【摘要】 空冷结构属钢-混凝土混合结构,刚度和质量沿竖向分布极不均匀,与动力设备耦合振动响应明显。通过大比例模型试验和ANSYS软件模拟计算,研究了空冷结构的动力性状和不同工况下不同频率时结构的动位移和动应变响应。结果表明,实测振型与计算模态吻合,扭转效应明显,振型高度耦合,模型频率计算值小于试验值,反推的原型频率值大于原型频率计算值。耦合振动响应测试结果与计算结果基本一致,低阶共振大于高阶共振,风机应避开结构前三阶频率。风机全开产生的动位移不容忽视,但其动应变仍在弹性范围内,应注意疲劳破坏,建议用良好冲击韧性和冷弯性能的钢材和摩擦高强螺栓。更多还原

【Abstract】 Air cooled structure is a steel-concrete vertical hybrid structure and its stiffness and mass is highly non-uniform at vertical direction.Power equipment-structural coupling vibration response is obvious.Air cooled structural dynamic property,its dynamic displacement response and dynamic strain response under different industrial conditions and different frequencies are studied by the experiment with a large-scale model and simulation calculation with ANSYS software.Results show that tested vibration mode tallies with the result of finite element analysis.Its torsion effect is significant.The vibration modes are highly coupled.Calculated model frequency is less than tested model frequency.Back-calculated archetypal structure frequency is larger than calculated archetypal structure frequency.The tested and calculated couple vibration response results are found to be in agreement with calculated results.Its low order resonance response is larger than that of high order.Fan frequency should be kept away from the first structural three frequencies.The structural dynamic displacement under the excitation of all fans can’t be neglected though its dynamic strain is still within its elastic range.Great attention should be paid to fatigue failure,and it is suggested that the steel with better shock flexibility and cold-bent property and bolts with good friction and high strength should be used.更多还原