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以刚性球撞击钢筋混凝土柱为例,研究了碰撞冲击荷载作用下钢筋混凝土柱的损伤程度评估以及防护技术。在钢筋混凝土柱粘结滑移模型基础之上,提出了一种基于竖向剩余承载力的损伤评估准则,用来判定碰撞冲击荷载下钢筋混凝土柱损伤破坏程度;并定量分析了刚性球质量、初速度与结构柱损伤度的关系。针对复合截面防护的情形,对碰撞冲击荷载作用下钢筋混凝土柱防护前后的动态响应及损伤进行了分析,并对比了外粘钢板及外敷泡沫铝两种防护措施的防护效果。结果表明:刚性球质量及速度在较小范围内时,损伤度的增长速率高于质量及速度的增长速率,且以质量和速度同时增加时损伤度增长最快;当刚性球质量及速度达到一定数值后,损伤度的增长速率一般会低于刚性球质量及速度的增长速率。外粘钢板、外敷泡沫铝两种复合截面防护方法均能有效降低碰撞冲击下钢筋混凝土柱的动态响应及损伤程度,且均能使钢筋混凝土柱的整体破坏模式由弯剪破坏向弯曲破坏转变。
Taking rigid-ball impacting on reinforced concrete columns as an example, the damage degree evaluation and protection technology of reinforced concrete columns under impact impact load were studied. Based on the bond-slip model of reinforced concrete columns, a criterion of damage assessment based on vertical residual bearing capacity is proposed to determine the damage degree of reinforced concrete columns under impact impact loads. The rigid ball mass, Relationship between initial velocity and structural column damage. In the case of composite cross-section protection, the dynamic response and damage of reinforced concrete columns before and after impact were analyzed. The protective effects of two kinds of protective measures, such as externally bonded steel plate and externally applied aluminum foam, were compared. The results show that when the rigid ball mass and velocity are in a relatively small range, the growth rate of damage degree is higher than the growth rate of mass and velocity, and the damage degree increases fastest when the mass and velocity increase simultaneously. When the mass and velocity of rigid ball reach After a certain value, the growth rate of damage degree will generally be lower than the rigid ball mass and velocity growth rate. Two kinds of composite cross-section protection methods such as externally bonded steel plate and externally applied aluminum foam can effectively reduce the dynamic response and damage of reinforced concrete columns under impact impact, and all of them can make the overall failure mode of reinforced concrete columns change from bending shear failure to bending failure.