混凝土受拉损伤本构关系的研究

Damage model for concrete under tension

尽管混凝土的基本破坏机理是微开裂 ,但是混凝土在受拉与受压时破坏机理仍有所区别。基于不可逆过程热力学 ,在已有受压损伤模型的基础上建立了混凝土受拉损伤模型。在模型中假定受拉与受压的差别主要表现在损伤演化上。在处理拉压应力同时发生的情形时 ,引入拉压相关因子COR,定义等效应力σeq=CORσ + +σ - ,仍采用受压的本构关系 ,只在考虑损伤演化时用等效应力代替Cauchy应力。

The failure mechanism of concrete under tension differs from that under compression In this paper, damage models for concrete under tension are developed within the general framework of continuum thermodynamics for irreversible process with internal variables It is supposed that damage evolution equation of tension differs from that of compression A simple and convenient method is proposed to account for the interaction between tension and compression COR an interaction factor is introduced Equivalence stress σeq=CORσ+σ- is defined Only equivalence stress σeq takes place of Cauchy stress σwhen evolution of damage D is derived Comparisons between the model and experimental results of Kupfer and of Zhang agree well