Engineering
Reliability-Based Design of a Timber Roof Truss Considering Moisture-Induced Creep
Quick fact
In conventional timber design, engineers apply partial safety factors to account for material and load uncertainties, but this deterministic approach cannot precisely tell you the probability that a truss will fail. Reliability-based design, on the other hand, calculates a numerical reliability index, like 3.8, which corresponds to a failure probability of about 1 in 14,000 over a 50-year design life.
Why this is interesting
Have you ever noticed how a wooden shelf in a damp garage slowly warps over years? Now imagine that happening to the roof over your head—how do engineers make sure it won't collapse?