Need to find the length and deflection of bending element

In summary, the task is to find the length and deflection of a pipe so that the stresses are within the allowable limits.
  • #1
Mantas777
4
0
Hi,
I have a task and don't know the good solution. (I add the picture of my task.) I need to find the right length and deflection and to check if the results didn't exceed the allowable stress. I know the value of "q" (force). Also I could choose myself the lenght, but I need to check, if my choice didn't exceed the allowable stress. (The value of allowable stress I also know). But I don't know exactly, which stresses I need to find to compare them with allowable stress? (I hope I explain understandable)
 

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  • #2
Is this task homework related or job related or other? You apparently have a given beam material and size and end conditions and loading, and need to determine max length to keep stresses within allowable?
 
  • #3
This task is job related. I have a pipeline and I need to find the length and the deflection to keep stresses allowable. My pipe material is Steel ST 37,0. There is one old straight pipe, and we project 200m distance new pipe, and we install it from bottom. And from bottom we connect new pipe with old. We do the same at both side of 200m distance. So I need to find the length of that bending and deflection to keep stresses allowable. Pipe dimensions: Diameter DN 300 323,9mm, wall thickness 5.6mm. Also I had calculated already that one metre of pipe weight 43.94kg.
 
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  • #4
I am unsure of your particular task, but if you are just looking for moments and deflections associated with a uniformly loaded beam fixed at one end and free to deflect but not rotate at the other, then look it up in beam tables like
www.engineersedge.com/beam_bending/beam_bending13.htm
since you know loading and allowable stress and can look up properties of pipe, solve for L max. Deflection is what it is, presumably not controlling your design? I don't know if I understand the problem correctly. I certainly don't want to do your design.
 
  • #5
I add the better picture of my task. I need to find the length of bending (L). The deflection is about 1,2m, but it may change when we have bigger length or smaller. So I need to find the length (L) and to keep stresses allowable. I could do that by the 1 or 2 scheme, because it have to give me the same results. But I don't know exactly how should I calculate that.
 

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  • #6
I had the discussion with the man who gives me this task. I could explain now everything better.
I marked the places on the picture, where I have to calculate the stress (red colour). I have to choose myself different length (L) till I will get the maximal stresses. I have to check, what the maximal length (L) could be till I don't exceed allowable stress. (Also I will get to know what is the deflection, because 1.2m it's just preliminary value, after the calculations I will get exact value). But I can't find the formulas which I could use in this situation.
 

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  • #7
Sorry, but i still don't understand what you are trying to do. Are you trying to replace an old 200 m length of pipe with a new one? How is it supported along its length? How will the new one be supported? It is not clear to me what the task is.
 

1. What is the purpose of finding the length and deflection of a bending element?

The length and deflection of a bending element are important factors in determining its structural integrity and performance. By understanding these measurements, engineers and designers can ensure that the element can withstand the necessary amount of load and stress without failing.

2. How do you calculate the length of a bending element?

The length of a bending element can be calculated by measuring the distance between the two points where it is supported or fixed. This distance is known as the span length and is typically denoted as 'L' in equations.

3. What factors affect the deflection of a bending element?

The deflection of a bending element is influenced by several factors, including the material properties (such as elasticity and stiffness), the cross-sectional shape and dimensions, and the applied load or force.

4. How do you measure the deflection of a bending element?

The deflection of a bending element can be measured by using instruments such as a dial gauge or a strain gauge. These instruments can accurately measure the displacement of the element at certain points, which can then be used to calculate the deflection.

5. What are some common methods for determining the deflection of a bending element?

Some common methods for determining the deflection of a bending element include using analytical equations, numerical methods such as finite element analysis, and physical testing. Each method has its own advantages and limitations, and the most appropriate one will depend on the specific application and requirements.

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