A Study of Temperature and Aging Effects on Eigenfrequencies of Concrete Bridges for Health Monitoring

• 作者: Arno Zuerbes Jean Mahowald Sebastian Schommer Stefan Maas Viet Ha Nguyen
• 来源期刊: 工程(英文)(1947-3931)
• 学科: 医学
• 关键词: DAMAGE Detection LONG-TERM Monitoring EIGENFREQUENCY AGING TEMPERATURE
• 年，卷（期）: gc-eng_2017,（5）
• 页码范围: 396-411
• 页数: 16页
• 分类号: R73

摘要

This paper discusses the influence of environmental factors and of normal material aging on the eigenfrequencies of concrete bridges based on monitoring data registered during 4 years of a specific bridge. It is a new composite steel-concrete bridge built in 2006 in Luxembourg. The measurements are analyzed and compared to literature data. The final objective is the use of real monitored eigenfrequencies for structural health monitoring and damage detection based on identification of stiffness losses in practical applications. Therefore, it is very important to identify and compensate for outdoor influences namely temperature, excitation force level and normal aging effects, like creep and shrinkage of concrete and their impact on material properties. The present paper aims at describing these effects in order to separate them from damage effects. It is shown that temperature change rates and temperature gradients within the bridge have an influence on the eigenfrequencies. Hence the key idea for assessment from the full database is to select only measurements with small temperature differences and slow temperature change rates.