Wave Shade Canopies Loads exerted on supports We have calculated the tension in the wires supporting a wave-shade canopy. For this calculation, we have assumed:
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The canopy weighs 2.7 kg/sqm The canopy is 2.5 metres wide by 4 metres long, with two supporting wires. The sag in the wires is 0.5% of span, i.e. span/200. (This works out as 20mm sag for a 4 metre span.) There is no wind or other load on the canopy.
For this situation, the tension in each wire is 3.5 kilonewtons, which is about 350kg weight. Wind loads could increase this figure dramatically, so the canopy should be retracted if it is being affected by wind. For other spans, the tension in the wire increases in direct proportion to the length of the span, as long as the span/200 sag ratio is maintained. So the tension doubles if the span doubles. Similarly, the tension decreases approximately in direct proportion to the sag ratio, so if the sag is increased to span/100, the tension is halved.