【摘要】 准确的模态频率测试是基于动力特性损伤识别的基础,而环境因素(特别是温度)会引起模态频率显著变化,造成损伤识别方法失效。文中以钢筋混凝土简支梁为研究对象,通过定量对比混凝土弹性模量、几何尺寸、边界条件、温度自应力变化对模态频率的影响程度,阐明了温度影响钢筋混凝土简支梁模态频率改变的内在机理。结果表明,混凝土弹性模量的温度依存性是造成模态频率变化的主要原因。更多还原

【Abstract】 Accurate modal frequency testing is the basis of dynamic-based damage identification. However, environment factors(temperature in particular) has been widely demonstrated to produce significantly change in modal frequency that lead to the failure of damage identification techniques. In this paper, the reinforced concrete simply supported beam is selected as research object. The influence of change in concrete elasticity modulus, physical dimension, boundary condition, temperature self-restrained stress is comparatively analyzed. And the mechanism of temperature effect on modal frequency is clarified. The results show that temperature dependence of concrete elastic modulus is the most important reason causing the change of modal frequency.更多还原