基于黏弹性本构的CFRP-钢界面应力参数敏感性分析

发布时间：2018-04-16 14:18

本文选题：桥梁工程 + 敏感性分析　；参考：《公路交通科技》2017年11期

【摘要】：为研究胶粘剂的黏弹性本构关系和粘贴CFRP加固钢梁各设计参数变化对CFRP-钢界面应力的影响,以改进的Maxwell模型表征胶粘剂的黏弹性本构关系。针对加固梁胶层以剪切变形为主的情况,对胶粘剂黏弹性本构进行简化分析,利用拉普拉斯变换和逆变换的数学方法,给出了改进的Maxwell模型各变量的求解方法,利用有限元软件ABAQUS对典型的粘贴CFRP加固简支钢梁进行有限元分析。分析了界面应力随加载时间的变化规律,详细地讨论CFRP弹性模量变化、CFRP厚度变化、胶层厚度变化和CFRP端部到支座的距离变化对CFRP-钢界面应力的影响。依据敏感性分析的基本原理,从定量分析的角度研究界面应力对各参数的敏感程度。结果表明:胶粘剂黏弹性会导致黏结界面发生应力重分布,界面峰值剪应力和峰值正应力随时间增加而减小;胶层越厚,CFRP越薄,CFRP弹模越小;CFRP离支座越近,黏结界面应力越小;对CFRP端部界面剪应力影响最大的参数为CFRP端部到支座的距离,其敏感度因子为1.359;对CFRP端部界面正应力影响最大的参数为CFRP厚度,其敏感度因子为0.956。
[Abstract]:In order to study the viscoelastic constitutive relation of adhesive and the influence of different design parameters on the interface stress of CFRP- steel strengthened with CFRP, the modified Maxwell model was used to characterize the viscoelastic constitutive relationship of the adhesive.In view of the shear deformation of the rubber layer of the strengthened beam, the viscoelastic constitutive equation of the adhesive is simplified and analyzed. Using the mathematical method of Laplace transform and inverse transformation, the solution method of each variable of the improved Maxwell model is given.The finite element analysis of simply supported steel beams strengthened with CFRP is carried out by using finite element software ABAQUS.The variation of interfacial stress with loading time is analyzed, and the influence of the thickness of CFRP elastic modulus, the thickness of adhesive layer and the distance from end to support of CFRP on the interfacial stress of CFRP-steel is discussed in detail.According to the basic principle of sensitivity analysis, the sensitivity of interface stress to various parameters is studied from the point of view of quantitative analysis.The results show that the viscoelasticity of the adhesive will lead to stress redistribution at the interface, the peak shear stress and the peak normal stress of the interface will decrease with the increase of time, and the thicker the adhesive layer is, the thinner the CFRP elastic modulus is, and the closer the CFRP is to the support, the smaller the stress at the interface.The maximum influence on the shear stress of the end of CFRP is the distance from the end of the CFRP to the support, and the sensitivity factor is 1.359, and the thickness of the CFRP is the most sensitive factor to the normal stress at the end of the CFRP, and the sensitivity factor is 0.956.
【作者单位】：内蒙古大学交通学院;西南交通大学土木工程学院;
【基金】：国家自然科学基金项目(51508474)
【分类号】：U441.5;U445.72

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