噪声与振动控制Issue(4)：148-152,5.DOI:10.3969/j.issn.1006-1335.2014.04.032
不同跨径比的两跨连续梁的模态分析试验
Modal Analysis Test of a Two-unequal-span Continuous Beam
摘要
Abstract
Influence of the span ratio of a two-unequal-span continuous beam on vibration mode is introduced, and the option of impact factor values is discussed. Using a channel-shaped continuous beam as the model, the finite element analysis code of Midas and the equipment of DASP are respectively employed for modal analysis, and the first three modals and frequencies of the continuous beam with different span ratios are obtained. Results of the analyses are compared with those of testing, and the vibration mode change is confirmed. The results demonstrate that (1) with the decreasing of the span ratio, the turning points of the 2nd and 3rd order modals may appear and the curvature of the vibration mode at the mid support will change greatly;(2) when the effect of positive bending moment at the mid-point of the span is considered, the impact factor should be calculated according to the fundamental frequencies shown in the standard of bridge construction;(3) when the effect of negative bending moment at the mid-support is considered, the impact factor should be calculated using the 2nd or 3rd order frequency.关键词
振动与波/连续梁/振型/冲击系数/有限元分析/模态分析Key words
vibration and wave/continuous beams/vibration mode/impact factor/finite element analysis/modal analysis分类
通用工业技术引用本文复制引用
郑仰坤,袁向荣..不同跨径比的两跨连续梁的模态分析试验[J].噪声与振动控制,2014,(4):148-152,5.基金项目
国家自然科学基金（基金编号51078093，51278137）；广州市科技计划项目（基金编号12C42011564）；广州大学土木工程学院硕士研究生创新实验项目 （）
