The modulus of elasticity (MOE, E) of wood is most commonly used in the calculation of deflections (sag) of wood beams. By `beams’ I include joists, rafters, girders, decking boards, any … wood used structurally to support loads across spans …

E (modulus of elasticity) of Wood Read more »

When we examine deflections of wood members (beams, joists, rafters, girders, etc.) we generally look at two kinds, actually three … the deflection due to the `live load’, e.g., people walking on a floor, wind on a wall, and so …

Deflections of Wood Beams Read more »

Let’s look at a post, say in a shop, or a barn, acting as a vertical cantilever. This means that the base of the post is held rigid (not allowed to rotate), while a lateral (horizontal, or sideways) load is …

Cantilever Post Deflection (Post and Bracket) Read more »

Pole barn versus post frame … how to keep the structure from flopping over? Consider a barn, or perhaps a shop, made using timber and `posts’. There are two main ways to keep it from flopping over. One way is …

`a constantly debated topic’ (pole barn versus post frame) Read more »

E (E and shear-free E) (c) Jeff R. Filler, 2022 The deflections calculated in earlier examples (link and link) are based on the standard engineering formula for beams based on beam-curvature theory – where the beam curvature is a result …

Shear-Free Eeee Read more »

Differential Deflections … and the Simpson Strong-Tie Strong-Drive® SDPW Deflector Screw (c) Jeff R. Filler, May 2022, Pell City, AL I haven’t tried one out yet … the Simpson Strong-Tie Strong-Drive® SDPW Deflector Screw … but the idea is fascinating …

Differential Displacements and the SST SDPW Deflector Screw Read more »

In the example (here) I discussed a person standing on a wood plank, and `examining’ the deflection. Talk is cheap. I grabbed three pieces of lumber (that I milled) in my shop: one piece a 1 x 5 Southern Pine …

Case(s) in Point Read more »

Shear Deflection – Prefab Wood I-Joist Example Calc (c) Jeff R. Filler, Pell City, 2022 Continuing our discussion on shear deflection of wood beams (joists, etc.), let’s look at a prefabricated wood I-joists. Basic design information for prefabricated wood I-joists …

Shear Deflection – Prefab Wood I-Joist Read more »

E min (c) Jeff R. Filler, Pell City, Alabama, 2022 But First, E apparent and E true `E min’ is calculated wood property used in the design of structural wood members (beams, columns, etc.). It is a derived property, derived …

E min Read more »

In the example above (link) we calculated a deflection of 0.599 in. How accurate is this number? (I showed it to three significant figures … accurate to half a percent?) Leaving out, for now, the accuracy/precision of the other input, …

Accuracy of Deflection Calcs (and Eee) Read more »