Research On Distinguish Damnify From Span Continuous Rigid Frame Bridges By MSECR

As a bridge across the structure, on the economic and social development has played a pivotal role. The end of 2010, China's total mileage will reach 2.3 million km, of which 65,000 km expressways by 2020, China's vehicle population will be over 100 million. With the rapid development of the transport sector, the bridge project has also been great development. China now has about 500,000 various types of bridges, bridge construction started a year for a thousand seats, China is the world's "Bridge Liang Daguo" to "bridge power" forward。Because congenital damage, injury and acquired damage native existence of structural damage caused by the bridge. Some experts believe the domestic use of the bridge more than 25 years entered the stage of aging, it is estimated that our bridge has about 40% of the total belong to this category. At this stage, the bridge health monitoring, damage identification and condition assessment to ensure that the structure of the safe operation within the design life has become a concern. The vibration damage assessment method applicable to the overall damage assessment of complex structures.This article describes the current status of damage detection research, methods, and some of the conclusions, the main contents of this issue. Outlines the calculation method of vibration parameters, focusing on the modal strain energy method. Retrieval of information compiled under the elastic modulus and geometric parameters on the damage sensitivity. As the damping of complex systems is difficult to determine, and measurement error, therefore, this analysis does not consider damping.Suppose after the structural quality structural damage has not changed, only the element stiffness matrix has changed, use the lower element stiffness simulation cell damage, mainly in the reduced elastic modulus to achieve. In this paper, a practical example a unit rate of change of modal strain energy MSECR (ie Modal Strain Energy Change Rating) as a damage detection indicators, continuous rigid frame bridge for a single injury, damage and intensive multi-injury asymmetric numerical simulation shows MSECR can identify the existence of injury, damage location and damage. With the degree of damage, the pier damage than the beam element on the structure of major damage. Because of structural damage and structural materials, structural geometry size, temperature loads, shrinkage and creep of concrete and many other factors, determine the location and extent of structural damage, how to judge the reasons for and take the work injury response remains to be analyzed.