(1. 湖南大學(xué) 汽車(chē)車(chē)身先進(jìn)設(shè)計(jì)制造國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410082；
2. 湖南大學(xué) 機(jī)械與運(yùn)載工程學(xué)院，長(zhǎng)沙 410082)
摘 要: 為建立精確描述材料變形時(shí)熱力學(xué)參數(shù)間重要關(guān)系的數(shù)學(xué)模型，采用Gleeble-3500熱模擬機(jī)測(cè)試研究6013鋁合金在溫度為340~500 ℃、應(yīng)變速率為0.001~10 s-1范圍內(nèi)的平面應(yīng)變熱壓縮變形行為，討論材料參數(shù)對(duì)冪函數(shù)(PF)和雙曲正弦函數(shù)(HS)本構(gòu)模型(CM)精度的影響，對(duì)比分析優(yōu)化后兩類(lèi)本構(gòu)模型各自的優(yōu)勢(shì)。結(jié)果表明：溫度系數(shù)(b)的修正對(duì)反求參數(shù)(a)的優(yōu)化效果顯著，將直接影響PFCM的預(yù)測(cè)精度；通過(guò)指數(shù)函數(shù)替換多項(xiàng)式對(duì)HSCM參數(shù)進(jìn)行修正，可在保證預(yù)測(cè)精度的同時(shí)大幅減少計(jì)算工作量；PFCM在 ≥0.01 s-1時(shí)的預(yù)測(cè)精度較高，平均相對(duì)誤差僅為5.209%；HSCM在 ≤0.01 s-1時(shí)的預(yù)測(cè)精度較高，平均相對(duì)誤差僅為5.226%。
關(guān)鍵字: 6013鋁合金；平面熱壓縮；流變應(yīng)力；本構(gòu)模型；材料參數(shù)修正
（1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University,
Changsha 410082, China;
2. College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China）
Abstract:In order to develop a precise constitutive model to describe the relationships among material thermodynamic parameters during hot deformation, the hot plane compression deformation behavior of 6013 aluminum alloy was investigated on Gleeble-3500 thermal-mechanical simulating tester in the temperature range from 340 to 500 ℃ and strain rate range from 0.001 to 10 s-1. The influences of material parameters on the accuracies of the power function (PF) and hyperbolic sine (HS) constitutive model (CM) were discussed. Additionally, the advantages of two kinds of optimized constitutive models were comparatively analyzed. The results show that the corrected value of temperature coefficient (b) has an obvious effect on the parameter (a) obtained by an inverse method, and directly impacts the accuracy of PFCM. It is indicated that the computational-workload can be reduced significantly with high accuracy, through modifying the material parameters of HSCM by power function instead of polynomial function. Under the deformation condition ( ≥0.01 s-1), the developed method of PFCM has higher precision of prediction, and the average relative error is only 5.209%; on the contrary, the proposed method of HSCM has higher precision of prediction under the deformation condition ( ≤0.01 s-1), and the average relative error is only 5.226%.
Key words: 6013 aluminum alloy; hot plane compression; flow stress; constitutive equation; material parameter modification
