C型环环向应力与加载载荷的公式推导与验证

Equation Derivation and Verification for Hoop Stress and Load of C-ring

基于任意C型环试样结构尺寸及其力学关系,建立了C型环内任意截面的力学模型,根据材料力学基本理论,推导出了其外壁和内壁任意一点环向应力与C型环试样加载位移、加载载荷之间的理论计算公式。为了验证本文推导的理论公式的正确性,建立了C型环试样的有限元计算的力学模型,当某试验要求C型环试样最大环向拉应力为650 MPa,对油管外径88.9 mm的C型环试样,通过有限元法和本文推导的理论公式对该结构工况进行计算和对比分析,得出有限元法和理论公式计算出需要施加的载荷和位移的误差分别为-1.82%和1.25%,证明推导文中推导的理论公式的正确性,为C型环硫化物应力腐蚀开裂(SSCC)和应力腐蚀开裂(SCC)实验加载参数的确定提供了简便的计算方法。

Based on the structural dimensions and mechanical relation of an arbitrary C-ring specimen, a mechanical model for an arbitrary cross section within a C-ring was established. According to the fundamental theories of mechanics of materials, a theoretical equation was derived to describe the relation between the hoop stress at any point on the outer and inner walls and the loading displacement and load of a C-ring specimen. To verify the equation derived in this study, a mechanical model of C-ring specimen based on finite element method was established. The C-ring specimen test required the largest hoop tensile stress to be 650 MPa. The results of the finite element method and theoretical equation were compared for a C-ring specimen with tubing outer diameter of 88.9 mm. The error of load and displacement obtained by using the finite element method and the theoretical equation were -1.82% and 1.25%, respectively. The results verify the theoretical equation, which provides a simple calculation method for determining the experimental loading parameters of sulfide stress corrosion cracking and stress corrosion cracking tests on C-ring.