Solar Canopy strength

[jay_gallagher]

First off, I’m an audio engineer. I’ve designed a solar canopy for my catamaran. All materials to be TIG welded 6061-T6. Assuming the connections to the deck are secure (thru-bolted with backing plates), I have two questions:

1. will it fall over in 110Kt winds (panel uplift rating)?
2. can it take a sudden stop from 7Kts (hit a reef)?

My calculations:
Weight of six solar panels = 455#. Weight of Structure = 440#


Uplift wind loading @ 110 Knots (50#/SqFt)
Surface area of canopy = 206 SqFt
206SqFt x 50#/SqFt = 10,030 #
Leg loadings: 10,030# / 12 legs= 835#
(excludes strut contribution)


Qnty & Materials:
4 Main Beams: 3” x 3” x .187 wall tube
2 Top Plate: 4.0” x 1.5” x .187” wall tube
12 Legs: 3” dia x .187 wall tube (2-‘W’, 2-straight, 2-ladder)
4 Struts: 1” x .25” wall tube

Any help would be appreciated

[Kelly_Bramble]

This is a question that we see on Engineers Edge occasionally. An engineering answer is impractical for a volunteer as that would require a significant amount of work -modeling, questions, right software, detail drafting, materials, etc.

My guess? 40 + hours for an experienced analysis engineer who happens to have the right expensive software. You're unlikely to get the help you are asking for.

My quick glance - it's strong enough to support properly installed solar panels, use marine grade aluminum and navigate the boat clear from hurricanes.

[fouadiboukhoulaf]

Regarding your questions:


Will it fall over in 110Kt winds (panel uplift rating)?
To determine whether the structure will withstand the wind forces, you need to evaluate the stability and structural integrity. The uplift force exerted by the wind will depend on various factors such as the shape, size, and orientation of the structure, as well as the wind speed. The uplift wind loading you calculated seems to be based on the panel area, assuming a wind pressure of 50 pounds per square foot. However, the structural design should also consider the distribution of these forces across the beams, legs, and connections. A structural engineer can analyze the design and evaluate the load-bearing capacity of the materials and connections to determine if the structure can withstand the uplift forces.


Can it take a sudden stop from 7Kts (hit a reef)?
Assessing the ability of the structure to withstand sudden impact forces requires considering factors such as the mass and velocity of the structure, the specific impact point, and the local response of the structure upon impact. It's important to analyze the potential stress concentration areas, including the connections to the deck and the overall structural integrity. A structural engineer can perform a detailed analysis to evaluate the design's ability to withstand sudden stops or impacts and ensure that it remains structurally sound.


In both cases, it's crucial to consider factors beyond the structural components, such as the dynamic behavior of the catamaran, possible vibrations, and the overall stability of the vessel. A comprehensive analysis by a qualified engineer will help ensure the safety and performance of your solar canopy design.


Remember, this is a general response, and it's essential to consult a structural engineer who can consider the specific details of your catamaran and provide accurate assessments based on the applicable codes, standards, and structural analysis techniques