摘要
由于混凝土的弹性模量与龄期有关，计算混凝土结构施工期徐变应力时，必须将时间划分为一系列时段，在每一时段都要建立和分解刚度矩阵，计算量非常大。本文提出一种迭代法，用一个与时间有关的对角阵和一个与时间无关的长期刚度矩阵的乘积作为近似刚度矩阵，由此产生的失衡力通过迭代消除。根据本文给出的对角阵取值方法，只要迭代三四次就可以得到满意的计算结果。在间歇期内的所有计算时段，长期刚度矩阵只要形成和分解一次，而对角阵的求逆运算相当简单，所以选代法所需计算量很少，当增加新的浇筑块时，本文利用三角形分解的特点，只要花少量计算量就可完成对新的长期刚度矩阵的形成和分解，使整个施工期徐变应力计算工作得到极大简化。
In creep stress analysis of concrete structures during construction period , the necessity to as-semble and decompose a large stiffness matrix for each time increment makes the computation verylengthy. In this paper , an iterative method is presented for the creep stress analysis. The stiffness matrix is approximated by a product of time-dependent diagonal matrix and a time-independent longtimestiffness matrix , and the consequent unbalance forces are eliminated by iteration. Following the wayof selection of the diagonal matrix given in this paper , satisfactory results can be obtained after 3-4iterations. The longtime stiffness matrix is assembled and decomposed only at the first time incrementof intermission , and the inverse operation of the diagonal matrix is quite simple. So the iterativemethod is very efficient. When a fresh concrete block is constructed, a few computation is done to de-compose the updated longtime stiffness matrix by the characteristics of the triangular decompsition ,which greatly simplifies the creep stress analysis for total construction period.
出处
《长江科学院院报》
CSCD
北大核心
1995年第1期45-50,共6页
Journal of Changjiang River Scientific Research Institute
关键词
混凝土结构
施工期
徐变应力
迭代法
creep stress
iterative method
construction period
concrete structure
