水碱盐溶液浸泡对碳纤维拉挤板材抗弯疲劳性能的影响

发布时间：2018-04-17 17:08

本文选题：CFRP拉挤板材 + 湿热老化　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：碳纤维增强树脂复合材料(CFRP,Carbon Fibre-Reinforced Plastic)具有轻质高强、耐腐蚀等优异性能,被广泛应用于土木工程结构的加固、修复或升级。在上述应用服役过程中,CFRP材料不仅面对严苛的室外环境(如湿热、浸泡等),同时还将受到循环荷载的作用(如CFRP加固桥面板受到的车辆循环荷载等)。CFRP在严苛环境及循环荷载作用下的性能演化对CFRP材料及其增强结构的服役寿命具有重要影响。鉴于此,本文拟研究水或强碱溶液(混凝土渗出水)浸泡对CFRP拉挤板材抗弯疲劳寿命性能的影响规律与机理,研究结果将促进高性能CFRP板材的研发及其土木工程安全应用。首先,本文整理归纳了国内外湿热老化对CFRP复合材料疲劳性能的研究进展;测试了两种环氧树脂基体的CFRP拉挤板材的基本力学与热性能;最后,研究了不同温度下水、碱溶液和海水浸泡对CFRP静态力学性能及疲劳性能的影响规律与机理。研究结果表明,水碱盐溶液浸泡导致CFRP板材的静态力学性能出现不同程度的退化;浸泡导致树脂-碳纤维界面粘结性能强度明显降低,但对CFRP的宏观性能(弯曲强度和弯曲模量)影响较小;由于吸收水分的塑化作用,导致CFRP玻璃化温度随浸泡时间增长逐渐降低。水碱盐溶液对CFRP板材力学性能的影响相近;温度升高,CFRP材料性能退化加速;另外,普通环氧树脂基CFRP拉挤板材浸泡后性能保持率好于海因树脂基CFRP拉挤板材。CFRP拉挤板材的弯曲疲劳结果表明,两种CFRP拉挤板材的弯曲疲劳破坏过程可以包含两阶段的刚度退化;CFRP拉挤板材抗弯疲劳的S-N疲劳寿命曲线表明,海因树脂基CFRP拉挤板材的弯曲疲劳性能优于普通环氧树脂基体CFRP板材。溶液浸泡后,CFRP拉挤板材中树脂基体发生开裂、碳纤维与树脂的界面产生脱离和分层,缩短了第一阶段刚度退化过程;海水浸泡导致海因树脂基CFRP拉挤板材疲劳性能的退化较普通环氧树脂基CFRP拉挤板材更为明显。
[Abstract]:Carbon fiber reinforced resin (CFRP) carbon Fibre-Reinforced plastic has been widely used in strengthening, repairing and upgrading of civil engineering structures for its excellent properties such as lightweight and high strength, corrosion resistance and so on.In the service of the above applications, CFRP materials not only face harsh outdoor environment (such as damp and heat),Soaking in the same time will also be affected by the cyclic load (such as the cyclic load on the deck of the bridge strengthened by CFRP and so on.) the evolution of the performance of the CFRP under harsh environment and cyclic load has an important influence on the service life of the CFRP material and its reinforced structure.In view of this, this paper intends to study the influence of water or strong alkali solution (concrete seepage water) on the flexural fatigue life of CFRP extruded sheet. The research results will promote the research and development of high performance CFRP sheet and its safety application in civil engineering.First of all, this paper summarized the research progress of CFRP composite fatigue properties caused by wet and thermal aging at home and abroad, tested the basic mechanical and thermal properties of two kinds of epoxy resin matrix CFRP pullout plates, finally, studied the water at different temperatures.Effect of alkali solution and seawater immersion on static mechanical properties and fatigue properties of CFRP.The results show that the static mechanical properties of CFRP plates degrade in varying degrees due to soaking in aqueous solution, and the bond strength at the interface between resin and carbon fiber decreases obviously after soaking.However, it has little effect on the macroscopic properties (bending strength and modulus) of CFRP, and the glass transition temperature of CFRP decreases with the increase of soaking time due to the plasticizing effect of absorbing water.The effect of aqueous alkali-salt solution on the mechanical properties of CFRP sheets is similar; the degradation of properties of CFRP materials is accelerated with the increase of temperature; in addition,The results of bending fatigue of ordinary epoxy resin based CFRP extruded sheet show that the retention rate of properties is better than that of Hydrin resin base CFRP pultrusion plate.The bending fatigue failure process of two kinds of CFRP pullout plates can include two stages of stiffness degradation. The S-N fatigue life curve shows that the bending fatigue life of the two CFRP pullout plates can be obtained.The flexural fatigue property of CFRP extruded board is better than that of common epoxy resin matrix CFRP sheet.After soaking in solution, the resin matrix cracks in CFRP extruded sheet, the interface between carbon fiber and resin is separated and delaminated, and the first stage stiffness degradation process is shortened.The degradation of fatigue properties of CFRP extruded board based on sea water is more obvious than that of CFRP extruded plate based on common epoxy resin.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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