钢结构动力失稳实用分析和监测控制研究

Practical analysis of dynamic buckling of steel structures subjected to combined actions of gravity loading and earthquake excitation will be carried out, emphasizing the thin-walled cross-section warping effect and the importance of non-uniform gravity loading on the adverse effects of the structural dynamic stability. A practical discriminant criteria for dynamic instability based on the structural total energy will be developed. The energy relationship between the structural static instability and dynamic instability will be established. The dynamic instability occurs when the total structural vibration energy under seismic excitation exceeds the critical energy. A practical calculation method for predicting the dynamic instability is proposed, with which the critical acceleration of dynamic instability of steel structures under earthquake excitation can be efficiently estimated. Structural dynamic instabilities are summarized in collapse modes and characteristics, and improvement measures to enhance the structural dynamic stability and countermeasures to prevent the occurrence of dynamic instability collapse are proposed. Furthermore, dynamic instability monitoring and control of steel structures will be carried out, in order to monitor the structural instability of the critical state on line, and to improve the structural dynamic stability with new theories, new methods and new technologies. With dynamic stability monitoring, structural dynamic instability will be identified in advance and warning signals are triggered, preventing structures from dynamic instability and sudden failure. With dynamic stability control, the ultimate capacity and ductility of structural dynamic stability will be improved, reducing the imperfection sensitivity and avoiding sudden instability failure. The project will promote the application of new theories and new technologies, and improve the reliability of steel structures under disastrous dynamic loading.

进行钢结构在重力荷载和地震共同作用下的动力失稳实用分析，强调薄壁截面翘曲效应，重视非均布重力荷载对结构动力稳定性的不利影响。推广基于结构总能量的动力稳定性实用判别准则：建立结构静力失稳与动力失稳之间的能量关系，在地震激励下当结构振动的总能量超过临界能量时，判别为动力失稳。提出预测动力失稳的实用计算方法，可高效地估算地震作用下钢结构动力失稳的临界加速度。总结结构动力失稳破坏的形式和特征，提出改善、提高结构动力稳定性的措施和防止发生动力失稳破坏的对策。进一步开展钢结构动力稳定监测和控制研究，探索及时监控结构稳定临界状态、主动改善结构动力稳定性的新理论、新方法和新技术。通过动力稳定监测，实现结构动力失稳的早期识别和预警，预防结构发生突然失稳破坏；通过动力稳定控制，有效地提高结构动力稳定承载力和延性，降低缺陷敏感性，避免失稳突发性。促进新理论、新技术的应用，提高钢结构在灾难性动力荷载下的可靠性。

进行钢结构在重力荷载和地震共同作用下的动力失稳实用分析，考虑非均布重力荷载缺陷对结构动力稳定性的不利影响。推广基于结构总能量的动力稳定性实用判别准则：建立结构静力失稳与动力失稳之间的能量关系，在地震激励下当结构振动的总能量超过临界能量时，判别为动力失稳。提出预测动力失稳的实用计算方法，可高效地估算地震作用下钢结构动力失稳的临界加速度。.开展钢结构动力稳定监测和控制研究，探索及时监控结构稳定临界状态、主动改善结构动力稳定性的新理论、新方法和新技术。通过动力稳定监测，实现结构动力失稳的早期识别和预警，预防结构发生突然失稳破坏；通过动力稳定控制，有效地提高结构动力稳定承载力和延性，降低缺陷敏感性，避免失稳突发性。促进新理论、新技术的应用，提高钢结构在灾难性动力荷载下的可靠性。.设计制作了十个稳定监控部件试件，完成了稳定监控部件试件的滞回性能试验。试验结果分析表明，两端刚接的轴压套管构件具有较好的滞回性能；当试件两端铰接时，内核与套管之间的刚性连接有利于试件获得更好的滞回性能。薄膜压力传感器能够有效地捕捉到内核与套管之间的接触。.设计试制了四个新型限制力装置试件，依次完成了先拉后压大位移往复试验、先压后拉大位移往复试验、先压后拉滞回试验和先拉后压滞回试验。试验结果分析表明，新型限制力装置能够提供双向轴力承载力和刚度，限制力由限制力装置最大允许轴向变形确定；有二次拉断失效的特征，其特殊构造具有抗连续倒塌的功效；等效粘滞阻尼系数随着变形增大而增大，骨架曲线为双线性。新型限制力装置可应用于空间网格结构以满足限制力和耗能减震功能要求，也可作为一种新型屈曲约束支撑和耗能减震装置。