冲击荷载作用下钢结构表面涂层的接触损伤

针对内蒙古中西部地区钢结构涂层长期遭受风沙颗粒冲击损伤的问题,采用自动球压冲击仪研究了钢结构聚氨酯涂层与氟碳涂层在冲击荷载下的损伤行为,并应用体式显微镜和超景深三维显微镜研究了钢结构涂层的冲击损伤形貌.结果表明:随着冲击高度的增加,钢结构涂层的冲击荷载峰值增大,二次冲击荷载峰值增大,二次冲击的时间间隔延长;氟碳涂层冲击荷载峰值与二次冲击荷载峰值均小于聚氨酯涂层,氟碳涂层抗冲击能力优于聚氨酯涂层;氟碳涂层的压痕尺寸的增长速率小于聚氨酯涂层,所承受的极限荷载值却大于聚氨酯涂层;冲击荷载下氟碳涂层未出现材料的堆积隆起,无明显的环向裂纹,径向裂纹较聚氨酯涂层少,裂纹宽度较细;相同冲击高度(34cm)下,氟碳涂层冲击压痕深度较聚氨酯涂层下降76%,压痕宽度明显小于聚氨酯涂层.

Contact Damage of Steel Structure Coatings under Impact Loading

Aiming at the problem of impact damage of steel structure coating caused by wind blown sand particles in a long time in the central and western of Inner Mongolia, an automatic impact ball pressure instrument was used to study damage behaviors of steel structure coatings. The impact damage morphology of steel structure coatings was studied by body microscope and super depth of field three dimensional microscope. The research shows that with the increase of impact height, the peak value of impact load of steel structure coatings increases, the peak value of secondary impact load increases, and the time interval becomes longer. The peak value of impact load and secondary impact load of fluorocarbon coatings are lower than that of polyurethane coatings, and the impact resistance of fluorocarbon coatings is better than that of polyurethane coatings. The indentation size growth rate of fluorocarbon coatings is lower than that of polyurethane coatings, but the ultimate load of fluorocarbon coatings is higher than that of polyurethane coatings. Under impact loading, no accumulation of material is observed on the surface of fluorocarbon coatings. There are no obvious circumferential cracks, less radial cracks and finer crack width than that of polyurethane coatings. At the same impact height(34cm), the indentation depth of fluorocarbon coating is 76% lower than that of polyurethane coating, and the indentation width is much smaller than that of polyurethane coating.