钢筋混凝土压弯构件的实用疲劳计算方法研究

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关键词钢筋混凝土，压弯构件，疲劳计算，轴压力，钢筋应力幅，疲劳应力中图分类号： 文献标志码：A DOI： 10.15935/j.cnki.jggcs.202503.0006

AbstractTo study the fatigue property of reinforced concrete （RC）compression-bending members，on the basis of combing the fatigue analysis method of RC bending members in the current codes，this paper deduces the practical fatigue calculation method of RC compresson-bending members based on plane section assumption and the conversion crosssection method.Based on the fatigue analysis method proposed in this paper，the necesity of fatigue calculation of compression-bending components is illustrated by engineering examples.The influence of axial pressure，tensile reinforcement area，concrete strength grade on fatigue calculation results is studied.The influence offatigue load on structural deflection is studied.The results show that forreinforced concrete compresson-bending members，the stressamplitude of steel bar in the tension zone and the maximum stress of concrete fiber at the edge of the compression zone will be significantly overestimated according to the fatigue calculation method of RC bending members.Whenthe bending moment of the section is fixed，the increase of theaxial force of the section can effectively reduce the fatigue stress of the tensile steel bars and increase the fatigue stress amplitude limit ofthe steelbar，but it has no efectonthe fatigue stress amplitude of the tensile steel bars.Fatigue stress can be effectively reduced by increasing the area of tensile bars，while the area of the compression bars and the strength grade of concrete have no effect on fatigue stress.The influence coeffcient of deflection increase considering the long-term effct of load in concrete specification cannot fully reflect the influence of long-term fatigue load.

KeywordsReinforced concrete，compresion-bending members，fatigue analysis，axial force，fatigue stress amplitude，fatigue stress

0 引言

在铁路公路工程中，钢筋混凝土构件除承担普通静载作用外，还承受车辆荷载、列车风荷载等长期疲劳荷载作用。（剩余13647字）