(北京工業(yè)大學(xué) 機(jī)械工程與應(yīng)用電子技術(shù)學(xué)院，北京 100124)
摘 要: 通過對(duì)2219-T6鋁合金攪拌摩擦焊對(duì)接接頭進(jìn)行金相觀察、疲勞試驗(yàn)和顯微硬度測(cè)量，對(duì)接頭的不均勻性和疲勞性能進(jìn)行分析。結(jié)果表明，接頭最低硬度和疲勞源基本都在熱影響區(qū)。基于接頭各區(qū)的顯微硬度、微觀形貌及微拉伸試驗(yàn)測(cè)試，建立接頭的彈塑性有限元模型，并在循環(huán)加載下模擬接頭的應(yīng)力和應(yīng)變分布。利用Smith-Watson-Topper損傷公式和性能薄弱區(qū)域的應(yīng)力、應(yīng)變數(shù)據(jù)對(duì)焊接接頭進(jìn)行疲勞壽命預(yù)測(cè)，預(yù)測(cè)結(jié)果與試驗(yàn)結(jié)果相比，壽命誤差基本在兩倍因子之內(nèi)。
關(guān)鍵字: 2219-T6鋁合金；FSW接頭；攪拌摩擦焊；疲勞壽命預(yù)測(cè)；有限元模擬
（College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology,
Beijing 100124, China）
Abstract:The inhomogeneity and fatigue properties of the friction stir welded butt joints for 2219-T6 aluminum alloy were analyzed by metallographic observation of different zones, fatigue tests and micro-hardness measurement. The results show that the lowest hardness and fatigue crack initiation sites are mainly located in heat affected zone. The elastic-plastic FE model was established based on the micro-hardness, microstructure and the mechanical properties obtained from micro-tensile tests of every zone. The stress and strain distributions of joints were simulated under cyclic loading. According to the FE simulations results, the fatigue lives were estimated by using the damage equation of Smith-Watson-Topper and the stress-strain data of the weak area in the joints. The results of estimations are compared with the test results and the errors are less than two times of factors.
Key words: 2219-T6 Al alloy; FSW joint; friction stir welding; fatigue life prediction; finite element simulation
