Global ETD Search

1	Bolstering Pine Lumber Value Through Statistical Analysis And Nondestructive Testing Owens, Frank Charles, IV 11 August 2017 (has links) In or around 2010, a nationwide reevaluation of the allowable properties for southern pine dimension lumber was initiated. This led to a 2013 reduction in the design values of visually graded southern pine dimension lumber and a resulting decrease in its commercial and utility value. This change compelled researchers and industry professionals to ponder what could be done to shore up the value of solid-sawn southern pine products going forward and potentially increase design values if appropriate. In pursuit of this question, this dissertation looks closely at three areas: 1) the possibility this reduction in mechanical performance is not merely limited to southern pine structural lumber but can also be observed in other solid-sawn softwood products and species, 2) flaws that might exist in commonly utilized statistical models for estimating allowable properties in lumber, and 3) the feasibility of using existing technologies to begin to compensate for the economic and/or utility losses attributed to the recent reduction in design values. This work is comprised of an introduction, a conclusion, and three independent content chapters utilizing a variety of statistical techniques to investigate whether strength and stiffness reduction might also be occurring in southern pine (and Douglasir) utility crossarms, evaluate the propriety of using a Weibull distribution model for estimating allowable properties in dimension lumber, and gauge the suitability of nondestructive testing methods for potentially identifying high-value premium grades in solid-sawn softwood products. bivariate Gaussian-Weibull distribution mixed bivariate normal distribution skew normal distribution 3-parameter beta distribution 2-parameter Weibull distribution mixed normal distribution normal distribution grading nondestructive Douglasir southern pine modulus of rupture modulus of elasticity bending stiffness mill run strength lumber Crossarms pseudo-truncated Weibull distribution lumber property distribution

Search results

Bolstering Pine Lumber Value Through Statistical Analysis And Nondestructive Testing