
Robert Jon RossUS Forest Service | FS · Forest Products Laboratory
Robert Jon Ross
Ph.D. Engineering Science
About
211
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3,969
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Introduction
Additional affiliations
January 2016 - present
January 2012 - present
June 2016 - present
Education
September 1981 - September 1984
September 1978 - May 1981
September 1974 - May 1978
Publications
Publications (211)
The effects of foam core density, foam discontinuity in the shear zone, and flexural properties based on the effect of duration of load testing on structural insulated panels (SIPs) were investigated. These characteristics were individually evaluated for two SIP depths: 6.5 inches and 12.25 inches. For each of the two depths, SIP specimens were ass...
One of the most significant contributions of the science of nondestructive evaluation to the forest products industry is the prediction of strength of wood products. Being a biological material, wood has inherent variability that other engineering materials do not. The ability to use various nondestructive techniques to predict the strength of wood...
This paper summarizes work conducted to assess the condition of members in historically significant timber sailing vessels. Four ship assessments are described, the USS Constitution, the USS Cairo, and the Wapama. Launched in 1797, the USS Constitution was nicknamed “Old Ironsides” and was a combat vessal used by the US Navy. “Old Ironsides” is a t...
This paper presents research conducted to examine the potential of using longitudinal vibration techniques to evaluate the modulus of elasticity and strength of cross-laminated timber (CLT). Twenty�four CLT panels were manufactured from southern pine dimension lumber in accordance with accepted manufacturing standards. Nominal 2 by 8 in. southern p...
Producing cross-laminated timber (CLT) has opened a new market for the lumber industry in North America, while few hardwood species have been studied in the U.S. for CLT production. Combining hardwood species in mixed hardwood CLT or in hybrid CLT can be a solution to boost the market of the undervalued hardwoods. However, the knowledge gap on bond...
As a material used in building construction, structural insulated panels (SIPs) deflect under flexural loading and creep over time. This work examines the deflection behavior of full-scale SIPs that were tested in bending. Approximately half of the matched specimens were tested after production and the other half were tested after a 90-day creep te...
The USDA Forest Service, Forest Products Laboratory, was asked to inspect the main support timbers of a historic building at the Veterans Affairs (VA) Medical Center in Tomah, Wisconsin. This report summarizes the results obtained from the inspection and assessment. It includes a summary of observations, wood species identification, and recommendat...
The effect of foam core density on the strength of structural insulated panels (SIPs) was investigated herein as part of a larger study to determine the creep performance of SIPs. Two depths (16.5 cm and 31.1 cm [6.5 in. and 12.25 in.]) of SIPs were tested in 1/3rd-point flexure according to the American Society of Testing and Materials standard AS...
Efficient use of the available wood resources is necessary to sustainably meet the long-term demand for wood products. This paper presents research about the potential of using transverse and longitudinal vibration techniques to evaluate the bending modulus of elasticity MOE (Eb) and tensile properties (Et and UTS) of 2 by 10 No. 2 grade southern p...
Considering the high demand for housing and the ongoing environmental issues our society faces, it's crucial to opt for more ecofriendly materials for building purposes. In that scenario, engineered wood products play an important role as they are not only based on a sustainable material but also can reduce the carbon footprint from construction. C...
Round timber and wood products are measured, sorted, and graded at different stages in the wood-value chain starting already at the stem level in the forest. This chapter gives an overview of grading methodologies and techniques for the measurement and grading of round timber, sawn timber, veneer, and wood-panel products. The section concerning rou...
The field of nondestructive evaluation (NDE) of materials is constantly evolving. This is especially true in the area of wood and fiber-based materials. A significant effort has been devoted toward the discovery and development of NDE technologies for use with wood-based products. Today, research and technology transfer efforts are underway through...
The effect of duration of load testing on flexural properties of structural insulated panels was investigated herein. Structural insulated panels were manufactured by a member of the Structural Insulated Panel Association (SIPA) in accordance with International Code Council-Evaluation Service Report 4689. Two panel depths 16.5 cm and 31.1 cm (6.5 i...
The objective of this study was to assess the flexural and tensile properties of 702 pieces of No. 2 grade 2 by 6 southern pine lumber using nondestructive testing (NDT) techniques. Longitudinal and transverse vibration techniques were used to test each specimen. The mean dynamic modulus of elasticity in the longitudinal direction was 11,246 MPa, a...
Bending modulus of elasticity (MOE) and tensile properties parallel to the grain were studied on 702 pieces of 2 X 6 and 285 pieces of 2 X 10 No. 2 visually graded southern pine lumber. The overall rings per inch (RPI) in 2 X 6 pieces was 4.82, whereas 2 X 10 had an RPI average of 3.82. For latewood percentage (LW), 2 X 6 pieces found 45.88% of LW...
The forest industry typically uses visual appearance to evaluate the wood quality when salvaging dead standing trees. We investigated whether the visual appearance of white spruce (Picea glauca (Moench) Voss) defoliated by the spruce budworm (Choristoneura fumiferana (Clem.)) accurately reflects wood quality measured using nondestructive techniques...
The effect of foam discontinuity in the shear zone of structural insulated panel (SIP) beams was investigated in the current research. Two depths of 15.24 cm and 31.11 cm (6.5 in and 12.25 in) (SIPs) were evaluated in 1/3-point bending. Panels were sawn into beams, each approximately 29.84 cm (11.75 in.) wide, for mechanical testing. Half of the pa...
Acoustic inspection is a reliable tool for assessing biological deterioration in wood. As wood decays, several mechanical properties are negatively affected. A variety of acoustic techniques have been developed to identify, and in some cases quantify, the extent to which the presence of decay has altered the wood. Knowledge of the extent of decay a...
The objective of this study was to investigate the effects of tree diameter and juvenile wood on acoustic wave propagation in standing trees. Two-layer tree models with various diameters and proportions of juvenile wood were constructed to examine the effects of these two factors on propagation patterns and velocity of acoustic waves. The simulatio...
The effect of thermomechanical densification treatment on the abrasion resistance of five hardwood species were investigated in this study. The species tested include ash (Fraxinus sp.), hickory (Carya sp.), red oak (Quercus sp.), sweetgum (Liquidambar styraciflua), and white oak (Quercus sp.). The abrasion test was performed according to the Ameri...
The wear resistance and Janka hardness of five United States hardwood species were evaluated for potential use in bridge decking and truck flooring. The species tested include ash (Fraxinus sp.), hickory (Carya sp.), red oak (Quercus sp.), sweetgum (Liquidambar styraciflua), and white oak (Quercus sp.). The specimens were prepared with the sizes of...
This paper presents research conducted to examine the potential of using longitudinal vibration techniques to evaluate the modulus of elasticity and strength of cross-laminated timber (CLT). Thirty-nine CLT panels were manufactured from southern pine dimension lumber in accordance with accepted manufacturing standards. Nominal 2 by 8 in. southern p...
Flexural properties of visually graded southern pine structural lumber were evaluated. Several grade controlling characteristics were considered relative to bending properties and compared with current design values. A total of 751 southern pine lumber specimens were obtained from a broad spectrum of regions in the southeastern United States. Visua...
To properly evaluate the reliability of lumber structures, good models for the strength distributions of their components are needed. Modulus of rupture (MOR) distributions of structural lumber grades have often been modeled as two-parameter Weibulls. However, in a series of papers, Verrill and others have established that strength properties of vi...
To properly evaluate the reliability of lumber structures, good models for the strength distributions of their components are needed. Modulus of rupture (MOR) distributions of grades of structural lumber have often been modeled as two-parameter Weibulls. However, in a series of papers, Verrill and others have established that strength properties of...
This study aims to investigate the feasibility of CLT panels fabricated from salvaged dead standing trees after the beetle outbreak by evaluating the flexural and shear properties through mechanical tests and computational analysis. White spruce (Picea glauca (Moench) Voss) lumber salvaged from the dead and dying trees resulting from recent spruce...
In this study, we investigated the durability of adhesive bonds in the cross-laminated lumber of seven hardwood and two softwood species from the Great Lakes region. The 2-layered cross-laminations were glued using phenol resorcinol- and melamine-based structural adhesives. A total of 720 cross-laminated wood blocks were tested for delamination by...
This study evaluated the mechanical properties of hybrid (mixed-species) cross-laminated timber (CLT) panels made of low-value sugar maple (Acer saccharum) and white spruce (Picea glauca). The modulus of elasticity (MOE) of the laminations was measured with a nondestructive method. Three-layer hybrid CLT panels with layup combinations of sugar mapl...
Southern yellow pine (SYP) is one of the most used softwood species in the world. Most of this raw material come from fast-grown plantation trees. It is of interest to determine if SYP clear wood properties may have changed over the long term, in particular whether such properties may have declined. Herein, specific gravity (SG), ultimate compressi...
When discussing structural southern yellow pine lumber, questions frequently are asked regarding changes over time. This is a significant area of discussion given that structural lumber properties (i.e., design values) were changed around 2012. Climate change, forest management, genetics, processing, and others are listed among the many possible co...
The interrelationships among specific gravity (SG), modulus of elasticity (MOE), and strength (modulus of rupture, MOR) are largely the foundational basis for non-destructive evaluation and testing. Resource monitoring and commercial structural lumber production often rely upon such non-destructive evaluation to predict the bending and/or tension s...
The objective of this study is to examine the mechanical performance of cross laminated timber (CLT) panels made of low-value sugar maple under out of plane loads through mechanical tests and numerical simulation. The laminations were sorted into High and Low classes based on the measured modulus of elasticity (MOE). Two 3-layer sugar maple CLT lay...
In China, preserving historic trees and ancient timber structures has attracted more attention from researchers and institutions. Nondestructive testing (NDT) technology has gained momentum in the application and research in recent years. This paper presents some examples of the application of NDT techniques in the protection of historic trees and...
It has been mathematically demonstrated that the distribution of modulus of rupture (MOR) in a graded lumber subpopulation does not have the same theoretical form as the distribution of the mill-run population from which the subpopulation is drawn. However, the distributional form of the graded lumber subpopulation does depend heavily on the distri...
This research article summarizes results from Part 1 of a study designed to examine using advanced signal processing techniques with acoustic-based lumber assessment technologies to evaluate the MOE, ultimate tension stress (UTS), and MOR of structural lumber. In Part 1 of this research article, a mathematical model of acoustic wave behavior in an...
This research article summarizes results from Part 1 of a study designed to examine the use of advanced signal processing techniques with acoustic-based lumber assessment technologies to evaluate the MOE and ultimate tension stress (UTS) of structural lumber. In Part 1 of this research, a mathematical model of acoustic wave behavior in an idealized...
To evaluate the reliability of lumber structures, we need (among many other things) good models for the strength and stiffness distributions of visual and machine stress rated (MSR) grades of lumber. Verrill et al. established theoretically and empirically that the strength properties of visual and MSR grades of lumber are not distributed as 2-para...
The aim of this research was to explore the potential of acoustic impact test to evaluate the condition of hardwood logs in regard to internal decay, void, crack and defect ratio using an acoustic signal separation and enhancement algorithm. Longitudinal acoustic signals were obtained from 15 logs of four hardwood species through acoustic impact te...
Metriguard’s grain angle meter (Model 511) measures grain angle in wood by assessing permittivity. This study evaluates the correlations between grain angle meter readings and bending properties of 1,400 kiln-dried 2 by 4 specimens of southern pine (Pinus spp.) lumber and considers its utility for providing supplementary data for predicting the str...
Machine lumber grading has been applied in commercial operations in North America since 1963, and research has shown that machine grading can improve the efficient use of wood. However, industry has been reluctant to apply research findings without clear evidence that the change from visual to machine grading will be a profitable one. For instance,...
To evaluate the reliability of lumber structures, good models for the strength and stiffness distributions of visual and machine stress–rated (MSR) grades of lumber are necessary. Verrill and coworkers established theoretically and empirically that the strength properties of visual and MSR grades of lumber are not distributed as 2-parameter Weibull...
The study summarized in this report was conducted to examine the relationships between nondestructive evaluation parameters and the modulus of elasticity (MOE) of spruce–pine–fir structural lumber. A random sample of lumber was obtained from a local lumber yard and conditioned to approximately 10% equilibrium moisture content in the laboratory. Sta...
The literature related to the phenomenon of pseudo-truncation has emphasized that the mechanical property distributions of graded lumber subpopulations are determined by the mechanical property distributions of the mill-run (or full) lumber populations from which the subpopulations are formed. Whereas previous studies have shown that the means and...
The objective of this study was to explore the potential of an acoustic impact test as a nondestructive evaluation procedure to assess the soundness of hardwood logs in terms of internal decay, void, and defect ratio. Fifteen logs of four hardwood species (black cherry, white oak, red oak, and cottonwood) were obtained and subjected to acoustic imp...
This report summarizes technical and scientific literature on the relationship between silvicultural practices and engineering properties of wood from northern hardwood species grown in the Great Lakes Region. Knowledge of engineering properties is critical to the utilization of hardwoods in engineered wood products, including but not limited to wo...
The modulus of elasticity (MOE) and modulus of rupture (MOR) of graded lumber populations are commonly modeled by normal, lognormal, or Weibull distributions, but recent research has cast doubt on the appropriateness of these models. Such modeling has implications for ultimate performance and efficiency of resource use. It has been shown mathematic...
The State of Wisconsin’s Department of Natural Resources is responsible for operating one of the largest state park systems in the United States. Potawatomi State Park, located on the Door County peninsula, consists of about 1,200 acres of flat to gently rolling upland terrain bordered by steep slopes and rugged limestone cliffs along Lake Michigan...
The objective of this study was to determine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve the accuracy of defect detection and quality assessment in hardwood logs. This article (Part 1) focused on exploring the potential of an acoustic impact testing method coupled with advanced wavef...
The objective of this study was to determine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve the accuracy of defect detection and quality assessment in hardwood logs. Using acoustic impact testing and high-resolution laser scanning techniques, 21 yellow poplar logs (Liriodendron tulipife...
This research focused on evaluating the bending stiffness and strength of structural lumber with transverse vibration nondestructive testing techniques. A random sample of nominal 2-in.-(standard 38-mm-) thick, Southern Pine dimension lumber was obtained from several mills in southeastern United States. After conditioning, the lumber specimens were...
It has been common practice to assume that the modulus of elasticity (MOE) of a grade of lumber is well-modeled by a normal distribution, and the modulus of rupture (MOR) of a grade of lumber is well-modeled by a normal, lognormal, or Weibull distribution. Recent theoretical results and empirical tests have called these assumptions into question. T...
Key messageField methods for rapid determination of wood density in trees have evolved from increment borer, torsiometer, Pilodyn, and nail withdrawal into sophisticated electronic tools of resistance drilling measurement. A partial resistance drilling approach coupled with knowledge of internal tree density distribution may offer an alternative so...
Increasing stringency of energy codes and the growing market demand for more energy efficient buildings gives structural insulated panel (SIP) construction an opportunity to increase its use in commercial and residential buildings. However, shear wall aspect ratio limitations and lack of knowledge on how to design SIPs with window and door openings...
This study aims to investigate the potential of ultrasound wave to detect defects in 19 years old of two
species of African mahogany planted in Brazil. Were used five 76 x 5 x 5 cm samples from each species
with different types of defects, and were conditioned to 12% moisture content. The samples were scanned
with ultrasound wave in longitudinal di...
Nondestructive testing (NDT) of wood products, such as lumber and veneer, for stiffness and strength evaluation has been proven and commercialized for many years. The NDT concept has been extended and commercialized in the Director HM-200™ tool for testing logs in advance of processing so manufacturers can make more informed log purchases and bette...
A localized fiber reinforcement places strong tensile strength fibers across a hypothetical split line near notches in beams to curtail split propagation caused by cross-grain tension that may otherwise significantly reduce the strength of a beam used as a spanning member. An adhesive coated patch may be applied after a notch is cut in the beam or...
The second glued-laminated structure built in the United States was constructed at the USDA Forest Products Laboratory (FPL) in 1934 to demonstrate the performance of wooden arch buildings. After 75 years of use the structure was decommissioned in 2010. Shortly after construction, researchers structurally evaluated the glued-laminated arch structur...
The objective of this study was to examine the potential of acoustic measurement as a rapid and nondestructive method to predict the dimensional stability of young-growth Sitka spruce and western hemlock. Ultrasonic velocity, peak energy, specific gravity, and radial and tangential shrinkages were measured on twenty-four 25-×102-×y 25-mm specimens...
In this study, we examined three individual log measures (acoustic velocity, log diameter, and log vertical position in a tree) for their ability to predict average modulus of elasticity (MOE) and grade yield of structural lumber obtained from Douglas-fir (Pseudotsuga menziesii [Mirb. Franco]) logs. We found that log acoustic velocity only had a mo...
Assessment of the quality of standing timber has become a crucial issue in the operational value chain as forestry and the wood processing industry are increasingly under economic pressure to maximize extracted value. A significant effort has been devoted toward developing robust nondestructive e