在工程中常见一些带有悬吊质量块的结构,例如悬吊锅炉等。在实测中发现这类结构的第一振型上部有向内凹陷的现象。本文把上述结构简化为:由骨架梁支持的厚板,在厚板上悬吊一质量块,并视厚板和悬吊质量块为刚体,视骨架梁为等截面梁。利用梁的弯曲振动理论和复合运动的分析方法,对上述简化模型进行了理论分析,进而对“凹陷现象”找到了理论解释。 In the construction of common structures with suspension mass, such as hanging boilers and so on. In the measurement, it is found that the upper part of the first mode of this type of structure has the phenomenon of inward depression. In this paper, the above structure is simplified as follows: a thick plate supported by a skeleton beam, a mass mass suspended on a thick plate, and considering the thick plate and the suspended mass as a rigid body, the visual skeleton beam is a cross-section beam. Based on the beam bending vibration theory and the composite motion analysis method, the above simplified model is theoretically analyzed, and a theoretical explanation of the “depression phenomenon” is found.