模数式伸缩装置中梁和支承梁疲劳寿命分析

Fatigue Life Analysis of Middle Beam and Supporting Beam in Modular Expansion Device

伸缩装置是公路桥梁的重要附属构件,其长期承受车辆荷载作用,容易产生疲劳破坏。基于某城市桥梁实测交通量建立车辆荷载谱,采用数值分析方法并基于miner疲劳累计损伤理论估算模数式桥梁伸缩装置中梁“王”字钢梁以及支承梁的疲劳寿命,同时分析支承梁间距和中梁截面刚度对中梁疲劳寿命的影响,主要得出以下结论:(1)中梁截面为80×120 mm,支承梁间距为1.5 m时,中梁疲劳寿命为19.5年,支承梁的疲劳寿命为136.6年;(2)减小支承梁间距和增大中梁截面刚度均可显著提高中梁的疲劳寿命。

Expansion device is an important component of highway bridge,which can bear the load of vehicles for a long time and is prone to fatigue damage.Based on measured traffic of a city bridge,the vehicle load spectrum was establish.This paper estimated the fatigue life of middle beam and supporting beam by numerical analysis method and based on the miner fatigue cumulative damage theory.The influence of the spacing of the supporting beams and the stiffness of the middle beam section on the fatigue life of the middle beam was analyzed.The study results shows that:(1)When the beam section is 80 mm×120 mm and supporting beam spacing is 1.5 m,the fatigue life of middle beam is 19.5 years,and the fatigue life of supporting beam is 136.6 years;(2)The fatigue life of the middle beam can be significantly improved by reducing the spacing of the supporting beams and increasing the section stiffness of the middle beam.