by calculated using the “single factor” flow stress formula, the metal machining process was simulated interatively with new flow stress. When simulating value was in good consistent with experimental result, the “three-high” data and flow stress data were obtained. By analyzing these data, it indicates that strain-rate can enhance the flow stress, while temperature will lower flow stress, and after remained in a steady state, each stress—strain curve will be parallel to the strain coordinate axis. Zerilli-Armstrong experience model was selected correspondingly. With the non-liner regression analysis, a dynamic constitutive model of aviation aluminum-alloy material during milling process was established. At last, the constitutive model is proved to be reasonable through test verification.
Key words: metal cutting process; finite element simulation; regression analysis; constitutive model
