预应力混凝土无梁屋盖的温度应力分析

Analysis of the Thermal Stress of Prestressed Concrete Girderless Roof

预应力混凝土无梁屋盖在日照和季节温差作用下容易出现开裂现象,为了研究其裂缝成因,针对屋盖所处的工作环境,应用ABAQUS软件,建立了日照和季节温差作用下预应力混凝土无梁屋盖的有限元分析模型,计算得到其应力分布云图.计算表明:这类预应力混凝土无梁屋盖在日照作用下,裂缝主要出现在托板附近,方向平行于托板边缘,托板顶角处的裂缝方向与对应的托板对角线垂直;而在季节温差作用下,裂缝主要出现在后浇带附近,方向平行于托板边缘,且存在贯穿裂缝的可能.

Prestressed concrete girderless roof under solar radiation and seasonal temperature difference is likely to crack.In order to study the mechanism of cracking,two finite element analysis models of the roof were developed with the finite element software ABAQUS.Their stress distribution nephograms were obtained.The results show that this kind of roof generally cracks near the fascias under solar radiation,and the cracking direction is parallel to the edge of the fascias or is perpendicular to the diagonal line of the fascias,while under seasonal temperature difference,the roof generally cracks near the post-pouring strip,and the cracking direction is parallel to the edge of the fascias and the cracks may be penetrating.