钢结构涂装层的力学试验与本构模型研究

Study on Mechanical Test and Constitutive Model of Steel Structure Coating

为研究钢结构桥梁涂装层的力学本构模型,以长效型涂装体系为试验对象进行单轴拉伸试验,得到面漆、中间漆、底漆和复合涂层的应力-应变曲线。通过无量纲化处理获得长效型涂装体系上升段本构方程的统一表达形式,并对每种漆膜具体的适用条件给出了相应的本构方程。结果表明:H06-X环氧富锌底漆(含80%锌)和长效型复合涂层的应力-应变曲线分为弹塑性阶段、应变强化阶段和破坏阶段;H06-C2环氧厚浆云母氧化铁中间漆的应力-应变曲线分为应变强化阶段和破坏阶段;E01-JY氟碳面漆的应力-应变曲线分为近似线弹性阶段和破坏阶段。依据应力-应变曲线得到了底漆、中间漆、面漆和复合涂层的弹性模量、泊松比、剪切模量、单轴拉伸强度和拉伸断裂应变等力学性能特征参数,发现单轴拉伸强度底漆最强,中间漆次之,面漆最差;变形性能面漆最佳,中间漆次之,底漆最差。

In order to study the mechanical constitutive model of steel bridge coating,uniaxial tensile tests was carried out on a long-acting coat system as the experimental object,and the stress-strain curves of topcoat,intermediate paint,primer and composite coating were obtained.The unified expression of the constitutive equation of the long-acting coat system was obtained by dimensionless processing,and the corresponding constitutive equation was given according to the specific applicable conditions of each coating film.The results show that the stress-strain curves of H06-X epoxy zinc-rich primer(80%zinc content)and long-acting composite coat were divided into elastic-plastic stage,strain strengthening stage and failure stage.The stress-strain curve of H06-C2 epoxy thick mica ferric oxide intermediate paint can be divided into strain strengthening stage and failure stage.The stress-strain curve of E01-JY fluorocarbon topcoat can be divided into approximate linear elastic stage and failure stage.Based on the stress-strain curve,the mechanical performance characteristic parameters of the primer,intermediate paint,topcoat,and composite coating were obtained,including elastic modulus,Poisson′s ratio,shear modulus,uniaxial tensile strength,and tensile fracture strain.The uniaxial tensile strength of the primer is the strongest,followed by intermediate paint,and the topcoat is the worst.The deformation performance of the topcoat is the best,followed by the intermediate coat,and the primer is the worst.