Vibration analysis of wind tunnel support

In order to enable a wind tunnel support to have a high enough natural frequency to prevent experiencing mechanical resonance and excessive vibration displacement, five kinds of wind tunnel support structures have been simulated and analyzed individually under five different load conditions by means of a nonlinear finite element numerical method. With natural frequency and three directions vibration displacement given, simulation and analyses indicated that additional supports is more beneficial than heightening the rigidity of steel reinforced concrete in support pillars and adopting steel wrappers on the pillars to increase natural frequency of support structure. Increasing the rigidity of steel reinforced concrete, adopting steel wrappers and providing additional supports are all helpful in reducing three directions vibration Max displacement. and additional supports are comparatively more effective. Therefore, a structure scheme with steel reinforced concrete support pillars, steel wrappers and additional supports should be adopted in practical wind tunnel support construction.

混合结构吸热塔抗震性能振动台试验研究

作为安全等级一级的构筑物,吸热塔结构具有质心高、荷载大、低阻尼的特点,设备本身易产生较大附加弯矩,在地震作用下易产生鞭梢效应,因此对该结构抗震性能的研究十分重要。以某242.7 m高,下部为混凝土、上部为钢构件的混合型吸热塔为研究对象,根据SAP 2000有限元软件的模拟结果,确定缩尺模型的简化设计方案,按缩尺比1∶20设计并加工制作了等效缩尺模型,并进行三向地震动输入的振动台试验。测试了模型的动力特性及在不同水准地震波作用下结构的加速度、位移及应变响应,结合有限元分析验证了模型设计和加工的合理性,并分析了模型的破坏情况和地震响应规律。试验结果表明:在多遇、设防、罕遇地震作用下结构最大位移角分别为1/516、1/281、1/145,说明该类型结构抗震性能满足其性能设计要求。混凝土底部和中部变截面位置为相对薄弱环节,钢结构部分鞭梢效应明显,需要予以注意。