太阳能塔气弹模型结构优化研究

以一座243 m高的太阳能塔为工程背景,采用ANSYS软件建立了原型结构的有限元模型,进行了动力特性分析,得到了气弹模型设计频率和振型目标参数。采用集中刚度法设计了该塔的多自由度气弹模型,对气弹模型的主要结构参数进行了优化研究。采用优化值制作了太阳能塔气弹模型,并进行了模型的动力参数识别,以验证模型设计和制作的合理性。结果表明,圆环型芯梁可有效减小芯梁质量,增加外衣壁厚,降低模型加工难度;适当增加相邻圆盘间距可增加外衣的稳定性,且对模型频率影响较小;调整集热筒底盘厚度对集热筒与塔身的连接刚度有明显影响;太阳能塔气弹模型较精确地模拟了原型结构前3阶频率及振型,且模型实测初始阻尼比小于0.30%。

Structural optimization of the solar tower aero-elastic model

Based on the engineering background of a 243 m high solar tower, the finite element model of the prototype structure was established by using ANSYS, and its dynamic characteristics were systematically investigated to obtain the frequency and mode parameters for aero-elastic model design. A multi degree of freedom aero-elastic model of the tower was designed by using the concentrated stiffness method, and the optimization designs with respect to the main structural parameters of the aero-elastic model were performed. Using the optimal structural parameters, an aero-elastic model was built and its dynamic parameters were identified to verify the rationality of the model design and building. The results show that toroidal cross-section can effectively reduce the mass of the core beam and increase the thickness of outer wall, thereby reducing the difficulty of model fabrication. Reasonable increase in the distance between adjacent circular plates improves the stability of the outer wall and has little effect on the model frequencies. The thickness of the collector chassis has a significant impact on the connection stiffness between the collector and the tower. The first three frequencies and mode shapes of the prototype solar tower can be accurately simulated by the aero-elastic model, and the measured initial damping ratio of the model is less than 0.30%.