复杂载荷下钢带缠绕增强复合管力学特性

Mechanical properties of reinforced composite pipe wound with steel strip under complex loads

为研究海洋油气输送用钢带缠绕增强复合管在复杂载荷下的力学响应特性,考虑非线性接触,建立钢带缠绕增强复合管数值计算模型,研究由内外压、弯曲及拉伸载荷组合作用下钢带缠绕增强复合管的变形及承载性能。结果表明,压差(外压大于内压,≤2 MPa)越大钢带缠绕增强复合管的柔性越高。与纯弯曲相比,拉伸载荷和压差的附加联合作用使钢带缠绕增强复合管柔性降低;与纯拉伸相比,弯曲载荷和压差的附加联合作用则使钢带缠绕增强复合管抗拉承载能力降低。与单一载荷相比,复杂载荷下内、外聚乙烯(PE)管的高应力区位置及内层钢带对称应力分布的路径发生改变。钢带螺旋角度及摩擦系数越大,钢带缠绕增强复合管柔性越低;增大摩擦系数,钢带缠绕增强复合管承载能力提高。组合弯曲载荷下随着钢带螺旋角增大,钢带缠绕增强复合管屈曲时的临界弯矩呈非单调变化,存在极大值。研究结果可为钢带缠绕增强复合管的设计、制造及安全评价提供理论依据。

In order to study the mechanical characteristics of reinforced composite pipe wound with steel strip for marine oil and gas transportation under complex loads,a numerical calculation model that considers non-linear contact was established.The model was studied to reflect the deformation and load-bearing properties of the composite pipe wound with steel strip under the combination of internal and external pressure,bending and tensile loads.The results show that the greater the pressure difference(the external pressure is greater than the internal one and≤2 MPa),the more flexible the reinforced composite pipe wound with steel strip.Compared with pure bending,the additional combined effect of tensile load and pressure difference reduces the flexibility of reinforced composite pipe wound with steel strip.Compared with pure stretching,the additional combined effect of bending load and differential pressure reduces the tensile load carrying capacity of the reinforced composite pipe wound with steel strip.Compared with a single load,the location of the high stress area of the inner and outer polyethylene(PE)pipes and the symmetrical stress distribution path of the inner strip change under the complex loads.The greater the spiral angle and friction coefficient of the strip,the lower the flexibility of reinforced composite pipe wound with steel strip.The greater the friction coefficient,the higher the bearing capacity of reinforced composite pipe wound with steel strip.With the increase of the spiral angle under the combined bending load,the critical bending moment during buckling is non-monotonic and has a maximum value.The results can provide theoretical basis for the design,manufacture,and safety evaluation of reinforced composite pipe wound with steel strip.