摘要
针对翘起情况的裸露悬跨管道,建立考虑轴向力影响的刚性土壤支承的悬跨管道模型。利用小挠度梁理论,推导出脱离土壤的翘起段和悬跨段管道在自重作用下的变形和内力公式。以静弯曲挠度为振型函数,用能量法给出第1阶固有频率。对简支梁、固支梁和文本模型在含有轴向力情况下的静变形和第1阶振动频率进行了对比研究。研究表明:该文模型与考虑土壤变形的裸露悬跨管道的变形偏差不大,内力偏差很小。与现有规范推荐的简支梁和固支梁模型相比,该文模型更能反映裸露悬跨管道的实际情况。该文提供的介于简支梁和固支梁中间的新模型可简化裸露悬跨管道的内力和固有频率计算,弥补了现有推荐做法的不足。
For a rising upward case of an unburied spanning pipeline,a new pipe model with an axial force on rigid soil is built.With small deflection beam theory,the deformations and internal forces formulae of the separated segment rising from supported soil and the spanning segment are derived under self-weight loading.Setting the static deflection as a modal function,the first order natural frequency formula is given by the energy balance method.The static deflections under self-weight and the first order natural frequency of a simply supported beam,a fixed-fixed supported beam and the presented model are compared under an axial force case.The research shows that the present model leads to a small difference in deflection and a very small difference in internal forces from the spanning pipeline model considering the soil deformation.Comparing with the simply-supported model and fixed-fixed model recommended in the present rules,the presented model is more reasonable both in static and free vibration characteristics for an unburied spanning pipeline.The recommended model and the formulae provide a calculation for the both internal force and natural frequency of the unburied spanning pipeline with the model as a simply-supported beam model or a fixed-fixed beam model,or in between them,and also complement the inadequacy in the present rules.
出处
《工程力学》
EI
CSCD
北大核心
2011年第12期87-91,共5页
Engineering Mechanics
基金
天津工业大学科研开发基金项目(029519)
教育部先进纺织复合材料重点实验室开放基金项目(2007ATC001)
关键词
悬跨管道
裸露悬跨
小挠度理论
自由振动
固有频率
spanning pipeline
unburied spanning pipeline
small deflection theory
free vibration
natural frequency
