基于多测点位移影响线的桥梁损伤识别研究

Research on Bridge Damage Identification Based on Multi-measuring Points Displacement Influence Line

根据位移影响线理论,提出基于多测点的位移影响线差值曲率的桥梁损伤识别方法,实现对桥梁结构损伤前初始数据未知情况下的损伤识别检测.推导了简支梁出现损伤时的多测点位移影响线差值曲率公式,并对简支梁桥结构不同测点位置、不同损伤程度、不同损伤位置及多损伤的情况进行损伤识别分析.为验证该损伤识别指标的适用性,以某固端梁和三跨连续梁为研究对象,建立数值分析模型来进行损伤识别研究.结果表明:该方法可以识别出简支梁桥的损伤位置,对于多处出现损伤也有良好的识别效果;多测点位移影响线差值曲率指标可以用于固端梁和连续梁的损伤识别;仅需利用4个位移测点,不需要损伤前数据,便于实现;损伤识别效果受测点影响,选取合适的测点位置能提高损伤识别的效果.

According to the theory of displacement influence line, a method of identifying bridge damage based on the difference curvature of multi-measuring point displacement influence line was measured, so as to realize the damage detection of bridge structure damage When the initial data is unknown. The difference cur- vature formula of the multi-measuring point displacement influence line is derived, and the damage identifica- tion of simply supported beam bridge structure was analyzed at aspects of different measurement locations, different damage degrees, different damage locations and different damage situations. In order to verify the applicability of the damage identification index, a fixed end beam and three-span continuous beam are taken as the research objects to establish a numerical analysis model to study the damage identification. It is found that the method can identify the damage location of simply supported beam bridge; and for multiple damage it also has a good recognition effect. The difference curvature of the multi-measuring point displacement influence line can be used to identify the damage of fixed end beam and continuous beam. The method only uses 4 dis- placement measurement points, no need data before the injury, so it is easy to be realized. The damage identi- fication results are affected by the measure points; so the appropriate locatoins measuring points should be se- lected so as to improve the effect of damage identification.