A sunshade blade is a continuous beam on bracket supports carrying a wind line-load, and its design is decided by the serviceability check: deflection between brackets, held to L/180–L/240 in most facade specifications — both for appearance down the array and to keep blade tips off the glass line. Beam deflection scales with q·L⁴/(E·I): the load and span are fixed by the architecture, the section by the sightline the architect will accept. The one lever left is E — the modulus of the blade material. That is the entire design case for the E40 plate in one sentence.
The arithmetic is direct. Deflection-limited bracket spacing scales with the cube root of modulus, so moving from a standard E23 pultrusion to the E40 plate buys 20% more span from the identical blade — or, holding the bracket grid, the same deflection limit is met by a blade about 17% thinner and lighter. And because stiffness — not strength — sizes the section, the working bending stress ends up at a small fraction of the laminate's ultimate, which is precisely the margin that makes the fatigue behavior below a non-issue.
One honest caveat belongs here: for horizontal louvers, self-weight is a sustained load, and polymer composites creep under sustained stress. On a thin blade at 2.0 g/cm³ the gravity stress is small, and we verify the sustained case with long-term modulus reduction factors as standard — so the creep deflection over a 50-year life stays invisible, checked rather than assumed.