中文摘要：

损伤是影响承载钢结构性能最重要的因素,及时、准确地诊断承载钢结构的损伤是保证系统安全可靠的前提。根据模态柔度比固有频率或振型对损伤更敏感的特点,提出了基于柔度矩阵的单位载荷变形差值曲率法识别承载钢结构的损伤。该方法将基于动力的柔度和静力测试中的变形结合起来,以动力测试数据反映结构静力特征的变化,当有损伤或损伤增大的时候,单位载荷变形差值曲率有更明显的变化。首先,建立了低阶的模态观测数据与柔度矩阵的表达式。其次,推导了单位载荷变形与柔度矩阵的关系,结合曲率模态和变形差值的思想,提出了基于单位载荷变形差值曲率识别承载结构损伤的方法。最后,通过对承载钢结构模型的损伤识别得出：该方法所需模态信息量小,只需一阶频率和振型信息即能够准确定位单损伤、两损伤;对于多损伤可以识别,精度有所下降,但基本可以满足工程要求。

英文摘要：

Damage is the most important factor that influences the capacity of load-carrying steel structures. To diagnose damage precisely and in time is premise to ensure the safety and reliability of the system. Because flexibility is more sensitive to damage than natural frequency and mode shape, a novel method based on deformation difference curvature in unit load from flexibility matrix is proposed for damage identification for load-carrying steel structures. The opinion of dynamic flexibility and static de- formation are combined into this method, so changing in static characteristics can be reflected when dynamic test dada changed. And deformation difference curyature in unit load will be changed more obviously once damage exist or enlarge. Firstly, flexibility matrix is built according to the low measurement modal data; secondly, the relational expression between deformation in unit load and flexibility matrix are derived; and then, combined the idea of modal curvature and deformation difference, the damage iden- tification method is demonstrated with deformation difference curvature in unit load; finally, damage of load-carrying steel structures model is identified by this method. Results show that single and two-damage can both be identified accurately only using the first frequency and modal shape; multi-damage can also be identified, but the accuracy is declined. On the whole, it is acceptable in engineering.