正交基函数无单元法在高层建筑筏板基础三维温度场中的应用

Application of element-free method based on orthogonal basis function in three-dimensional temperature field of raft foundation of high-rise building

无单元法以其在分析计算中只需要节点信息而不需要单元信息在各领域得到广泛应用,并且能够在不增加前处理基础上,随需要布置不同密度的节点。在无单元伽辽金法基础上对其基函数进行了正交处理,避免了计算过程中可能出现的矩阵不可逆情况,而且编程容易实现且计算效率高。把它应用在高层建筑基础底板混凝土浇筑早期瞬态温度场中,通过对带电梯井的筏板基础三维模型的分析,提取有代表性点的不同部位计算值,将计算结果和有限元模拟值及现场实测数据进行了比较分析,从温度随时间变化的趋势和最高值出现的时间都能很好地反映出无单元法解决这类问题有很好的收敛性。这对进一步进行大体积混凝土温度场和非线性应力场的耦合分析提供了研究基础。

The element-free method is used in various fields because it only needs nodal data and does not need element connectivity.Moreover,the nodes are arranged with different densities as needed without adding pre-processing.By using the orthonormal basis functions,the improved element-free Galerkin method was introduced to analysis the transient temperature field of high-rise building foundation slab during early concrete pouring.The calculated values of different parts of representative points were extracted in the three-dimensional model of the raft with elevator shaft.It is concluded that the calculated results are in good agreement with the monitoring data and the results by the finite element method.This provides a research foundation for further coupled analysis of the temperature field and nonlinear stress field of mass concrete.