采用半分离-整体式模型的填充墙干缩开裂过程模拟与分析

Simulation and analysis of infilled-wall cracks’ development by shrinkage using semi-discrete and whole type model

考虑到计算效率,采用"半分离-整体式"计算模型对框架填充墙干缩开裂过程进行了数值模拟,结构模型采用了符合工程实际的二层单跨填充墙结构。对不同柱刚度、开洞率、连接刚度下结构的变形、应力、裂缝规律进行了影响因素的分析。模拟的裂缝形态和宽度与工程实践具有可比性。研究表明:计算时不能忽略自重和竖向荷载作用的影响;干缩一般会导致窗洞等产生非结构性的损坏;不同的柱刚度、洞口率和连接刚度下的裂缝发生位置、发展趋势和变形结果有差异,采用统一的构造措施并不能完全解决问题;对于没有采取任何构造措施的框架填充墙结构在等效温差-5℃下即发生局部的微裂缝,干缩下最终的裂缝宽度预计会超出使用要求范围。最后对干缩作用下的墙体裂缝宽度进行了评价,并补充了若干措施建议。

For computational efficiency, numerical simulation analysis of cracks’ development by dry shrinkage effect has been carried out on a practical meeting two-storey and single span wall-infilled frame structure. FEM models are used as semi-discrete type and whole type. Different column rigidity, opening sizes, and connection rigidity are discribed with deformation, stress, crack development results. The crack morphology and width can be comparable with practice.Gravity and vertical loads should be considered in model. Shrinkage causes large deformation near openings. Different column rigidity, opening sizes and connection rigidity cause different crack development and deformation. The uniform construction detailing is not enough for all. Primary crack of non-constructional detailing wall-infilled frame may happen at -5 ℃ equivalent temperature, and the ultimate crack width can exceed usage permission. At last wall crack width by dry shrinkage is assessed, and some proposals are given.