无扩口管接头试验件弯扭复合疲劳断口特征及断裂部位的应力反推方法  

Fracture characteristics of bending-torsion composite fatigue for flareless tube joint test piece and stress inversion method of fracture position

作　　者：邓瑛 郑远泊 张荣霞 吴为 曾元松 李荣生 Deng Ying;Zheng Yuanbo;Zhang Rongxia;Wu Wei;Zeng Yuansong;Li Rongsheng(Room 106,AVIC Manufacturing Technology Institute,Beijing 100024,China;Aeronautical Key Laboratory for Plastie Forming Technologies,Beijing 100024,China;Beijing Key Laboratory of Digital Plasticity Forming Technology and Equipment,Beijing 100024,China;302,AVIC Manufaturing Technology Institute,Beijing 100024,China)

机构地区：[1]中国航空制造技术研究院106室,北京100024 [2]塑性成形技术航空科技重点实验室,北京100024 [3]数字化塑性成形技术及装备北京市重点实验室,北京1_24 [4]中国航空制造技术研究院302中心,北京100024

出　　处：《锻压技术》2021年第4期229-234,共6页Forging & Stamping Technology

摘　　要：分析了某型无扩口管接头试验件疲劳试验的断口特征,其宏观断口呈现台阶状,断裂形成表面上存在明显的环向摩擦痕迹,并且其局部区域与管接头轴向不垂直。显微尺度下,管材和管套的接触面上存在与管材轴线成0°、45°和-55°等多个夹角的摩擦痕迹,表明试验装置对试验件施加了不稳定的扭转附加载荷,试验件在弯扭复合载荷作用下产生了疲劳破坏。通过有限元软件和理论分析相结合的方法,分析了扭转与弯曲载荷幅值、相位差对管材和管套接触面摩擦痕迹特征的影响规律,两个方向载荷的相对大小影响了摩擦方向与管材轴向夹角的斜率,两者的相位差影响了摩擦痕迹的曲率,以此为基础计算得到试验件断裂位置处附加扭转应力的幅值为401.1 MPa。The fracture characteristics of a certain type of flareless tube joint test piece in fatigue test were analyzed,the macroscopic fracture showed stepped shape,and there were obvious circumferential friction marks on the surface of fracture formation,which was not perpendicular to the tube joint axis in its partial area.Then,at the microscopic scale,there were friction marks on the contact surface of tube and tube sleeve at multiple angles of 0°,45° and-55° with the tube axis,indicating that the test device had applied an unstable additional torsional load on the test piece and the test piece had fatigue failure under the action of combined bending and torsion loads.Furthermore,the influences of bending-torsion load amplitude and phase difference on friction mark characteristics on the contact surface of tube and tube sleeve were studied by combining finite element method and theoretical analysis.The results show that the relative magnitude of load in the two directions affects the slope of angle between friction direction and tube axis direction,and the phase difference between the loads affects the curvature of friction marks.Based on the above,the amplitude of additional torsional stress at the fracture position of test piece is calculated to be 401.1 MPa.

关 键 词：无扩口管接头 弯曲 扭转 复合疲劳 断口特征 载荷计算 

分 类 号：TH16[机械工程—机械制造及自动化]