(1．清華大學(xué) 機械工程系 摩擦學(xué)國家重點實驗室 先進成形制造教育部重點實驗室，北京 100084；
2．北京宇航系統(tǒng)工程研究所，北京 100076；
3. 中國運載火箭技術(shù)研究院，北京 100076)
摘 要: 為了闡明貯箱Y形環(huán)環(huán)縫焊接殘余應(yīng)力對其承載行為的影響，以大型運載火箭貯箱Y形環(huán)為研究對象，采用數(shù)值模擬計算得到Y(jié)形環(huán)與箱筒段環(huán)縫焊后殘余應(yīng)力；然后分別在考慮和不考慮殘余應(yīng)力情況下，進一步計算Y形環(huán)承受內(nèi)壓載荷時的應(yīng)力分布。結(jié)果表明：環(huán)縫焊接在接頭區(qū)域產(chǎn)生很大的殘余應(yīng)力，最大等效應(yīng)力位于部分熔化區(qū)，最大值達到358 MPa；焊接殘余應(yīng)力對遠離接頭的部位承載時的應(yīng)力基本沒有影響，主要導(dǎo)致接頭區(qū)域的應(yīng)力提高，且使Y形環(huán)承載時的等效應(yīng)力最大值也略有增大；焊接殘余軸向應(yīng)力和內(nèi)壓產(chǎn)生的軸向應(yīng)力在接頭內(nèi)表面都是拉應(yīng)力，兩者疊加導(dǎo)致軸向拉應(yīng)力明顯增大。
關(guān)鍵字: 貯箱；Y形環(huán)；殘余應(yīng)力；數(shù)值模擬；焊接
（1. The State Key Laboratory of Tribology, Key Laboratory for Advanced Materials Processing Technology,
Ministry of Education, Department of Mechanical and Engineering, Tsinghua University, Beijing 100084, China;
2. Beijing Institute of Astronautical Systems Engineering, Beijing 100076, China;
3. China Academy of Launch Vehicle Technology, Beijing 100076, China）
Abstract:According to the Y-ring of a heavy lift launch vehicle tank, the welding residual stress (WRS) between Y-ring and cylindrical shell was calculated by thermal-elastic-plastic finite element method. Then, stress distributions of the Y-ring under internal pressure loading with and without considering WRS were calculated in order to investigate the effect of WRS on loading behavior of the Y-ring structure. The results show that the WRS caused by the girth weld between Y-ring and cylindrical shell is very high, and the maximum Mises stress reaching 358MPa is located in partially melted zone. The WRS basically has little influence on stress distribution under loading in the region away from the joint, but increases the stress in the joint significantly, and also enlarges a little the maximum stress of the Y-ring under loading. In addition, the axial stresses at the inside surface generated by both the girth weld and internal pressure are tension stress, therefore the axial tension stress is obviously enlarged by the combined action of WRS and internal pressure.
Key words: propellant tank; Y-ring; residual stress; numerical simulation; welding
