蠕变对液压胀接的管板接头残余接触压力的影响分析  

Effect of Creep on Residual Contact Stress of Hydraulically Expanded Tube-to-tubesheet Joints

作　　者：姚兴安[1] 王海峰[1] Yao Xingan Wang Haifeng(Nanjing Tech University, Nanjing 211816, China)

机构地区：[1]南京工业大学,江苏南京211816

出　　处：《钛工业进展》2016年第5期41-45,共5页Titanium Industry Progress

摘　　要：利用非线性有限元方法对TA2换热管与TA2-Q345R复合管板连接接头进行胀接模拟,并将胀接后的残余接触压力场作为蠕变分析的预定义场,进行蠕变顺次耦合分析,研究不同温度下TA2纯钛蠕变对胀接残余接触压力的影响。结果表明,胀接后的接触面存在两个高应力环带,TA2纯钛管与钛覆层胀接区域的接触压力较高。受TA2纯钛蠕变的影响,胀接接头的残余接触压力开始下降很快,之后趋于平缓,但80℃工况下的最终残余接触压力比20℃要低。当温度达到150℃时,TA2纯钛出现了蠕变饱和现象,使得残余接触压力相对提高,延长了热交换器液压胀接接头的使用寿命。当温度达到225℃以后,TA2纯钛蠕变特征不再出现,残余接触压力只受热应力的影响,随温度升高而降低。The expansion simulation for connection joint of TA2 tube and TA2-Q345R composite tubesheet was carried out by nonlinear finite element method. Then the subsequent coupling analysis of creep was performed by regarding the residual contact stress field of the post-expanded joint as the predefined field of creep analysis. The effect of the creep for TA2 on the residual contact stress, namely the connection strength and tightness of tube-to-tubesheet joints were invest/gated under different temperatures. The results show that there are two high stress zones on the contact surfaces, and the contact stress between TA2 tube and TA2 tubesheet is higher. The results also show that the residual contact stress of the joint drops quickly at the beginning and then tends to even as a result of creep for TA2. But the residual contact stress at 80 ℃ is lower than at 20 ℃. When the temperature approaches 150 ℃, creep saturation appears and the residual contact stress is enhanced relatively, which prolongs the working life of expanded tube-to-tubesheet joints of heat-exchanger. When the temperature approaches 225 ℃, the creep behavior no longer exists, and the residual contact stress is only susceptible to temperature and drops with the rise of temperature.

关 键 词：TA2纯钛 复合管板 残余接触应力 顺次耦合 蠕变饱和 

分 类 号：TK172[动力工程及工程热物理—热能工程] TG394[金属学及工艺—金属压力加工]