(1. 西安石油大學(xué) 材料科學(xué)與工程學(xué)院，西安 710065；
2. 西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，西安 710072)
摘 要: 基于環(huán)形試樣軸壓實(shí)驗(yàn)、有限元模擬、回歸分析和遺傳算法相結(jié)合的反求方法對厚壁鈦管壓縮狀態(tài)下的塑性材料參數(shù)進(jìn)行快速識別，利用試驗(yàn)方法研究機(jī)床彈性變形時TA18厚壁鈦管不同圓環(huán)壓縮試樣高度下試樣鼓肚率和機(jī)床彈性變形的變化情況，并在此基礎(chǔ)上確定了試樣高度范圍，獲得了試驗(yàn)力-位移曲線。利用反求方法確定了其壓縮應(yīng)力應(yīng)變關(guān)系，并將其應(yīng)用在不同高度鈦管環(huán)形試樣軸壓模擬中，與試驗(yàn)進(jìn)行對比，以發(fā)現(xiàn)反求獲得的應(yīng)力-應(yīng)變曲線可以較好地預(yù)測鈦管軸向壓縮變形行為，對壓縮試樣變形后最大直徑和載荷的預(yù)測誤差分別不超過1.5%和11%。
關(guān)鍵字: 厚壁鈦管；圓環(huán)壓縮試樣；反求方法；壓縮應(yīng)力狀態(tài)；應(yīng)力-應(yīng)變關(guān)系
（1. School of Materials Science and Engineering, Xi’an Shiyou University, Xi’an 710065, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:An inverse method for fast and accurate identifying the material parameters of thick-walled titanium alloy tube under compressive stress state was developed combing ring axial compression test, FE method, regression analysis and genetic algorithm. Considering the evitable elastic deformation of testing machine, the specimen barreling and machine elastic deformation were examined in testing thick-walled TA18 tube specimen with varying heights. Then, a reasonable range of specimen height and the experimental load-displacement curves were determined accordingly. Employing the curves, the material parameters of tube were obtained by using the inverse method. In order to verify the reliability of the identified parameters, FE simulations of ring compression tests were carried out using the determined material parameters and compared with experiments. Comparison results show that the obtained stress-strain curves can describe the compressive deformation behaviors of tube material with prediction errors of maximum diameter, and the load deviates from the experiments less than 1.5% and 11%, respectively.
Key words: thick-walled titanium alloy tube; ring compression specimen; reverse method; compressive stress state; stress-strain relationship
