Cable Tent Structure

[LouieLouie]

Does anyone have any suggestions for the design of a cable supported mesh structure without using finite elements. It is a 100' diameter, 8 sided plan view with a central mast. In other words, how would we have done this 25 years ago. The simplified hand calculation method is what I am looking for. Any help is greatly appreciated.

 

[ishvaaag]

More likely the mast
1) 2 cables
2) 3 cables
3) maybe even 1 cable

would have been understood to take the total wind load.

Vertical loads and for some hypothesis that of wind would be distributed between a number of cables.

Safe assumption of the forces would be made, given the possibility of concave zones forming. Examination would be made of any possible snow loads standing.

This would oblige compatibility of stresses wehn more than one, according to the geometry. To dismiss secondary stressing from anchors and bends big safety factors, in the range of 5 to 8 would be used. Contemplation of prestress if any would be made. And of course vert careful design of the mast would be made, usually with maybe as well bigger safety factors than usual for buildings. Capacity of the details better would have taken from look-up experimental tables, if available.

 

[phuduhudu]

If I understand correctly you have an octagonal plan shape so you must have 8 hips supported by cables with a covering over them. Now depending on the height of your mast and the loading from the covering on your hips you can vary the pretension in your cables which will in turn vary their sag. You need to decide how much pretension you need to ensure that they never go slack under maximum wind uplift pressures. Otherwise you will get flapping and loss of support to the mast. Carl Bauer

http://www.bauerconsultbotswana.com