Proof Test Load Value Determination for Maximum Economic Return

In-line production proofload testing of lumber requires that a test load value be chosen. For lumber failure distributions having high variability, and optimum test may break as much as 10 percent or more of the lumber tested, but the economic value increase for surviving material can more than compensate for the breakage. Justification for the method of optimizing the load value depends on an identifiable relationship between price and proof test load value. Knowledge of the lower tail of the failure distribution obtained either a priori or from test data is used to determine the optimum test load value. Fewer failures will occur at the optimum test load when the failure distribution is more tightly dispersed. If a correlated measurement, such as modulus of elasticity, is known, and if the proof test load value can be adjusted for each piece, then an improvement can be effected. The improvement increases with correlation coefficient and with dispersion of the failure distribution.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member