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钢结构在运行一段时间后,其母材或焊缝附近易产生裂纹,因此需要对裂纹进行修复以延长使用寿命.文中研究了碳纤维增强复合材料(CFRP)加固裂纹钢板的疲劳寿命及加固参数.首先采用粘结力理论,建立CFRP加固裂纹钢板的有限元模型,计算得到裂纹尖端的应力强度因子;然后进行4组对比疲劳试验,利用试验数据和Paris公式计算材料常数C和n,将计算的应力强度因子代入Paris公式预测试件的疲劳寿命;最后利用有限元模型对CFRP加固的刚度、长度、宽度等加固参数进行了研究.结果表明:根据有限元模型计算的应力强度因子幅和Paris公式可以准确预测CFRP加固裂纹钢板的疲劳寿命;CFRP加固可以减小裂纹尖端的应力强度因子,有效提高裂纹钢板的疲劳寿命.
After the steel structure is operated for a period of time, cracks easily occur near the base metal or weld, so the crack needs to be repaired to prolong the service life.This paper studies the fatigue life and strengthening parameters of CFRP reinforced cracked steel plate. Firstly, the finite element model of CFRP strengthened cracked steel plate is established by using the theory of bond force, and the stress intensity factor of the crack tip is calculated. Then four groups of comparative fatigue tests are carried out, and the material constants C and n are calculated by using the experimental data and the Paris formula. Stress intensity factor into the Paris formula to predict the fatigue life of the test piece.Finally, the finite element model was used to study the reinforcement parameters such as stiffness, length and width of the CFRP reinforcement.The results show that according to the finite element model calculated stress intensity factor amplitude and Paris formula Which can accurately predict the fatigue life of CFRP strengthened cracked steel plate. The CFRP reinforcement can reduce the stress intensity factor at the crack tip and effectively improve the fatigue life of the cracked steel plate.