CAJ | 학술논문

纤维增强复合材料(FRP)加固钢筋混凝土(RC)梁的疲劳行为是国内外土木工程界的前沿课题.文中将18根尺寸为1850 mm×100mm×200mm的碳纤维薄板(CFL)增强RC梁分为4组进行弯曲疲劳实验,探讨其疲劳性能.通过理论分析及对上述疲劳实验数据的分析和讨论,按照所提出的CFL增强梁的容许疲劳寿命和极限疲劳寿命的新概念,得到了相应的两类S-N和P-S-N曲线,发现CFL增强梁的容许疲劳寿命和极限疲劳寿命分别是其静载极限强度的65%和67%;推导了增强梁的跨中最大挠度与载荷循环数、单根梁的疲劳寿命及应力水平之间的关系式,在此基础上,提出了一种只需少量循环加载(研究中建议取n=100～1000)的非破坏性弯曲疲劳试验数据就能预测该增强梁疲劳寿命的新方法.最后通过另外3根CFL增强梁的疲劳试验对所提出的寿命预测方法进行了验证.
섬유증강복합재료(FRP)가고강근혼응토(RC)량적피로행위시국내외토목공정계적전연과제.문중장18근척촌위1850 mm×100mm×200mm적탄섬유박판(CFL)증강RC량분위4조진행만곡피로실험,탐토기피로성능.통과이론분석급대상술피로실험수거적분석화토론,안조소제출적CFL증강량적용허피로수명화겁한피로수명적신개념,득도료상응적량류S-N화P-S-N곡선,발현CFL증강량적용허피로수명화겁한피로수명분별시기정재겁한강도적65%화67%;추도료증강량적과중최대뇨도여재하순배수、단근량적피로수명급응력수평지간적관계식,재차기출상,제출료일충지수소량순배가재(연구중건의취n=100～1000)적비파배성만곡피로시험수거취능예측해증강량피로수명적신방법.최후통과령외3근CFL증강량적피로시험대소제출적수명예측방법진행료험증.
The fatigue behavior of RC ( Reinforced Concrete) beams strengthened with FRP ( Fiber Reinforced Polymer ) is an important subject in civil engineering in the world. In this paper, 18 RC beams (1 850mm × 100 mm × 200 mm) strengthened with CFLs (Carbon Fiber Laminates) are divided into 4 groups and are tested to investigate their fatigue behaviors under bending loads. Based on the data of fatigue test and theoretical analyses, S-N and P-S-N curves of the RC beams strengthened with CFLs are obtained according to the new conceptions of permissive and extreme fatigue lives, finding that the ratios of the permissive and extreme fatigue strength to the ultimate static strength are respectively 65% and 67%. The relationships among the mid-span deflection, the loading cycle number, the individual fatigue life and the stress level are then deduced and validated. Afterwards, a new method that only needs some nondestructive experimental data of fatigue (the fatigue load cycles n recommended here is 100 ～ 1000) is proposed to predict the individual fatigue life. The proposed prediction method is finally validated by the fatigue tests of another three RC beams strengthened with CFLs.