摘要
胶接钢-木组合构件中,受胶黏剂在钢材表面附着力弱的制约,钢材和木材的粘接强度不高。为改善胶黏剂在钢材上的粘附能力,提出采用激光在钢材表面形成微织构增加胶黏剂与钢材接触面积及嵌入深度。通过单搭接剪切试验,探究织构形状(方形凹坑、竖向沟槽、横向沟槽)对钢材和木材粘接强度的影响;借助激光共聚焦轮廓仪检测钢材表面粗糙度和织构深度,采用扫描电镜(SEM)观察激光处理后钢材表面形貌特征及断口特征,基于检测数据构建有限元模型,探究织构形状对钢材和木材间胶层应力分布影响;总结钢材表面织构对钢材和木材粘接强度影响规律和机制。结果表明:钢材表面织构能有效提升钢材和木材粘接强度;织构形状对钢材和木材粘接强度起决定性作用;在相同激光设置参数和相同织构设计参数(宽度和间距)下,沟槽织构比方形织构更有利于增加胶黏剂与钢材粘结强度;织构周围存在的激光熔融物有利于提高胶黏剂与钢材粘结强度。研究成果可为提高钢材和木材间粘接强度提供技术支撑,也为织构在胶接型钢-木组合构件中的应用与设计提供新思路。
Composite components made of wood and steel glued together have the advantages of these two materials,which improve the mechanical properties of single-material components.An increasing number of steel-wood composite parts are used in buildings.However,the surface roughness of untreated steel is low,and pollutants and oxide films are present on the steel surface.These factors are not conducive to the adhesion of adhesives on steel,resulting in a low bonding strength between steel and wood in the steel-wood composite member,weakening the ability of steel and wood to bond together.This paper aims to improve the adhesive adhesion ability of steel to enhance its bonding strength with wood.The use of lasers is proposed to form microtextures on steel surfaces to increase the contact area and embedment depth of the adhesive.A single-lap shear test is conducted to evaluate the effects of the texture shape(square pits,vertical grooves,and transverse grooves)and textured steel with and without sanding treatment on the bonding strength of steel and wood.A laser confocal profilometer is used to detect the roughness of the steel surface before and after the laser treatment,the roughness of the textured steel before and after the sanding treatment,and the texture depth.The surface morphological features of the laser-treated steel,surface characteristics of the textured steel after sandpaper grinding or without sandpaper grinding,and the shear bonding fracture characteristics of the specimens are examined using scanning electron microscopy(SEM).A finite element model is constructed based on the design parameters and test data(texture width,spacing,and depth)to study the influence of the texture shape on the stress distribution of the adhesive layer between the steel and wood and the trend of the bond strength between the steel and timber.The law and mechanism of influence of the steel surface texture on the bonding strength of steel and wood are summarized.The results showed that the microtexture processed on the steel surface by the laser could effectively increase the surface roughness of the steel.The rough surface expands the contact area between the adhesive and steel.This promotes the mechanical interlocking of the adhesive and steel,thereby improving the bond strength between steel and wood.The numerical simulations and experiments showed that the texture shape affects the roughness of the steel surface and the body of the“glue nail”formed by the adhesive penetrating the micropores,which plays a controlling role in the adhesion of the bond to the steel.Under the same laser setting and texture design parameters(width and spacing),the groove texture improved the roughness more than the square texture,which was more conducive to increasing the bond strength between the adhesive and steel.The laser melts existing around the surface can increase the roughness and hinder the bond failure of the glue in the shear direction to a certain extent,which is conducive to improving the bond strength between the adhesive and steel.The research results can provide technical support for enhancing the bonding strength of steel and wood and provide a new idea for the application and design of texture in steel-wood composite components formed by gluing.
作者
林宇杰
柏亚双
徐国林
李洪毅
LIN Yujie;BAI Yashuang;XU Guolin;LI Hongyi(College of Civil Engineering,Southwest Forestry University,Kunming 650224,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2024年第1期216-224,共9页
China Surface Engineering
基金
国家自然科学基金(52268051,51768065)。
关键词
激光表面处理
微织构
粘接强度
胶接钢-木组合构件
laser surface treatment
micro-texture
bonding strength
bonded steel-wood composite member
