平板贯穿裂纹高强螺栓止裂加固试验研究

Experimental research on crack prevention and reinforcement with high-strength bolts for flat plate through cracks

为了验证高强螺栓止裂对平板贯穿型疲劳裂纹的加固效果,基于有限元模拟探究了高强螺栓止裂加固机理,通过单边裂纹钢板和横隔板足尺模型疲劳试验,验证了高强螺栓止裂加固的有效性,定量比较了高强螺栓规格对修复后钢板疲劳寿命的影响。试验结果表明:单边裂纹钢板高强螺栓止裂加固后的疲劳寿命是传统止裂孔加固的近5倍,螺栓规格(螺栓直径、强度等级)对加固效果影响显著,单边裂纹钢板用10.9级M14高强螺栓止裂的疲劳寿命是8.8级M12高强螺栓的3倍以上。横隔板足尺模型高强螺栓止裂加固后疲劳寿命达到200万次以上,满足规范疲劳强度等级要求。单边裂纹钢板和横隔板足尺模型疲劳试验中,高强螺栓止裂后构件均表现出优异的抗疲劳性能。

In order to verify the reinforcement effect of high-strength bolts on flat plate through-type fatigue cracks, the mechanism of crack prevention and reinforcement of high-strength bolts was explored based on finite element simulation. The effectiveness of crack prevention and reinforcement with high-strength bolts was verified through the fatigue tests of single-side cracked steel plate and the diaphragm plate full-scale model. The influence of high-strength bolt size on the fatigue life of repaired steel plate was quantitatively compared.The test results show that the fatigue life of single-side cracked steel plate after crack prevention and reinforcement with high-strength bolts is nearly 5 times as much as that of traditional crack prevention hole reinforcement. Bolt specifications(bolt diameter, strength grade) have a significant impact on the reinforcement effect. The fatigue life of single-side crack steel plate repaired by 10.9 grade M14 high-strength bolt is more than 3 times of that repaired by 8.8 grade M12 high-strength bolt. The fatigue life of transverse diaphragm full-scale model after crack prevention and reinforcement with high-strength bolts reaches more than 2 million times, which meets the requirements of fatigue strength level in the specification. In the fatigue test of the single-sided cracked steel plate and diaphragm plate full-scale model, the components after the crack prevention with high-strength bolts all showed excellent fatigue resistance.