- #1

SJB

- 7

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Hi,

Thank you for taking the time to look at my problem.

I am considering a vertical pole fixed in the ground at the bottom and experiencing a horizontal point load at the top. This pole is fixed with guy ropes from the top to the ground at a certain angle. See attached image.

Assuming that the guy rope/cable is of infinite strength then the mode of failure for this arrangement will be that the pole will buckle (correct?). As the tip force P increases as will the force in the guy rope and the resultant vertical force on the pole itself will reach a point where the euler buckling condition is not satisfied...

However it's what happens next that I need to understand. In a normal euler buckling scenario the vertical load is fixed and once the beam has buckled it will collapse. In this case though as the beam begins to buckle (as per image attached) the angle of the guy rope increases and therefore the vertical component of this force gets less. However once the beam has started to buckle it is only able to take a fraction of the vertical load it could pre-buckling.

So, where to go from here? Once the initial buckling load has been satisfied will the beam always collapse? Or, in the right conditions will the pole reach a stable equilibrium with a certain bend? If the latter then how do I go about calculating the actual failure load?

Thank you very much for reading this and any guidance or advise would be very much appreciated.

Thanks

Simon

Thank you for taking the time to look at my problem.

I am considering a vertical pole fixed in the ground at the bottom and experiencing a horizontal point load at the top. This pole is fixed with guy ropes from the top to the ground at a certain angle. See attached image.

Assuming that the guy rope/cable is of infinite strength then the mode of failure for this arrangement will be that the pole will buckle (correct?). As the tip force P increases as will the force in the guy rope and the resultant vertical force on the pole itself will reach a point where the euler buckling condition is not satisfied...

However it's what happens next that I need to understand. In a normal euler buckling scenario the vertical load is fixed and once the beam has buckled it will collapse. In this case though as the beam begins to buckle (as per image attached) the angle of the guy rope increases and therefore the vertical component of this force gets less. However once the beam has started to buckle it is only able to take a fraction of the vertical load it could pre-buckling.

So, where to go from here? Once the initial buckling load has been satisfied will the beam always collapse? Or, in the right conditions will the pole reach a stable equilibrium with a certain bend? If the latter then how do I go about calculating the actual failure load?

Thank you very much for reading this and any guidance or advise would be very much appreciated.

Thanks

Simon