正交异性钢桥面铺装层疲劳寿命的断裂力学分析.docx

正交异性钢桥面铺装层疲劳寿命的断裂力学分析黄卫 1林广平 1钱振东 1刘振清 2( 1. 东南大学, 江苏南京 210096; 2. 交通部公路科学研究所, 北京 100088)摘要: 计算和分析正交异性钢桥面铺装层表面裂缝应力强度因子, 在此基础上应用 Paris 扩展公式预测铺装层疲劳寿命。将奇异单元布置在铺装层表面裂缝前沿, 建立正交异性钢桥面系三维断裂力学有限元模型, 计算铺装层 表面裂缝的应力强度因子; 分析裂缝应力强度因子随轴载作用位置的变化规律, 确定了带裂缝铺装层轴载作用的 最不利荷位; 以最不利荷位作为轴载作用的标准荷位, 计算应力强度因子随裂缝扩展深度的变化, 并数值拟合得 到了应力强度因子与裂缝深度的关系式; 将应力强度因子的深度关系式代入 Paris 公式, 积分得到铺装层的疲劳 寿命。计算结果表明, 基于钢桥面铺装层带裂缝工作的事实, 应用断裂力学方法预测钢桥面铺装层疲劳寿命是可 行的。关键词: 正交异性钢桥面板; 钢桥面铺装; 断裂力学; 应力强度因子;Paris 公式;疲劳寿命中图分类号:U443.33文献标识码:A文章编号: 1000-131X ( 2006) 09-0112-06Fr actur e-mechanics analysis of the fatigue life of thepavement on or thotr opic steel br idge decksHuang Wei1Lin Guangping 1Qian Zhendong 1Liu Zhenqing2( 1.South-east university, Nanjing 210096, China;2.Research Institute of Highway, Ministry of Communications, Beijing 100088, China)Abstr act: The stress intensity factor (SIF) for the surface crack of the pavement on orthotropic steel bridge decks is calculated and analyzed. The Paris’formula is employed to forecast the fatigue life of the pavement. A three-dimen-sional fracture-mechanics finite element model of orthotropic steel bridge deck systems is developed. According to the change in the SIF with the change in the loading position of the axle-load, the worst loading position of the axle-load on the cracking pavement of the steel bridge deck is determined, the change in the SIF with the change in the crack depth is analyzed, and the relationship between the SIF and the crack depth is established. The expression of the SIFis substituted into the Paris’formula, and the fatigue life of the pavement is calculated by using an integral of theParis’formula. The result indicates that fracture mechanics can be employed to forecast the fatigue life of the pave- ment on orthotropic steel bridge decks.Keywor ds: orthotropic steel bridge deck; paving of steel bridge deck; fracture mechanics; stress intensity factor;Paris’formula: fatigue lifeEmail: mailto:lgp215@lgp215@箱梁桥建设的一道技术难题。因其复杂的受荷条件,钢桥面铺装层