摘要
为了模拟部分预应力混凝土(partially prestressed concrete,PPC)梁疲劳裂缝扩展过程,建立在疲劳荷载作用下PPC梁裂缝宽度数值计算模型。首先,以静载黏结应力-滑移关系为基础,提出非预应力钢筋疲劳黏结应力-滑移关系;然后给出疲劳荷载作用下开裂截面非预应力钢筋应力计算方法,重点考虑不同类型受拉钢筋之间的应力重分布、累计残余应变(混凝土和非预应力钢筋)及受拉钢筋面积损伤的影响。最后,基于黏结-滑移理论,建立疲劳裂缝宽度计算模型,并利用2组(H1和H2组)PPC梁疲劳试验对其进行验证。研究结果表明:裂缝宽度计算值与试验结果吻合较好,同时对于低配筋率的H1组试验梁而言,利用该模型得到的裂缝宽度相对保守,因此,适于PPC构件的抗疲劳设计及验算参考使用。
In order to simulate the propagation process of fatigue crack of partially prestressed concrete（PPC） beams, a numerical calculation model for the crack width of PPC beams under fatigue loading was developed. Firstly, on the base of the bond-slip relationship under monotonic loading, a fatigue bond-slip relationship of the non-prestressed reinforcement was established. Secondly, a method was presented to obtain the non-prestressed steel stress in the cracked section under fatigue loading, which took into account the effect of changing steel stress due to the stress redistribution between the different types of the tensile reinforcement and cumulative residual strains（including concrete and non-prestressed reinforcement） and area damage of the tensile reinforcement. Finally, an analytical model for estimating the fatigue crack width was developed by using the bond-slip theory. The model was illustrated by two tests（H1 and H2series） of PPC beams under fatigue loading. The results show that good agreement between analytical and experimental results for the fatigue crack of PPC beams is observed. Meanwhile, for the beams of series H1 with the lower reinforcing index, the fatigue crack prediction is relatively conservative. Therefore, the analytical model can be applied to fatigue design and fatigue assessment.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第11期3977-3985,共9页
Journal of Central South University:Science and Technology
基金
国家高技术研究发展计划("863"计划)项目(2007AA11Z133)
辽宁省教育厅科技计划项目(2008T231)~~
