开槽混凝土夹芯板受弯状态开裂荷载分析

Cracking load analysis of slotted concrete sandwich panels under bending condition

为了减弱裂缝对混凝土结构承载能力以及耐久性的影响,提出了开槽混凝土夹芯板;研究了槽深以及开槽位置对于夹芯板吊装以及正常使用过程中开裂行为的影响,通过ABAQUS建立了有限元模型并验证了其可靠性,在此基础上以槽深以及开槽位置为变量进行了参数化分析,最后通过理论公式对模拟结果进行对比验证。结果表明:在有效控制裂缝位置的前提下,对夹芯板板底合理开槽不会导致其在吊装过程中产生裂缝;在两端简支条件下,开槽构造主要影响夹芯板的开裂荷载,而对于极限荷载影响较小;在裂缝发展的前中期,通过设置适当的槽深以及位置,由于应力集中效应可使得夹芯板拉应力在槽及其附近达到较大值,从而达到控制裂缝产生位置的效果;随着槽深以及槽数量增加,裂缝产生位置得到有效控制,但将导致夹芯板开裂荷载减小。

In order to reduce the impact of cracks on the bearing capacity and durability of concrete structures,slotted concrete sandwich panels were proposed.The effects of slot depth and position on the cracking behavior of sandwich panels during lifting and normal use were studied.A finite element model was established using ABAQUS and its reliability was verified.Based on this,parametric analysis was conducted using slot depth and position as variables.Finally,the simulation results were compared and verified using theoretical formulas.The results show that on the premise of effectively controlling the location of cracks,reasonable slotting of the bottom of sandwich panel will not cause cracks to occur during lifting process.Under the condition of simple support at both ends,the slotted structure mainly affects the cracking load of sandwich panel,and has a relatively small impact on the ultimate load.In the early stage of crack development,by setting appropriate slot depth and position,the stress concentration effect can cause the tensile stress of sandwich panel to reach a large value in the slot and its vicinity,thereby achieving the effect of controlling the location of crack generation.As the depth and number of slot increase,the location of cracks is effectively controlled,but it will lead to a decrease in the cracking load of sandwich panel.