ABSTRACT

Fibreglass reinforced flexible pipe (FGRFP) is a kind of composite thermoplastic pipe serving as a preferred application in the field of oil transportation. This paper studies the mechanical behaviour of FGRFPs under pure bending by experimental, numerical and theoretical methods. Full-scale four-point bending tests are conducted and the curvature-bending moment relations of specimens are recorded. In the numerical simulation method (NSM), a detailed finite element model considering both material and geometric nonlinear behaviour is established, and the composite is defined as an orthotropic elastic-plastic material. Based on the Euler–Bernoulli beam theory, a simplified theoretical method (STM) is proposed to predict the ultimate bending moment. In the parametric study, a simple formula is introduced to modify STM to make it more accurate. Good agreements proves the reasonability of the proposed NSM and STM. Additionally, STM could make a contribution to engineers in terms of a concise and relatively accurate way in ultimate status analysis.

摘要

玻璃纤维增​​强柔性管（FGRFP）是一种复合热塑性管材，是石油运输领域的首选应用。本文通过实验、数值和理论方法研究了纯弯曲下 FGRFPs 的力学行为。进行全尺寸四点弯曲试验，记录试件的曲率弯矩关系。在数值模拟方法（NSM）中，建立了考虑材料和几何非线性行为的详细有限元模型，并将复合材料定义为正交各向异性弹塑性材料。基于欧拉-伯努利梁理论，提出了一种简化理论方法（STM）来预测极限弯矩。在参数研究中，引入了一个简单的公式来修改STM，使其更加准确。良好的协议证明了提议的 NSM 和 STM 的合理性。此外，STM可以在最终状态分析中以简洁和相对准确的方式为工程师做出贡献。