On the stresses on pipes and supports
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This post was last edited by williananm on 2018-9-27 08:05. I have some questions while reading books recently; please help me out. 1. Does the friction force acting on the sliding supports (beams) of a pipeline have a direction? Which direction? Or is it related to the flow direction of the medium? 2. Will the fixed supports (fixing points) of the pipeline be subject to friction, and is it related to the inclination of the pipeline? 3. For ordinary thermal pipelines, structures such as “Z” shapes or three-dimensional configurations may exist; therefore, how should the thrust exerted by the supports be taken into account, and what data need to be provided to the civil engineering team? There is also a directionality. The book I read only covered whether flexibility is met. 4. Formulas can be used to calculate the elastic forces Fx, Fy, and Fz at the fixed points. What is the relationship between these elastic forces and the thrusts acting on the structure, and how should this information be conveyed to the civil engineering team? All of the above are based on manual calculation
1. It is related to the direction of pipe deformation, not to the medium. 2. The fixed bracket has no friction; only a thrust force is generated. 3. It transmits the complete load of the bracket to the civil engineering structure. 4. Elastic force is merely the reaction force resulting from pipe deformation; there are many other forces involved in the overall stress, such as frictional force, blind plate force, and additional loads, etc. PS: Manual calculations are not accurate, especially when simplified formulas are used; they can only be used as a reference, not for actual application. Of course, manual calculation can also be accurate, but it’s completely different from those simplified formulas you see now. Judging from your questions, you seem to be a beginner in piping work. I recommend finding a mentor to guide you and studying books on your own; it’s difficult to get the hang of this field, especially when dealing with those heat pipeline design manuals, which contain many errors.
1. Does the friction force acting on the sliding support (beam) of the pipeline have a direction? Which direction? Or is it related to the flow direction of the medium? Reply: Generally, it is mainly in the axial direction, as the tube expands and contracts; therefore, both directions are possible ； Also, there will be cases where there is an offset in the Y-direction due to friction. 2. Will the fixing brackets of the pipeline (the fixing points) be affected by friction, and is this related to the inclination of the pipeline? Reply: The fixed bracket has no friction; it is a dead point ；