摘要
通常采用的分时段逐步推进边界元法在分析氯盐对混凝土的侵蚀问题时存在缺陷。为此,研究建立了全时域初值推进边界元法,据此计算了氯盐侵蚀环境中钢筋混凝土结构的服役寿命,分析了氯离子扩散维数对混凝土中氯离子浓度和服役寿命的影响。研究了分时段逐步推进边界元法计算氯离子扩散时产生问题的原因。算例结果表明:混凝土中氯离子扩散的维数将直接影响到混凝土结构的服役寿命,必须在设计中加以考虑。而且,全时域初值推进边界元法可以消除混凝土中氯离子扩散域内的积分项,避免域内离散,因此与分时段逐步推进边界元法相比,能够简化计算格式,提高迭代收敛过程的稳定性和计算结果的精度,减少计算耗时。
The problems rendered from the conventional time marching, referring to stepwise time marching scheme （STMS） adopted in boundary element method （BEM） for chloride diffusion in concrete structures, were investigated, and a new time marching, referring to initial time marching scheme （ITMS） in BEM, was developed for evaluation of service life of the concrete structures under chloride environment. Results of the numerical examples show that the ITMS-BEM proposed can eliminate domain integral and simplify the computational model, so that the stability in iteration process can be improved, resulting in better efficiency and accuracy, compared with the STMS-BEM. It can also be concluded that the dimensions of the diffusion of chloride can affect the service life of the concrete structure significantly, which should be taken into account in structural design.
出处
《土木建筑与环境工程》
CSCD
北大核心
2013年第3期57-62,共6页
Journal of Civil,Architectural & Environment Engineering
基金
国家自然科学基金(51168003)
广西自然科学基金项目(2010GXNSFD169008,2011GXNSFB018013)
广西自然科学基金重大项目(2012GXNSFEA053002)
关键词
混凝土结构
氯盐环境
服役寿命
边界元法
时间进程
concrete structure
chloride environment
service life
boundary element method
timemarching scheme
