scholarly journals Modelling of Elevated Temperature Performance of Adhesives Used in Cross Laminated Timber: An Application of ANSYS Mechanical 2020 R1 Structural Analysis Software

2020 ◽  
Vol 3 (1) ◽  
pp. 46
Author(s):  
Ivan Moses Okuni ◽  
Tracy Ellen Bradford
Keyword(s):  
Thermal Properties ◽  
Adhesive Layer ◽  
Solid Wood ◽  
Wood Products ◽  
Structural Performance ◽  
Timber Species ◽  
Cross Laminated Timber ◽  
Steady State Model ◽  
Engineered Wood Products ◽  
Composite Solid

There is difficulty in accurately modelling adhesive influence in structural performance of cross laminated timber (CLT), due to a lack of available knowledge on the heat performance of adhesives. Therefore, the main aim of this research was to evaluate the thermal and mechanical properties of adhesives used in production of engineered wood products like CLT. The properties of the timber species and the adhesive types used in the simulation were derived from published literature and handbooks. ANSYS mechanical 2020 R1 was employed because it has a provision for inserting the thermal condition and the temperature of the system set to the required one for analysis. The simulations were conducted for temperatures 20, 100, 140, 180, 220, and 260 °C, within which Zelinka et al. conducted their experiments, which have been the basis for the current study. The main findings were, the adhesive layer had little influence on the thermal properties of CLT composite (solid wood had the same thermal properties as CLT), but had a significant effect on the structural properties of CLT composite, the stresses and strains of the simulated wood species reduced with increase in temperature, the adhesives strengths at room temperature were greater than for solid wood at the same temperature and finally, the stresses and strains of the simulated wood adhesives reduced with increase in temperature. It is also important to note that computations for temperature distribution from the char layer were lower than computed using heat transfer equation, and the simulated values from steady state model. All in all, the objectives of this research were met and more research in thermal structural modelling using ANSYS should be conducted in the future.

Surface and Subsurface Quality Evaluation of Engineered Wood Products by Ultrasonic Means

2014 ◽  
pp. 182-220
Author(s):  
Frank C. Beall ◽  
Henrique Reis
Keyword(s):  
Product Development ◽  
Material Properties ◽  
Rapid Evolution ◽  
Solid Wood ◽  
Wood Products ◽  
Assessment And Evaluation ◽  
Engineered Wood Products ◽  
Engineered Wood ◽  
History Of ◽  
Ultrasonic Techniques

The use of ultrasonic techniques to evaluate the properties of engineered wood-based materials is discussed with respect to research to date and the use of more advanced techniques. The latter is critical because of the rapid evolution from solid wood to reconstituted structural materials. In addition, although considerable research has been done, there have been few introductions into manufacturing. This chapter traces the history of the use and latest developments of ultrasonics in several key areas, particularly the measurement of adhesive curing and quality in composites and laminates, and detection of flaws in solid wood materials. The techniques reviewed apply to product development, material properties, process control, product quality assessment, and evaluation of products in service.

Markets, Products and Technology in the 21st Century – A Canadian Solid Wood Products Perspective

1990 ◽  
Vol 66 (6) ◽  
pp. 567-571 ◽  
Author(s):  
Albert T. Schuler ◽  
Jamie K. Meil
Keyword(s):  
Multinational Corporations ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Protection ◽  
Technology Products ◽  
Engineered Wood Products ◽  
The Future ◽  
Product Technology ◽  
Wood Products Industry ◽  
Conversion Technologies

This paper explores trends in the future development of the Canadian wood products industry in relation to technology, products and markets. Our analysis suggests that the wood products industry of the future may be characterized by: smaller economic units; vertical and horizontal integration to better utilize the resource and add value; market diversification; large multinational corporations; shift from commodities to engineered wood products; resource neutral conversion and product technology; shift from structural to semistructural applications and a move to more environmentally acceptable products and conversion technologies such as biocontrol for wood protection and preservation and energy-self sufficient mills. Key words: Markets, solid wood products industry, technology, competitive position.

Pinus elliottii (slash pine).

2021 ◽  
Author(s):  
Andrew Praciak
Keyword(s):  
Pinus Elliottii ◽  
Site Index ◽  
Solid Wood ◽  
Slash Pine ◽  
South Florida ◽  
Wood Products ◽  
Dendroctonus Frontalis ◽  
Small Range ◽  
Timber Species ◽  
Tree Form

Abstract P. elliottii var. elliottii is an important timber species native to the lower coastal plain within the southeastern USA. Because of its rapid early growth and its production of highly valuable wood products, it has been widely introduced into other countries. As an exotic, it is used in Africa, especially in southern Africa, and in Australia and South America for various products ranging from lumber to pulpwood. In Brazil, it makes an important contribution to the resin production industry. The preferred method of regenerating P. elliottii is by clearcutting followed by chemical or mechanical site preparation, then direct seeding or planting of nursery stock. Although natural regeneration by seedtree, shelterwood, or group selection is an option, availability of genetically superior stock usually makes planting the favoured method of regeneration. Rotation lengths vary according to product objective. The optimum pulpwood rotation is about 25 years. In unthinned plantations, this age increases to 30 from 23 years as density increases and site index declines. South Florida slash pine (P. elliottii var. densa) is characterized by a grasslike, almost stemless stage, that lasts for 2 to 6 years. Variety densa has a small range, a less desirable tree form than var. elliottii, and is more difficult to regenerate. P. elliottii is particularly susceptible to fusiform rust (caused by Cronartium fusiforme) and is frequently attacked by the southern pine bark beetle (Dendroctonus frontalis). The best protection against insect attack is to maintain vigorous, healthy stands through good forest management. The wood is used for a wide variety of products. Markets and size and quality of the material determine whether it is used for sawlogs, veneer logs, poles, pilings, posts, pulpwood, particle board, or chip-n-saw logs. The straightness of the bole makes P. elliottii particularly suited for poles, pilings, and solid-wood products. Although it may often grow more slowly than P. patula and P. taeda, it can produce higher pulpwood yields due to its higher wood density. P. elliottii yields the best quality and highest quantity of commercial turpentine of all American pitch pines (Streets, 1962). However, this use has declined significantly as other sources of resins have become more readily available.

Use of LA-ICP-MS for determination of elemental concentrations of boron in preservative treated solid wood and engineered wood panels

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert B. Currie ◽  
Bobby Kanji ◽  
Alexander Bruce ◽  
Robert G. Schmidt
Keyword(s):  
Inductively Coupled Plasma ◽  
Solid Wood ◽  
Wood Products ◽  
Inductively Coupled ◽  
Elemental Boron ◽  
Icp Ms ◽  
Engineered Wood Products ◽  
Engineered Wood ◽  
Plasma Mass Spectrometry

AbstractThis study has been completed to review the applicability and benefits of using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as an analytical tool for analysis of preservative concentration and penetration across boron treated solid wood and engineered wood products. LA-ICP-MS is shown to be effective at evaluating the penetration while simultaneously measuring the elemental boron concentration profile continuously across a sample.

scholarly journals Strand-Based Engineered Wood Products in Construction

2021 ◽  
Author(s):  
Zizhen Gao ◽  
Meng Gong
Keyword(s):  
Oriented Strand Board ◽  
Forest Resources ◽  
Wood Products ◽  
Engineering Properties ◽  
Manufacturing Processes ◽  
Cross Laminated Timber ◽  
Engineered Wood Products ◽  
Engineered Wood ◽  
Hybrid Cross ◽  
Selection Of

Strand-based engineered wood products (EWPs) have been widely employed in construction since their emergence in the 1970s. The use of strand-based EWPs can significantly increase the yield of forest resources by utilizing submarginal logs and branches. In this chapter, the strand-based EWPs, including oriented strand board (OSB), laminated strand lumber (LSL), and oriented strand lumber (OSL), are discussed in terms of their fabrication, properties, and uses in construction. Specifically, the manufacturing requirements for elements (i.e., strands), such as dimension, density, and moisture content, are introduced. The major manufacturing processes, such as selection of adhesives, pressing parameters, and thickness control, are also discussed. In addition, the engineering properties and uses of these EWPs are illustrated. Furthermore, some innovative applications of these products such as hybrid cross-laminated timber are presented in this chapter.

Einsatzmöglichkeiten von Holzwerkstoffen im Bauwesen | Possibilities of the use of wood-based materials in construction

2003 ◽  
Vol 154 (12) ◽  
pp. 472-479
Author(s):  
Peter Niemz
Keyword(s):  
Solid Wood ◽  
Wood Products ◽  
New Developments ◽  
Laminated Veneer Lumber ◽  
General Overview ◽  
Thermally Processed ◽  
Engineered Wood Products ◽  
Engineered Wood ◽  
Fibre Products ◽  
Parallel Strand Lumber

Wood-based materials and wood products are becoming increasingly important in construction. Engineered wood products, especially, are being used as a substitute for solid wood. The use of thermally processed solid wood is also increasing. Following a general overview of materials (materials based on solid wood, or laminated, veneer and fibre products)we describe their composition and most important characteristics. Emphasis is given to new developments as, for example, laminated strand lumber (LSL), laminated veneer lumber (LVL) and parallel strand lumber (parallam). We conclude with an overview of the possibilities for the use of woodbased materials in construction.

Non-destructive estimation of fibre morphological parameters and chemical constituents of Tectona grandis L.f. wood by near infrared spectroscopy

2021 ◽  
pp. 096703352199911
Author(s):  
SR Shukla ◽  
S Shashikala ◽  
M Sujatha
Keyword(s):  
Near Infrared ◽  
Cross Validation ◽  
Chemical Constituents ◽  
Fibre Diameter ◽  
Tectona Grandis ◽  
Cost Effective ◽  
Wood Products ◽  
Timber Species ◽  
Morphological Parameters ◽  
Mean Square Errors

Near infrared (NIR) spectroscopy is developing as an advanced and non-invasive tool in the wood, wood products and forestry sectors. It may be applied as a rapid and cost effective technique for assessment of different wood quality parameters of timber species. In the present study, NIR spectra of heartwood samples of Tectona grandis (teak) were collected before measuring fibre morphological parameters (fibre length, fibre diameter and fibre lumen diameter)and main chemical constituents (cellulose, hemicellulose, lignin and extractives) using maceration and wet chemistry methods respectively. Multivariate partial least squares (PLS) regression was applied to develop the calibration models between measured values of wood parameters and NIR spectral data. Pre-processing of NIR spectra demonstrated better predictions based on higher values of correlation coefficient for estimation (R2), validation (Rcv 2 ), ratio of performance to deviation (RPD), and lower values of root mean square errors of estimation (RMSEE), cross-validation (RMSECV) and number of latent variable (rank). Internal cross-validation was used to find the optimum rank. Robust calibrations models with high R2 (>0.87), low errors and high RPD values (> 2.93) were observed from PLS analysis for fibre morphological parameters and main chemical constituents of teak. These linear models may be applied for rapid and cost effective estimation of different fibre parameters and chemical constituents in routine testing and evaluation procedures for teak.

scholarly journals Improving the accuracy of wood moisture content estimation in four European softwoods from Spain

2021 ◽  
Vol 30 (1) ◽  
pp. e002
Author(s):  
Juan I. Fernández-Golfín ◽  
Maria Conde Garcia ◽  
Marta Conde Garcia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Moisture Content ◽  
Accurate Estimation ◽  
Wood Moisture ◽  
Mathematical Functions ◽  
Measured Moisture Content

Aim of study: To obtain improved models to predict, with an error of less than ± 2.0%, the gravimetric moisture content in four different softwoods commonly present in the Spanish and European markets, based on electrical resistance measurements. This improved moisture content estimation is useful not only for assessing the quality of wood products, especially in the case of laminated products, during the transformation and delivery process, but also for accurately monitoring the evolution of moisture in wood present in bridges and buildings, which is of great importance for its maintenance and service life improvement.Area of study: The study was carried out on samples of Scots, laricio, radiata and  maritime pines of Spanish provenances.Material and methods: On 50x50x20 mm3 solid wood samples (36 per species, 9 per condition), conditioned at 20ºC (±05ºC) and 40±5%, 65±5%, 80±5% or 90±5% Relative Humidity (RH), electrical resistance and oven-dry moisture content was measured. The Samuelsson's model was fitted to data to explain the relationship between the two variables. The accuracy of the model was evaluated by the use of an external sample.Main results: With the proposed mathematical functions the wood moisture content can be estimated with an error of ±0.9% in the four species, confirming the effectiveness of this nondestructive methodology for accurate estimation and monitoring of moisture content.Research highlights: our results allow the improvement of the moisture content estimation technique by resistance-type methodologies.Keywords: Resistance-type moisture meter; species correction.Abbreviations used: MC: Moisture content; RH: relative Humidity; R: electrical resistance; RP: wood electrical resistance measured parallel to the grain; RT: electrical resistance measured perpendicular (transversally) to the grain; GM-MC: gravimetrically measured moisture content.

Sign in / Sign up

Export Citation Format

Share Document