【摘要】 疲劳强度是进行结构抗疲劳设计的重要力学参量。通过对5组24条碳纤维薄板(CFL)增强RC梁进行三点弯曲常幅疲劳试验,得到了增强梁的容许疲劳寿命和极限疲劳寿命S-N曲线及其相应的表达式,并推定其容许疲劳强度和极限疲劳强度分别为其极限承载力的62%和68%。还给出了新的疲劳寿命曲线的表达形式:载荷做功的功率H与增强梁的疲劳寿命N的关系曲线(H-N曲线),并由此推定了增强梁的容许疲劳强度和极限疲劳强度所对应的功率值。更多还原

【Abstract】 Fatigue strength is an important mechanical parameter for structural fatigue design.In this paper,24 simple supported reinforced concrete(RC)beams strengthened with carbon fiber laminate(CFL)were divided into 5 groups and tested under cyclic bending loads.Based on the fatigue testing results,the S-N curves and the corresponding expressions of permissive fatigue lives and extreme fatigue lives are obtained,respectively.The ratio of permissive fatigue strength to static ultimate strength and the ratio of extreme fatigue strength to static ultimate strength are about 62% and 68%,respectively.Moreover,one new kind of curve is proposed for the fatigue lives of the beams,namely,the relationship curve between power rate of outer work,H,and the fatigue lives,N,is discussed.The values of the power rates corresponding to the fatigue strength of permissive fatigue lives and extreme fatigue lives are respectively established.更多还原