基于改进Sherwood-Frost模型的钢结构重防腐涂装本构研究  

Constitutive model of heavy-duty anti-corrosion coating of steel structure based on improved Sherwood-Frost model

作　　者：蔺鹏臻[1] 陈星 LIN Pengzhen;CHEN Xing(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《铁道科学与工程学报》2024年第9期3719-3731,共13页Journal of Railway Science and Engineering

基　　金：甘肃省交通运输厅科研项目(2022-26);甘肃省高等学校产业支撑计划项目(2024CYZC-21);甘肃省重点研发计划-工业类项目(23YF-GA0042)。

摘　　要：为探究影响钢结构重防腐涂装层单轴拉伸力学行为的关键因素,并据此构建其综合多重因素影响的本构模型。选取底漆、中间漆、面漆结合的3层钢结构重防腐涂装体系为研究对象,使用控制变量法对涂层进行单轴拉伸试验,记录各项拉伸力学性能指标,包括拉伸强度、断裂伸长率等。试验在-20~50℃的温度范围内进行,应变率设置在6.67×10^(-4)~1.67×10^(-2) s^(-1)内,中间漆厚度则在140~700μm之间变化。量化分析各因素对钢结构涂装层力学性能的影响程度,并揭示各影响规律产生的原因。基于Sherwood-Frost模型理论,结合涂层材料特性及试验结果,确定本构模型温度项、应变率项及厚度项,构建多因素钢结构涂装层本构模型。通过对钢结构重防腐涂装层进行应变率恒定,不同温度和中间漆厚度2种工况耦合的单轴拉伸试验,验证该模型的可靠性。研究发现,在试验条件范围内,随着温度升高或应变率降低,涂层的拉伸强度减小而断裂延伸率增大。在中间漆厚度方面,当厚度为560μm时,涂层的力学性能响应最为明显。构建的本构模型预测值与试验结果的相关系数r均在0.97及以上,能够描述和预测在各种单因素或多因素耦合影响下涂装层的拉伸力学性能表现。研究可以为钢结构重防腐涂装层的设计和应用提供理论支持,并为相似结构的防腐设计和研究提供参考。This study explored key factors affecting the uniaxial tensile mechanical behavior of heavy-duty anti-corrosion coating layers in steel structures.It aimed to build a comprehensive constitutive model,considering multiple factors.Selecting a three-layer coating system for steel structures,comprising primer,intermediate paint,and topcoat,as the subject of study.Uniaxial tensile tests were performed using the controlled variable method,recording mechanical performance indicators including tensile strength and fracture elongation rate.The experiments were conducted over a temperature range of 20℃ to 50℃,with strain rates varying from 6.67×10^(-4)s^(-1)to 1.67×10^(-2)s^(-1),and with intermediate paint thicknesses ranging from 140μm to 700μm.The study quantitatively analyzed the impact of each factor on the mechanical properties of the coating layer.Based on the Sherwood-Frost model theory,combined with the material characteristics of the heavy anti-corrosion coating and experimental results,a constitutive model incorporating temperature,strain rate,and thickness was established.The reliability of this model was verified through uniaxial tensile tests under constant strain rate,considering the coupled conditions of temperature and intermediate paint thickness.The research results are shown as follows.Within the range of 20℃ to 50℃,an increase in temperature significantly increases the fracture elongation rate and decreases the elastic modulus of the coating.Within the given strain rate range,an increase in strain rate significantly enhances both the tensile strength and elastic modulus of the coating.The most pronounced mechanical response concerning the thickness of the intermediate paint is observed at 560μm.The constitutive model developed in this study,with a correlation coefficient of 0.97 or higher,effectively describes and predicts the tensile mechanical performance of the coating layer under various single or combined factor influences.This research can provide theoretical support for the design an

关 键 词：钢结构 重防腐涂装 力学性能 影响因素 本构模型 

分 类 号：TQ0[化学工程]